Classification of Heart Failure Events by Severity: Insights From the VICTORIA Trial

Background: Hospitalization due to heart failure (HFH) is a major source of morbidity, consumes significant economic resources and is a key endpoint in HF clinical trials. HFH events vary in severity and implications, but they are typically considered equivalent when analyzing clinical trial outcomes. Objectives: We aimed to evaluate the frequency and severity of HF events, assess treatment effects and describe differences in outcomes by type of HF event in VICTORIA (Vericiguat Global Study in Subjects with Heart Failure with Reduced Ejection Fraction). Methods: VICTORIA compared vericiguat with placebo in patients with HF with reduced ejection fraction (< 45%) and a recent worsening HF event. All HFHs were prospectively adjudicated by an independent clinical events committee (CEC) whose members were blinded to treatment assignment. We evaluated the frequency and clinical impact of HF events by severity, categorized by highest intensity of HF treatment (urgent outpatient visit or hospitalization treated with oral diuretics, intravenous diuretics, intravenous vasodilators, intravenous inotropes, or mechanical support) and treatment effect by event categories. Results: In VICTORIA, 2948 HF events occurred in 5050 enrolled patients. Overall total CEC HF events for vericiguat vs placebo were 43.9 vs 49.1 events/100 patient-years (P = 0.01). Hospitalization for intravenous diuretics was the most common type of HFH event (54%). HF event types differed markedly in their clinical implications for both in-hospital and post-discharge events. We observed no difference in the distribution of HF events between randomized treatment groups (P = 0.78). Conclusion: HF events in large global trials vary significantly in severity and clinical implications, which may have implications for more nuanced trial design and interpretation.