Introduction: Hospital readmission for heart failure (HF) is an increasingly important quality metric; influenced by clinical status, but also by socioeconomic issues, caregiver assistance, and medical complexity. Early readmission for HF within 30 days of initial hospital discharge, is a focus of medical management and cost containment for hospitals, and a deleterious outcome for patients.Hypothesis: Plasma b-type natriuretic peptide (BNP) is historically used to identify HF in patients presenting to the emergency department (ED) with acute symptomatic dyspnea. Novel biomarkers, such as matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), cytokines, and vascular growth factors (i.e. VEGF) may be reflective of a high-risk HF phenotype, and may be useful to identify patients at increased risk of readmission.
Methods: We performed a prospective analysis of 730 patients that presented to the ED of two major US academic medical centers. Of the 730 patients, 590 patients were adjudicated for a HF diagnosis at the initial evaluation (HF not present, HF present but not primary diagnosis, or HF primary diagnosis) and a readmission outcome (no readmission in 30 days or readmission in 30 days). The association between biomarkers and 30-day readmission was tested using a logistic regression model adjusting for other known markers of risk including; patient age, cardiac troponin, BNP, serum Cr, hematocrit. To examine the model’s discrimination ability, concordance statistics (C-statistics) were calculated.
Results: 59 patients (10%) had a 30 day HF readmission. Patient age (P=NS) was not associated with 30 day HF readmission, but BNP (P=0.003), serum Cr (P=0.006), MMP-7 (P=0.002), MMP-8 (P=0.02), MMP-13 (p=0.02), and IL-6 (P=0.02) were. The baseline model had good discriminating ability for 30 day HF readmissions (C = 0.685). Adding TIMP-1, increased model performance (C = 0.707), as did a model including MMP-1, IL-6, and VEGF receptor 3 (C=0.74).
Conclusions: A biomarker logistic regression model demonstrated ability to predict 30 day HF readmissions in patients with an initial ED presentation for dyspnea. Combined with clinical evaluation, novel biomarkers may identify patients at risk for HF readmission.