The effect of endurance training on exercise capacity following cardiac resynchronization therapy in chronic heart failure patients: a pilot trial

BACKGROUND

Both endurance training (ET) and cardiac resynchronization therapy (CRT) improve quality of life (QOL) and exercise tolerance in patients with advanced chronic heart failure (CHF).

DESIGN

A randomized intervention trial to study the effect on exercise capacity of ET in addition to CRT in patients with CHF and dyssynchrony.

METHODS

Seventeen patients (eight men, aged 59+/-9 years) with CHF and dyssynchrony were randomized to CRT with (n=8) or without (n=9) ET and compared with two matched control CHF groups (standard care with ET: n=9, standard care only: n=10). At baseline and after 5 months, exercise tolerance, left ventricular (LV) remodelling, QOL and NT-pro brain natriuretic peptide (NT-proBNP) levels were assessed.

RESULTS

Peak oxygen consumption (VO2peak), maximal workload (Wattmax), circulatory power, LV ejection fraction, dyssynchrony and QOL improved in both CRT groups. However, the increase in VO2peak (+40% versus +16%, P=0.005), Wattmax (+43% versus +13%, P=0.0005), and circulatory power (+74% versus +32%, P=0.01), was significantly greater in the trained versus the untrained CRT patients. Comparison of the four patient groups confirmed the cumulative effects of CRT plus ET.

CONCLUSIONS

ET in resynchronized CHF patients is feasible and further enhances exercise tolerance. Patients with severe CHF should be prescribed an exercise training programme after implantation in order to maximize the expected benefit.

VE/Vco2 slope and oxygen uptake efficiency slope in patients with coronary artery disease and intermediate peakVo2

BACKGROUND

Peak exercise oxygen uptake (peakVO2) is a widely used prognosticator. Novel spirometric parameters, less affected by submaximal performance, such as the rate of increase of minute ventilation per unit decrease of carbon dioxide production (VE/VCO2 slope) and the oxygen uptake efficiency slope (OUES) have recently been introduced.

AIM

To evaluate the discriminative value of OUES, as compared to VE/VCO2 slope in patients with coronary artery disease (CAD) and intermediate peakVO2 values.

METHODS AND RESULTS

Bicycle spiroergometry was applied in 214 patients with CAD (age 67+/-8 years, 85% men). OUES was strongly related to peakVO2 (r=0.79). New York Heart Association (NYHA) class, 6-min walking distance, N-terminal pro-brain natriuretic peptide (NT-proBNP), inflammatory markers, left ventricular (LV) volumes and ejection fraction were evaluated. NT-proBNP levels predicted independently VE/VCO2-slope and OUES. Patients with intermediate peakVO2 (12-18 ml/kg per min) and increased VE/VCO2-slope (> or = 35) had higher NYHA class, lower walking distance, higher NT-proBNP levels and higher LV volumes as compared to patients with a similar peakVO2 but lower VE/VCO2-slope. Similar findings were found for patients with intermediate peakVO2 and high OUES/kg (median value>15.3).

CONCLUSION

In CAD patients, OUES was strongly correlated with peakVO2. Both VE/VCO2 slope and OUES were independently associated with NT-proBNP levels. Both VE/VCO2 slope and OUES/kg were able to identify a subgroup of patients with an intermediate peakVO2 that was characterized by advanced remodelling and a higher degree of neurohumoral activation.

Minimally invasive mitral valve repair for functional mitral regurgitation in severe heart failure: MitraClip versus minimally invasive surgical approach

OBJECTIVES

To compare the outcomes of MitraClip versus minimally invasive surgical mitral valve repair in high-risk patients with significant functional mitral regurgitation (FMR) and severe heart failure in a centre having pilot versus extensive experience with the MitraClip and the minimally invasive surgical approach, respectively.

METHODS

The MitraClip group consisted of 24 high-surgical-risk patients [age 75 ± 9 years, 75% males, NYHA III/IV 88%, left ventricular (LV) ejection fraction 31 ± 9%, EuroSCORE II 18 ± 14%], while the surgical group consisted of 48 patients matched for age, NYHA class and LV ejection fraction.

