Recent trends in the incidence rates of and death rates from atrial fibrillation complicating initial acute myocardial infarction: a community-wide perspective.

BACKGROUND: Limited information is available about recent trends in the incidence and death rates from atrial fibrillation (AF) complicating acute myocardial infarction (AMI). The purpose of this study was to examine the impact and trends over time of AF complicating initial AMI.
METHODS: We conducted a longitudinal study of 2596 residents of the Worcester, Massachusetts, metropolitan area with initial AMI and without previous AF who were hospitalized at all area hospitals in 5 annual periods between 1990 and 1997.
RESULTS: A total of 13% of hospitalized patients developed AF. There was a marked decrease in the proportion of patients who developed AF over time (18% in 1990; 11% in 1997). Patients hospitalized during the most recent study years remained at significantly lower risk for developing AF than patients hospitalized in 1990 after controlling for factors that might affect the risk of AF. Patients with AF were more likely to die during hospitalization than those without AF even after controlling for other prognostic factors. Despite the adverse impact of AF, we observed trends toward improved hospital survival during the most recent study years in patients developing AF. Patients discharged after developing AF had higher long-term death rates than patients who did not develop AF, although these differences were attenuated after adjusting for other factors.
CONCLUSIONS: The results of this community-wide study suggest a significant decline in the incidence of AF complicating AMI. Although patients with AF had higher hospital death rates, we observed trends of improved survival for these patients. AF remains a common complication of AMI to which targeted treatment efforts appear warranted.