AHA 2008: Microalbuminuria associated with development and progression of coronary calcium

New Orleans-Subjects without symptoms of heart disease who have microalbuminuria are more likely to have coronary artery calcium and are more likely to have progression of coronary artery calcium over time than those without microalbuminuria, says Andrew P. DeFilippis, MD.

As part of the Multi-ethnic Study of Atherosclerosis (MESA), data on urinary albumin creatinine ratio (UACR) were available for 5,666 of the subjects. MESA included Caucasian, African American, Chinese American, and Hispanic ethnicities.

Using computed tomography scans, the incidence of subclinical atherosclerosis was assessed among those not having coronary artery calcium at baseline, and the progression of coronary artery calcium was measured in those who did have it at baseline. The association between microalbuminuria, defined as UACR of 30 to 300 mg/g, and incident coronary artery calcium and progression of coronary artery calcium was assessed.

Some 424 of the 5,666 subjects had microalbuminuria. Those with microalbuminuria were older, more likely to have hypertension, diabetes, and dyslipidemia, and had a lower calculated glomerular filtration rate than those without microalbuminuria. Sixty-two percent of subjects with microalbuminuria had coronary artery calcium at baseline compared with 48 percent without microalbuminuria (P < 0.0001).

At a median follow-up of 2.4 years, microalbuminuria increased the odds of developing coronary artery calcium over the course of the study by 76 percent (P = 0.005), says Dr. DeFilippis, Johns Hopkins Ciccarone Preventive Cardiology Center, Baltimore. When looking at the presence of microalbuminuria as a continuous variable, UACR remained significant as a predictor of the development of coronary artery calcium (P = 0.016).

Among those with coronary artery calcium at baseline, the risk of progression of the disease was nine-fold higher among those with microalbuminuria (P = 0.009). When microalbuminuria was examined as a continuous variable, those with microalbuminuria were three times as likely to have progression of their coronary calcium (P = 0.009).

“Further study is needed to determine the degree to which microalbuminuria precedes and predicts progression of atherosclerosis, and how this information can be used to reduce cardiovascular events,” says Dr. DeFilippis.