Coronary artery calcification is an independent stroke predictor in the general population

Abstract

Background and purpose: Coronary artery calcification (CAC) is a noninvasive marker of plaque load that predicts myocardial infarcts in the general population. Herein, we investigated whether CAC predicts stroke events in addition to established risk factors that are part of the Framingham risk score.

Methods: A total of 4180 subjects from the population-based Heinz Nixdorf Recall study (45-75 years of age; 47.1% men) without previous stroke, coronary heart disease, or myocardial infarction were evaluated for stroke events over 94.9 ± 19.4 months. Cox proportional hazards regressions were used to examine CAC as stroke predictor in addition to established vascular risk factors (age, sex, systolic blood pressure, low-density lipoprotein, high-density lipoprotein, diabetes mellitus, smoking, and atrial fibrillation).

Results: Ninety-two incident strokes occurred (82 ischemic, 10 hemorrhagic). Subjects suffering a stroke had significantly higher CAC values at baseline than the remaining subjects (median, 104.8[Q1;Q3, 14.0;482.2] vs 11.2[0;106.2]; P<0.001). In a multivariable Cox regression, log10(CAC+1) was an independent stroke predictor (hazards ratio, 1.52 [95% confidence interval, 1.19-1.92]; P=0.001) in addition to age (1.35 per 5 years [1.15-1.59]; P<0.001), systolic blood pressure (1.25 per 10 mm Hg [1.14-1.37]; P<0.001), and smoking (1.75 [1.07-2.87]; P=0.025). CAC predicted stroke in men and women, particularly in subjects <65 years of age and independent of atrial fibrillation. CAC discriminated stroke risk specifically in participants belonging to the low (<10%) and intermediate (10%-20%) Framingham risk score categories.

Conclusions: CAC is an independent stroke predictor in addition to classical risk factors in subjects at low or intermediate vascular risk.