ORCID Profile
0000-0003-2093-6909
Current Organisations
Royal Adelaide Hospital
,
University of Adelaide
,
John Hunter Hospital
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Publisher: Elsevier BV
Date: 11-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2019
DOI: 10.1161/CIRCEP.118.007005
Abstract: The posterior left atrium is an arrhythmogenic substrate that contributes to the initiation and maintenance of atrial fibrillation (AF) however, the feasibility, safety, and efficacy of posterior wall isolation (PWI) as an AF ablation strategy has not been widely reported. We undertook a systematic review and meta-analysis of studies performing PWI to assess (1) acute procedural success including the ability to achieve PWI and the number of procedure-related complications, (2) Long-term, clinical success including rates of arrhythmia recurrence and posterior wall reconnection, and (3) The efficacy of PWI compared with pulmonary vein isolation on preventing arrhythmia recurrence. MEDLINE, EMBASE, and Web of Science databases were searched in May 2018 to retrieve relevant studies. Results were pooled using a random effects model. Seventeen studies (13 box isolation, 3 single ring isolation, and 1 debulking ablation) comprising 1643 patients (31.3% paroxysmal AF, left atrial diameter 41±3.1 mm) were included in the final analysis. In studies focusing specifically on PWI, the acute procedural success rate for achieving PWI was 94.1% (95% CI, 87.2%–99.3%). Single-procedure 12-month freedom from atrial arrhythmia was 65.3% (95% CI, 57.7%–73.9%) overall and 61.9% (54.2%–70.8%) for persistent AF. Randomized control trials comparing PWI to pulmonary vein isolation (3 studies, 444 patients) yielded conflicting results and could not confirm an incremental benefit to PWI. Fifteen major complications (0.1%), including 2 atrio-esophageal fistulas, were reported. PWI as an end point of AF ablation can be achieved in a large proportion of cases with good rates of 12-month freedom from atrial arrhythmia. Although the procedure-related complication rate is low, it did not eliminate the risk of atrio-esophageal fistula. URL: www.crd.york.ac.uk rospero . PROSPERO registration number: CRD42018107212.
Publisher: American College of Physicians
Date: 21-01-2020
DOI: 10.7326/L19-0708
Publisher: Wiley
Date: 06-2020
DOI: 10.1111/IMJ.14855
Publisher: Elsevier BV
Date: 07-2021
Publisher: Oxford University Press (OUP)
Date: 30-01-2020
Abstract: There is growing evidence that magnetic resonance imaging (MRI) scanning in patients with non-conditional cardiac implantable electronic devices (CIEDs) can be performed safely. Here, we aim to assess the safety of MRI in patients with non-conditional CIEDs. English scientific literature was searched using PubMed/Embase/CINAHL with keywords of ‘magnetic resonance imaging’, ‘pacemaker’, ‘implantable defibrillator’, and ‘cardiac resynchronization therapy’. Studies assessing outcomes of adverse events or significant changes in CIED parameters after MRI scanning in patients with non-conditional CIEDs were included. References were excluded if the MRI conditionality of the CIEDs was undisclosed number of patients enrolled was & or studies were case reports/series. 35 cohort studies with a total of 5625 patients and 7196 MRI scans (0.5–3 T) in non-conditional CIEDs were included. The overall incidence of lead failure, electrical reset, arrhythmia, inappropriate pacing and symptoms related to pocket heating, or torque ranged between 0% and 1.43%. Increase in pacing lead threshold & .5 V and impedance & Ω was seen in 1.1% [95% confidence interval (CI) 0.7–1.8%] and 4.8% (95% CI 3.3–6.4%) respectively. The incidence of reduction in P- and R-wave sensing by & % was 1.5% (95% CI 0.6–2.9%) and 0.4% (95% CI 0.06–1.1%), respectively. Battery voltage reduction of & .04 V was reported in 2.2% (95% CI 0.2–6.1%). This meta-analysis affirms the safety of MR imaging in non-conditional CIEDs with no death or implantable cardioverter-defibrillator shocks and extremely low incidence of lead or device-related complications.
