Association Between Serum Albumin And Length Of Hospital Stay Among Patients With Acute Heart Failure

Background

Acute heart failure (AHF) is associated with hypoalbuminemia due to a dilution effect from excessive fluid overload. Albumin plays an important role in the improvement of osmotic pressure and hemodynamics. The lower level of serum albumin may cause pulmonary congestion, and myocardial edema, and subsequently deteriorate myocardial dysfunction, diuresis resistance, and fluid retention. The purpose of this study was to assess the association between serum albumin and lengths of hospital stay.

Hypothesis

Our hypothesis was AHF patients with increased albumin might have a shorter length of hospital stay.

Methods

Using Electronic Medical Records, patients admitted from May 2020 through May 2021: aged > 18 years old, ICD-10, and positive Framingham Heart Failure Diagnostic Criteria were included. We excluded patients without albumin records and eGFR less than 30 mL/min/1.73m². Prolonged hospitalization was > 7 days. The length of the hospital stay was right skewed and was corrected with log₁₀ transformation. Descriptive, t-test/Mann-Whitney U test, Chi-square test, and regression were performed.

Results

Among 287 symptomatic patients (New York Heart Association (NYHA) II-IV) aged median 68 years (IQR, 60-78), 60% (n=173) were female, predominantly White (75%, n=208), 61% (175), etiology of ischemic cardiomyopathy, and high comorbid burden measured using Charleston Comorbidity index score [median, IQR (5,4-7)]. One-third (26%, n=74) of the patients had albumin levels < 3.5g/dL. The median length of hospital stay was 7 days (IQR, 4-14). Comparing differences between lengths of hospital stays (< 7 versus > 7 days), there was a statistical difference across systolic BP (133 vs 124, p=0.007), diastolic BP (78 vs 72, p=0.01), NT-ProBNP (4188 vs 6441, p=0.006), albumin (3.9 vs3.6, p=<0.001), hemoglobin (12 vs 11, p=0.03), hematocrit (39 vs 37, p=0.03) and LVEF (43 vs 32, p=0.04). In the linear regression model, there was a collective significant effect between the age, sex, serum albumin, systolic BP, and length of hospital stay (F (4,280) =10.97, p<0.001, R²=0.12). The individual predictors included increased systolic BP (t=-4.9, 95% CI: -0.005 to -0.002, p=<0.001) and higher serum albumin (t=-5.06, 95% CI: -0.27 to -0.12, p=<0.001) which were significant predictors of decreased length of hospital stay.

Conclusion

Increased serum albumin and systolic BP were associated with a decreased hospital stay. Early correction of serum albumin and control of systolic blood pressure at the ED might prevent hospital admission and longer hospital stay.