Coronary Calcium Deposits Predicts Stroke Risk

A new study reveals that among those with low-to-intermediate cardiovascular risk, coronary artery calcification (CAC) score can predict the occurrence of stroke, even after accounting for traditional risk factors.

Researchers at University Hospital Essen (Germany) studied a total of 4,180 subjects (47.1% men, 45–75 years of age) from the population-based Heinz Nixdorf Recall study, held in three cities in the industrialized Ruhr area of Germany. All subjects without previous stroke, coronary heart disease (CHD), or myocardial infarction (MI) were evaluated for stroke events over an average of 8 years of follow-up. The researchers examined CAC as a stroke predictor, in addition to established vascular risk factors, including age, sex, systolic blood pressure, low-density lipoprotein (LDL), high-density lipoprotein (HDL), diabetes mellitus, smoking, and atrial fibrillation (AF).

The results showed that 92 (2.2%) incident strokes occurred (82 ischemic, 10 hemorrhagic) during the study period. Subjects suffering a stroke had significantly higher CAC values at baseline than the remaining subjects; log10 (CAC+1) was an independent stroke predictor in addition to age, systolic blood pressure, and smoking. CAC predicted stroke in both men and women, particularly in subjects younger than 65 years of age, and independent of AF. CAC also discriminated stroke risk specifically in participants belonging to the low (<10%) and intermediate (10%–20%) Framingham risk score categories.

“That CAC, as we now have shown, is able to predict stroke events independent of established risk factors, [makes] this marker promising for risk stratification not only in the hands of cardiologists but also in the hands of neurologists,” concluded lead author Dirk Hermann, MD, of and colleagues. “These observations indicate that among cohorts without apparent risk, subjects exist that nonetheless exhibit a high stroke incidence; on the basis of our data, CAC is suitable to identify those subjects.”

CAC is a noninvasive marker of plaque load in coronary arteries that is almost always indicative of atherosclerotic plaque (but bears no relationship to plaque stability or instability). It is usually determined by electron beam computerized tomography scan (EBCT). The main disadvantages of CAC scoring is that it lacks information regarding a patient's functional capacity, which could be inferred from an exercise tolerance test, and lack of data in ethnic groups.

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