Background— Heart failure (HF) is an important predictor of poor outcome after acute myocardial infarction (AMI). However, limited data exist about the clinical significance of HF in the coronary reperfusion era and the impact of its timing on hospital outcomes. The objective of this study was to determine the clinical impact of HF complicating AMI in the National Registry of Myocardial Infarction (NRMI). A secondary objective was to determine differences in demographic and clinical characteristics, treatment, and hospital death rates in patients presenting with HF compared with those developing HF after presentation.

Methods and Results— The study sample consisted of patients with AMI and without a history of HF included in the NRMI. Of 606 500 cases included from July 1, 1994 to June 30, 2000, 123 938 (20.4%) patients had HF at the time of hospital presentation and 52 220 (8.6%) developed HF thereafter. Patients with HF were older, more likely female, had more comorbidities, and were less likely to receive effective cardiac medications compared with patients without HF. The multivariable adjusted odds for in-hospital death were higher for patients with HF at presentation and thereafter (3.1 and 5.5, respectively) than those without HF.

Conclusions— Results from this nationwide registry suggest that the incidence and hospital death rates associated with HF complicating AMI remain high. Patients developing HF after hospital admission are at even greater risk than those presenting with HF. Effective cardiac therapies remain underutilized in these patients, and the reasons for this underutilization need to be explored.