Anemia, CKD are cardiac risk factors

Two studies confirm that chronic kidney disease (CKD) is associated with coronary heart disease (CHD) and its severity. In one of the studies, anemia was also a predictor of CHD and its severity.

In one study of 1,580 patients with suspected CHD who underwent clinical evaluation and myocardial perfusion imaging, those with both anemia and CKD were more than twice as likely to have perfusion defects than patients with normal hemoglobin levels and renal function, reported Jeffrey R. Cook, MD, from the University of Wisconsin, Madison.

Myocardial perfusion defects were discovered in 48% of those with no anemia or CKD, 65% of those with CKD but no anemia, 59% of those with anemia but no CKD, and 72% of those with both anemia and CKD.

An abnormal perfusion scan, as defined by a mean summed stress score ≥4, was also more prevalent in patients with both anemia and CKD than the other groups, indicating more severe CHD.

A high-risk scan-as determined by a summed stress score ≥8, transient ischemic dilation, or a left ventricular ejection fraction ≤40%-was present in 48% of those with combined anemia and CKD compared with 28% with neither anemia nor CKD, and about 38% with either anemia or CKD.

"Anemia alone appears to confer a similar risk of abnormal or high-risk scans compared to patients with CKD alone," Dr. Cook said.

In the second study, 2,114 high-risk asymptomatic patients with an occluded coronary artery who were enrolled in a study comparing percutaneous coronary intervention with medical therapy were grouped into CKD stages by their glomerular filtration rate (stage 1:≥90 mL/min; stage 2: 60 to 89 mL/min; stage 3: 30 to 59 mL/min; stage 4: 15 to 29 mL/min).

The prevalence of heart failure increased as the CKD stage increased, said lead investigator Vinod Jorapur, MD. Heart failure was present in 15.5% of patients with stage 1 CKD, 18.0% with stage 2 CKD, and 29.3% with stage 3 or stage 4 CKD.

"The magnitude of the difference was greater in patients with preserved ejection fraction than in patients with depressed ejection fraction," Dr. Jorapur said.