RESULTS

Patients undergoing MitraClip versus those undergoing surgical repair showed higher prevalence of ischaemic LV dysfunction and larger LV end-diastolic diameter (both P < 0.05). Both the MitraClip and the surgical repair groups had similar 30-day mortality rates (4 vs 13%, P = 0.41) and prevalence of serious adverse events (25 vs 38%, P = 0.43). The median follow-up was 1028 days (IQR: 272-1564 days) in the MitraClip group and 890 days (IQR: 436-1381 days) in the surgical group (P = 0.95). Total all-cause mortality (54 vs 60%, log-rank P = 0.64) and rates of rehospitalizations for heart failure (42 vs 29%, log-rank P = 0.68) did not differ significantly between groups. Both techniques were associated with significant decrease in NYHA class and severity of FMR (P < 0.001 for all) and with a similar degree of stabilization of LV remodelling (P = NS).

CONCLUSION

Despite the significant baseline differences in accumulated expertise and risk profile between the surgical and the MitraClip groups, both minimally invasive techniques were associated with similar 30-day and long-term outcomes.

In Heart Failure Patients with Left Bundle Branch Block Single Lead MultiSpot Left Ventricular Pacing Does Not Improve Acute Hemodynamic Response To Conventional Biventricular Pacing. A Multicenter Prospective, Interventional, Non-Randomized Study

INTRODUCTION

Recent efforts to increase CRT response by multiSPOT pacing (MSP) from multiple bipols on the same left ventricular lead are still inconclusive.

AIM

The Left Ventricular (LV) MultiSPOTpacing for CRT (iSPOT) study compared the acute hemodynamic response of MSP pacing by using 3 electrodes on a quadripolar lead compared with conventional biventricular pacing (BiV).

METHODS

Patients with left bundle branch block (LBBB) underwent an acute hemodynamic study to determine the %change in LV+dP/dtmax from baseline atrial pacing compared to the following configurations: BiV pacing with the LV lead in a one of lateral veins, while pacing from the distal, mid, or proximal electrode and all 3 electrodes together (i.e. MSP). All measurements were repeated 4 times at 5 different atrioventricular delays. We also measured QRS-width and individual Q-LV durations.

RESULTS

Protocol was completed in 24 patients, all with LBBB (QRS width 171±20 ms) and 58% ischemic aetiology. The percentage change in LV+dP/dtmax for MSP pacing was 31.0±3.3% (Mean±SE), which was not significantly superior to any BiV pacing configuration: 28.9±3.2% (LV-distal), 28.3±2.7% (LV-mid), and 29.5±3.0% (LV-prox), respectively. Correlation between LV+dP/dtmax and either QRS-width or Q-LV ratio was poor.

CONCLUSIONS

In patients with LBBB MultiSPOT LV pacing demonstrated comparable improvement in contractility to best conventional BiV pacing. Optimization of atrioventricular delay is important for the best performance for both BiV and MultiSPOT pacing configurations.

TRIAL REGISTRATION

ClinicalTrials.gov NTC01883141.

Rationale and design of the Aortic Valve replAcemenT versus conservative treatment in Asymptomatic seveRe aortic stenosis (AVATAR trial): A randomized multicenter controlled event-driven trial

Aortic valve replacement (AVR) therapy is an obvious choice for symptomatic severe aortic stenosis (AS) patients as it improves symptoms, left ventricular function, and survival. The treatment decisions and indication for AVR in asymptomatic patients with severe AS and normal left ventricular ejection fraction are less well established and the subject of ongoing debate. Many efforts have been made to define the best treatment option in asymptomatic AS patients with normal left ventricular ejection fraction. Retrospective and observational data imply that elective AVR for asymptomatic severe AS may lead to improvement in outcomes in comparison to surgery performed after onset of symptoms. The AVATAR trial will aim to assess outcomes among asymptomatic AS patients randomized to either elective early AVR or medical management with vigilant follow-up. In the latter group, AVR would be delayed until either the onset of symptoms or changes in predefined echocardiographic parameters. To the best of the authors' knowledge, it will be the first large prospective, randomized, controlled, multicenter clinical trial that will evaluate the safety and efficacy of elective AVR in this specific group of patients.

