Coronary artery calcification, intima-media thickness, and ankle-brachial index are complementary stroke predictors

Janine Gronewold; Marcus Bauer; Nils Lehmann; Amir A Mahabadi; Hagen Kälsch; Christian Weimar; Klaus Berger; Susanne Moebus; Karl-Heinz Jöckel; Raimund Erbel; Dirk M Hermann; Heinz Nixdorf Recall Study Investigative Group

doi:10.1161/STROKEAHA.114.005626

Coronary artery calcification, intima-media thickness, and ankle-brachial index are complementary stroke predictors

Stroke. 2014 Sep;45(9):2702-9. doi: 10.1161/STROKEAHA.114.005626. Epub 2014 Aug 12.

Affiliations

¹ From the Departments of Neurology (J.G., C.W., D.M.H.) and Cardiology (M.B., A.A.M., H.K., R.E.), University Hospital Essen, Essen, Germany; Institute of Medical Informatics, Biometry, and Epidemiology, University of Duisburg-Essen, Essen, Germany (N.L., S.M., K.-H.J.); and Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany (K.B.).
² From the Departments of Neurology (J.G., C.W., D.M.H.) and Cardiology (M.B., A.A.M., H.K., R.E.), University Hospital Essen, Essen, Germany; Institute of Medical Informatics, Biometry, and Epidemiology, University of Duisburg-Essen, Essen, Germany (N.L., S.M., K.-H.J.); and Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany (K.B.). dirk.hermann@uk-essen.de.

PMID: 25116876
DOI: 10.1161/STROKEAHA.114.005626

Abstract

Background and purpose: Coronary artery calcification (CAC), a marker of coronary atherosclerosis, predicts stroke in addition to established risk factors. Whether CAC's predictive value can be improved by peripheral atherosclerosis markers, namely carotid intima-media thickness (CIMT) and ankle-brachial index (ABI), was unknown.

Methods: A total of 3289 participants of the population-based Heinz Nixdorf Recall study (45-75 years; 48.8% men) without previous stroke or coronary heart disease were evaluated for incident stroke for 9.0±1.9 years. CAC, CIMT, and ABI were examined as stroke predictors.

Results: Eighty-four strokes occurred during follow-up. In multivariable Cox proportional hazard regressions, CAC (hazard ratio, 1.45 [95% confidence interval, 1.11-1.88] per SD increase in ln(CAC+1); SD, 2.40), CIMT (1.34 [1.08-1.66] per SD increase; SD, 0.127 mm), and ABI (1.55 [1.32-1.82] per SD decrease; SD, 0.148) were associated with stroke in addition to established risk factors. When combined with each other, ln(CAC+1)'s hazard ratio remained similar when CIMT (1.41 [1.09-1.83]) was inserted into the multivariable model, but slightly decreased when ABI (1.31 [1.01-1.72]) or CIMT and ABI (1.29 [0.99-1.68]) were included. Although CAC alone did not significantly elevate the area under the curve in Harrell's c-statistics (by 0.009; P=0.379) in addition to established risk factors, the combination of CAC and ABI increased area under the curve (by 0.029; P=0.047), as did ABI (by 0.025; P=0.038) but not CIMT (by 0.002; P=0.795) alone. The combination of CAC and ABI also resulted in significant category-free net reclassification and integrated discrimination improvement.

Conclusions: CAC, CIMT, and ABI provide complementary information about stroke risk. ABI, which is distinctive in a small subpopulation, had the highest and CIMT, which is distributed across a larger range of values, had the lowest predictive value.

Keywords: carotid atherosclerosis; coronary artery disease; peripheral arterial disease.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Ankle Brachial Index*
Area Under Curve
Calcinosis / diagnostic imaging
Calcinosis / physiopathology*
Carotid Intima-Media Thickness*
Coronary Artery Disease / physiopathology*
Coronary Vessels / diagnostic imaging
Coronary Vessels / physiopathology*
Female
Humans
Incidence
Male
Middle Aged
Predictive Value of Tests
Proportional Hazards Models
Risk Factors
Stroke / diagnosis*
Stroke / diagnostic imaging
Stroke / physiopathology*
Tomography, X-Ray Computed