Predictive Value of a Zero Coronary Artery Calcium Score in Major Adverse Cardiac Events in Old Age

Background: By estimating the total coronary plaque burden, the Coronary Artery Calcium (CAC) score determines the risk of Coronary Artery Disease (CAD). The presence of a zero CAC score may be highly predictive of very low risk patients for Major Cardiac Adverse Events (MACEs) due to its close relation with the severity of CAD. Objective: The present study aimed to evaluate the value of a zero CAC score for predicting MACEs in patients older than 60 years suspected of CAD. Methods: Between April 2011 and March 2012, 128 patients aged > 60 years with a zero CAC score on admission without a previous history of CAD were consecutively included in this study with a mean follow-up period of 45.7 months. The continuous variables were compared using t-test or Mann–Whitney U test and the categorical ones were compared using chi-square test. The statistical analyses were done using the SPSS statistical software, version 23.0. Results: This study was conducted on 128 patients (35 males and 93 females). The incidence of MACEs was 2.3% in a mean follow-up period of 45.7 months and 0.6 per 100 patient-years. Additionally, the MACE-free survival rates were 99.1%, 99.1%, and 87.7% in one, three, and five years, respectively. The negative predictive value of a zero CAC score for predicting long-term MACEs was 100% in the patients older than 70 years and 96.8% in those aged between 60 and 70 years. No cardiac-related death was recorded within the follow-up period. Conclusion: A zero CAC score had a high negative predictive value for predicting longterm MACEs in elderly patients with mild to moderate pretest probability of CAD, which reached 100% among the patients older than 70 years.