What is the clinical evidence from this study?

Study design: Cohort. Population: Heart failure (n=5307). Intervention: Cardiac resynchronisation therapy defibrillator (CRT-D) vs. Cardiac resynchronisation therapy pacemaker (CRT-P). Primary outcome: Survival (HR 0.95, 95% CI 0.77-1.16, p=0.61).

January 19, 2017Open Access

Sex-specific outcomes with addition of defibrillation to resynchronisation therapy in patients with heart failure

Key Result

In heart failure patients, CRT-D showed no survival advantage over CRT-P after propensity score matching in men (HR 0.95; 95% CI 0.77-1.16) or women (HR 1.30; 95% CI 0.83-2.04).

Study Design

Type

Cohort (n=5,307)

Multicenter

Yes

Structured PICO

Does the addition of defibrillator functionality to CRT (CRT-D) improve survival compared to CRT-P in primary prevention patients with heart failure, and does this effect differ by sex?

Population

5,307 patients with ischaemic or non-ischaemic dilated cardiomyopathy and no history of sustained ventricular arrhythmias receiving CRT, followed for a median of 34 months.

Exposure

Cardiac resynchronisation therapy with defibrillator functionality (CRT-D)

Comparator

Cardiac resynchronisation therapy pacemaker (CRT-P) without defibrillator functionality

Outcome

Survival (all-cause mortality) at median 34 months follow-uphard clinical

The addition of a defibrillator to cardiac resynchronization therapy in primary prevention heart failure patients may provide a survival benefit in men but not in women.

Main Result

Hazard Ratio: 0.95 (95% CI 0.77–1.16)

p-value: p=0.61

Abstract

OBJECTIVE: Among primary prevention patients with heart failure receiving cardiac resynchronisation therapy (CRT), the impact of additional implantable cardioverter defibrillator (ICD) treatment on outcomes and its interaction with sex remains uncertain. We aim to assess whether the addition of the ICD functionality to CRT devices offers a more pronounced survival benefit in men compared with women, as previous research has suggested. METHODS: Observational multicentre cohort study of 5307 consecutive patients with ischaemic or non-ischaemic dilated cardiomyopathy and no history of sustained ventricular arrhythmias having CRT implantation with (cardiac resynchronisation therapy defibrillator (CRT-D), n=4037) or without (cardiac resynchronisation therapy pacemaker (CRT-P), n=1270) defibrillator functionality. Using propensity score (PS) matching and weighting and cause-of-death data, we assessed and compared the outcome of patients with CRT-D versus CRT-P. This analysis was stratified according to sex. RESULTS: After a median follow-up of 34 months (interquartile range 22-60 months) no survival advantage, of CRT-D versus CRT-P was observed in both men and women after PS matching (HR=0.95, 95% CI 0.77 to 1.16, p=0.61, and HR=1.30, 95% CI 0.83 to 2.04, p=0.25, respectively). With inverse-probability weighting, a benefit of CRT-D was seen in male patients (HR 0.78, 95% CI 0.65 to 0.94, p=0.012) but not in women (HR 0.87, 95% CI 0.63 to 1.19, p=0.43). The excess unadjusted mortality of patients with CRT-P compared with CRT-D was related to sudden cardiac death in 7.4% of cases in men but only 2.2% in women. CONCLUSIONS: In primary prevention patients with CRT indication, the addition of a defibrillator might convey additional benefit only in well-selected male patients.