Obstructive coronary artery disease in symptomatic diabetics with zero coronary calcium score: are we missing something?

Abstract

Prevalence and severity of coronary artery disease (CAD) in symptomatic patients with zero coronary artery calcium score (CACS) are unclear, particularly in regard to the diabetic population, which represents, per se, a subgroup at increased cardiovascular risk. The aim of this study was to investigate the prevalence and severity of CAD by coronary computed tomography angiography (CCTA) in a symptomatic diabetic cohort with zero CACS. All consecutive symptomatic diabetics referred for CAD suspicion were included in this study. All subjects underwent a noncontrast coronary artery calcium scan followed by CCTA. CACS was quantified using the Agatston method. CAD was defined as a total plaque score (TPS) greater than zero. Obstructive and severe obstructive CAD were defined respectively as luminal stenosis >50% and >70% in at least one coronary segment. We identified 1722 symptomatic diabetics (mean age 62.5 ± 12.9 years, 62% men). One hundred and eleven subjects had zero CACS and TPS >0 (mean age was 49.5 ± 14.8, 58% women, 56% Hispanics). Sixty-five patients (58.5%) had one-vessel disease, followed by 30 (27%) with two-vessel disease and 14 (12.6%) with ≥ three-vessel disease. Obstructive CAD was found in 11 subjects and, among these, three were categorized as severe obstructive CAD. In symptomatic diabetic patients with zero CACS, CAD, including obstructive disease, can still occur and is predominant in middle-aged adults, women and Hispanics. In symptomatic diabetics CCTA is a critical step for accurate risk stratification even when CACS would have placed some of these individuals in a lower-risk category.