Coronary artery calcium score as a predictor for incident stroke: Systematic review and meta-analysis

Background: Coronary artery calcium score (CACS) is a well-established test for risk stratifying asymptomatic patients for overall cardiovascular or coronary events. However; the prognostic value for incident stroke remains controversial. The objective of this study was to investigate the predictive value of CACS obtained by non-contrast electrocardiogram-gated computed tomography for incident stroke. Methods: We searched PubMed, EMBASE, Cochrane databases for prospective longitudinal studies of CACS which reported the incidence of stroke. Incidence of strokewas compared in patients with and without coronary calcification. Results: Three studies evaluated 13,262 asymptomatic patients (mean age = 60 years, 50% men) without apparent cardiovascular diseases. During a follow-up of 7.2 years (median 5 years, range 4.4-9.5 years, 95,434 patient years), the overall pooled incidence of stroke was 0.26%/year. The pooled risk ratio of CACS > 0 for incident stroke was 2.95 (95% CI: 2.18-4.01, p < 0.001) compared to CACS = 0. The heterogeneity among studies was low (I-2 = 0%). The pooled incidence rate of stroke categorized by CACS was 0.12%/year for CACS 0, 0.26%/year for CACS 1-99, 0.41%/year for CACS 100-399 and 0.70%/year for CACS >= 400. Conclusions: In asymptomatic patients without apparent cardiovascular diseases, the incidence of stroke was overall low. The presence and severity of coronary artery calcification were associated with incident stroke over mid-long term follow-up. (C) 2017 Elsevier B.V. All rights reserved.