Publisher: BMJ
Date: 16-10-2020
DOI: 10.1136/HEARTJNL-2020-317418
Abstract: To characterise the rate, causes and predictors of cessation of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF). Consecutive patients with AF with a long-term anticoagulation indication treated with NOACs (dabigatran, apixaban and rivaroxaban) in our centre from September 2010 through December 2016 were included. Prospectively collected data with baseline characteristics, causes of cessation, mean duration-to-cessation and predictors of cessation were analysed. The study comprised 1415 consecutive patients with AF, of whom 439 had a CHA 2 DS 2 -VASc≥1 and were on a NOAC. Mean age was 71.9±8.7 years and 37% were females. Over a median follow-up of 3.6 years (IQR=2.7–5.3), 147 (33.5%) patients ceased their index-NOAC (113 switched to a different form of OAC), at a rate of 8.8 per 100 patient-years. Serious adverse events warranting NOAC cessation occurred in 28 patients (6.4%) at a rate of 1.6 events per 100 patient-years. The mean duration-to-cessation was 4.9 years (95% CI 4.6 to 5.1) and apixaban had the longest duration-to-cessation with (5.1, 95% CI 4.8 to 5.4) years, compared with dabigatran (4.6, 95% CI 4.2 to 4.9) and rivaroxaban (4.5, 95% CI 3.9 to 5.1), pairwise log-rank p=0.002 and 0.025, respectively. In multivariable analyses, age was an independent predictor of index-NOAC cessation (HR 1.03, 95% CI 1.01 to 1.05 p=0.006). Female gender (HR 2.2, 95% CI 1.04 to 4.64 p=0.04) independently predicted serious adverse events. In this ‘real world’ cohort, NOAC use is safe and well-tolerated when prescribed in an integrated care clinic. Whether apixaban is better tolerated compared with other NOACs warrants further study.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.HRTHM.2018.07.029
Abstract: Battery longevity is an important factor that may influence the selection of cardiac implantable electronic devices (CIEDs). However, there remains a lack of industry-wide standardized reporting of predicted CIED longevity to facilitate informed decision-making for implanting physicians and payers. The purpose of this study was to compare the predicted longevity of current generation CIEDs using best-matched CIEDs settings to assess differences between brands and models. Data were extracted for current model pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy-defibrillators (CRT-Ds) from product manuals and, where absent, by communication with the manufacturers. Pacemaker longevity estimations were based on standardized pacing outputs (2.5V, 0.40-ms pulse width, 500-Ω impedance) and pacing loads of 50% or 100% at 60 bpm. ICD and CRT-D longevity were estimated at 0% pacing and 15% atrial plus 100% biventricular pacing, with essential capacitor reforms and zero clinical shocks. Mean maximum predicted longevity of single- and dual-chamber pacemakers was 12.0 ± 2.1 and 9.8 ± 1.9 years, respectively. Use of advanced features such as remote monitoring, prearrhythmia electrogram storage, and rate response can result in ∼1.4 years of reduction in longevity. Mean maximum predicted longevity of ICDs and CRT-Ds was 12.4 ± 3.0 and 8.8 ± 2.1 years, respectively. Of note, there were significant variations in predicted CIED longevity according to device manufacturers, with up to 44%, 42%, and 44% difference for pacemakers, ICDs, and CRT-Ds, respectively. Contemporary CIEDs demonstrate highly variable predicted longevity according to device manufacturers. This may impact on health care costs and long-term clinical outcomes.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Wiley
Date: 02-02-2022
DOI: 10.1111/JCE.15387
Abstract: Although single ring isolation is an accepted strategy for undertaking pulmonary vein (PV) and posterior wall isolation (PWI) during atrial fibrillation (AF) ablation, the learning curve associated with this technique as well as procedural and clinical success rates have not been widely reported. Prospectively collected data from 250 consecutive patients undergoing de novo AF ablation using single ring isolation. PWI was achieved in 212 patients (84.8%) and PV isolation without PWI was achieved in 37 patients (14.4%). Thirty-one cases (12.4%) demonstrated inferior line sparing where PWI was achieved without a continuous posterior wall inferior line. A learning curve was observed, with higher rates of PWI (98% last 50 vs. 82% first 50 cases, p = .016), higher rates of inferior line sparing (20% last 50 vs. 8% first 50 cases, p = .071) and lower ablation times (43.8 min (interquartile range [IQR]: 34.6-57.0 min) last 50 versus. 96.5 min (IQR: 80.8-115.8 min) first 50 cases p < .001). Three (1.3%) major procedure-related complications were observed. Twelve-month, single-procedure freedom from atrial arrhythmia without drugs was 70.5% (95% confidence interval [CI]: 61.5%-77.7%) and 60.0% (95% CI: 50.2%-68.4%) for paroxysmal and persistent/longstanding persistent AF. Twelve-month multi-procedure freedom from atrial arrhythmia was 92.2% (95%CI: 85.6%-95.9%) and 85.6% (95%CI: 77.2%-91.0%) for paroxysmal and persistent/longstanding persistent AF. Employing a single ring isolation approach, PWI can be achieved in most cases. There is a substantial learning curve with higher rates of PWI, reduced ablation times, and higher rates of inferior line sparing as procedural experience grows. Long-term freedom from arrhythmia is comparable to other AF ablation techniques.
