Influence of diabetes on long-term outcome among unselected patients with acute coronary events.

Objective: The aims of this study were to investigate the prognostic influence of diabetes after an episode of unstable angina pectoris or non-Q-wave myocardial infarction (MI) and to investigate whether diabetes is independently associated with increased short- and long-term mortality risk following these episodes.
Design: Consecutive patients with a diagnosis of unstable angina pectoris or non-Q-wave MI, admitted to the Coronary Care Unit at Ostra Hospital, Göteborg, Sweden during 1988-1998 were included. The primary endpoint was 2-year mortality collected from the Swedish cause-specific mortality register.
Results: The study included 4341 patients, 722 (17%) had diabetes. Diabetes was associated with increased mortality during initial hospitalization (10.2% vs 5.7%, p < 0.0001), after 30 days (13% vs 7.5%, p < 0.0001), and at 2 years (33.7% vs 20.2%, p < 0.0001). After adjustment for potentially confounding factors, diabetes remained an independent predictor of 2-year mortality following unstable coronary syndromes, the hazard ratio (HR) of death (HR = 1.6; 95% CI 1.4-1.9).
Conclusions: Among patients with unstable coronary syndromes, diabetes is an independent risk factor associated with increased mortality during hospitalization, short- and long-term follow-up.