Wasted septal work in left ventricular dyssynchrony: a novel principle to predict response to cardiac resynchronization therapy

Aims

Cardiac resynchronization therapy (CRT) in heart failure is limited by many non-responders. This study explores whether degree of wasted left ventricular (LV) work identifies CRT responders.

Methods and results

Twenty-one patients who received CRT according to guidelines were studied before and after 8 ± 3 months. By definition, segments that shorten in systole perform positive work, whereas segments that lengthen do negative work. Work was calculated from non-invasive LV pressure and strain by speckle tracking echocardiography. For each myocardial segment and for the entire LV, wasted work was calculated as negative work in percentage of positive work. LV wall motion score index (WMSI) was assessed by echocardiography. Response to CRT was defined as ≥15% reduction in end-systolic volume (ESV). Responder rate to CRT was 71%. In responders, wasted work for septum was 117 ± 102%, indicating more negative than positive work, and decreased to 14 ± 12% with CRT (P < 0.01). In the LV free wall, wasted work was 19 ± 16% and showed no significant change. Global LV wasted work decreased from 39 ± 21 to 17 ± 7% with CRT (P < 0.01). In non-responders, there were no significant changes. In multiple linear regression analysis, septal wasted work and WMSI were the only significant predictors of ESV reduction (β = 0.14, P = 0.01; β = 1.25, P = 0.03). Septal wasted work together with WMSI showed an area under the curve of 0.86 (95% confidence interval 0.71–1.0) for CRT response prediction.

Conclusion

Wasted work in the septum together with WMSI was a strong predictor of response to CRT. This novel principle should be studied in future larger studies.

Circulating Stromal Cell-Derived Factor 1α Levels in Heart Failure: A Matter of Proper Sampling

Background

The chemokine Stromal cell-derived factor 1α (SDF1α, CXCL12) is currently under investigation as a biomarker for various cardiac diseases. The correct interpretation of SDF1α levels is complicated by the occurrence of truncated forms that possess an altered biological activity.

Methodology

We studied the immunoreactivities of SDF1α forms and evaluated the effect of adding a DPP4 inhibitor in sampling tubes on measured SDF1α levels. Using optimized sampling, we measured DPP4 activity and SDF1α levels in patients with varying degrees of heart failure.

Results

The immunoreactivities of SDF1α and its degradation products were determined with three immunoassays. A one hour incubation of SDF1α with DPP4 at 37°C resulted in 2/3 loss of immunoreactivity in each of the assays. Incubation with serum gave a similar result. Using appropriate sampling, SDF1α levels were found to be significantly higher in those heart failure patients with a severe loss of left ventricular function. DPP4 activity in serum was not altered in the heart failure population. However, the DPP4 activity was found to be significantly decreased in patients with high SDF1α levels

Conclusions

We propose that all samples for SDF1α analysis should be collected in the presence of at least a DPP4 inhibitor. In doing so, we found higher SDF1α levels in subgroups of patients with heart failure. Our work supports the need for further research on the clinical relevance of SDF1α levels in cardiac disease.

Integrate and boost: bioscaffolds nurture the cardiac regenerative paradigm

The traditional cardiac regenerative paradigm using non-modified adult stem cells with various routes of delivery into the myocardial target has thus far yielded unconvincing clinical outcomes. Besides factors related to heterogeneity in trial methodology, inter-patient variability and the rare incidence of adult stem cells with intrinsic repair potency underscore the importance of further optimization and standardization of regenerative platforms. Cardiac tissue engineering seizing upon the advances of cellular, molecular, and biomaterial development is shaping the next generation of the regenerative paradigm and thereby fostering disruptive curative treatments in heart failure.

