Increase in N-terminal fragment of the prohormone brain-type natriuretic peptide as a measure for predicting outcome after urgent heart transplantation

OBJECTIVE: When candidates in urgent status for heart transplantation (HTx) show high levels of N-terminal brain-type natriuretic peptide (NT-proBNP), the prognosis of the patients is poor. However, identification of these high-risk patients is a matter for discussion. We investigated increase of NT-proBNP after listing with Eurotransplant for urgent HTx as a measure to predict outcome after HTx. METHODS: Plasma NT-proBNP was measured before and after urgency listing in 72 HTx candidates who did not receive mechanical circulatory support. The ratio of the increase in maximal value of NT-proBNP after the urgency listing compared with that before the urgency listing was defined as delta max NT-proBNP. When the cut-off value for this parameter was determined as 20%, 23 patients were assigned to the group with an increase in maximal NT-proBNP value after urgency listing (group INC) and the rest to group NON (n=49). We evaluated the over 20% increase in maximal NT-proBNP value after urgency listing as a prognostic factor after urgent HTx. RESULTS: Actuarial survival in group INC was significantly worse than in group NON (p=0.040). The 30-day mortality rate after HTx in group INC was significantly higher than in group NON (39.1% vs 12.2%, p=0.013). Incidence of infection and frequency of prolonged mechanical respiratory support (longer than 4 days) were significantly higher in group INC than in group NON (60.9% vs 18.4%, p=0.0008, 91.3% vs 55.1%, p=0.0027, respectively). Univariate Cox regression analysis demonstrated that the over 20% increase in maximal NT-proBNP value after urgency listing, age at HTx and donor age were significant risk factors for mortality. Multivariate Cox regression analysis revealed that the over 20% increase in maximal NT-proBNP value was the sole significant risk factor for mortality (hazard ratio 2.441, 95% confidence interval 1.061-5.618, p=0.036). CONCLUSIONS: Patients with over 20% increase in the maximal NT-proBNP value after urgency listing are at higher risk for post-HTx mortality and complications. Ventricular assist device (VAD) implantation may be a socially valid approach in these patients.