Prognostic impact of plasma volume estimated from hemoglobin and hematocrit in heart failure with preserved ejection fraction

Background: Plasma volume (PV) estimated from Duarte's formula (based on hemoglobin/hematocrit) has been associated with poor prognosis in patients with heart failure (HF). There are, however, limited data regarding the association of estimated PV status (ePVS) derived from hemoglobin/hematocrit with clinical profiles and study outcomes in patients with HF and preserved ejection fraction (HFpEF).

Methods and results: Patients from North and South America enrolled in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial (TOPCAT) with available hemoglobin/hematocrit data were studied. The association between ePVS (Duarte formula and Hakim formula) and the composite of cardiovascular mortality, HF hospitalization, or aborted cardiac arrest was assessed. Among 1747 patients (age 71.6 years; males 50.1%), mean ePVS derived from Duarte formula was 4.9 ± 1.0 mL/g. Higher Duarte-derived ePVS was associated with prior HF admission, diabetes, more severe congestion, poor renal function, higher natriuretic peptide level, and E/e'. After adjustment for potential covariates including natriuretic peptide, higher Duarte-derived ePVS was associated with an increased rate of the primary outcome [highest vs. lowest ePVS quartile: adjusted-HR (95%CI) = 1.79 (1.28-2.50), p < 0.001]. Duarte-derived ePVS improved prognostic performance on top of clinical and routine variables (including natriuretic peptides) (NRI = 11, p < 0.001), whereas Hakim-derived ePVS did not (p = 0.59). The prognostic value of Duarte-derived ePVS was not modified by renal function (P interaction > 0.10 for all outcomes).

Conclusion: ePVS from Duarte's formula was associated with congestion status and improved risk stratification regardless of renal function. Our findings suggest that Duarte-derived ePVS is a useful congestion variable in patients with HFpEF.