ORCID Profile
0000-0002-9217-8177
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National Institutes of Health
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Publisher: Elsevier BV
Date: 12-1995
DOI: 10.1016/0002-8703(95)90142-6
Abstract: The efficacy of myocardial perfusion imaging for cardiac-risk stratification of patients undergoing vascular surgery has been disputed recently. In comparison with conventional techniques, positron emission tomography (PET) has the benefit of permitting a true resting scan, allows accurate measurement of the extent of ischemia, and is highly specific for the diagnosis of coronary disease. We therefore investigated the use of PET for risk stratification at the time of vascular surgery and subsequent follow-up in 78 patients (aged 67 +/- 11 years, 52 men), selected for testing before the performance of extensive surgery or because of one or more clinical risk factors. Perfusion images were obtained by using a standard rubidium 82 protocol before and after dipyridamole-handgrip stress. With use of a quantitative color scale in a 24-segment model of the left ventricle, scans were reported as showing normal perfusion, resting defects, or stress-induced defects (deterioration > 15% with stress). After exclusion of 6 patients referred for myocardial revascularization, 72 patients were followed up in the perioperative period and for 18 +/- 12 months for late cardiac death, myocardial infarction, or unstable angina. Perioperative events occurred in 14 patients (5 with myocardial infarction and 9 with unstable angina), 10 of whom had ischemia at PET (sensitivity, 71% predictive value of a positive test, 45%). Isolated resting perfusion defects were not associated with events. The presence of extensive ischemia (more than five segments) had a positive predictive value of 64%, and its absence gave a negative predictive value of 89%.(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher: Elsevier BV
Date: 03-1999
DOI: 10.1016/S0735-1097(98)00606-8
Abstract: The study aim was to determine observational differences in costs of care by the coronary disease diagnostic test modality. A number of diagnostic strategies are available with few data to compare the cost implications of the initial test choice. We prospectively enrolled 11,372 consecutive stable angina patients who were referred for stress myocardial perfusion tomography or cardiac catheterization. Stress imaging patients were matched by their pretest clinical risk of coronary disease to a series of patients referred to cardiac catheterization. Composite 3-year costs of care were compared for two patients management strategies: 1) direct cardiac catheterization (aggressive) and 2) initial stress myocardial perfusion tomography and selective catheterization of high risk patients (conservative). Analysis of variance techniques were used to compare costs, adjusting for treatment propensity and pretest risk. Observational comparisons of aggressive as compared with conservative testing strategies reveal that costs of care were higher for direct cardiac catheterization in all clinical risk subsets (range: $2,878 to $4,579), as compared with stress myocardial perfusion imaging plus selective catheterization (range: $2,387 to $3,010, p < 0.0001). Coronary revascularization rates were higher for low, intermediate and high risk direct catheterization patients as compared with the initial stress perfusion imaging cohort (13% to 50%, p 0.20). Observational assessments reveal that stable chest pain patients who undergo a more aggressive diagnostic strategy have higher diagnostic costs and greater rates of intervention and follow-up costs. Cost differences may reflect a diminished necessity for resource consumption for patients with normal test results.
Publisher: Elsevier BV
Date: 06-1998
DOI: 10.1016/S0002-9149(98)00162-3
Abstract: Left ventricular (LV) cavity obliteration during dobutamine echocardiography (DE) indicates a vigorous inotropic response to stress. Such a response may suggest the absence of coronary artery disease (CAD), but a small LV cavity may also preclude recognition of wall motion abnormalities. We sought to determine the frequency, correlates, accuracy, and prognostic value of the LV cavity obliteration response in 336 consecutive patients who underwent coronary angiography within 1 year of DE. Cavity obliteration was defined by contact of the opposite walls in the apical views during DE, and ischemia by detection of a new or worsening wall motion abnormality. Sensitivity was based on comparison with coronary anatomy in 220 patients without prior revascularization. The prognostic implications of cavity obliteration were examined by follow-up of 324 patients (96%) over 23 +/- 9 months for death, myocardial infarction, and late revascularization. Cavity obliteration was present in 86 of the 336 DE studies (26%). Baseline and stress hemodynamics were not predictive of cavity obliteration, which was associated with LV hypertrophy and female gender (p <0.0001), and inversely related to LV systolic dysfunction and use of angiotensin-converting enzyme inhibitors or diuretics (p <0.02). The sensitivity of DE was less in patients with cavity obliteration than the remainder, especially in single vessel (46% vs 92%, p <0.001) but also in multivessel CAD (73% vs 95%, p = 0.01). Irrespective of DE and angiographic results, cavity obliteration was a negative predictor for cardiac events (RR 0.42, 95% confidence interval [CI] 0.21 to 0.87, p = 0.02) and death (RR 0.14, 95% CI 0.02 to 1.09, p = 0.06). Even after exclusion of patients with LV dysfunction, cavity obliteration was an independent predictor of freedom from events (RR 0.41, 95% CI 0.19 to 0.88, p = 0.02). Thus, LV cavity obliteration is a frequent response to DE, which compromises the sensitivity of DE but is correlated paradoxically with a favorable clinical outcome.
