Serum Vitamin D Levels Predict 30-Day Readmission Rate and Length of Stay in Hospitalized Patients with an Acute Heart Failure Syndrome Due to Reduced Ejection Fraction

Introduction: More than 90% of patients with heart failure with reduced ejection fraction (HErEF) are vitamin D deficient. Lower vitamin D levels have been linked to higher NYHA classes and increased mortality among HFrEF patients. However, data on the relationship between serum vitamin D level and hospitalization are scarce. Our study aims to assess the association of serum vitamin D level with 30-day readmission rate and length of stay (LOS) in patients with acute heart failure (AHF) syndrome due to HFrEF. Methods: A retrospective, single-center study of 2,087 patients admitted between January 1, 2005 and December 31, 2014 for an AHF syndrome was performed. Patients without a vitamin D level or measured as 25-dihydroxyvitamin D (25[OH]D were excluded from our study. 25(OH)D deficiency was defined by having serum concentration levels of less than 20 ng/mL. Normal levels were defined as ≥30 ng/mL. We assessed levels of 25(OH)D in relation to predicting the 30-day readmission rate, length of stay (LOS) and mortality rate. Results: Among the 2,087 patients admitted to our hospital for an AHF syndrome, 180 patients had a history of HFrEF and documented levels of vitamin D, of which 42 patients (23.3%) had normal 25(OH)D levels, 83 patients (46.1%) had 25(OH)D deficiency and 55 patients (30.6%) had 25(OH)D insufficiency. The average age of the patients admitted for an AHF syndrome was 62.7 years in HFrEF-25(OH)D deficiency group versus 69.9 years in HFrEF-normal 25(OH)D level (P = .007). After standardizing medical therapy in each group, the 30-day readmission rate among HFrEF-25(OH)D deficiency was 40% versus 16.6% in HFrEF-normal 25(OH)D level (Odds ratio (OR) 3.4, 95% CI: 1.3–9.3, P = .01). Average LOS among HFrEF-25(OH)D deficiency group was 8.2 days versus 4.1 days in HFrEF-normal 25(OH)D level (P = .04). Mortality rate did not differ between the two groups. Subgroup analysis among HFrEF-25(OH)D deficiency, average age during the AHF syndrome admission was 60.1 years among male patients versus 67 years in female patients (P = .04). Furthermore, female patients had a higher 30-day readmission rate compared to male patients (26.7% vs 11.8%) with a trend toward statistical significance (P = .07). LOS did not differ between the male and female subgroups (P = .8). Conclusions: Vitamin D deficiency seems to be a significant independent predictor for an early age of hospitalization, 30-day readmission rate and LOS among HFrEF patients admitted for an AHF syndrome. Further studies are warranted to evaluate vitamin D supplementation on patient outcomes.