Prevalence of coronary artery stenosis on computed tomography angiography of the coronary arteries in stable patients with zero coronary calcium score in Angola

Coronary artery calcium is a component of atherosclerosis and a marker for the presence of coronary artery disease (CAD). It can be quantified based on non-contrast computed tomography (CT) using coronary calcium score (CCS) according to the Agatston method. This study aimed to assess the prevalence of CAD in a population with a zero CCS, using 64-slice CT in Angola. A total of 204 patients were included in the study. Of the total sample, 60.3% of the patients were male. The mean age was 56.46±9.19 years. The mean CCS of the cohort was 44.4±117(range, 0–889). Among 204 patients, CCS was zero in 136 (66.7%) patients, and 68 (33.3%) patients had a CCS ≥1. Compared to CCS ≥1, patients with CCS=0 were younger (age 54.7±9.3 years vs. 59.9±7.9 years, p <0.001) and the proportion of women was significantly higher (47.1% vs. 25.0%, p 0.002). Patients with CCS zero had also less history of diabetes mellitus, dyslipidemia, and smoking in the past. Of the 136 patients with CCS=0, one (0.7%) had obstructive CAD, and 16 (11.8%) had non-obstructive CAD. Our results suggest that the absence of calcium was associated with a very low probability of significant stenosis of the coronary arteries.