Publisher: Elsevier BV
Date: 1994
DOI: 10.1016/S0002-9149(97)00871-0
Abstract: Exercise treadmill testing is frequently performed to screen for coronary artery disease (CAD) in asymptomatic in iduals however, its clinical value is unclear. We examined a consecutive cohort of asymptomatic adults undergoing exercise treadmill testing at the Cleveland Clinic Foundation between September 1990 and December 1993. End points included (1) identification of subjects with severe CAD and (2) performance of any second diagnostic study within 90 days of the index exercise treadmill test. Screening exercise treadmill testing was performed in 4,334 adults (median age 51, 89% men) only 34% had > or = 1 cardiac risk factor and 15% exhibited an abnormal response to exercise. A second test after treadmill testing was performed in 215 patients (in 110, coronary angiography in 105, stress thallium scintigraphy, followed by coronary angiography in 16). The strongest predictor of referral for a second test was an ischemic ST-segment response (adjusted odds ratio [OR] 34, 95% confidence intervals [Cl] 24 to 47, p < 0.0001). The only clinical variable independently associated with referral for a second test was female gender (adjusted OR 0.35, 95% CI 0.21 to 0.60, p <0.0001). Of the 126 patients who underwent coronary angiography, severe CAD was identified in only 19 in iduals (10.44% of the original cohort, 95% CI 0.26% to 0.62%) coronary artery bypass grafting was performed in 14 of these patients. The estimated cost of exercise treadmill testing to identify 1 case of severe CAD for which surgical revascularization may provide a survival benefit was $39,623. The estimated cost per year of life saved was at least $55,274. Thus, as used in actual practice in 1 center, screening exercise treadmill testing has a low yield and is costly. This is perhaps in part because of the low-risk population that was selected and the failure to incorporate pretest variables, increasing probability of disease into post-test clinical decision making.
Publisher: Oxford University Press (OUP)
Date: 15-01-2000
Publisher: Elsevier BV
Date: 11-1997
DOI: 10.1016/S0002-8703(97)80003-8
Abstract: Controversy exists as to whether a sex bias exists that affects the diagnostic approach to suspected coronary artery disease: previous studies have used coronary angiography, but not other noninvasive testing, as a primary end point. This investigation examined posttest sex differences in diagnostic evaluation after exercise treadmill testing according to a broader end point than just coronary angiography alone. The design was a cohort analytic study with a 90-day follow-up. The study was done at the Cleveland Clinic Foundation, an academic group practice. Patients included consecutive adults (1023 men and 579 women) with chest pain but no documented coronary disease who were referred for symptom-limited exercise treadmill testing without adjunctive imaging none had undergone prior invasive cardiac procedures. Main outcome measures included (1) performance of any subsequent diagnostic study (invasive or noninvasive) and (2) performance of coronary angiography as the next diagnostic study. During follow-up, 89 (8.7%) men and 48 (8.3%) women underwent a second diagnostic study (odds ratio 0.95 95% confidence interval 0.66 to 1.37 p > 0.8), whereas 64 (6.3%) men and 21 (3.6%) women went straight to coronary angiography (odds ratio 0.56 95% confidence interval 0.34 to 0.93 p = 0.02). In multivariable logistic regression analyses, which considered baseline clinical characteristics, the ST-segment response, and other prognostically important exercise responses, women tended to be less likely than men to be referred to any second test (adjusted odds ratio 0.70 95% confidence interval 0.42 to 1.19 p > 0.1) but were markedly and significantly less likely to be referred straight to coronary angiography (adjusted odds ratio 0.33 95% confidence interval 0.17 to 0.65). After exercise treadmill testing, women were only slightly less likely than men to be referred for subsequent diagnostic testing they were, however, much less likely to be referred straight to coronary angiography as opposed to another noninvasive study.
Publisher: Elsevier BV
Date: 12-1995
DOI: 10.1016/S0002-9149(99)80347-6
Abstract: Inappropriate chronotropic response to exercise has been observed to correlate with poor prognosis in patients with coronary disease, but the mechanism for this association is not well defined. We attempted to examine the association between chronotropic response to exercise and angiographic severity of coronary disease in patients with suspected or stable coronary artery disease. The chronotropic response, expressed as peak heart rate, chronotropic index (ratio of heart rate reserve and metabolic reserve utilized), or percent maximal heart rate achieved, was correlated with angiographic findings obtained within 180 days of the test. Significant coronary disease was defined as > or = 1 stenosis of > or = 50% in a major epicardial artery or its main branches severe coronary disease was defined as > or = 50% stenosis in all 3 epicardial arteries, or in the left main coronary trunk, or 2-vessel disease with > or = 70% proximal left anterior descending artery stenosis. We observed that peak heart rate and percent maximal heart rate achieved were independent negative predictors of both significant and severe coronary disease by logistic regression. The chronotropic index predicted severe coronary disease only. All 3 parameters of chronotropic response exhibited a significant gradient of abnormality across the spectrum of coronary disease (p < 0.01 for all), expressed by the number of vessels involved and correlated with left anterior descending artery involvement (p < 0.05 for all). We conclude that chronotropic response to exercise predicts the presence and angiographic severity of coronary disease. This association is likely related to the proportion of left ventricular myocardium rendered ischemic during stress.
Publisher: Elsevier BV
Date: 12-1999
DOI: 10.1016/S0002-9149(99)00562-7
Abstract: The clinical importance of an exaggerated systolic blood pressure (BP) response to exercise, or exercise hypertension, is unclear. We have previously reported that exercise hypertension is associated with less severe angiographic coronary artery disease. This study sought to examine the association between exercise hypertension and ischemic "burden," as assessed by thallium-201 single-photon emission computed tomography. The cohort was comprised of consecutive adults (2,216 men, 1,229 women) referred for symptom-limited exercise thallium testing to evaluate known or suspected coronary artery disease. The main variable measured was exercise hypertension, defined as a peak systolic BP > or =210 mm Hg in men and > or =190 mm Hg in women. Thallium perfusion defects were described as: (1) any perfusion abnormality, (2) reversible abnormalities, and (3) any abnormality in > or =3 of 12 myocardial segments ("extensive abnormalities"). Exercise hypertension was present in 1,319 subjects (39%). Patients with exercise hypertension were less likely to have any thallium perfusion abnormality (16% vs 25%, odds ratio [OR] 0.58, 95% confidence intervals [CI] 0.49 to 0.69, p <0.001), reversible thallium abnormalities (7% vs 12%, OR 0.71, 95% CI 0.57 to 0.90, p <0.001), and extensive abnormalities (8% vs 14%, OR 0.53, 95% CI 0.42 to 0.67, p <0.001). After adjusting for possible confounders, the same trend was seen. During 6 years of follow-up there were 283 deaths with no association between exercise hypertension and mortality risk. Thus, exercise hypertension is associated with a lower likelihood of myocardial perfusion abnormalities and is not associated with an increased mortality rate.
