Cardiovascular Risk Prediction Is Improved by Adding Asymptomatic Coronary Status to Routine Risk Assessment in Type 2 Diabetic Patients

Abstract

OBJECTIVE To evaluate if silent myocardial ischemia (SMI) and silent coronary artery disease (CAD) provide significant additional value to routine cardiovascular risk assessment in type 2 diabetic patients. RESEARCH DESIGN AND METHODS We followed up to a first cardiovascular event 688 subjects (322 men, aged 59 ± 8 years) out of 731 consecutive asymptomatic type 2 diabetic patients with ≥1 additional risk factor who had been prospectively screened between 1992 and 2006 for SMI by stress myocardial scintigraphy and for silent CAD by coronary angiography. RESULTS SMI was found in 207 (30.1%) patients and CAD in 76 of those with SMI. Of the patients, 98 had a first cardiovascular event during a 5.4 ± 3.5 (range: 0.1–19.2) year follow-up period. Cox regression analysis considering parameters predicting events but not SMI and CAD (“routine assessment”) showed in univariate analyses that macroproteinuria (hazard ratio [HR] 3.33 [95% CI 1.74–6.35]; P < 0.001), current multifactorial care (0.27 [0.15–0.47]; P < 0.001), and peripheral/carotid occlusive arterial disease (PCOAD; 4.33 [2.15–8.71]; P < 0.001) independently predicted cardiovascular events. When added into the model, SMI (HR 1.76 [1.00–3.12]; P = 0.05) and CAD (2.28 [1.24–4.57]; P < 0.01) were also independently associated with events. SMI added to the prediction of an event in the following 5 years above and beyond routine assessment risk prediction (c statistic with or without SMI 0.788 [0.720–0.855] and 0.705 [0.616–0.794], respectively). CONCLUSIONS Although screening for SMI and silent CAD should not be systematic, these complications are predictive of cardiovascular events in type 2 diabetic patients in addition to routine risk predictors, especially represented by PCOAD, macroproteinuria, and nonintensive management.