Abstract 18480: Mortality Risk in Married and Unmarried ICD and CRT-D Patients With Mild Heart Failure: A MADIT-CRT Sub-study

Abstract

Background: Married patients have been shown to have a lower risk for adverse cardiovascular outcomes. However, the risk of heart failure or death, and death alone in married versus unmarried patients with left ventricular (LV) dysfunction and an implantable cardioverter defibrillator (ICD), and the effect of cardiac resynchronization therapy with defibrillator (CRT-D) are unknown. Methods: In MADIT-CRT, we evaluated the long-term clinical outcomes of all-cause mortality, and heart failure (HF) or death in married and common law patients compared to the unmarried (single/divorced/widowed) with left bundle branch block (LBBB) and CRT-D vs. an ICD-only. Results: There were 937 married patients and 344 unmarried patients with LBBB. Married patients were more likely to be men, white, smokers, and heavier. During a median follow-up of 5.6 years, married/common law ICD patients had a significantly lower incidence of death compared to unmarried patients (p=0.004) (Figure). In multivariate analysis in the ICD-only sub-group, married or common-law patients had a 39% lower risk of all-cause mortality (HR 0.46, 95% CI 0.30 - 0.71, p<0.001) when compared to the unmarried. However, in the CRT-D group, the survival benefit was attenuated in married/common-law patients (HR 0.74, 95% CI 0.51 - 1.06, p=0.10) compared to the unmarried (HR 0.40, 95% CI 0.23 - 0.69, p<0.001, interaction p=0.07). There were no differences in clinical outcomes of HF or death in married and unmarried patients with an implanted CRT-D vs. ICD-only, or in patients with non-LBBB ECG pattern. Conclusions: During long-term follow-up of mild HF patients with LV dysfunction, married/common-law patients were at a significantly lower risk for death compared to those not married. In married patients, CRT-D was associated with an attenuated survival benefit when compared to their unmarried counterparts.