N-Terminal Pro B-Type Natriuretic Peptide as a Screening Tool for Inpatient Echocardiogram Requirement Among Patients With Suspected Heart Failure: Using NT-proBNP to Reduce Hospital Length of Stay.

Abstract

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker with diagnostic and prognostic utility in patients with heart failure (HF). Whether NT-proBNP can be used to triage inpatient transthoracic echocardiogram (TTE) requirements, and whether this impacts hospital length of stay (LOS), is not clear. Clinical and biochemical data were prospectively recorded on all inpatients at The Wollongong Hospital who had a TTE ordered for suspected HF over a 6-month period. NT-proBNP was used to triage TTE priority, where high-priority inpatient TTE, lower-priority inpatient TTE and outpatient (OP) TTE were performed for serum NT-proBNPs of ≥900, 300-899 and <300, respectively. Outcomes were compared to a baseline cohort of HF inpatients in whom TTE requirement was not guided by NT-proBNP. A total of 236 patients were evaluated-31, 31, and 174 in the low, intermediate and high NT-proBNP cohorts, respectively, and 199 patients were in the baseline cohort. Average hospital LOS was significantly reduced in the study cohort compared to baseline (9.97 vs 13.87 days, p<0.001). Of the 31 patients with a very low NT-proBNP who were discharged for OP TTE, seven were readmitted within 30 days, though none were HF-related. There were no deaths at 30 days in the low or intermediate NT-proBNP groups. Using NT-proBNP to triage requirements for inpatient TTE reduces hospital LOS. A very low NT-proBNP may help identify which patients with suspected HF can be safely discharged for OP TTE.