Heart failure is characterized by multiple hospital readmissions and increased risk of death. Our study assesses acute change in NTproBNP (a cardiac biomarker) and its association with readmission and mortality using a parametric analysis. This method allows visualization of the baseline hazard, communication in terms where the metric is time, and can remove the proportional hazards assumption.
Data were analyzed from a cohort of 240 consecutive patients ages 25 and older who were admitted to an urban tertiary care hospital from June 2006 to April 2007 with a primary diagnosis of heart failure and received intravenous furosemide. Creatinine and NTproBNP levels were measured at admission and discharge of the first admission. Patient demographics, comorbidities, and hospital length of stay were collected. Patients were prospectively grouped into two categories based on acute changes in NTproBNP: a decline of =50% or <50% in discharge NTproBNP level as compared to admission. Decision to discharge was independent of NTproBNP. This analysis examined the relative time to readmission in the two NTproBNP groups, accounting for death as a competing event. We examined multiple parametric models with different distributions, graphically compared the survival and parametric distributions, and performed loglikelihood ratio testing to assess the goodness of fit. We selected the most parsimonious, best fit model and performed a competing risks analysis for death.
After excluding patients who died during the initial admission (n=3) or those with incomplete records (n=20), 45% (n=97) and 55% (n=120) had a decline of =50% or <50% in discharge NTproBNP level respectively. Our study population was 50% male and 67% NonWhite with a mean age of 63 years (SD: [pm]14), median creatinine of 1.2 mg/dL [IQR: 1.0, 1.7], median admission NTproBNP level of 5913 pg/mL [1831, 10989], median ejection fraction of 30% [15, 55], and median duration of hospital stay of 5 days [3, 8]. Comorbid medical conditions included hypertension (70%), diabetes (48%), and coronary artery disease (43%). Fortyeight patients died and 86 were readmitted at least once. Rates of readmission and death in the <50% versus =50% groups respectively were 2.0 vs. 1.8 (readmission; p=0.45) and 1.2 vs. 0.4 (death; p=0.003) per 1,000 patientdays. An acute decline in NTproBNP of <50% was associated with sooner readmission (Relative Time: 0.73; 95% CI: 0.36, 1.45; p=0.37) and death (Relative Time: 0.27; 95% CI: 0.09, 0.83; p=0.02) in the fully adjusted model, although only death was statistically significant.
Independent of demographic, clinical and laboratory variables, a decline of <50% in NTproBNP was associated with shorter survival and possibly sooner readmissions as compared to the =50% group. Individuals with <50% change in NTproBNP may benefit from more intensive medical treatment, monitoring, and followup to prevent subsequent readmissions or death.
To cite this abstract:Campbell C, Brotman D, Park H, Michtalik H, Yeh H, Haq N, Clarke W. Acute Changes in Nterminal Probtype Natriuretic Peptide (Ntprobnp) During Hospitalization and Its Association with Time to Readmission and Death in Patients with Heart Failure. Abstract published at Hospital Medicine 2012, April 1-4, San Diego, Calif. Abstract 97645. Journal of Hospital Medicine. 2012; 7 (suppl 2). https://www.shmabstracts.com/abstract/acute-changes-in-nterminal-probtype-natriuretic-peptide-ntprobnp-during-hospitalization-and-its-association-with-time-to-readmission-and-death-in-patients-with-heart-failure/. Accessed July 17, 2019.