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.

BACKGROUND: 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. METHODS: Clinical and biochemical data were prospectively recorded on all inpatients at Wollongong Hospital, NSW, Australia, 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 with a baseline cohort of HF inpatients in whom TTE requirement was not guided by NT-proBNP. RESULTS: 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. CONCLUSIONS: 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.