Comparison of Clinical Outcomes Following Acute Myocardial Infarctions in Hypertensive Patients With or Without Diabetes

Background and Objectives It is thought that patients with diabetes mellitus (DM) have a poor prognosis after an acute myocardial infarction (AMI), but the effect of diabetes on the outcomes of hypertensive patients with AMIs has not been elucidated in the Korean population. The aim of this study was to investigate the effects of diabetes on long-term clinical outcomes following AMIs in patients with hypertension. Subjects and Methods Using data from the Korea Acute Myocardial Infarction Registry (November 2005 to December 2006), 2,233 hypertensive patients with AMIs were grouped as follows based on the presence of DM: group I, diabetic hypertension (n=892, 544 men, mean age=66.2±10.9 years); and group II, non-diabetic hypertension (n=1341, 938 men, mean age=63.9±12.8 years). The primary study outcomes included in-hospital death and major adverse cardiac events (MACE; cardiac death, myocardial infarction (MI), repeat percutaneous coronary intervention, and coronary artery bypass surgery) at the 1 year follow-up. Results Hypertensive patients with DM were older and more likely to be women. The diabetic group had lower blood pressure (p<0.001), a lower left ventricular ejection fraction (p<0.001), a more severe degree of heart failure (p<0.001), a longer duration of coronary care unit admission (p<0.001), and a higher incidence of hyperlipidemia (p=0.007). The N-terminal pro-brain natriuretic peptide level (4602.5±8710.6 pg/mL vs. 2320.8±5837.9 pg/mL, p<0.001) was higher and the creatinine clearance (62.4±29.9 mL/min vs. 73.0±40.8 mL/min, p<0.001) was lower in the diabetic group than the non-diabetic group. Coronary angiographic findings revealed more frequent involvement of the left main stem (p=0.002) and multiple vessels (p<0.001) in the diabetic group. The rate of in-hospital death was higher in the diabetic group (p<0.001). During follow-up, the rates of composite MACE at 1 month, 6 months, and 12 months were higher in the diabetic group (p<0.001). Conclusion In hypertensive patients with AMI, DM was associated with worse clinical and angiographic features, with a higher risk of development of severe heart failure, and an increased risk of MACE on long-term clinical follow-up.