Trends in mortality of acute myocardial infarction after discharge from the hospital

Abstract

Background: We assessed trends in the prognosis of patients with acute myocardial infarction hospitalized in New Jersey hospitals. In recent decades, in-hospital mortality has declined markedly but the decline in longer-term mortality is less pronounced, implying that mortality after discharge has worsened.

Methods and results: Using the Myocardial Infarction Data Acquisition System (MIDAS), we examined the outcomes of 285 397 patients hospitalized for a first acute myocardial infarction between 1986 and 2007. Mortality at discharge decreased by 9.4% from 16.9% to 7.5% (annual change, -0.44; 95% confidence interval, -0.49 to -0.40), but the decrease at 1 year was less pronounced (6.4%) because of an increase in mortality from discharge to 1 year after discharge (from 12.1% to 13.9%; annual change, +0.15; 95% confidence interval, +0.10 to +0.20). Mortality from 30 days after discharge to 1 year, a measure not affected by length of stay, increased by 1.2% (annual change, +0.10; 95% confidence interval, +0.06 to +0.23). The effect was more evident in the older age groups and was due to noncardiovascular mortality, especially from respiratory and renal diseases, septicemia, and cancer. All effects remained statistically significant (P<0.0001) after adjustment for demographics, comorbidities, infarction type, complications, and interventions. Piecewise linear regressions confirmed these trends.

Conclusions: Postdischarge mortality of patients with acute myocardial infarction is increasing, primarily because of higher noncardiovascular mortality in the older age groups.