Impact of cardiac resynchronization therapy in patients with left ventricular assist devices: A systematic review and meta-analysis

Background: Many patients with left ventricular assist devices (LVADs) have cardiac resynchronization therapy (CRT). However, the impact of CRT on their clinical and hemodynamic outcomes remains unclear. Methods: We conducted a systematic review and meta-analysis to evaluate CRT's impact on survival in LVAD patients. We searched PUBMED, EMBASE, and Cochrane databases from inception through April 30, 2025, for studies reporting outcomes in LVAD patients with CRT. The primary outcome was all-cause mortality in patients with versus without CRT. Secondary clinical outcomes included ventricular arrhythmias (VAs) and shocks delivered. Hemodynamic outcomes included heart rate, right atrial pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, thermodilution cardiac output, pulmonary artery saturation, right ventricular stroke work index, and left ventricular end-diastolic diameter. Results: Thirteen studies, including 3,665 patients, were analyzed. Cardiac resynchronization therapy (CRT) did not demonstrate any significant survival benefit, whether comparing CRT-D versus ICD (OR 1.12 [0.85-1.48]), CRT on versus CRT off (OR 1.48 [0.87-2.53]), CRT versus no device (OR 0.99 [0.61-1.59]), or CRT versus no device or ICD (OR 1.00 [0.16-6.31]). Similarly, none of the tested comparisons showed significant differences in VAs incidence or shock rates. Biventricular pacing demonstrated no advantage for any hemodynamic outcomes, whether compared to right ventricular pacing or intrinsic rhythm. Conclusion: In this meta-analysis, CRT was not associated with overall survival benefit in LVAD recipients, nor with hemodynamic improvement. Future randomized trials may be warranted to definitively establish CRT's value in this population and refine patient selection criteria for optimal outcomes.