Endpoints in stem cell trials in ischemic heart failure

Despite multimodal regimens and diverse treatment options alleviating disease symptoms, morbidity and mortality associated with advanced ischemic heart failure remain high. Recently, technological innovation has led to the development of regenerative therapeutic interventions aimed at halting or reversing the vicious cycle of heart failure progression. Driven by the unmet patient need and fueled by encouraging experimental studies, stem cell-based clinical trials have been launched over the past decade. Collectively, these trials have enrolled several thousand patients and demonstrated the clinical feasibility and safety of cell-based interventions. However, the totality of evidence supporting their efficacy in ischemic heart failure remains limited. Experience from the early randomized stem cell clinical trials underscores the key points in trial design ranging from adequate hypothesis formulation to selection of the optimal patient population, cell type and delivery route. Importantly, to translate the unprecedented promise of regenerative biotherapies into clinical benefit, it is crucial to ensure the appropriate choice of endpoints along the regulatory path. Accordingly, we here provide considerations relevant to the choice of endpoints for regenerative clinical trials in the ischemic heart failure setting.

Epicardial catheter-based ventricular reconstruction (ECVR) in a patient with ischemic heart failure and an anteroapical aneurysm

Extended anterior myocardial infarction (MI) is frequently followed by left ventricular (LV) remodeling ensuing in heart failure and aneurysmatic transformation of the infarcted myocardial segment. Therapies that attenuate or reverse pathological LV remodeling have been shown to improve functional status and outcomes. This case reports our recent experience with a catheter based technique for ventricular restoration.

Activation of the ergoreceptors in cardiac patients with and without heart failure

BACKGROUND

The presence of ergoreflex activity and its current relationship to hyperventilation and prognosis in cardiac patients is unclear. Therefore, we evaluated ergoreflex activity in cardiac patients with and without heart failure (CHF) as well as in healthy subjects, and we examined how ergoreceptor activity was related to a mortality risk score in CHF (MAGGIC).

METHODS AND RESULTS

Twenty-five healthy subjects and 76 patients were included, among whom were 25 with ischemic heart disease (IHD), 24 with stable CHF, and 27 with unstable CHF. Ergoreflex activity was measured with a dynamic handgrip exercise, followed by post-handgrip regional circulatory occlusion (PH-RCO). Ergoreflex activity contributed significantly to ventilation (median [interquartile range] %V) in unstable CHF (81 [73-91] %V without PH-RCO, 92 [82-107] %V with PH-RCO, and 11 [6-20] difference in %V; P < .001) and was positively correlated with the MAGGIC risk score (Spearman ρ = 0.431; P = .002). No ergoreflex activity was observed in healthy subjects (-4 [-10 to 5] difference in %V), IHD (0 [-8 to 3] Diff in %V) and stable CHF (-3 [-11 to 6] difference in %V).

CONCLUSIONS

Ergoreflex activity contributes to hyperventilation, but only in CHF patients with persistent symptoms, and is closely related to the MAGGIC risk score. Ergoreflex activity was not present in patients with IHD or stable CHF, suggesting other reasons for the increased ventilatory drive in those patients.

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 < or = 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 > or = 5% (P = 0.05). At one year, MR < or = 2+ and NYHA class < or = 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.

Self-limiting left ventricular wall rupture following myocardial infarction: a case report and literature review

We report the case of a 62-year-old woman presenting with symptoms and findings of myocardial infarction and a left ventricular free wall rupture. Coronary angiography revealed a critical stenosis in the middle right coronary artery. A contrast left ventriculogram revealed extravasation of contrast through the inferolateral wall of the left ventricle. Left ventricular free wall rupture is a rare complication of acute myocardial infarction, occurring in approximately 2% of cases. It is often fatal because of the development of haemopericardium and tamponade. Some patients, like the one described in this case, may present with small leaks that might close spontaneously by epicardial fibrin deposits, thus self-limiting, without requiring surgical intervention. This patient received only intense medical treatment. Indeed, blood clots at the endocardial and the epicardial site of the rupture have often been identified, suggesting protection for further rupture.