Relationship of red blood cell mass profiles and anemia type to outcomes and cardiopulmonary exercise performance in chronic heart failure.

BACKGROUND

Blood volume analysis (BVA) allows direct measurement of red blood cell mass (RBCM) and differentiation of true and dilutional anemia in heart failure (HF). This study aimed to characterize the relationships of RBCM profiles and anemia types to HF outcomes and cardiopulmonary exercise test (CPET) parameters.

METHODS

Chronic stable HF patients were prospectively enrolled. All patients underwent BVA; a subset underwent supine invasive CPET within 24 hours of BVA. RBCM profiles were defined using RBCM %deviation (deficit: <-10%, normal: -10 to 10%, excess: >10%). Anemia defined by World Health Organization criteria alone was categorized using RBCM %deviation (<-10% true anemia, ≥-10% dilutional pseudo-anemia). HF hospitalization at 6 months and CPET parameters were compared among RBCM profiles and anemia types.

RESULTS

One-hundred twenty patients (58 years, 40% female, 41% Black, 63% HFrEF) were enrolled. Forty percent had RBCM deficit, 37.5% had normal RBCM, and 22.5% had excess RBCM. Fifty-eight patients (48%) were anemic: 60% true anemia and 40% dilutional pseudo-anemia. Patients with dilutional pseudo-anemia had a higher incidence of HF hospitalization (44.8%) compared to no anemia (22.7%) and true anemia (20.6%) (P = .040). There was no difference in HF hospitalization among RBCM profiles (P = .99). There was a nonsignificant trend toward worse peak VO2 in RBCM deficit and true anemia, with no differences in other CPET parameters.

CONCLUSIONS

Dilutional pseudo-anemia demonstrated higher HF hospitalizations compared to true anemia, while true anemia had a trend towards worse peak VO2. The implications of BVA-identified RBCM profiles and anemia types for clinical management warrant further investigation.