ORCID Profile
0000-0001-7308-1268
Current Organisations
Norwegian University of Science and Technology
,
Hospital for Sick Children
,
Katholieke Universiteit Leuven Faculteit Letteren
,
University of Toronto
,
SickKids Research Institute
,
Katholieke Universiteit Leuven Faculteit Geneeskunde
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Publications
Retraining an Artificial Intelligence Algorithm to Calculate Left Ventricular Ejection Fraction in Pediatrics
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1053/J.JVCA.2022.05.004
Abstract: Identifying patients with low left ventricular ejection fraction (LVEF) and monitoring LVEF responses to treatment are important clinical goals. Can a deep-learning algorithm predict pediatric LVEF within clinically acceptable error? The study authors wanted to fine-tune an adult deep-learning algorithm to calculate LVEF in pediatric patients. A priori, their objective was to refine the algorithm to perform LVEF calculation with a mean absolute error (MAE) ≤5%. A quaternary pediatric hospital PARTICIPANTS: A convenience s le (n = 321) of echocardiograms from newborns to 18 years old with normal cardiac anatomy or hemodynamically insignificant anomalies. Echocardiograms were chosen from a group of healthy controls with known normal LVEF (n = 267) and a dilated cardiomyopathy patient group with reduced LVEF (n = 54). The artificial intelligence model EchoNet-Dynamic was tested on this data set and then retrained, tested, and further validated to improve LVEF calculation. The gold standard value was LVEF calculated by clinical experts. In a random subset of subjects (n = 40) not analyzed prior to selection of the final model, EchoNet-Dynamic calculated LVEF with a MAE of 8.39%, R The fine-tuned model calculates LVEF in a range of pediatric patients within clinically acceptable error. Potential advantages include reducing operator error in LVEF calculation and supporting independent LVEF assessment by inexperienced users.
Imaging for the Assessment of Heart Failure in Congenital Heart Disease
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.HFC.2013.09.013
Abstract: Although heart failure is a diagnosis made on clinical grounds, cardiac imaging remains essential for quantifying ventricular remodeling and function, and for identifying potentially reversible causes of heart failure. Various nongeometric methods for the assessment of ventricular function have been developed, and 3-dimensional imaging is also gaining ground in its clinical applications. This review focuses on the application of noninvasive imaging strategies in the assessment of heart failure in congenital heart disease, specifically echocardiography, cardiac magnetic resonance imaging, and computed tomography. Both traditional and emerging techniques are discussed, and their potential applications and limitations explored.
Determinants and clinical significance of flow via the fenestration in the Fontan pathway: A multimodality study
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.IJCARD.2012.10.008
Abstract: The use of a fenestration in the Fontan pathway remains controversial, partly because its hemodynamic effects and clinical consequences are insufficiently understood. The objective of this study was to quantify the magnitude of fenestration flow and to characterize its hemodynamic consequences after an intermediate interval after surgery. Twenty three patients with a fenestrated extracardiac conduit prospectively underwent investigation by cardiac magnetic resonance (CMR), echocardiography, and invasive manometry under the same general anesthetic 12 ± 4 months after Fontan surgery. Fenestration flow was determined using phase contrast CMR by subtracting flow in the Fontan pathway above the fenestration from Fontan flow below the fenestration. Fenestration flow constituted a mean of 31 ± 12% (range 8-50%) of ventricular preload. It was associated with a lower Qp/Qs (r = -0.64, p=0.001) and oxygen saturation (r = -0.74, p<0.0001). Fenestration flow volume was correlated with pulmonary vascular resistance (r = 0.45, p = 0.04) and markers of ventricular diastolic function (early diastolic strain rate r = 0.57, p = 0.008 and ventricular untwist rate r = 0.54, p = 0.02). In 14 patients (61%) all of the net inferior vena cava flow and part of the superior vena cava flow were erted into the systemic atrium and did not reach the lungs. Fenestration flow can be measured accurately with CMR. In two-thirds of the patients not only all of the inferior vena cava flow, but also some of the superior vena cava flow is erted through the fenestration. Fenestration flow is driven by a balance between pulmonary vascular resistance and early diastolic ventricular function.
Right Ventricular Remodeling in Hypoplastic Left Heart Syndrome is Minimally Impacted by Cardiopulmonary Bypass: A Comparison of Norwood vs. Hybrid
Publisher: Springer Science and Business Media LLC
Date: 10-10-2020
Aortopulmonary collateral flow volume affects early postoperative outcome after Fontan completion: A multimodality study
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.JTCVS.2012.03.032
Abstract: Aortopulmonary collaterals are a frequent phenomenon in patients after bidirectional cavopulmonary connection. The aortopulmonary collateral flow volume can be quantified using cardiac magnetic resonance imaging. However, the significance of aortopulmonary collateral flow for the postoperative outcome after total cavopulmonary connection is unclear and was sought to be determined. The data from 33 patients were prospectively studied with cardiac magnetic resonance, echocardiography, and cardiac catheterization before the total cavopulmonary connection operation. The early postoperative outcomes after total cavopulmonary connection completion were recorded. Aortopulmonary collateral flow was 1.59 L/min/m(2) ± 0.65 L/min/m(2) (range, 0.54 L/min/m(2)-3.34 L/min/m(2)), constituting 43% ± 13% (range, 12-87%) of pulmonary blood flow and 35% ± 12% (range, 11-62%) of the cardiac index, resulting in a pulmonary blood flow/systemic blood flow ratio of 1.06 ± 0.17 (range, 0.79-1.55). The aortopulmonary collateral flow correlated with pulmonary blood flow/systemic blood flow ratio (r = 0.69, P < .0001), oxygen saturation (r = 0.42, P = .018), and cardiac index (r = 0.53, P = .002). Of the 36 patients, 24 underwent fenestrated total cavopulmonary connection during the study period. The aortopulmonary collateral flow, relative to the cardiac index, correlated with the duration of hospital stay (r = 0.48, P = .02) and pleural drainage (r = 0.45, P = .03). Patients whose pleural drainage lasted 1 week or less had less aortopulmonary collateral flow before the Fontan operation than those with a longer period until chest tube removal (1.23 L/min/m(2) ± 0.38 L/min/m(2) vs 1.73 L/min/m(2) ± 0.76 L/min/m(2) P = .03). Compared with a contemporary group of total cavopulmonary connection patients with fenestration in their extracardiac conduit who were studied prospectively, with a similar protocol, the bidirectional cavopulmonary connection had a greater amount of aortopulmonary collateral flow (1.59 L/min/m(2) ± 0.65 L/min/m(2) vs 1.30 L/min/m(2) ± 0.57 L/min/m(2), P = .04). Patients after bidirectional cavopulmonary connection routinely acquire a large amount of aortopulmonary collateral flow. The hemodynamic consequences of aortopulmonary collateral flow translate into adverse outcomes early after total cavopulmonary connection completion.