Publisher: Elsevier BV
Date: 03-1999
DOI: 10.1016/S0735-1097(98)00642-1
Abstract: The aim of this study was to evaluate whether preoperative clinical and test data could be used to predict the effects of myocardial revascularization on functional status and quality of life in patients with heart failure and ischemic LV dysfunction. Revascularization of viable myocardial segments has been shown to improve regional and global LV function. The effects of revascularization on exercise capacity and quality of life (QOL) are not well defined. Sixty three patients (51 men, age 66+/-9 years) with moderate or worse LV dysfunction (LVEF 0.28+/-0.07) and symptomatic heart failure were studied before and after coronary artery bypass surgery. All patients underwent preoperative positron emission tomography (PET) using FDG and Rb-82 before and after dipyridamole stress the extent of viable myocardium by PET was defined by the number of segments with metabolism-perfusion mismatch or ischemia. Dobutamine echocardiography (DbE) was performed in 47 patients viability was defined by augmentation at low dose or the development of new or worsening wall motion abnormalities. Functional class, exercise testing and a QOL score (Nottingham Health Profile) were obtained at baseline and follow-up. Patients had wall motion abnormalities in 83+/-18% of LV segments. A mismatch pattern was identified in 12+/-15% of LV segments, and PET evidence of viability was detected in 30+/-21% of the LV. Viability was reported in 43+/-18% of the LV by DbE. The difference between pre- and postoperative exercise capacity ranged from a reduction of 2.8 to an augmentation of 5.2 METS. The degree of improvement of exercise capacity correlated with the extent of viability by PET (r = 0.54, p = 0.0001) but not the extent of viable myocardium by DbE (r = 0.02, p = 0.92). The area under the ROC curve for PET (0.76) exceeded that for DbE (0.66). In a multiple linear regression, the extent of viability by PET and nitrate use were the only independent predictors of improvement of exercise capacity (model r = 0.63, p = 0.0001). Change in Functional Class correlated weakly with the change in exercise capacity (r = 0.25), extent of viable myocardium by PET (r = 0.23) and extent of viability by DbE (r = 0.31). Four components of the quality of life score (energy, pain, emotion and mobility status) significantly improved over follow-up, but no correlations could be identified between quality of life scores and the results of preoperative testing or changes in exercise capacity. In patients with LV dysfunction, improvement of exercise capacity correlates with the extent of viable myocardium. Quality of life improves in most patients undergoing revascularization. However, its measurement by this index does not correlate with changes in other parameters nor is it readily predictable.
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.JACC.2006.10.054
Abstract: We examined the safety and efficacy of nonculprit multivessel compared with culprit-only stenting in patients with multivessel disease presenting with unstable angina or non-ST-segment elevation myocardial infarction (non-ST-segment elevation acute coronary syndromes [NSTE-ACS]). In patients presenting with NSTE-ACS, multivessel coronary artery disease (CAD) is associated with adverse outcome. Patients with multivessel CAD and NSTE-ACS that underwent percutaneous coronary intervention were included. The culprit lesion was defined by reviewing each patient's angiographic report, electrocardiogram, echocardiogram and, if available, nuclear stress test. All patients had at least 2 vessels with > or =50% stenosis, and the angiographic severity of CAD was assessed using the Duke Prognostic Angiographic Score. Patients with coronary bypass grafts, chronic total occlusions, and those with uncertain culprit lesions were excluded. Our end point was the composite of death, myocardial infarction, or any target vessel revascularization. From January 1995 to June 2005, 1,240 patients with ACS and multivessel CAD underwent percutaneous coronary intervention with bare-metal stenting and met our study criteria. Of these, 479 underwent multivessel and 761 underwent culprit-only stenting. There were 442 events during a median follow-up of 2.3 years. Multivessel intervention was associated with lower death, myocardial infarction, or revascularization after both adjusting for baseline and angiographic characteristics (hazard ratio 0.80 95% confidence interval 0.64 to 0.99 p = 0.04) and propensity matched analysis (hazard ratio 0.67 95% confidence interval 0.51 to 0.88 p = 0.004). In patients with multivessel CAD presenting with NSTE-ACS, multivessel intervention was significantly associated with a lower revascularization rate, which translated to a lower incidence of the composite end point compared with culprit-only stenting.
Publisher: Elsevier BV
Date: 10-1997
DOI: 10.1016/S0002-9149(97)00537-7
Abstract: Myocardial perfusion imaging using positron emission tomography (PET) may be more accurate for the diagnosis of coronary artery disease (CAD) than conventional imaging. The purpose of this study was to evaluate the prognostic implications of perfusion abnormalities in 685 patients (age 62 +/- 11 years, 199 women) studied by PET, and to assess the incremental value of these data in relation to prognostic implications of clinical and angiographic findings. Rubidium (Rb)-82 PET was performed before and after dipyridamole stress. Transient defects were detected in 227 patients (33%), and were moderate or greater in severity (> 15% of the left ventricle) in 84 (12%). Resting defects were present in 435 (64%) and were moderate or greater in severity in 216 (32%). The total extent of abnormally perfused myocardium was small ( 3 months after PET). Normal scans had a 90% event-free survival, compared with 87% in patients with small, 75% with moderate, and 76% with extensive defects (log rank chi-square 30, p <0.0001). Functional class, extent of CAD, and the presence and extent of perfusion defects (both at rest and during stress) were independent predictors of cardiac death and total cardiac events. In sequential Cox proportional-hazards models, the results of PET were incremental to those of clinical and angiographic evaluation. Thus, the presence and extent of damaged and jeopardized myocardium are independent and incremental predictors of outcome in patients undergoing Rb-82 PET.
