Baseline Right Ventricular Dysfunction Predicts Worse Outcomes in Patients Undergoing Cardiac Resynchronization Therapy Implantation.

INTRODUCTION

Cardiac resynchronization therapy (CRT) has been shown to improve survival in patients with systolic heart failure, wide QRS duration, and left-bundle-branch-block. However, CRT outcomes stratified by right ventricular (RV) function at implant have not been well studied.

METHODS

We retrospectively reviewed patients at Cleveland Clinic who underwent CRT implantation (n = 777) from 2003 to 2011 with a diagnosis of heart failure, echocardiography with both pre-CRT left ventricular ejection fraction (LVEF) ≤35% and available post-CRT echocardiography at 6 months post-implant. CRT response was defined as LVEF improvement ≥5%. Patients were separated into 2 groups: normal or mild RV dysfunction (n = 570) labeled Normal RV; moderate to severe dysfunction (n = 207) labeled RV DYSFXN based on qualitative echocardiography assessment. Survival was calculated as time from CRT implant to death, left ventricular assist device implant, or heart transplant.

RESULTS

CRT response was significantly higher in patients with Normal RV (67%) compared with patients with RV DYSFXN (56%; P = .006). Kaplan-Meier analysis showed that CRT patients with Normal RV had significantly greater survival compared with patients with RV DYSFXN (P < .001). In multivariable Cox regression accounting for a priori covariates, RV DYSFXN was associated with worse survival (HR 1.41 [95% CI: 1.14-1.75], P = .002) and lower CRT response (HR 0.66 [95% CI: 0.44-0.97], P = .03).

CONCLUSION

Baseline RV dysfunction at CRT implant is an important predictor of worsened left ventricular remodeling and survival in CRT patients.