Left Ventricular Reverse Remodeling With Biventricular Versus Right Ventricular Pacing in Patients With Atrioventricular Block and Heart Failure in the BLOCK HF Trial

Abstract

Background-Biventricular pacing in heart failure (HF) improves survival, relieves symptoms, and attenuates left ventricular (LV) remodeling. However, little is known about biventricular pacing in HF patients with atrioventricular block because they are typically excluded from biventricular trials. Methods and Results-The Biventricular versus Right Ventricular Pacing in Heart Failure Patients with Atrioventricular Block (BLOCK HF) trial randomized patients with atrioventricular block, New York Heart Association symptom classes I to III HF, and LV ejection fraction ≤50% to biventricular or right ventricular pacing. Doppler echocardiograms were obtained at randomization (after 30 to 60 days of right ventricular pacing postimplant) and every 6 months through 24 months. Data analysis comparing changes in 10 prespecified echo parameters over time was conducted using a Bayesian design. LV end systolic volume index was also evaluated as a predictor of mortality/morbidity. Of 691 randomized subjects, 624 had paired Doppler echocardiogram data for ≥1 analyses at 6, 12, 18, or 24 months. Biventricular pacing significantly reduced LV volume indices and intraventricular mechanical delay, and improved LV ejection fraction, consistent with LV reverse remodeling. These parameters showed little change with right ventricular pacing alone, indicating no systematic reverse remodeling with right ventricular pacing. LV end systolic volume index was predictive of mortality/morbidity; the estimated risk increased up to 1% for every 1 mL/m 2 increase in LV end systolic volume index. Conclusions-LV end systolic volume index is a significant predictor of mortality/morbidity in this population. Cardiac structure and function are improved with biventricular pacing for patients with atrioventricular block and LV systolic dysfunction. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00267098.

Benefit of cardiopoietic mesenchymal stem cell therapy on left ventricular remodelling: results from the Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART‐1) study

“…The echocardiographic results of the CHART‐1 study at 52 weeks suggest that intramyocardial administration of cardiopoietic stem cells (C3BS‐CQR‐1) has a beneficial effect on LV remodelling, both on LVEDV and LVESV, during a 52‐week follow‐up. The magnitude of the decrease in LV volumes compares favourably with the effects of beta‐blockers, renin–angiotensin–aldosterone system blockers and CRT on ventricular remodelling, an effect that has been consistently associated with improved long‐term outcomes in larger studies . Of note, these significant effects of cardiopoietic cell therapy were obtained upon a background of maximally‐tolerated standard‐of‐care therapy, where the vast majority of patients were treated with ACEi or ARBs, beta‐blockers and CRT where applicable .…”

Prognostic Implications of QRS Duration in Third-Degree Atrioventricular Block Patients with Heart Failure Treated with Cardiac Resynchronization Therapy

“…CRT implantation in patients with AVB accompanied by heart failure has been reported in the literature since 2005. 5,18) The publication of the results related to the BLOCK-HF study 6,7,19) confirmed that CRT could significantly improve the clinical symptoms, myocardial remodeling, and prognosis of patients with AVB accompanied by heart failure. Consistent with the above findings, the results of this study demonstrated that CRT significantly improved the myocardial remodeling and prognosis of the patients with third-degree AVB accompanied by HF.…”

“…However, in clinical practice, CRT does not show desirable efficacy in all patients with AVB accompanied by HF. The BLOCK-HF study 7) assessed the efficacy of CRT in patients with AVB accompanied by heart failure using the LVESV index (LVESVI) and found that only 43% of the patients had reductions of more than 15% in LVESVI after 12 months of biventricular pacing, while 35% of the patients had increased LVESVI, and 14% of the patients had increases of more than 15% in LVESVI. Sairaku,et al 20) compared the CRT efficacies in patients with LVEF !35% and QRS duration "120 ms, patients with treatment upgraded to CRT, and AVB patients with LVEF !…”

“…Effective CRT was defined as a reduction of "15% in the LVESV at 12 months after surgery. 7,10) Statistical analysis: Data processing and statistical analysis were performed using the software SPSS 17.0. Count data were expressed as rates or percentages, and their comparison was performed using the chi-squared test.…”

“…For patients with third-degree or greater AVB accompanied by decreased cardiac function, direct implantation of a CRT device can delay or even reverse myocardial remodeling and improve prognosis. [5][6][7][8] However, it is still unclear which patients benefit from CRT in this patient population. Identifying reliable predictors for preoperative screening of patients will be conducive to decreasing operative risk and medical costs.…”