Publisher: Elsevier BV
Date: 12-1995
DOI: 10.1016/0735-1097(95)00388-6
Abstract: This study was designed to assess the angiographic and prognostic implications of an exaggerated systolic blood pressure response to exercise ("exercise hypertension") in adults undergoing evaluation for suspected coronary artery disease. The clinical implications of exercise hypertension are unclear. Subjects for this prospective cohort study were derived from a consecutive s le of 9,608 adults who were referred for treadmill testing and who augmented their systolic blood pressure by at least 10 mm Hg. There were 594 subjects who underwent coronary angiography within 90 days of treadmill testing. Exercise hypertension was defined as a peak exercise systolic blood pressure > or = 210 mm Hg in men and > or = 190 mm Hg in women. Severe angiographic coronary disease was defined as left main coronary artery disease (> or = 50% diameter stenosis), three-vessel disease (> or = 70% diameter stenosis) or two-vessel disease with > or = 70% diameter stenosis of the proximal left anterior descending coronary artery. All-cause mortality was assessed during a follow-up period of approximately 2 years. Exercise hypertension was present in 196 subjects (33%). Severe coronary disease was less common in subjects with exercise hypertension (14% vs. 25%, odds ratio 0.51, 95% confidence interval [CI] 0.32 to 0.81, p = 0.004). Exercise hypertension remained associated with a lower rate of severe coronary disease even after adjusting for rest hypertension, age, gender, exercise capacity and other possible confounders. During the follow-up period, there were 23 deaths only 2 occurred in the group with exercise hypertension. After adjusting for severity of coronary disease, exercise hypertension remained associated with a lower mortality rate (adjusted relative risk 0.20, 95% CI 0.05 to 0.84, p = 0.03). In adults evaluated for coronary artery disease, exercise hypertension is associated with a lower likelihood of angiographically severe disease and a lower adjusted mortality rate.
Publisher: Elsevier BV
Date: 02-1999
DOI: 10.1016/S0002-9343(98)00388-X
Abstract: The association between myocardial perfusion imaging defects and cardiac mortality in women is undefined. We examined whether myocardial perfusion imaging predicted cardiac mortality in men and women and compared this with other variables influencing prognosis. Six academic institutions with high-volume nuclear cardiology laboratories consecutively studied 5,009 men aged 62 +/- 12 years (mean ISD) and 3,402 women aged 66 +/- 11 years with symptomatic known or suspected coronary artery disease undergoing exercise (n = 7,486) or pharmacologic stress (n = 925) myocardial perfusion imaging. A pretest clinical risk index was calculated from age, history of myocardial infarction, diabetes, hypertension, and hypercholesterolemia. Myocardial perfusion images were analyzed for stress-induced defects or any defect in the territories of the three major coronary arteries. Stress-induced perfusion defects were seen in 39% of men and 25% of women (P = 0.0001). Extensive stress-induced or fixed defects (>2 vascular territories) were less common in women than men (10% vs 19%, and 4% vs 18%, both P = 0.0001). During a mean of 2.4 +/- 1.5 years of follow-up, 143 patients died of cardiac causes. The clinical risk index and number of territories with perfusion defects were associated with cardiac mortality in women and men. In women undergoing exercise myocardial perfusion imaging, the number of abnormal territories remained the strongest correlate of mortality after adjustment for exercise variables. The results of myocardial perfusion imaging are important, independent predictors of survival in both women and men.
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0735-1097(98)00377-5
Abstract: This study sought to examine the prognostic importance of chronotropic incompetence among patients referred for stress echocardiography. Although chronotropic incompetence has been shown to be predictive of an adverse prognosis, it is not clear if this association is independent of exercise-induced myocardial ischemia. Consecutive patients (146 men and 85 women mean age 57 years) who were not taking beta-adrenergic blocking agents and were referred for symptom-limited exercise echocardiography were followed for a mean of 41 months. Chronotropic incompetence was assessed in two ways: (1) failure to achieve 85% of the age-predicted maximum heart rate and (2) a low chronotropic index, a heart rate response measure that accounts for effects of age, resting heart rate and physical fitness. The primary end point, a composite of death, nonfatal myocardial infarction, unstable angina and late (>3 months after the exercise test) myocardial revascularization, occurred in 41 patients. Failure to achieve 85% of the age-predicted maximum heart rate was predictive of events (relative risk [RR] 2.47, 95% confidence interval [CI] 1.28 to 4.79, p=0.007) similarly, a low chronotropic index was predictive (RR 2.44, 95% CI 1.31 to 4.55, p=0.005). Even after adjusting for myocardial ischemia and other possible confounders, failure to achieve 85% of age-predicted maximum heart rate was predictive (adjusted RR 2.20, 95% CI 1.11 to 4.37, p=0.02). A low chronotropic index also remained predictive (adjusted RR 1.85, 95% CI 0.98 to 3.47, p=0.06). Chronotropic incompetence is predictive of an adverse cardiovascular prognosis even after adjusting for echocardiographic myocardial ischemia.
