Background: We compared 1) monthly rates of hospitalizations by disease severity and heart failure types, 2) measures of in-hospital care process, 3) and 30-day clinical outcomes of patients with acute decompensated heart failure (ADHF) hospitalized during COVID-19 pandemic with those admitted in pre-pandemic periods.

Methods: Retrospective study of 8989 ADHF hospitalizations (6769 unique patients, mean age 74 years, men 56%) at Mayo Clinics in Arizona, Florida, and Minnesota, Oct 2018 – Oct 2020. Study population were divided into two timeframes: COVID-19 pandemic (Mar- Oct 2020), pre-COVID-19 comparison period (Oct 2018 – Feb 2020). A control group representing corresponding calendar months in 2019 (Mar – Oct 2019) was used as an additional comparator for sensitivity analysis. Study was approved by institutional review board (IRB ID 20-004920). A metanalysis (PROSPERO ID: 292697) of comparative studies on ADHF hospitalization in COVID-19 vs pre-COVID-19 periods was conducted.

Results: Comparative data for study time frames are presented as COVID-19 pandemic (Mar – Oct 2020) vs pre-COVID-19 control (Oct 2018 – Feb 2020). Mean age was lower, 73.7 vs 74.2 y(P= 0.006) whereas sex, race, marital status, body mass index, were similar; prevalence of atrial fibrillation, coronary artery disease, cancer, dementia, dyslipidemia, hypertension, or other psychiatric illnesses was lower (Odds ratio [OR] 0.49 – 0.90) and diabetes mellitus was higher (OR 1.17). PRIMARY OUTCOMES: decreased 30-day all-cause readmissions 10% vs 13% (relative risk reduction [RRR] 23%, number needed to avoid (NNA) one additional readmission 33.3, HR 0.77, 95% CI 0.66 – 0.89), increased all-cause mortality 11.3% vs 9.7% (relative risk increase [RRI] 16%, number of admissions needed for one additional death 62.5; HR 1.19, 95% CI 1.02 – 1.39). SECONDARY OUTCOMES: Higher percentage of admissions to family medicine (OR 1.31) and other specialty services (OR 5.75). Guideline-directed medical or surgical therapy remained unchanged except for increased prescription rates for statins (OR 1.27) and anticoagulants (1.14) and a decreased incidence of valve surgery (OR 0.71); incidence of shock and myocardial infarction remained comparable, but in-hospital mortality was decreased, 2.3% vs 3.4% (OR 0.58, 95% CI 0.50 – 0.92); More patients were discharged to home with selfcare driven by decreased discharges to other destinations. METANALYSIS: search thorough October 2021 yielded 1682 citations of which 17 cohort studies with 67039 participants. The metanalysis of 3 studies including our study data showed an 18% increased 30-day mortality after index ADHF hospitalization in COVID-19 pandemic (OR 1.18, 95% CI interval 1.03 – 1.34, P 0.14, I2 48%, n = 46246).

Conclusions: In COVID-19 pandemic, compared with pre-pandemic period, a significant reduction in readmission rate potentially had unintended consequence of increased 30-day all-cause mortality after index hospitalization for ADHF, a finding partly supported by metanalysis data. A decline in monthly ADHF hospitalizations for ADHF in pandemic could be attributed to prioritization of elderly with high burden of comorbidities not to seek hospital admission in COVID-19 pandemic. Despite unprecedented reconfiguration of healthcare delivery and changing heart failure phenotype, overall adherence to guideline-directed interventions were broadly comparable with even favorable in-hospital clinical outcome in COVID-19 pandemic compared to pre-pandemic period.

IMAGE 1: Figure 1. Kaplan-Meier estimates of readmission and mortality at 30-day followup startified by COVID-19 and pre-COVID-19 time frames

IMAGE 2: Figure 2. Cox regression analysis with forest plot, hazard ratios and 95% confidence intervals for readmisison and mortality across time frames