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 stroke was compared in patients with and without coronary calcification. Results Three studies evaluated 13,262 asymptomatic patients (mean age=60years, 50% men) without apparent cardiovascular diseases. During a follow-up of 7.2years (median 5years, range 4.4–9.5years, 95,434patient-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 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.