Coronary Artery Calcium Score And Risk Of Cardiovascular Events Without Established Coronary Artery Disease: A Systemic Review And Meta-Analysis

BackgroundCoronary artery calcium (CAC) is an indicator of atherosclerosis, and the CAC score is a useful noninvasive assessment of coronary artery disease.ObjectiveTo compare the risk of cardiovascular outcomes in patients with CAC > 0 versus CAC = 0 in asymptomatic and symptomatic population in patients without an established diagnosis of coronary artery disease.MethodsA systematic search of electronic databases was conducted until January 2018 for any cohort study reporting cardiovascular events in patients with CAC > 0 compared with absence of CAC.ResultsForty-five studies were included with 192 080 asymptomatic 32 477 symptomatic patients. At mean follow-up of 11 years, CAC > 0 was associated with an increased risk of major adverse cardiovascular and cerebrovascular events (MACE) compared to a CAC = 0 in asymptomatic arm [pooled risk ratio (RR) 4.05, 95% confidence interval (CI) 2.91-5.63, P < 0.00001, I-2 = 80%] and symptomatic arm (pooled RR 6.06, 95% CI 4.23-8.68, P < 0.00001, I-2 = 69%). CAC > 0 was also associated with increased risk of all-cause mortality in symptomatic population (pooled RR 7.94, 95% CI 2.61-24.17, P < 0.00001, I-2 = 85%) and in asymptomatic population CAC > 0 was associated with higher all-cause mortality (pooled RR 3.23, 95% CI 2.12-4.93, P < 0.00001, I-2 = 94%). In symptomatic population, revascularization in CAC > 0 was higher (pooled RR 15, 95% CI 6.66-33.80, P < 0.00001, I-2 = 72) compared with CAC = 0. Additionally, CAC > 0 was associated with more revascularization in asymptomatic population (pooled RR 5.34, 95% CI 2.06-13.85, P = 0.0006, I-2 = 93). In subgroup analysis of asymptomatic population by gender, CAC > 0 was associated with higher MACE (RR 6.39, 95% CI 3.39-12.84, P < 0.00001).ConclusionAbsence of CAC is associated with low risk of cardiovascular events compared with any CAC > 0 in both asymptomatic and symptomatic population without coronary artery disease.