Publisher: Elsevier BV
Date: 11-1999
DOI: 10.1016/S0894-7317(99)70142-2
Abstract: A quantitative technique is required to reduce the subjectivity and improve the reproducibility of stress echocardiography. Tissue Doppler imaging may offer these benefits, but its feasibility with exercise echocardiography (ExE) is undefined. This study sought the determinants of the exercise tissue Doppler velocity (TDV) response and the feasibility and accuracy of color TDV during ExE. Fifteen volunteers and 85 patients (age 60 +/- 10 years, 19 women) with known or suspected coronary artery disease were studied with standard 2-dimensional (2D) echocardiography and pulsed wave (PW) and color TDV before and after they underwent exercise treadmill testing. After the study PW TDV was measured in 6 basal segments, and off-line software was used to display color TDV data from all myocardial segments. Color TDV was compared with PW TDV in the basal segments at rest and stress with the use of linear regression. Color TDV in mid and basal segments was compared with wall motion on 2D echocardiography. The predictors of the TDV response to exercise were defined in a multiple linear regression. A logistic regression model was used to integrate clinical, exercise, and TDV variables for prediction of abnormal regional left ventricular function. Color and PW correlated well at rest (r = 0.81) and stress (r = 0.84), but PW was greater than color velocities at rest and stress. On the basis of 2D echocardiography, 752 myocardial segments were classified as normal in patients without evidence of coronary disease, 309 were normal in patients with abnormal wall motion in another territory, and 128 showed ischemia or scar. Segmental comparison of velocities assessed by color TDV showed that scar segments had a lower velocity than normal segments at rest and stress (P <.001). Ischemic segments had a lower peak TDV and less increment in velocity than normal segments. Heart rate, functional capacity, and regional dysfunction (scar or ischemia) were independent predictors of TDV at peak exercise. With the use of receiver operating characteristic analysis, the "correction" of TDV by these other variables increased the accuracy of the technique for the detection of regional left ventricular dysfunction. Color TDV is feasible during ExE. The correlation found between TDV and wall motion analysis of experienced observers indicates that TDV may be useful as a quantitative tool for interpretation of ExE.
Publisher: American Medical Association (AMA)
Date: 14-01-1998
Abstract: Approximately 0.5% of all patients who undergo exercise testing develop a transient left bundle-branch block (LBBB) during exercise, but its prognostic significance is unclear. To determine whether exercise-induced LBBB is an independent predictor of mortality and cardiac morbidity. Matched control cohort study. Between September 1990 and February 10, 1994, 17277 exercise stress tests were performed on patients. Tertiary care, academic medical center. From the cohort, 70 cases of exercise-induced LBBB were identified. The controls comprised 70 in iduals without LBBB at rest or during exercise that matched the 70 cases based on age, test date, sex, prior history of coronary artery disease, hypertension, diabetes, smoking, and beta-blocker use. All-cause mortality, percutaneous coronary intervention, open heart surgery, nonfatal myocardial infarction, documented symptomatic or sustained ventricular tachydysrhythmia, or implantation of a permanent pacemaker or an implantable cardiac defibrillator. A total of 37 events (28 events from the exercise-induced LBBB cases and 9 from the control cohort) occurred in 25 patients (17 exercise-induced LBBB patients and 8 control patients) during a mean follow-up period of 3.7 (0.9 years) (median, 3.8 years [range, 0.9-5.2 years]). There were 7 deaths, of which 5 occurred among patients with exercise-induced LBBB. Four-year Kaplan-Meier event rates were 19% among exercise-induced LBBB patients and 10% among controls (log-rank chi2, 5.2 P=.02). After further adjusting for small differences in age, exercise-induced LBBB remained associated with a higher risk of primary events (adjusted relative risk, 2.78 95% confidence interval, 1.16-6.65 P=.02). Exercise-induced LBBB independently predicts a higher risk of death and major cardiac events.
Publisher: Elsevier BV
Date: 09-2000
DOI: 10.1016/S0002-9149(00)01036-5
Abstract: Chronotropic incompetence, or an attenuated heart rate response to exercise, has been shown to be associated with an adverse outcome. It is not known whether chronotropic incompetence predicts all-cause mortality independent of angiographic severity of coronary artery disease (CAD). Study subjects included consecutive patients who underwent first-time, symptom-limited exercise treadmill testing and coronary angiography within 90 days no patient was taking beta blockers or had a history of heart failure, valve disease, or prior revascularization. Chronotropic response was measured in 2 ways: (1) failure to reach 85% of the age-predicted maximum heart rate, and (2) a low chronotropic index, a measure of exercise heart rate response that accounts for effects of age, physical fitness, and resting heart rate. Angiographic severity of CAD was assessed using the Duke Prognostic Weight Score, with a score > or = 42 considered to be indicative of severe CAD. Among 384 eligible patients, failure to reach 85% of the age-predicted maximum heart rate occurred in 61 (16%) and a low chronotropic index was noted in 133 (35%). Severe CAD was present in 63 (16%). During 6 years of follow-up there were 56 deaths. Mortality was predicted by failure to reach target heart rate (RR 1.85, 95% confidence interval [CI] 1.01 to 3.39, chi-square = 4, p = 0.05), by severe CAD (RR 2.21, 95% CI 1.24 to 3.95, chi-square = 8, p = 0.007), and, most strongly, by a low chronotropic index (RR 2.72, 95% CI 1.60 to 4.61, chi-square = 15, p = 0.0002). In a multivariable model, low chronotropic index remained predictive of death (adjusted RR 2.22, 95% CI 1.29 to 3.82, p = 0.004), whereas severe CAD no longer predicted death (adjusted RR 1.27, 95% CI 0.70 to 2.31, p > 0.4). Thus, chronotropic incompetence is a strong and independent predictor of death, even after accounting for the angiographic severity of CAD.
