Predictors and prognostic impact of silent coronary artery disease in asymptomatic high-risk patients with diabetes mellitus.

AIMS

Evaluation of predictors of silent coronary artery disease (SCAD) in high-risk asymptomatic diabetic patients and to evaluate their two-year outcome.

METHODS AND RESULTS

Four hundred diabetic patients without prior CAD but at high CAD risk underwent myocardial perfusion scintigraphy (MPS) in this prospective multicentre outcome trial. MPS were abnormal in 22% of patients. Male sex (OR 2.223, 1.152-4.290; p=0.017), diabetes duration (OR 1.049,1.015-1.085; p=0·005), peripheral artery disease (OR 2.134, 1·150-3.961; p=0.016), smoking (OR 2.064, 1.109-3.839; p=0·022), systolic blood pressure (OR 1.014, 1.00-1.03, p=0·056), brain natriuretic peptide (OR 1.002, 1.001-1.004, p=0·005) independently predicted an abnormal MPS: if <2 and >3 predictors were present, 3.2% and 47% patients had an abnormal MPS, respectively (p<0·001). Two-year major adverse cardiac event rates increased from 2·9% to 14·6%, cardiac death rates from 0·6% to 4·1% in patients with summed stress scores ≤10 and >10%, respectively (each p<0.045).

CONCLUSIONS

Male sex, diabetes duration, peripheral artery disease, smoking, elevated systolic blood pressure and increased brain-natriuretic peptides independently predicted SCAD. In presence of >3 predictors, almost 50% of patients had an abnormal MPS. They may benefit from screening by MPS since the extent of the MPS abnormality discriminated clearly between a favourable compared to a bad 2-year outcome. However, even highest risk patients without objective evidence of CAD had a benign prognosis without need for specific evaluation or therapy.

TRIAL REGISTRATION NUMBER

ISRCTN87953632.