Coronary artery calcium score and its association with stroke: A systematic review and meta-analysis

BACKGROUND: The relationship between coronary artery calcium (CAC) score and incident stroke is controversial.

METHODS: We conducted a systematic review of the literature evaluating CAC score and incident stroke. A search of MEDLINE and EMBASE was performed, and data were extracted from relevant studies. Statistical pooling with random-effects meta-analysis was undertaken to evaluate the risk of incident stroke with any CAC vs. no CAC, 1-100 CAC vs. no CAC, and >100 CAC vs. no CAC.

RESULTS: Data from nine different cohort studies from the United States and Europe with a total of 61,096 patients were included in this review. The mean age of patients in the studies ranged from 44 to 69 years, and follow-up duration ranged from a median of 5.5 years to 12.3 years. The crude stroke event varied from 1.6% to 9.5%. Meta-analysis of risk of incident stroke with any vs. no CAC (RR 1.70 95% CI 0.87-3.31, I 2 = 95%) and for CAC 1-100 vs. no CAC (RR 1.54 95% CI 0.75-3.17, I 2 = 93%) was not statistically significant. For CAC >100, the risk of incident stroke was significantly higher compared with no CAC (RR 2.61 95% CI 1.51-4.52, I 2 = 89%). When one study which included only young adults was excluded, there was significant increase in risk of incident stroke with all categories of CAC.

CONCLUSIONS: There is an association between high CAC score and incident stroke, but more studies are needed to determine how patients with incidental CAC should be managed from the perspective of stroke prevention.