Publisher: Elsevier BV
Date: 02-1999
DOI: 10.1016/S0002-9149(98)00908-4
Abstract: This study sought to determine the association of exercise-induced ventricular ectopic activity with thallium perfusion defects and severity of angiographic coronary artery disease (CAD). Two cohorts consisting of adults without heart failure or known severe ventricular ectopic activity at rest were studied. The first cohort consisted of adults (n = 2,743) who underwent maximum exercise thallium stress testing. The second cohort consisted of adults (n = 423) who underwent coronary angiography within 90 days of treadmill testing. Significant exercise-induced ventricular ectopic activity was defined as frequent ventricular premature complexes or nonsustained ventricular tachycardia. Severe CAD was defined as left main CAD (> or = 50% stenosis), 3-vessel CAD (> or = 70% stenosis), or 2-vessel CAD with > or = 70% stenosis of the proximal left anterior descending artery. In the thallium cohort, exercise-induced ventricular ectopic activity was associated with a greater frequency of thallium defects (35.2% vs 18.7%, odds ratio [OR] 2.35, 95% confidence intervals [CI] 1.62 to 3.42, p <0.001) after adjusting for possible confounders, this association persisted (for any defect adjusted OR 1.66, 95% CI 1.09 to 2.53, p = 0.02 for septal defect adjusted OR 2.77, 95% CI 1.51 to 5.07, p <0.001). There was no association between exercise-induced ventricular ectopic activity and mortality during 2 years of follow-up. In the angiographic cohort, there was no association of exercise-induced ventricular ectopy with severe CAD (19% vs 20%, OR 0.93, 95% CI 0.41 to 2.09, p = NS). Exercise-induced ventricular ectopic activity was associated with a greater likelihood of thallium perfusion defects, but was not associated with angiographic severity of coronary disease or with short-term mortality.
Publisher: Massachusetts Medical Society
Date: 04-08-2005
DOI: 10.1056/NEJMOA044154
Publisher: Elsevier BV
Date: 02-1998
DOI: 10.1016/S0140-6736(97)07062-1
Abstract: Chronic inflammation is associated with various chronic diseases, including cardiovascular disease, neurodegenerative disease, and cancer, which severely affect the health and quality of life of people. Oxidative stress induced by unbalanced production and elimination of reactive oxygen species (ROS) is one of the essential risk factors for chronic inflammation. Recent studies, including the studies of mushrooms, which have received considerable attention, report that the antioxidant effects of natural compounds have more advantages than synthetic antioxidants. Mushrooms have been consumed by humans as precious nourishment for 3,000 years, and so far, more than 350 types have been identified in China. Mushrooms are rich in polysaccharides, peptides, polyphenols, alkaloids, and terpenoids and are associated with several healthy biological functions, especially antioxidant properties. As such, the extracts purified from mushrooms could activate the expression of antioxidant enzymes through the Keap1/Nrf2/ARE pathway to neutralize excessive ROS and inhibit ROS-induced chronic inflammation through the NF-κB pathway. Recently, the antioxidant properties of mushrooms have been successfully applied to treating cardiovascular disease (CAD), neurodegenerative diseases, diabetes mellitus, and cancer. The present review summarizes the antioxidant properties and the mechanism of compounds purified from mushrooms, emphasizing the oxidative stress regulation of mushrooms to fight against chronic inflammation.
Publisher: Elsevier BV
Date: 08-1996
DOI: 10.1016/S0002-9149(96)00277-9
Abstract: Considerable controversy exists regarding whether women are less likely than men to be referred to coronary angiography after an abnormal noninvasive test. This prospective cohort study analyzed consecutive subjects (2,351 men and 1,318 women) with no prior history of invasive cardiac procedures who were referred for treadmill thallium testing at the Cleveland Clinic Foundation. The primary end point was performance of coronary angiography within 90 days of treadmill thallium testing. A secondary end point was all-cause mortality during 1.8 years of follow-up. Women were less likely than men to undergo coronary angiography (6% vs 14%, odds ratio [OR] 0.42, 95% confidence interval [Cl] 0.33 to 0.54, p < 0.001), but were also less likely to have an abnormal thallium scan (8% vs 29%, p 0.9). Women were less likely to have severe coronary disease on angiography (15% vs 30%, p = 0.006). During 1.8 years of follow-up there were 26 deaths (2%) among women and 84 deaths (4%) among men. After adjusting for age, thallium abnormalities, and clinical characteristics in Cox regression analyses, women had a lower mortality rate than men (relative risk 0.58, 95% Cl 0.36 to 0.94, p = 0.03). Thus, gender-related differences in referral for coronary angiography after treadmill thallium testing can be explained by a higher rate of abnormal tests in men. No evidence of a post-test gender bias was detected, but a pretest bias affecting referral to nuclear testing cannot be excluded. Furthermore, women have a lower prevalence of severe coronary disease and a lower adjusted mortality rate.
Publisher: Elsevier BV
Date: 07-2000
DOI: 10.1016/S0002-9149(00)00819-5
Abstract: Effective allocation of medical resources in stable chest pain patients requires the accurate diagnosis of coronary artery disease and the stratification of future cardiac risk. We studied the relative predictive value for cardiac death of 3 commonly applied noninvasive strategies, clinical assessment, stress electrocardiography, and myocardial perfusion tomography, in a large, multicenter population of stable angina patients. The multicenter observational series comprised 7 community and academic medical centers and 8,411 stable chest pain patients. All patients underwent pretest clinical screening followed by stress (exercise 84% or pharmacologic 16%) electrocardiography and myocardial perfusion tomography. Risk-adjusted multivariable Cox proportional hazards models were developed to predict cardiac death. Kaplan-Meier rates of time to cardiac catheterization were also computed. Cardiac mortality was 3% during the 2.5 +/- 1.5 years of follow-up. The number of infarcted vascular territories and pretest clinical risk factors were strong predictors of cardiac mortality, whereas the number of ischemic vascular territories gained increasing importance when determining post-test resource use requirements (i.e., the decision to perform cardiac catheterization). Exertional ST-segment depression in a population with a high frequency of electrocardiographic abnormalities at rest was not a significant differentiator of cardiac death risk. Stable chest pain patients are accurately identified as being at high risk for near-term cardiac events by both physicians' screening clinical evaluation and by the results of stress myocardial perfusion imaging. Disease management strategies for stable chest pain patients aimed at risk reduction should incorporate knowledge of relevant end points in treatment and guideline development.
