Background: There is considerable interest in the trending discrepancy between ischemic heart disease (IHD) and heart failure (HF) in vital statistics. Clinically, acute myocardial infarction (AMI) and stroke are closely associated with HF, but their contribution to HF as the underlying cause of death (UCD) is unclear.Methods and Results: In 1990 and 1992-1993, we enrolled a total of 140,420 residents of Japanese nationality (aged 40-69 years) from 11 public health center areas. We prospectively examined the occurrence of cardiovascular disease (CVD), including AMI, sudden cardiac death within 1 h (SCD), and stroke, and analyzed the 14,375 participants without a history of CVD at baseline who died during the 20-year follow-up. A time-dependent Cox proportional hazards model was used to estimate hazard ratios and the population attributable fraction (PAF) of AMI, AMI+SCD, stroke, and CVD for deaths due to HF, IHD, and cerebrovascular disease as the UCD, adjusted for individuals' lifestyles and comorbid conditions. The PAF of AMI for HF deaths was 2.4% (95% confidence interval [CI] 1.7-2.9%), which increased to 12.0% (95% CI 11.6-12.2%) for AMI+SCD. The PAF of CVD-attributed HF deaths was estimated to be 17.6% (95% CI 15.9-18.9%).
Conclusions: HF as the UCD was partly explained by CVD. The data imply that most HF deaths reported in vital statistics may be associated with underlying causes other than CVD.
Keywords: Acute myocardial infarction; Epidemiology; Heart failure; Stroke; Underlying cause of death.