Effective blood hemoglobin level to predict prognosis in heart failure with preserved left ventricular ejection fraction: results of the Japanese heart failure syndrome with preserved ejection fraction registry

High prevalence of anemia in heart failure with preserved left ventricular ejection fraction (HFpEF) has been reported. However, little is known about the association of anemia and gender with prognosis in HFpEF patients. In addition, effective blood hemoglobin (Hb) level for prognosis in HFpEF patients remains largely unknown. In this study, we investigated the association between anemia, gender, and prognosis in 535 HFpEF patients enrolled in Japanese heart failure syndrome with preserved ejection fraction registry. Furthermore, we assessed effective blood Hb level to predict prognosis in HFpEF patients. According to the World Health Organization criteria, the prevalence rate of anemia on admission was about 70% in both male and female HFpEF patients. Kaplan-Meier analysis for all-cause mortality demonstrated that anemic patients had poor prognosis compared with non-anemic patients in both male and female HFpEF patients. Interestingly, multivariate analysis revealed that blood Hb level at discharge was an independent predictor of all-cause mortality in both male and female HFpEF patients. According to survival classification and regression tree analysis, blood Hb level at discharge of 9.4 g/dL for male and 12.3 g/dL for female was more accurate cutoff value to predict all-cause mortality in HFpEF patients. Anemia was implicated in poor prognosis in both male and female HFpEF patients. In particular, blood Hb level at discharge was an independent predictor of all-cause mortality in both male and female HFpEF patients. Effective cutoff value of blood Hb level at discharge to predict all-cause mortality was lower in male than in female HFpEF patients.