Catherine De Maeyer

Aerobic interval training and continuous training equally improve aerobic exercise capacity in patients with coronary artery disease: the SAINTEX-CAD study.

BACKGROUND Exercise-based cardiac rehabilitation increases peak oxygen uptake (peak VO₂), which is an important predictor of mortality in cardiac patients. However, it remains unclear which exercise characteristics are most effective for improving peak VO₂ in coronary artery disease (CAD) patients. Proof of concept papers comparing Aerobic Interval Training (AIT) and Moderate Continuous Training (MCT) were conducted in small sample sizes and findings were inconsistent and heterogeneous. Therefore, we aimed to compare the effects of AIT and Aerobic Continuous Training (ACT) on peak VO₂, peripheral endothelial function, cardiovascular risk factors, quality of life and safety, in a large multicentre study. METHODS Two-hundred CAD patients (LVEF >40%, 90% men, mean age 58.4 ± 9.1 years) were randomized to a supervised 12-week cardiac rehabilitation programme of three weekly sessions of either AIT (90-95% of peak heart rate (HR)) or ACT (70-75% of peak HR) on a bicycle. Primary outcome was peak VO₂; secondary outcomes were peripheral endothelial function, cardiovascular risk factors, quality of life and safety. RESULTS Peak VO₂ (ml/kg/min) increased significantly in both groups (AIT 22.7 ± 17.6% versus ACT 20.3 ± 15.3%; p-time<0.001). In addition, flow-mediated dilation (AIT+34.1% (range -69.8 to 646%) versus ACT+7.14% (range -66.7 to 503%); p-time<0.001) quality of life and some other cardiovascular risk factors including resting diastolic blood pressure and HDL-C improved significantly after training. Improvements were equal for both training interventions. CONCLUSIONS Contrary to earlier smaller trials, we observed similar improvements in exercise capacity and peripheral endothelial function following AIT and ACT in a large population of CAD patients.

Unraveling new mechanisms of exercise intolerance in chronic heart failure. Role of exercise training

Despite remarkable progress in the therapeutic approach of patients with chronic heart failure (CHF), exercise intolerance remains one of the hallmarks of the disease. During the past two decades, evidence has accumulated to underscore the key role of both endothelial dysfunction and skeletal muscle wasting in the process that gradually leads to physical incapacity. Whereas reverse ventricular remodeling has been attributed to aerobic exercise training, the vast majority of studies conducted in this specific patient population emphasize the reversal of peripheral abnormalities. In this review, we provide a general overview on underlying pathophysiological mechanisms. In addition, emphasis is put on recently identified pathways, which contribute to a deeper understanding of the main causes of exercise tolerance and the potential for reversal through exercise training. Recently, deficient bone marrow-related endothelial repair mechanisms have received considerable attention. Both acute exercise bouts, as well as exercise training, affect the mobilization of endothelial progenitor cells and their function. The observed changes following exercise training are believed to significantly contribute to improvement of peripheral endothelial function, as well as exercise capacity. With regard to skeletal muscle dysfunction and energy deprivation, adiponectin has been suggested to play a significant role. The demonstration of local skeletal muscle adiponectin resistance may provide an interesting and new link between the insulin resistant state and skeletal muscle wasting in CHF patients.

Exercise training in chronic heart failure

The syndrome of heart failure (HF) is a growing epidemic that causes a significant socio-economic burden. Despite considerable progress in the management of patients with HF, mortality and morbidity remain a major healthcare concern and frequent hospital admissions jeopardize daily life and social activities. Exercise training is an important adjunct nonpharmacological treatment modality for patients with HF that has proven positive effects on mortality, morbidity, exercise capacity and quality of life. Different training modalities are available to target the problems with which HF patients are faced. It is essential to tailor the prescribed exercise regimen, so that both efficiency and safety are guaranteed. Electrical implanted devices and mechanical support should not exclude patients from exercise training; however, particular precautions and a specialized approach are advised. At least 50% of patients with HF, older than 65 years of age, present with HF with preserved ejection fraction (HFPEF). Although the study populations included in studies evaluating the effect of exercise training in this population are small, the results are promising and seem to support the idea that exercise training is beneficial for HFPEF patients. Both the short- and especially long-term adherence to exercise training remain a major challenge that can only be tackled by a multidisciplinary approach. Efforts should be directed towards closing the gap between recommendations and the actual implementation of training programmes.

Rationale and design of a randomized trial on the effectiveness of aerobic interval training in patients with coronary artery disease: The SAINTEX-CAD study

BACKGROUND Exercise-based cardiac rehabilitation is considered an important adjunct treatment and secondary prevention measure in patients with coronary artery disease (CAD). However, the issues of training modality and exercise intensity for CAD patients remain controversial. OBJECTIVE Main aim of the present study is to test the hypothesis that aerobic interval training (AIT) yields a larger gain in peak aerobic capacity (peakVO2) compared to a similar training programme of moderate continuous training (MCT) in CAD patients. STUDY DESIGN In this multicentre study stable CAD patients with left ventricular ejection fraction>40% will be randomized after recent myocardial infarction or revascularization (PCI or CABG) to a supervised 12-week programme of three weekly sessions of either AIT (85-90% of peak oxygen uptake [peakVO2], 90-95% of peak heart rate) or MCT (60-70% of peakVO2, 65-75% of peak heart rate). The primary endpoint of the study is the change of peakVO2 after 12 weeks training. Secondary endpoints include safety, changes in peripheral endothelial vascular function, the evolution of traditional cardiovascular risk factors, quality of life and the number and function of circulating endothelial progenitor cells as well as endothelial microparticles. Possible differences in terms of long-term adherence to prescribed exercise regimens will be assessed by regular physical activity questionnaires, accelerometry and reassessment of peakVO2 12 months after randomization. A total number of 200 patients will be randomized in a 1:1 manner (significance level of 0.05 and statistical power of 0.90). Enrolment started December 2010; last enrolment is expected for February 2013.

