NEW ORLEANS — Poor kidney function is the strongest indicator for anemia in patients with heart failure, according to the results of a large study in HMO patients.
A reduced glomerular filtration rate emerged as the strongest risk factor for developing anemia in 41,754 heart failure (HF) patients free of anemia at baseline, Alan S. Go, M.D., reported at the annual scientific sessions of the American Heart Association.
Anemia was a common occurrence in this HMO population with HF, with an incidence of 9% per year, according to Dr. Go of Kaiser Permanente of Northern California, Oakland. The study featured nearly 83,000 person-years of follow-up.
Chronic renal impairment is extremely common among HF patients. Roughly 40% of patients had a baseline glomerular filtration rate of less than 60 mL/min per 1.73 m2. The risk of developing anemia during follow-up was proportionate to their degree of baseline renal impairment.
Heart failure patients with an estimated GFR of 45–59 mL/min per 1.73 m2 were 34% more likely to become anemic than were those with a GFR of 60 or more. Those with a GFR of 30–44 had a more than twofold increased incidence of anemia, while patients with a GFR of 15–29 were at more than fourfold increased risk.
Among those patients with a baseline GFR less than 15 mL/min per 1.73 m2 who weren't on dialysis, the incidence of anemia during follow-up was more than eight times greater than in patients with a GFR of at least 60. In those on dialysis, the rate increased nearly fivefold.
Other independent predictors of the development of anemia in a multivariate analysis included cirrhosis, with an adjusted 2.3-fold relative risk, compared with noncirrhotic patients, and HIV infection, which conferred an 80% increase in risk. African descent and age greater than 70 years were each associated with a 40% increased risk of becoming anemic, he said.