Increased Mortality and Complication Rates in Weekend Admissions for Acute Decompensated Heart Failure: A Five-Year National Study

Background/Objectives: The “weekend effect,” characterized by increased mortality and complication rates for weekend hospital admissions, is well documented in myocardial infarction and stroke but has been less thoroughly investigated in acute decompensated heart failure (ADHF). This study evaluates the weekend effect in ADHF using a national cohort. Methods: A retrospective cohort study was conducted using the 2016–2020 Nationwide Inpatient Sample (NIS). Adult ADHF admissions were identified by ICD-10 codes and classified as weekend or weekday admissions. Over 30 variables, including age, sex, and comorbidities, were analyzed. Propensity score matching (1:1) yielded 489,204 patients per group. Univariate and multivariate logistic regression models were used to assess outcomes, adjusting for key covariates. Results: Of 2,131,915 ADHF hospitalizations, 501,076 (23.5%) occurred on weekends. The cohort was 48% female, with a mean age of 72 years (SD ± 12.3). After 1:1 matching, weekend admissions had higher odds of cardiac arrest (aOR: 1.10; 95% CI: 1.06–1.13, p < 0.001), inpatient mortality (aOR: 1.07; 95% CI: 1.05–1.09, p < 0.001), acute kidney injury (AKI; aOR: 1.07; 95% CI: 1.06–1.08, p < 0.001), and acute respiratory failure (ARF; aOR: 1.28; 95% CI: 1.27–1.30, p < 0.001). No significant differences were observed in mechanical circulatory support (MCS) use or length of stay. Conclusions: Weekend ADHF admissions were associated with a higher risk of mortality and complications, which may be attributable to reduced specialist availability or delayed diagnostics. These findings underscore the need for standardized ADHF protocols to ensure equitable care throughout the week.