BOCA RATON, FLA. — Heart failure patients who had either low or very high hemoglobin levels had increased in-hospital mortality and decreased 1-year survival in a study of nearly 3,000 patients.
It is well accepted that anemia adversely affects outcome in heart failure patients, but how high hemoglobin levels might influence the disease course is not well established, Kismet Rasmusson said in an interview at the annual meeting of the Heart Failure Society of America.
“Anemia has become more recognized and more prevalent in heart failure,” said Ms. Rasmusson, a family nurse-practitioner in the Heart Failure Prevention and Treatment Program, LDS Hospital, Salt Lake City, during a poster presentation. “It's important to know how to screen and treat patients not just for heart failure, but for their comorbidities.”
Ms. Rasmusson and her associates used ICD-9 codes to identify 2,816 patients with a primary diagnosis of heart failure from a 20-hospital integrated health care system database. All the patients in the study had a left ventricular ejection fraction of 40% or less; 48% were men.
“This was not a clinical trial setting. These are real patients out in the community,” Ms. Rasmusson said.
The researchers compared mortality rates in patients grouped by their first hemoglobin measure: low (below 12.5 g/dL), normal (12.5–13.5 g/dL), high (13.6–15.3 g/dL), or extremely high (greater than 15.3 g/dL).
“The extremes—very low and very high—had an increased risk of mortality,” Ms. Rasmusson said.
After adjustment for age, gender, and severity of heart failure, the extremely high hemoglobin group had the greatest risk of in-hospital mortality (odds ratio 3.15). The low-hemoglobin group had an increased risk as well (OR 1.96). Both these findings were statistically significant, compared with the normal hemoglobin group.
One-year survival was significantly less for patients in the low-hemoglobin group (OR 1.46), compared with those with normal hemoglobin. Patients with a hemoglobin level below 12.5 g/dL made up 44% of the cohort studied.