Current CAD screening guidelines from the American Diabetes Association recommend testing asymptomatic patients with diabetes and two or more additional risk factors. The guidelines state that asymptomatic diabetic patients with none or only one other CAD risk factor do not require cardiac testing, Dr. Roldano Scognamiglio and colleagues from the University of Padua Medical School note in the January 3rd Journal of the American College of Cardiology.
In an attempt to "verify the effectiveness" of these guidelines, the researchers studied 1,899 asymptomatic type 2 diabetic patients aged 60 or younger. They divided patients into two groups: group A included 1,121 patients with two or more CAD risk factors, and group B included 778 patients with no or only one CAD risk factor.
All subjects underwent stress myocardial contrast echocardiography, and those with myocardial perfusion defects underwent coronary angiography.
According to the team, the prevalence of abnormal stress echocardiography findings was similar in group A and group B (59.4% vs. 60%), as was the prevalence of significant CAD (64.6% vs. 65.5%).
This suggests that a "substantial number of asymptomatic diabetic patients with few risk factors might have occult CAD," Dr. Scognamiglio and colleagues point out. "These patients might have been missed on the basis of current ADA guidelines."
Moreover, "patients with CAD unmasked by an 'aggressive' approach had a more favorable angiographic anatomy of coronary vessels," the team reports.
Patients in group B, they explain, were more apt to have one-vessel disease and less likely to have three-vessel disease, "diffuse disease," and occlusion. Based on the coronary anatomy picture, revascularization was not an option in 45% of patients with two or more risk factors.
Summing up, the researchers say, in this study, the screening criterion of two or more risk factors "did not help to identify asymptomatic patients with a higher percentage of CAD and is only related to a more severe CAD with unfavorable coronary anatomy."