Zero Coronary Artery Calcification: A Promising Value in Acute Chest Pain Evaluation

Chest pain is the second most common reason for emergency room visits, accounting for approximately 11 million encounters annually. While benign conditions are often the underlying cause, life-threatening diagnoses such as acute coronary syndrome remain significant. Timely, accurate, and cost-effective assessment is, therefore, critical. The 2022 American Heart Association and American College of Cardiology guidelines recommend using clinical decision pathways followed by functional tests or coronary computed tomography (CT) angiography for patients with intermediate risk of acute coronary events. However, these conventional tests face challenges, including availability and complexity. Nongated, noncontrasted cardiac CT for coronary artery calcification (CAC) detection is fast and simple, and requires minimal technical expertise. Although traditionally validated in stable coronary artery disease (CAD), recent evidence supports CAC's utility in acute settings. Notably, the absence of CAC (known as CAC Zero) demonstrates exceptional accuracy, including a ~98% negative predictive value for CAD, and predicts excellent short- and intermediate-term prognoses in patients with acute chest pain. Despite its promise, caution is advised when applying CAC Zero in younger populations, as they are more likely to have noncalcified plaques. This article reviews recent evidence on the value and limitations of CAC Zero in evaluating acute chest pain.