The Relationship Between Anemia, Change in Hematocrit Over Time and Change in Health Status in Patients With Heart Failure After Myocardial Infarction

Abstract

Background Studies have identified anemia as a potential therapeutic target in patients with heart failure, with the goal of improving survival and health status. However, whether changes in hematocrit are associated with changes in health status is unknown. Methods and Results We studied 1382 patients with heart failure after myocardial infarction who had serial hematocrits and health status assessments with the Kansas City Cardiomyopathy Questionnaire (KCCQ). Linear regression models assessed the relationship between change in hematocrit and change in health status between 1 month (baseline) and 3 months after hospitalization. During follow-up, 12.6% of patients experienced a greater than 2% decline in hematocrit, 32.5% experienced a greater than 2% improvement in hematocrit, and 54.9% had no significant hematocrit change. After multivariable adjustment there was a highly significant interaction ( P = .007) between baseline hematocrit and change in hematocrit, suggesting that the effects of changes in hematocrit on health status vary as a function of patients' initial hematocrits. Patients with severe anemia initially (hematocrit ≤ 33%) experienced marked decrements in health status (−4.4 point KCCQ change per 1% hematocrit decline, P = .006) with further declines in hematocrit, but only modest health status gains with hematocrit improvements (0.6 point KCCQ change per 1% hematocrit improvement, P = .3). Less pronounced changes were observed among patients with a baseline hematocrit greater than 33% to 39%, and no significant changes were seen in patients with hematocrit levels greater than 39%. Conclusion Among anemic patients with heart failure, a decrease in hematocrit is associated with marked decline in health status, whereas health status gains associated with hematocrit improvements are modest.