Publisher: Elsevier BV
Date: 08-2020
DOI: 10.1016/J.HLC.2019.11.006
Abstract: Studies have shown that suboptimal anticoagulation quality, as measured by time in therapeutic range (TTR), affects a significant percentage of patients with atrial fibrillation (AF). However, TTR has not been previously characterised in Indigenous Australians who experience a greater burden of AF and stroke. Indigenous and non-Indigenous Australians with AF on warfarin anticoagulation therapy were identified from a large tertiary referral centre between 1999 and 2012. Time in therapeutic range was calculated as a proportion of daily international normalised ratio (INR) values between 2 and 3 for non-valvular AF and 2.5 to 3.5 for valvular AF. INR values between tests were imputed using the Rosendaal technique. Linear regression models were employed to characterise predictors of TTR. Five hundred and twelve (512) patients with AF on warfarin were included (88 Indigenous and 424 non-Indigenous). Despite younger age (51±13 vs 71±12 years, p<0.001), Indigenous Australians had greater valvular heart disease, diabetes, and alcohol excess compared to non-Indigenous Australians (p<0.05 for all). Time in therapeutic range was significantly lower in Indigenous compared to non-Indigenous Australians (40±29 vs 50±31%, p=0.006). Univariate predictors of poorer TTR included Indigenous ethnicity, younger age, diuretic use, and comorbidities, such as valvular heart disease, heart failure and chronic obstructive pulmonary disease (p<0.05 for all). Valvular heart disease remained a significant predictor of poorer TTR in multivariate analyses (p=0.004). Indigenous Australians experience particularly poor warfarin anticoagulation quality. Our data also suggest that many non-Indigenous Australians spend suboptimal time in therapeutic range. These findings reinforce the importance of monitoring warfarin anticoagulation quality to minimise stroke risk.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2021
Publisher: Elsevier BV
Date: 04-2022
Publisher: BMJ
Date: 08-2021
DOI: 10.1136/BMJOPEN-2020-047642
Abstract: Atrial fibrillation (AF) is associated with significantly impaired quality-of-life. Iron deficiency (ID) is prevalent in patients with AF. Correction of ID in other patient populations with intravenous iron supplementation has been shown to be a safe, convenient and effective way of improving exercise tolerance, fatigue and quality-of-life. The IRON-AF (Effect of Iron Repletion in Atrial Fibrillation) study is designed to assess the effect of iron repletion with intravenous ferric carboxymaltose in patients with AF and ID. The IRON-AF study is a double-blind, randomised controlled trial that will recruit at least 84 patients with AF and ID. Patients will be randomised to receive infusions of either ferric carboxymaltose or placebo, given in repletion and then maintenance doses. The study will have follow-up visits at weeks 4, 8 and 12. The primary endpoint is change in peak oxygen uptake from baseline to week 12, as measured by cardiopulmonary exercise testing (CPET) on a cycle ergometer. Secondary endpoints include changes in quality-of-life and AF disease burden scores, blood parameters, other CPET parameters, transthoracic echocardiogram parameters, 6-minute walk test distance, 7-day Holter/Event monitor burden of AF, health resource utilisation and mortality. The study protocol has been approved by the Central Adelaide Local Health Network Human Research Ethics Committee, Australia. The results of this study will be disseminated through publications in peer-reviewed journals and conference presentations. Australian New Zealand Clinical Trials Registry (ACTRN12620000285954).