Publisher: Elsevier BV
Date: 07-1997
DOI: 10.1016/S0735-1097(97)00217-9
Abstract: We sought to determine the relative influence of estimated functional capacity and thallium-201 (Tl-201) single-photon emission computed tomographic (SPECT) findings on prediction of short-term all-cause and cardiac-related mortality. Decreased functional capacity and abnormal Tl-201 SPECT findings are predictive of increased cardiovascular risk and mortality. However, the relative importance of these variables as predictors of all-cause mortality is not well established. Analyses were based on 3,400 consecutive adults undergoing symptom-limited exercise Tl-201 SPECT testing at the Cleveland Clinic Foundation between September 1990 and December 1993 none had previous invasive procedures, heart failure or valve disease. Estimated functional capacity, classified by age and gender, and thallium perfusion defects, expressed as a stress extent thallium score on a 12-segment scale, were analyzed to determine their relative prognostic importance during 2 years of follow-up. Of 3,400 patients, 108 (3.2%) died during follow-up 32 deaths were identified as cardiac related. On univariable analysis, estimated functional capacity was a strong predictor of death, with 62 (57%) deaths occurring in patients achieving < 6 metabolic equivalents (METs) (log-rank chi-square 86, p < 0.0001). On multivariable analysis, the strongest independent predictors of all-cause mortality were fair or poor functional capacity (adjusted relative risk [RR] 3.96, 95% confidence interval [CI] 2.36 to 6.64, chi-square 27, p < 0.0001) and age (adjusted RR for 10 years 2.25, 95% CI 1.80 to 2.80, chi-square 27, p < 0.0001). The presence of SPECT thallium perfusion defects was a less powerful predictor of death (for each two additional segments with defects, adjusted RR 1.21, 95% CI 1.03 to 1.43, chi-square 5, p = 0.02). Cardiac mortality was predicted by both fair or poor functional capacity (adjusted RR 4.37, 95% CI 1.59 to 12.00, chi-square 8, p = 0.004) and by stress extent thallium score (adjusted RR 1.62, 95% CI 1.25 to 2.11, chi-square 13, p = 0.0003). In this clinically low risk group, estimated functional capacity was a strong and overwhelmingly important independent predictor of all-cause mortality among patients undergoing exercise Tl-201 SPECT testing. The extent of myocardial perfusion defects was of comparable importance for the prediction of cardiac mortality.
Publisher: American Medical Association (AMA)
Date: 10-02-1999
Abstract: Chronotropic incompetence, an attenuated heart rate response to exercise, is a predictor of all-cause mortality in healthy populations. This association may be independent of exercise-induced myocardial perfusion defects. To examine the prognostic significance of chronotropic incompetence in a low-risk cohort of patients referred for treadmill stress testing with thallium imaging. Prospective cohort study conducted between September 1990 and December 1993. Tertiary care academic medical center. Consecutive patients (1877 men and 1076 women mean age, 58 years) who were not taking beta-blockers and who were referred for symptom-limited treadmill thallium testing. Association of chronotropic incompetence, defined as either failure to achieve 85% of the age-predicted maximum heart rate or a low chronotropic index, a heart rate response measure that accounts for effects of age, resting heart rate, and physical fitness, with all-cause mortality during 2 years of follow-up. Three hundred sixteen patients (11%) failed to reach 85% of the age-adjusted maximum heart rate, 762 (26%) had a low chronotropic index, and 612 (21%) had thallium perfusion defects. Ninety-one patients died during the follow-up period. After adjustment for age, sex, thallium perfusion defects, and other confounders, failure to reach 85% of the age-predicted maximum heart rate was associated with increased risk of death (adjusted relative risk [RR], 1.84 95% confidence interval [CI], 1.13-3.00 P=.01), as was a low chronotropic index (adjusted RR, 2.19 95% CI, 1.43-3.44 P<.001). Among patients with known or suspected coronary disease, chronotropic incompetence is independently predictive of all-cause mortality, even after considering thallium perfusion defects. Incorporation of chronotropic response into the routine interpretation of stress thallium studies may improve the prognostic power of this test.
Publisher: Elsevier BV
Date: 1996
DOI: 10.1016/0735-1097(95)00393-2
Abstract: This study sought to establish the prognostic implications of ischemic and viable myocardium identified by dobutamine echocardiography in patients with left ventricular dysfunction. Recent studies have suggested that in patients with viable myocardium identified by positron emission tomography, medical treatment is associated with recurrent cardiac events. Dobutamine echocardiography has been used to identify viable myocardium in patients with left ventricular dysfunction, but the prognostic significance of this test is undefined. One hundred thirty-six consecutive patients (mean [+/- SD] age 67 +/- 7.9 years 104 men) with moderate or severe left ventricular dysfunction (left ventricular ejection fraction 30 +/- 5%) undergoing dobutamine echocardiography were included in the study. Dobutamine was administered using a standard incremental protocol (5 to 40 micrograms/kg body weight per min intravenously in 3-min stages) with additional atropine (1 mg intravenously) as required. Standard body weight echocardiographic views were digitized on-line and compared using a side-by-side display. Viable myocardium was identified by enhancement of regional function at low dose (< 10 micrograms) scar was diagnosed by akinesia at rest or dyskinesia without change and ischemia as new or worsening dysfunction. One hundred thirty patients (95%) were followed up for 16 +/- 8 months after the original study for major cardiac events (cardiac death, myocardial infarction or severe unstable angina requiring late myocardial revascularization). No significant complications occurred during dobutamine echocardiography. Viable myocardium was detected in 26 patients (19%), ischemia in 23 (17%), both viability and ischemia in 13 (10%) and scar in 74 (54%). Of 108 patients treated medically, 46 had viable or ischemic myocardium, and 62 had scar only. There were no significant differences in age or other clinical characteristics, stress response, left ventricular dimensions and ejection fraction between the two groups. Cardiac events occurred in 26 medically treated patients (24%): 18 died of cardiac-related causes 4 had a nonfatal myocardial infarction and 4 had late revascularization because of unstable angina. The event rate was greater in patients with viable or ischemic myocardium than those with scar (43% vs. 8%, p = 0.01 by log-rank test). In a Cox regression model, the presence of viable or ischemic myocardium was found to predict subsequent events (relative risk 3.51, p = 0.02) independently of ejection fraction and age. Viable or ischemic myocardium detected at dobutamine echocardiography in patients with left ventricular dysfunction is associated with an adverse prognosis, independent of age and ejection fraction.
