Right ventricular function and long‐term clinical outcomes after cardiac resynchronization therapy: A cardiovascular magnetic resonance study

Background Right ventricular (RV) dysfunction has been linked to a poor response to cardiac resynchronization therapy (CRT). We sought to determine whether cardiovascular magnetic resonance (CMR)-derived measures of RV function influence clinical outcomes after CRT. Methods In this retrospective study, we used CMR to assess pre-implant RV volumes and RV ejection fraction (RVEF) in relation to clinical outcomes after CRT implantation. Results Among 243 patients (age: 70.3 +/- 10.8 years [mean +/- SD]; 68.7% male; 121 [49.8%]) with ischemic cardiomyopathy and 122 (50.2%) with nonischemic cardiomyopathy, 141 (58%) after CRT-defibrillation (CRT-D) and 102 (42%) after CRT-pacing (CRT-P), 101 (41.6.0%) patients died, 61 (25.1%) from cardiac causes and 24 (9.88%) from noncardiac causes, over 5.87 years (median; interquartile range: 4.35-7.73). Two (0.82%) patients underwent cardiac transplantation and four (1.64%) had a left ventricular assist device (LVAD). A total of 41 (16.9%) met the composite endpoint of sudden cardiac death (SCD), ventricular tachycardia, or ventricular fibrillation. In univariate analyses, no measure of RV function was associated with total mortality or the arrhythmic endpoint. RVEF was associated with cardiac mortality on univariate analyses (HR per 10%: 0.82, 95% CI 0.70-0.96), but not on multivariate analyses that included left ventricular ejection fraction. Conclusions There is no relationship between measures of RV function, such as RV volumes and RVEF, and the long-term clinical outcome of CRT. These findings indicate that such measures should not be considered in patient selection.