At the ESC 2025 Congress in Madrid, a Portuguese research team from the District Hospital of Santarém presented real-world evidence on predictors of response to cardiac resynchronization therapy (CRT) upgrade. The study focused on patients with right ventricular (RV) pacing and heart failure with reduced ejection fraction (HFrEF), a group often at risk of worsening outcomes from pacing-induced dyssynchrony.

In this single-center, retrospective analysis, 55 patients who underwent CRT upgrade between 2015 and 2024 were evaluated. The cohort was predominantly male (78%), with a mean age of 76 years, and 54% had ischemic cardiomyopathy. At the time of CRT revision, patients had a mean left ventricular ejection fraction (LVEF) of 29% and were in NYHA functional classes II–III.

CRT response, defined as a ≥5% increase in LVEF and at least one class improvement in NYHA status, was achieved in 64% of patients. Responders demonstrated a mean LVEF increase of 10.7%, with corresponding improvements in functional status; nearly half improved to NYHA class I within a year.

Factors such as gender, rhythm status, or device type did not significantly influence outcomes.

The results support expanding CRT upgrade programs in real-world clinical practice, particularly outside of tertiary centers. Future studies may focus on refining selection criteria, tailoring strategies for ischemic cardiomyopathy, and exploring earlier intervention in younger patients to maximize long-term outcomes.