Comparison between cardiac resynchronization therapy with and without defibrillator on long-term mortality: A propensity score matched analysis.

BACKGROUND

Cardiac resynchronization therapy (CRT)-defibrillator (CRT-D) has been more widely implanted than CRT-pacemaker (CRT-P) in patients of heart failure with reduced ejection fraction and prolonged QRS duration. However, the superiority of CRT-D over CRT-P in improving prognosis has not been well established.

METHODS

Consecutive patients who underwent CRT implantation between 2005 and 2016 were retrospectively recruited and followed up to December 2017. Baseline characteristics were collected and all-cause mortality was compared between CRT-D and CRT-P recipients. Propensity score matched analysis was further performed to validate the results.

RESULTS

A total of 345 patients (219 CRT-D, 126 CRT-P) were included. During a median follow-up of 36 months, there were 81 deaths (37.0%) in the CRT-D group compared to 56 deaths (44.4%) in the CRT-P group. There was no significant difference in the risk of mortality between CRT-D and CRT-P groups [hazard ratio (HR) 0.99, 95% CI 0.70-1.40, p = 0.95]. Propensity score matching yielded 111 cases per group, and there was no significant difference in the risk of mortality between CRT-D and CRT-P groups (HR 0.87, 95%CI 0.57-1.34, p = 0.53). No significant difference between CRT-D and CRT-P in reducing mortality was observed in any pre-specified subgroups, although the difference between CRT-D and CRT-P was more pronounced in patients with left bundle branch block (p = 0.01 for interaction).

CONCLUSIONS

CRT-D did not reduce all-cause mortality compared with CRT-P in this retrospective propensity score matched study. A comprehensive score system incorporating multiple factors is needed for risk stratification and guidance on device selection.