CT Scans Assess Heart Disease Risk in Kidney Disease Patients

Using CT scans to measure calcium levels, researchers at Johns Hopkins Bloomberg School of Public Health say that calcium buildup in the coronary arteries of chronic kidney disease (CKD) patients may be a strong indicator of heart disease risk, according to a new study in the Journal of the American Society of Nephrology.

Researchers assert that coronary calcium outperforms two other commonly used measures of subclinical atherosclerosis in predicting the risk of heart disease among individuals with kidney disease.

Approximately 50% of all patients with CKD die from cardiovascular disease, but some previous studies concluded that conventional risk factors for predicting heart disease, such as blood pressure and lipid levels, were not as useful in CKD patients. 

Kunihiro Matsushita, MD, PhD, an assistant scientist in the Bloomberg School’s department of epidemiology, and his colleagues investigated whether other tests might be more helpful in predicting cardiovascular disease in CKD patients. They compared three measures of atherosclerosis: calcium levels within blood vessel walls, the thickness of the carotid artery walls, and the narrowing of arteries in the legs. Although the amount of coronary calcium is a potent predictor of heart disease in the general population, Matsushita says it wasn’t clear whether it would be as useful in people with CKD. The kidneys help regulate the body’s calcium levels, and individuals with CKD often have an altered calcium metabolism, which researchers were concerned could influence the usefulness of calcium in the coronary artery walls as a predictor of heart disease.

The 6,553 adults in the multiethnic study of atherosclerosis were between ages 45 and 84 and did not have prior cardiovascular disease; 1,284 of them had CKD. After about eight years, 650 cardiovascular events (coronary heart disease, stroke, heart failure, and peripheral artery disease) had occurred, with 236 of the events occurring in those with CKD. The researchers determined that calcium buildup was more accurate in determining CKD patients’ risk of cardiovascular disease (especially coronary heart disease and heart failure) than measures of thickening of the carotid artery walls or narrowing of arteries in the legs.