The long-term effects of a randomized trial comparing aerobic interval versus continuous training in coronary artery disease patients: 1-year data from the SAINTEX-CAD study.

Background Aerobic interval training (AIT) and aerobic continuous training (ACT) both improve physical fitness (peak VO2) in coronary artery disease patients. However, little is known about the long-term effects of AIT and ACT on peak VO2 and exercise adherence. Design This study is a randomized clinical multicenter trial. Methods In total, 163 patients were assessed after 12 weeks of AIT or ACT and 12 months after their enrollment. Physical fitness and physical activity measures served as the primary outcomes, and peripheral endothelial function, cardiovascular risk factors and quality of life (QoL) served as the secondary outcomes. Results Twenty-six patients dropped out during the intervention; 11 were lost during the follow-up period. Dropouts (n = 37) consisted of more women (p = 0.001) compared to completers (n = 163). Physical fitness (VO2, heart rate and workload at peak and at thresholds) and physical activity (steps, active energy expenditure [kcal], physical activity duration [minutes]) were preserved at the 1-year follow-up (p-time > 0.05) after both AIT and ACT (p-interaction > 0.05). Forty percent of patients showed increased peak VO2, 52% showed increased active energy expenditure and 91.2% met the recommended levels of 150 minutes/week of moderate physical activity (p-group > 0.05). Further, peripheral endothelial function, QoL and cardiovascular risk factors, except systolic blood pressure (p-time < 0.05), remained stable (p-time > 0.05) after both AIT and ACT (p-interaction > 0.05). Conclusion The short-term improvements of center-based AIT and ACT on physical fitness, physical activity, peripheral endothelial function, cardiovascular risk factors and QoL are sustained after a 1-year follow-up period. The majority of patients (>90%) met the recommended physical activity levels of 150 minutes/week.

Late gadolinium enhancement CMR in primary mitral regurgitation.

The appropriate timing for surgery in severe asymptomatic primary mitral regurgitation (MR) remains controversial. It has been shown that late gadolinium enhancement on cardiovascular magnetic resonance (LGE CMR), which may identify myocardial fibrosis, is associated with a worse outcome in various cardiomyopathies. We sought to investigate the prevalence and significance of delayed enhancement in primary MR.

Percutaneous mitral valve repair in high-risk patients: initial experience with the Mitraclip system in Belgium.

Aims Treatment with percutaneous edge-to-edge mitral valve repair (Mitraclip®) has recently been recommended as an alternative to conventional mitral valve repair for high surgical risk patients with symptomatic severe mitral regurgitation (MR). In this study, we report the first use of Mitraclip® therapy in Belgium. Methods and results This prospective registry includes 41 consecutive patients treated with the Mitraclip® in two Belgian centres from October 2010 to June 2013. Acute procedural success, in-hospital safety end points and clinical status were analysed on an intention-to-treat basis up to one year after the procedure. In addition, determinants of major adverse cardiac events (MACE, death, surgical mitral valve intervention, and rehospitalization for heart failure) were analysed. Acute procedural success (successful clip placement and reduction of colour Doppler flow MR to ≤ 2) was obtained in 32 patients (78%) and 18 of these patients received two clips. The primary safety end point was reached in 36 pts (88%): one patient died due to intracranial bleeding, there were three urgent surgical interventions and one severe access site bleeding. The MACE rate after one year was 41% (17 patients). There were 11 deaths (27%), six surgical interventions (15%) and 10 rehospitalizations for heart failure (24%). Additional subgroup analysis revealed that the one-year MACE rate was particularly high in patients with left ventricular ejection fraction (LVEF) < 25%: 62% vs. 36% in patients with LVEF ≥ 25% (P = 0.05). At one year, MR ≤ 2+ and NYHA class ≤ 2 was present in 83% of the surviving patients Conclusion In high-risk patients with functional MR, treatment with the Mitraclip®-device is a feasible and safe option resulting in improvement of MR severity and clinical symptoms. However, as MACE is high in some subgroups (e.g. LVEF < 25%), careful patient selection is crucial to ensure the maximum benefit from this new technique.

Exercise-induced biphasic increase in circulating NT-proBNP levels in patients with chronic heart failure

Exercise increases natriuretic peptide levels in chronic heart failure (CHF) patients, but the effect is considered minor. We assessed acute and short‐term release (<24 h) of NT‐proBNP in CHF patients after a maximal cardiopulmonary exercise test (CPET) and 2 different submaximal training sessions.

Exercise training as an essential component of cardiac rehabilitation

To the Editor we read with interest, but also great concern, the paper by West, et al 1 on their multi-centre randomised cardiac rehabilitation study, suggesting negligible results. This study was covered in the Belgian press and already led to questions about further reimbursement of such multi- disciplinary programs. We agree that re-evaluation of cardiac rehabilitation in the era of early revascularisation and thoroughly changed secondary prevention, is timely. However, this study does …

Mechanism of Symptomatic Improvement After Percutaneous Therapy for Secondary Mitral Regurgitation: Resting and Exercise Hemodynamics.

Percutaneous mitral valve repair using the MitraClip (Abbott Vascular, Santa Clara, California) is a promising technique to treat symptomatic severe mitral regurgitation (MR) in patients at high or prohibitive surgical risk. Large observational registries of patients treated with this device for