Impact of COVID-19 in patients with heart failure with mildly reduced or preserved ejection fraction enrolled in the DELIVER trial.

Aim: COVID-19 may affect clinical risk in patients with heart failure. DELIVER began before and was conducted during the COVID-19 pandemic. This study aimed to evaluate the association between COVID-19 and clinical outcomes among DELIVER participants.

Methods and results: Participants with chronic heart failure with mildly reduced or preserved ejection fraction (HFmrEF/HFpEF) were randomized to dapagliflozin or placebo across 350 sites in 20 countries. COVID-19 was investigator-reported and the contribution of COVID-19 to death was centrally adjudicated. We assessed (i) the incidence of COVID-19, (ii) event rates before/during the pandemic, and (iii) risks of death after COVID-19 diagnosis compared to risks of death in participants without COVID-19. Further, we performed a sensitivity analysis assessing treatment effects of dapagliflozin vs. placebo censored at pandemic onset. Of 6263 participants, 589 (9.4%) developed COVID-19, of whom 307 (52%) required/prolonged hospitalization. A total of 155 deaths (15% of all deaths) were adjudicated as definitely/possibly COVID-19-related. COVID-19 cases and deaths did not differ by randomized assignment. Death rate in the 12 months following diagnosis was 56.1 (95% confidence interval [CI] 48.0-65.6) versus 6.4 (95% CI 6.0-6.8)/100 participant-years among trial participants with versus without COVID-19 (adjusted hazard ratio [aHR] 8.60, 95% CI 7.18-10.30). Risk was highest 0-3 months following diagnosis (153.5, 95% CI 130.3-180.8) and remained elevated at 3-6 months (12.6, 95% CI 6.6-24.3/100 participant-years). After excluding investigator-reported fatal COVID-19 events, all-cause death rates in the 12 months following diagnosis among COVID-19 survivors (n = 458) remained higher (aHR 2.46, 95% CI 1.83-3.33) than rates for all trial participants from randomization, with censoring of participants who developed COVID-19 at the time of diagnosis. Dapagliflozin reduced cardiovascular death/worsening HF events when censoring participants at COVID-19 diagnosis (HR 0.81, 95% CI 0.72-0.91) and pandemic onset (HR 0.72, 95% CI 0.58-0.89). There were no diabetic ketoacidosis or major hypoglycaemic events within 30 days of COVID-19.

Conclusion: DELIVER is one of the most extensive experiences with COVID-19 of any cardiovascular trial, with >75% of follow-up time occurring during the pandemic. COVID-19 was common, with >50% of cases leading to hospitalization or death. Treatment benefits of dapagliflozin persisted when censoring at COVID-19 diagnosis and pandemic onset. Patients surviving COVID-19 had a high early residual risk.

Clinical trial registration: ClinicalTrials.gov Identifier NCT03619213.