Coronary Artery DiseaseImpact of Diabetes Mellitus on Long-Term Mortality in Patients Presenting for Coronary Angiography

To understand the current impact of diabetes mellitus (DM) on long-term outcomes among patients referred for coronary angiography, we studied 14,337 consecutive patients (5,279 diabetic patients [37%]) referred to coronary angiography for assessment or treatment of coronary artery disease. We investigated long-term all-cause mortality and its interaction with hypoglycemic therapy and presenting coronary status. At baseline, patients with DM had more hypertension, hyperlipidemia, and renal failure; more were women, overweight, and more had previous coronary interventions. Mortality was higher in those with DM and was related to treatment status: multivariate adjusted hazard ratio during a median follow-up period of 78 months was 1.41 (95% CI 1.11 to 1.80, p = 0.006) for diet only-treated DM, 1.63 (95% CI 1.51 to 1.77, p <0.001) for DM treated with oral hypoglycemics, and 2.50 (95% CI 2.20 to 2.85, p <0.001) for DM requiring insulin therapy. The earlier findings were similar in magnitude in patients presenting with acute or stable coronary syndromes. In addition, long-term mortality of medically treated DM presenting with a stable coronary syndrome was even higher than that of nondiabetic patients presenting with an acute coronary syndrome (hazard ratio 1.21, 95% CI 1.08 to 1.35, p = 0.001). In conclusion, in patients referred for coronary angiography in the current era, DM remained an independent predictor of long-term mortality regardless of the coronary presentation and mortality increased in direct relation to intensity of hypoglycemic therapy at presentation.