The Effect of Cardiac Resynchronization Therapy on Right Ventricular Function: A Systematic Review and Meta-Analysis

Background: Right ventricular (RV) failure is an important predicting factor regarding overall and event-free survival regardless of baseline left ventricular (LV) function in patients with severe heart failure (HF). Previous studies have indicated that cardiac resynchronization therapy (CRT) improves LV and RV reverse remodeling in patients with systolic dyssynchrony within the left ventricle. However, there is conflicting evidence regarding the role of CRT in RV function. The aim of this systematic review and meta-analysis was to examine the implications of CRT on RV function indices. Methods: A systematic literature search was conducted using the MedLine and EMBASE databases and the Cochrane Library from their inception until 18 March 2024. Eligible were studies providing information on RV function indices, both at baseline and after CRT. Evidence was summarized using random-effects meta-analytic models. Results: In total, 30 studies were deemed eligible. CRT resulted in a significant improvement in right ventricular fractional area change (mean difference (MD) 5.11%, 95% confidence interval (CI) 2.83 to 7.39), tricuspid annular plane systolic excursion (TAPSE, MD 1.63 mm, 95% CI 1.10 to 2.16), and myocardial systolic excursion velocity (MD 1.85 cm/s, 95% CI 1.24 to 2.47) as well as a significant decrease in pulmonary artery systolic pressure (MD -6.24 mmHg, 95% CI -8.32 to -4.16). A non-significant effect was observed on TAPSE to PASP ratio and right ventricular global longitudinal strain. Conclusions: Our meta-analysis demonstrates that CRT is associated with a significant improvement in echocardiographic parameters of RV function. Further investigation is necessary to elucidate how these changes, both independently and in conjunction with LV improvement, impact patients' long-term prognosis, and to identify the specific patient populations expected to derive the greatest benefit.