New-onset anemia and its association with ventricular arrhythmias and sudden cardiac death in patients with heart failure with preserved ejection fraction.

Background: Anemia is a common comorbidity associated with adverse outcomes in patients with heart failure with preserved ejection fraction (HFpEF). However, the clinical relevance of new-onset anemia to sudden cardiac death (SCD) in patients with HFpEF remains unclear. This study investigated the association between new-onset anemia with ventricular arrhythmias (VAs) and SCD. Methods: Anemia was defined as a hemoglobin (Hb) level of <13 g/dL in men and <12 g/dL in women. Patients with Hb levels above these thresholds were categorized as without anemia. We analyzed data of 686 patients with symptomatic HFpEF (ejection fraction ≥ 50 %, New York Heart Association class II-IV) without anemia at baseline from a multicenter prospective observational CHART-2 study. The primary endpoint was a composite of ventricular tachycardia, ventricular fibrillation, and SCD. Results: At the 1-year follow-up, 109 patients developed new-onset anemia (median Hb, 11.9 g/dL), whereas 577 remained without anemia (median Hb, 14.0 g/dL). Over a median follow-up of 9.2 years, patients with new-onset anemia had a significantly higher incidence of composite outcomes (12.8 % vs. 5.2 %, P = 0.008). After adjusting for potential confounders, new-onset anemia was associated with an elevated risk of the composite outcome (adjusted hazard ratio 2.20, 95 % confidence interval 1.10-4.42, P = 0.027). The association between new-onset anemia and lethal arrhythmias was independent of heart failure hospitalization or myocardial infarction occurring before the primary endpoint. Conclusions: New-onset anemia was significantly associated with an increased risk of VAs and SCD in patients with HFpEF, underscoring the importance of monitoring Hb levels for risk stratification.