Intracranial artery calcification scores can predict asymptomatic CAD

For patients with ischemic stroke, intracranial artery calcification (IAC) scores quantified using unenhanced CT have significant correlation with coronary calcium scores, according to a study published online May 14 in Radiology.

The results showed that IAC scores could serve as an independent predictor of asymptomatic coronary artery disease (CAD) in patients with ischemic stroke, according to Sung Soo Ahn, MD, of Yonsei University College of Medicine, in Seoul, Korea, and colleagues.

“CAD is an important cause of morbidity and mortality in ischemic stroke, and asymptomatic CAD is prevalent in patients with stroke; therefore, identifying patients at high risk for asymptomatic CAD by using brain CT would be helpful in the care of patients with stroke by providing guidelines for CAD screening,” wrote the authors.

A total of 314 consecutive patients were included in the retrospective study. All had acute ischemic stroke and underwent both brain and coronary CT within one month of stroke. Agatston scores—the area of calcification multiplied by a weighted value assigned to its highest Hounsfield unit—were calculated, as well as volumes on thin-section unenhanced images, and these data were correlated with coronary calcium scores and volumes

The correlation coefficients for IAC and CAC by Agatston scores and volumes were 0.665 and 0.663, respectively, reported the authors. A graded association was found between IAC scores and presence of asymptomatic CAD, they added.

Multiple logistic regression analysis revealed that both IAC scores of 120.11 or greater and diabetes mellitus were independent predictors for asymptomatic CAD. “Therefore, adding IAC score to the analytic model that included conventional vascular risk factors and the presence or absence of extracranial ICA stenosis significantly improved the separability for asymptomatic CAD,” wrote the authors.

Ahn and colleagues noted that their study may not represent the general stroke population as it was a retrospective study performed in a selected group of patients who underwent both brain CT and CT coronary angiography.

“Because of the risk associated with radiation exposure, it may not be ethical to perform both brain CT and coronary CT in patients with stroke who have no vascular risk factors,” wrote the authors. “Nevertheless, our study aimed to stratify the risk for asymptomatic CAD in patients with ischemic stroke because asymptomatic CAD is prevalent in patients with stroke and it would be useful to be able to identify high-risk patients who might benefit from additional therapeutic measures. The results of this study could provide guidelines for asymptomatic CAD screening for patients with acute ischemic events.”