Publisher: Elsevier BV
Date: 07-2005
DOI: 10.1016/J.AMJCARD.2005.03.055
Abstract: The prognostic values of tissue Doppler imaging and color M-mode diastolic indexes were studied in 225 patients who had symptomatic systolic heart failure in the ADEPT study. The primary end point of death, transplantation, or hospitalization due to heart failure occurred in 65 patients and was independently predicted by shorter deceleration time, lower ratio of pulmonary vein systolic to diastolic velocity, and increasing levels of the ratios of early transmitral velocity to early annular velocity or velocity of propagation. For the ratio of early transmitral velocity to early annular velocity, this prediction was additive to deceleration time. Newer diastolic indexes provide an independent prediction of clinical outcomes.
Publisher: Elsevier BV
Date: 09-1998
DOI: 10.1016/S0002-9149(98)00462-7
Abstract: Functional testing is recommended for risk stratification of medically treated patients with unstable angina. Exercise echocardiography is used in this situation, but its safety and prognostic value are not well defined. The objective of this study was to assess the incremental prognostic value of exercise echocardiography in 226 consecutive patients (128 men, age 59+/-13 years) with medically treated unstable angina, who underwent exercise echocardiography from 1991 to 1996. Clinical risk was designated as low in 108 patients, intermediate in 116, and high in 2 patients according to the unstable angina practice guidelines. There were no major complications from the stress tests. The exercise electrocardiogram was nondiagnostic in 57 patients (25%). Ischemia was identified by exercise electrocardiography in 33 patients and exercise echocardiography in 55 patients. Patients were followed for 29+/-18 months. After exclusion of 38 patients who underwent early revascularization, 28 patients had cardiac death, nonfatal infarction, and late (>3 months) revascularization. Ischemia at exercise echocardiography was associated with a 24-month event-free survival of 81%, compared to 95% with negative exercise echocardiography (p=0.02). A positive exercise electrocardiogram was associated with a 24-month event-free survival of 84%, compared to 93% with negative exercise electrocardiograms (p=0.08). In a Cox regression model, event-free survival was predicted by ischemia at exercise echocardiography (relative risk 2.8, confidence interval: 1.3 to 6.3, p=0.05), but not at exercise electrocardiography (relative risk 2.1, confidence interval 0.7 to 5.8, p=0.16).
Publisher: Elsevier BV
Date: 02-1997
DOI: 10.1016/S0002-8703(97)70201-1
Abstract: This study investigated the association between age and referral to coronary angiography among ambulatory adults with an abnormal treadmill thallium scan. The subjects studied were 416 consecutive adults who were > or = 30 years old, under the care of cardiologists, and had an abnormal treadmill thallium scan between 1990 and 1993 at the Cleveland Clinic Foundation. The primary end point was performance of coronary angiography within 90 days of the treadmill test. Coronary angiography was performed in 163 subjects. Coronary angiography was performed in 46% of patients aged 30-49 years, in 53% of those aged 50 to 64 years, in 33% of those aged 65 to 74 years, and in only 18% of those aged > or = 75 years (chi2 test for trend, p < 0.0001). After adjustment for potential confounders, age remained associated with a lower rate of referral to angiography (p 74 years (cumulative rate 31%, 95% confidence interval 16% to 47%). The number of abnormal thallium scan segments was predictive of death (p = 0.02). These data suggest that increasing age is associated with a lower rate of referral to coronary angiography after an abnormal treadmill thallium test.
Publisher: Elsevier BV
Date: 09-1999
DOI: 10.1016/S0735-1097(99)00269-7
Abstract: This study was performed to determine whether a delayed decline in systolic blood pressure (SBP) after graded exercise is an independent correlate of angiographic coronary disease. The predictive importance of the rate of SBP decline after exercise relative to blood pressure changes during exercise has not been well explored. Among adults who underwent symptom-limited exercise treadmill testing and who underwent coronary angiography within 90 days, a delayed decline in SBP during recovery was defined as a ratio of SBPs at 3 min of recovery to SBP at 1 min of recovery >1.0. Severe angiographic coronary artery disease was defined as left main disease, three-vessel disease or two-vessel disease with involvement of the proximal left anterior descending artery. There were 493 subjects eligible for analyses (age 59 +/- 11 years, 78% male). Severe angiographic coronary disease was noted in 102 (21%). There were associations noted between a delayed decline in SBP during recovery and severe angiographic coronary disease (34% vs. 17%, odds ratio [OR] 2.59, confidence interval [CI] 1.58 to 4.25, p = 0.001). In multivariate logistic regression analyses adjusting for SBP changes during exercise and other potential confounders, a delayed decline in SBP during recovery remained predictive of severe angiographic coronary disease (adjusted OR 2.22, 95% CI 1.27 to 3.87, p = 0.005). A delayed decline in SBP during recovery is associated with a greater likelihood of severe angiographic coronary disease even after accounting for the change in SBP during exercise.
No related grants have been discovered for Michael Lauer.