Renin–angiotensin–aldosterone system genotype and serum BNP in a contemporary cohort of adults late after Fontan palliation
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.IJCARD.2015.06.018
Abstract: Adults with single ventricle physiology palliated with a Fontan circulation experience high mortality due to circulatory failure. Renin-angiotensin-aldosterone system (RAAS) genotype contributes to adverse cardiovascular outcomes in acquired heart failure. This study evaluated associations between RAAS genotype, ventricular mass and function in a contemporary cohort of adults with a Fontan circulation. This single-center prospective study included adults (n=106) seen after the Fontan operation (mean age 27±9years). Patients were genotyped for 5 pro-hypertrophic RAAS gene polymorphisms. Serum BNP, ventricular mass and function, and clinical events were compared between those with ≥2 homozygous risk genotypes ("high-risk", n=31) versus those with ≤1 homozygous risk genotypes ("low risk", n=75). "High-risk" genotype was associated with diastolic dysfunction and higher serum BNP levels. There was no association between RAAS genotype and either ventricular mass or systolic function. During a mean follow-up duration of 9.5±7.6years, late Fontan failure occurred in 20% (n=21) of patients, including 7 deaths. Serum BNP emerged as an independent predictor of late Fontan failure (HR 1.11 [CI 1.01-1.23] for each 50unit increase in BNP, p=0.04) and death alone (HR 1.25 [CI 1.07-1.47] for each 50unit increase in BNP, p=0.006). RAAS genotype was not associated with adverse clinical events. Fontan failure is common among adults with single ventricle physiology. RAAS genotype is not associated with increased ventricular mass but does appear to influence diastolic function late after the Fontan operation. Elevated BNP is an independent predictor of Fontan failure and mortality in adulthood.
Pilot study on the feasibility of limited focused real‐time echocardiography during pediatric renal transplantation
Publisher: Wiley
Date: 27-05-2016
DOI: 10.1111/PETR.12726
Abstract: Pediatric renal transplantation protocols describe supraphysiological blood pressure and CVP to optimize graft perfusion. Ideal CVP and blood pressure targets in children are uncertain and difficult to achieve and/or sustain without incurring morbidity. We correlated intra-operative ECHO with standard monitoring to assess intravascular volume at critical intra-operative stages. A feasibility pilot study of real-time limited ECHO images during four critical stages of pediatric renal transplantation (baseline venous and arterial cl s on cl s off 5-10 min post-cl release) was conducted. Simultaneous CVP, SBP and DBP measurements were obtained with ECHO images. A surgeon blinded to the ECHO study assessed the quality of graft perfusion. Thirteen patients (nine TTE and four TEE) were enrolled. The CI increased in all patients at vascular cl removal and the post-resuscitation period (average increase in CI 20%, range 8-49%). SBP, DBP and CVP were inconsistent. ECHO data confirmed an appropriate CI increase even when the targeted CVP and BP values described in protocols were not achieved. The surgeons were satisfied with graft perfusion in 12 of 13 cases, with one locally obstructed vessel. We suggested that aiming for fixed targets in CVP and BP is not necessary to augment CI and encourage good renal perfusion.
Standardization of left atrial, right ventricular, and right atrial deformation imaging using two-dimensional speckle tracking echocardiography: a consensus document of the EACVI/ASE/Industry Task For
Publisher: Oxford University Press (OUP)
Date: 27-03-2018
DOI: 10.1093/EHJCI/JEY042
Abstract: The EACVI/ASE/Industry Task Force to standardize deformation imaging prepared this consensus document to standardize definitions and techniques for using two-dimensional (2D) speckle tracking echocardiography (STE) to assess left atrial, right ventricular, and right atrial myocardial deformation. This document is intended for both the technical engineering community and the clinical community at large to provide guidance on selecting the functional parameters to measure and how to measure them using 2D STE.This document aims to represent a significant step forward in the collaboration between the scientific societies and the industry since technical specifications of the software packages designed to post-process echocardiographic datasets have been agreed and shared before their actual development. Hopefully, this will lead to more clinically oriented software packages which will be better tailored to clinical needs and will allow industry to save time and resources in their development.
Related Organisations
Katholieke Universiteit Leuven Faculteit Geneeskunde
Location: Belgium
Related Funding Activities
No related grants have been discovered for Luc Mertens.