Long-term Prognosis and Clinical Characteristics of Patients with Newly Diagnosed Diabetes Mellitus Detected after First Acute Myocardial Infarction: from KAMIR-NIH Registry

BACKGROUND AND OBJECTIVES After the first acute myocardial infarction (AMI), a considerable proportion of patients are newly diagnosed with diabetes mellitus (DM). However, in AMI, controversy remains regarding the disparity in prognosis between previously diagnosed DM (known-DM) and newly diagnosed DM (new-DM). METHODS The study included 10,455 patients with AMI (non-DM, 6,236; new-DM, 659; known-DM, 3,560) admitted to one of 15 participating centers in Korea between November 2011 and January 2016 (average follow-up, 523 days). We compared the characteristics and clinical course of patients with known-DM and those with new- or non-DM. RESULTS Compared to patients with known-DM, those with new-DM or non-DM were younger, more likely to be male, and less likely to have hypertension, dyslipidemia, prior stroke, angina, or myocardial infarction. Compared to patients with new-DM or non-DM (reference), those with known-DM had higher risks of major adverse cardiac events (hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.06-1.35; p=0.004), cardiac death (HR, 1.26; 95% CI, 1.01-1.57; p=0.042), and congestive heart failure (HR, 1.58; 95% CI, 1.20-2.08). Unlike known-DM, new-DM did not increase the risk of cardiac events (including death). CONCLUSIONS Known-DM was associated with a significantly higher risk of cardiovascular events after AMI, while new-DM had a similar risk of cardiac events as that noted for non-DM. There were different cardiovascular outcomes according to diabetes status in patients with AMI.