Abstract
Background: It is essential to identify the risk factors for poor clinical outcomes in patients with acute myocardial infarction (AMI). The coronary artery calcium score (CACS) is gathering attention as a predictor for future cardiovascular events. This study aimed to (1) measure CACSs in patients with AMI by non-ECG-gated computed tomography (CT), (2) compare clinical outcomes between patients with a high CACS and a low-intermediate CACS and (3) to elucidate the association between high CACS and clinical outcomes. Methods: We defined the high CACS group as the highest quantile of CACS (Q4) and defined the low-intermediate CACS group as the other quantiles of CACS (Q1-Q3). The primary endpoint was major adverse cardiovascular events (MACE), which were defined as the composite of all-cause death, re-admission for heart failure, non-fatal MI and target vessel revascularization. We included 548 patients with AMI who underwent non-ECG-gated CT and divided them into the high CACS group (CACS ≥ 5346.5, n = 137) and the low-intermediate CACS group (CACS ≤ 5329.3, n = 411). Results: During the median follow-up duration of 535 days, 150 MACE were observed. The Kaplan-Meier curves showed that MACE occurred more frequently in the high CACS group than in the low-intermediate CACS group (p < 0.001). Multivariable Cox hazard analysis revealed that a high CACS was significantly associated with MACE (hazard ratio 1.597, 95% confidence interval 1.081-2.358, p = 0.019) after controlling for multiple confounding factors. Conclusions: Clinical outcomes were worse in AMI patients with a high CACS than in those with a low-intermediate CACS. A high CACS was significantly associated with MACE in multivariate analysis.