# Harmonizing Heartbeats: The Mosaic of Cardiac Resynchronization Therapy Responders—A Comprehensive Exploration of Diverse Criteria and Predictors

## TL;DR

This study examines different ways to define patients who benefit from cardiac resynchronization therapy and finds factors that predict better outcomes.

## Contribution

The study introduces a nuanced, patient-centered approach to defining CRT-D responders and identifies novel predictors of therapy success.

## Key findings

- CRT-D responders defined by NYHA, LVEF, or proBNP criteria show improved survival after 2 and 3 years.
- Young age, absence of recent MI, and normal right ventricular parameters predict positive CRT-D response.
- LVEF ≥ 5% and proBNP decrease ≥ 25% are independent predictors of extended survival.

## Abstract

Background: Heart failure (HF) remains a challenging healthcare issue necessitating innovative therapies like cardiac resynchronization–defibrillation therapy (CRT-D). However, the definition of a CRT-D response lacks uniformity, impeding effective clinical evaluation. This study explores diverse CRT-D responder definitions encompassing functional, echocardiographic and laboratory criteria. Materials & Methods: A single-center study involving 132 CRT-D patients scrutinized responder criteria including NYHA stage, LVEF increase and proBNP decrease. Statistical analyses such as Kaplan–Meier curves and Cox hazard regression were employed to evaluate responder characteristics and survival outcomes. Results: Responder rates varied across criteria, revealing nuanced patient profiles. CRT-D responders defined by NYHA decrease, LVEF increase or proBNP decrease exhibit improved survival rates after 2 and 3 years (p < 0.050). Young age, absence of recent myocardial infarction and normal right ventricular echocardiographic parameters emerge as predictors for positive response. In part, drug-based HF therapy correlates with increased responder rates. Cox regression identified LVEF ≥ 5% and proBNP decrease ≥ 25% as independent predictors of extended survival. Conclusions: CRT-D responder definitions exhibit considerable variability, emphasizing the need for a nuanced patient-centered approach. Factors like right ventricular function, drug therapy, atrial fibrillation and renal function influence responses. This study enriches our understanding of CRT-D response and contributes to the foundation for personalized HF management.