Aims The prognostic significance of polycythemia in acute decompensated heart failure (ADHF) is unclear. This study aimed to evaluate the clinical profile and prognostic implications of polycythemia compared with anemia and normocythemia in patients hospitalized with ADHF. Materials and methods We retrospectively analyzed adult patients hospitalized with ADHF between 2007 and 2017. Patients were categorized by hemoglobin according to World Health Organization criteria: anemic (18.5 g/dL men, > 16.5 g/dL women). Mahalanobis distance matching (MDM; 1:3:3) balanced baseline characteristics, with outcomes compared for in-hospital mortality, 30-day readmission, and long-term survival. Entropy balancing (EBAL) served as sensitivity analysis in the full cohort. Results Of 8,332 patients, 5,615 (67.4%) were anemic, 2,639 (31.7%) normocythemic, and 78 (0.9%) polycythemic. Polycythemic patients were younger, predominantly male, and more likely to undergo coronary interventions and receive cardioprotective discharge medications. In the matched cohort (N = 546; 234 anemic, 234 normocythemic, 78 polycythemic), in-hospital mortality rates were similar (5.6%, 3.8%, 7.7%; p = 0.381). One-year mortality was highest in anemia (27.4%) vs. normocythemia (17.5%) and polycythemia (19.2%; p = 0.030). Five-year Kaplan–Meier survival was poorest in anemia, with overlapping curves for polycythemia and normocythemia (log-rank p = 0.027). Cox analysis (reference = normocythemia) showed higher mortality with anemia (HR 1.30, 95% CI 1.03–1.63) but not polycythemia (HR 0.90, 95% CI 0.64–1.27). Post-hoc pairwise log-rank tests (Bonferroni-corrected) confirmed no difference between polycythemia and normocythemia. EBAL-weighted analysis yielded consistent results (log-rank p < 0.001; anemia HR 1.76, 95% CI 1.61–1.92; polycythemia HR 1.14, 95% CI 0.83–1.57). Conclusions Polycythemia is rare in hospitalized ADHF and, unlike anemia, is not associated with adverse short- or long-term outcomes.
Perets et al. (Mon,) studied this question.