Marital Status and Long-Term Outcomes in Mild Heart Failure Patients With an Implantable Cardioverter Defibrillator or Cardiac Resynchronization Therapy With Defibrillator

Abstract

Married patients have been shown to have a lower risk for adverse cardiovascular outcomes. However, the risk of heart failure (HF) or death 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. In Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT), in patients with left bundle branch block, we evaluated long-term clinical outcomes of all-cause mortality or HF events in married (including common law status) compared with unmarried (single/divorced/widowed) patients with CRT-D versus an ICD-only. There were 937 married patients and 344 unmarried patients with left bundle branch block. Multivariate analysis showed that married patients had a 54% lower risk of all-cause mortality (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.30 to 0.71, p <0.001) compared with the unmarried. However, the survival benefit associated with marital status was pronounced in ICD patients (HR 0.40, 95% CI 0.23 to 0.69, p <0.001) and attenuated in CRT-D patients (HR 0.74, 95% CI 0.51 to 1.06, p = 0.10), interaction (p = 0.07). Consistently, during the median follow-up of 5.6 years, in patients with ICD, married patients had a significantly lower incidence of death (24%) compared with unmarried patients (42%; p = 0.004), whereas the corresponding mortality rates in CRT-D patients were not significantly different (p = 0.814). In conclusion, during long-term follow-up of mild HF patients with LV dysfunction, married patients were at a significantly lower risk for death compared with those not married. The survival benefit associated with marital status was pronounced in patients implanted with an ICD and is attenuated in those implanted with a CRT-D device.