Early discharge after clinical stabilization in acute decompensated heart failure: associations with short-term outcomes.

Abstract

Background: Hospital length of stay (LOS) in acute decompensated heart failure (ADHF) lacks standardized thresholds. Prior studies using administrative data have reported neutral all-cause outcomes with very short hospital stays (1-2 days) despite higher cardiovascular readmissions, raising concerns about residual confounding from unmeasured clinical severity.

Methods: This is a retrospective cohort study of adults (≥ 18 years) hospitalized with ADHF at a single center in Israel between 2007 and 2017. We excluded in-hospital deaths and coronary artery bypass grafting (CABG) surgery cases. LOS was categorized as short (1-2 days), standard (3-6 days, reference), or prolonged (≥ 7 days).

Primary outcome: 30-day all-cause readmission or mortality. Cox models adjusted for age, sex, ischemic heart disease, atrial fibrillation, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, and anemia. Restricted cubic splines with three knots at approximately the 10th, 50th, and 90th percentiles modeled continuous LOS, using 5 days as reference.

Results: Among 8332 patients with first ADHF hospitalization, 7455 were analyzed after excluding 707 in-hospital deaths and 170 CABG cases. Distribution by LOS: 1072 short (14.4%), 3457 standard (46.4%), 2926 prolonged (39.2%). Patients with a short LOS were younger (median 75 vs. 78 and 79 years), less often female, and had lower CKD (29.9% vs. 33.5% and 35.2%) and anemia (61.9% vs. 65.0% and 70.2%; all p ≤ 0.006), with favorable discharge labs. Unadjusted 30-day composite rates were 19.9% (short), 21.6% (standard), and 28.6% (prolonged; p < 0.001). Adjusted HR for short vs. standard: 0.86 (95% CI 0.73-1.02, p = 0.081); prolonged vs. standard: 1.37 (95% CI 1.23-1.52, p < 0.001). Spline analysis showed a J-shaped curve: protective effect (HR < 1.0) for LOS 2-5 days, risk rising significantly beyond 6 days.

Conclusion: In a clinically detailed ADHF cohort, discharge after 1-2 days was not associated with higher 30-day readmission or mortality among patients selected for early discharge. In contrast, prolonged hospitalization identified a subgroup at substantially higher short-term risk, underscoring hospital length of stay as a marker of clinical complexity rather than a determinant of outcomes.