Abstract 16212: Warranty Period of Zero Coronary Artery Calcium Score in Asymptomatic Korean Individuals
Introduction: Zero coronary artery calcium (CAC) is a reliable predictor of absent atherosclerosis and serves as a useful adjunct for identifying those at low risk. Despite this, the “warranty period” that displays the protective value associated with the absence of CAC towards experiencing a cardiovascular event among Asians is not well established. Hypothesis: To examine whether the absence of CAC displays a more favorable warranty period for all-cause death compared with the presence of CAC in a Korean cohort. Methods: A total of 48,215 asymptomatic Koreans (mean age: 54±8.8 years; 25% women) were enrolled and stratified by the absence or presence of CAC. Time to exceeding 1% of cumulative all-cause death was estimated in order to identify low-risk individuals. Hazard ratios (HR) with 95% confidence intervals (95% CI) for all-cause death were estimated according to prespecified cardiac risk factors and the presence of CAC. Results: In total, 30,605 (63.5%) individuals presented with a zero CAC. Across a median follow-up of 4.4 years (Interquartile range: 2.7-6.6 years), 415 (0.9%) individuals experienced the endpoint of all-cause death. For those with a zero CAC, the time to exceeding 1% risk was found to be 9 years, indicating a substantially longer warranty period compared with participants with a CAC>0 (e.g., 5 year warranty period). The time to exceeding 1% risk tended to decline for individuals on the background of increasing CAC scores. For each of the other prespecified risk factor groups, a zero CAC provided a longer cumulative event free period than in the presence of any CAC. Cox regression analyses also revealed that the absence of CAC was independently associated with a lower risk of all-cause death in each of the respective risk factor groups when compared with CAC>0. Conclusions: In a large cohort of asymptomatic Korean individuals, the absence of CAC evokes a strong protective effect against all-cause death as demonstrated by a longer warranty period.