Atherosclerosis severity but not undiagnosed diabetes predicts new cardiovascular events of subjects in secondary cardiovascular prevention

Objective: Undiagnosed diabetes (DM2), especially in individuals that have experienced a major atherosclerotic vascular event, could increase the risk of a second major cardiovascular (CV) event. The aim of this study was to evaluate the impact of type 2 diabetes (DM2), diagnosed after a major cardiovascular event, on subsequent CV disease in high risk individuals. Methods: 411 subjects without known DM2 and with a history of a prior major CV event were followed for a second major CV event (fatal and nonfatal MI, fatal and nonfatal stroke or any arterial revascularization procedure). At baseline, each individual underwent a physical, biochemical examination, an OGTT and dosed A1c. In addition, patients were classified as having monovascular or polyvascular disease. The average follow-up duration was 31 months. Results: The incidence of second CV events was 10.70 per 100 person-years (114 events/1066 person-years). The diagnosis of occult DM2 was not associated with major CV events, either using A1c values ≥6.5%, fasting glucose ≥126 mg/dL or 2 h post-load glucose ≥200 mg/dL. Polyvascular disease was the only significant predictor of a second major CV event (HR 2.60, 95% CI 1.72-3.95) after adjustment for age, BMI, smoking status, systolic blood pressure, high-density and low-density lipoprotein cholesterol and high sensitivity C-reactive protein. Conclusion: DM2 that was newly diagnosed after established vascular atherosclerotic disease did not increase the risk of new major CV events. In our population only the polyvascular disease was able to identify the subjects at high risk for a second major cardiovascular event.