The Coronary Artery Calcium Score Paradox: Evaluating the Discordance Between Coronary Artery Calcium Burden and Coronary Artery Disease Severity on Computed Tomography Angiography.
DOI:
https://doi.org/10.58889/PJCVI.6.1.70.82Keywords:
Coronary Artery Calcium Score, Coronary Artery Disease, Coronary CT Angiography, Obstructive Coronary Artery Disease, Non-Calcified Plaque, Agatston ScoreAbstract
Background: Coronary artery calcium (CAC) scoring is a non-invasive tool to estimate atherosclerotic burden and stratify cardiovascular risk. A CAC score of zero is traditionally considered indicative of low probability of obstructive coronary artery disease (CAD) and favorable prognosis. However, clinically significant non-calcified atherosclerosis may occur despite absent calcification, particularly among symptomatic individuals. This study aimed to investigate the relationship between CAC burden and CAD severity and evaluate the diagnostic performance of CAC scoring.
Methodology: In this retrospective observational study, 337 adults who underwent CAC scoring and coronary computed tomography angiography (CCTA) at Sheikh Zayed Hospital, Rahim Yar Khan, Pakistan (2018–2023) were included. CAC was quantified using the Agatston method and categorized as CAC = 0 or CAC > 0. CAD severity on CCTA was classified as normal, non-obstructive (<50% stenosis), moderate obstructive (50–70%), or severe obstructive (>70%).
Results: The cohort comprised 245 males (72.7%) and 92 females (27.3%), mean age 50.3 ± 11.2 years. CAC = 0 was observed in 190 (56.4%) patients, among whom 61 (32.1%) had CAD, including 13 with obstructive CAD (p < 0.001). Obstructive CAD with zero CAC was more frequent in patients <45 years (25.0% vs 6.0% in older patients; p < 0.001). CAC discriminated plaque well (AUC 0.808, 95% CI 0.762–0.855; p < 0.001). CAC >0 showed 88.2% sensitivity, 78.0% specificity, 66.0% positive predictive value, and 93.2% negative predictive value for obstructive CAD.
Conclusion: CAC scoring demonstrates good diagnostic performance and high negative predictive value for obstructive CAD. Nonetheless, a notable proportion of symptomatic patients, especially younger individuals, had CAD despite zero CAC, emphasizing the need to combine CAC assessment with clinical evaluation and anatomical imaging for accurate risk stratification.