Publisher: Wiley
Date: 18-01-2021
DOI: 10.1111/PACE.14161
Abstract: To characterize contemporary pacemaker procedure trends. Nationwide analysis of pacemaker procedures and costs between 2008 and 2017 in Australia. The main outcome measures were total, age- and gender-specific implant, replacement, and complication rates, and costs. Pacemaker implants increased from 12,153 to 17,862. Implantation rates rose from 55.3 to 72.6 per 100,000, a 2.8% annual increase (incidence rate ratio [IRR] 1.028 95% CI, 1.02-1.04 p < .001). Pacemaker implants in the 80+ age group were 17.37-times higher than the < 50 group (95% CI 16.24-18.59 p < .001), and in males were 1.48-times higher than in females (95% CI 1.42-1.55 p < .001). However, there were similar increases according to age (p = .10) and gender (p = .68) over the study period. Left ventricular lead rates were stable (IRR 0.995 95% CI 0.98-1.01 p = .53). Generator replacements decreased from 20.5 to 18.3 per 100,000 (IRR 0.975 95% CI 0.97-0.98 p < .001). Although procedures for generator-related complications were stable (IRR 0.995 95% CI 0.98-1.01 p = .54), those for lead-related complications decreased (IRR 0.985 95% CI 0.98-0.99 p < .001). Rates for all pacemaker procedures were consistently greater in males (p < .001). Although annual costs of all pacemaker procedures increased from $178 million to $329 million, inflation-adjusted costs were more stable, rising from $294 million to $329 million. Increasing demand for pacemaker implants is driven by the ageing population and rising rates across all ages, while replacement and complication procedure rates appeared more stable. Males have consistently greater pacemaker procedure rates than females. Our findings have significant clinical and public health implications for healthcare resource planning.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.HLC.2018.10.003
Abstract: Ventricular arrhythmias are one of the leading causes of death in patients with a prior myocardial infarction. Implantable cardioverter-defibrillators (ICDs) are very effective in the prevention of sudden cardiac death but the risk of recurrence remains an issue since defibrillation does not alter the underlying substrate. Recurrent ICD shocks are distressing and are associated with an increase in mortality. Catheter ablation is an effective treatment for recurrent ventricular tachycardia in these patients, particularly when antiarrhythmic therapy produces side effects or is ineffective. This paper reviews the underlying mechanisms of VT in patients with a prior myocardial infarction, and the indications, strategies and outcomes of catheter ablation.
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.HLC.2019.03.017
Abstract: Pulmonary vein isolation using cryoballoon ablation is an effective treatment for patients with atrial fibrillation. We sought to compare outcomes with the first and second generation cryoballoon, with the second generation balloon incorporating the Achieve Lasso catheter, in terms of freedom from symptomatic recurrence and major complications. The first 200 patients who underwent cryoballoon ablation with the first generation balloon were compared with the first 200 patients using the second-generation balloon. All patients had symptomatic atrial fibrillation and had failed at least one antiarrhythmic drug. The primary efficacy endpoint was freedom from symptomatic recurrence of atrial fibrillation (AF) after a single pulmonary vein isolation (PVI) procedure using the cryoballoon. The primary safety endpoint was major procedural complications. At 12 months, freedom from symptomatic AF after a single procedure in the first generation cohort was 64.3% compared with 78.6% in the second-generation cohort (p = 0.002). At 24 months, freedom from symptomatic AF in the first generation cohort was 51.3% compared with 72.6% in the second-generation cohort (p < 0.001). Procedural time (150 min vs 101 min p < 0.001) and fluoroscopy time (32.5 min vs 21.4 min p < 0.001) was lower in the second-generation group. The rate of major complications was comparably low in both groups. The second-generation cryoballoon was associated with improved freedom from symptomatic AF with reduction in procedure and fluoroscopy time, with a similar low rate of major complications.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.CJCA.2021.10.012
Abstract: Chronological aging is one of the major risk factors of cardiovascular (CV) disease (CVD) however, the effect of biological aging on CVD and outcomes remain poorly understood. Herein, we evaluated the association between leukocyte telomere length (LTL), a marker of biological age, and CV outcomes. We searched PubMed, Embase, Ovid Medline, and Web of Science Core Collection for the studies on the association between LTL and myocardial infarction (MI), CV death, and/or CVD risk factors from inception to July 2020. Extracted data were pooled in a random-effects meta-analysis and summarized as risk ratio (RR) and corresponding 95% confidence interval (CI) per LTL tertile. A total of 32 studies (n = 144,610 participants) were included. In a pooled analysis of MI and LTL in a multivariate-adjusted model, the shortest LTL was associated with a 39% higher risk of MI (RR, 1.39 95% CI, 1.16-1.67 P < 0.001). After adjusting for chronological age and traditional covariance, we showed a 28% increased risk of CV death in the shortest tertile of LTL (RR, 1.28 95% CI, 1.05-1.56 P = 0.01). Analysis of the studies that investigated the association between CV risk factors and LTL (n = 7) showed that diabetes mellitus is associated with a 46% increased risk of LTL attrition (RR, 1.46 95% CI, 1.46-2.09 P = 0.039). This study shows a strong association between LTL, a marker of biological aging, and the risk of MI and CV death. Cardiometabolic risk factors contribute to telomere attrition and therefore accelerates biological aging.
Publisher: Elsevier BV
Date: 04-2020
No related grants have been discovered for Mehrdad Emami.