Prognostic value of preoperative NT-proBNP in patients with obstructive hypertrophic cardiomyopathy undergoing septal myectomy

Abstract

Background

Proper risk stratification tools for patients with obstructive hypertrophic cardiomyopathy (oHCM) undergoing septal myectomy are lacking. Our objective was to assess the predictive value of preoperative N-terminal pro-brain natriuretic peptide (NT-proBNP) on perioperative outcomes and late survival in patients with oHCM undergoing transaortic septal myectomy.

Methods

Between 2008 and 2021, 834 patients with preoperative NT-proBNP measurements underwent septal myectomy. Restrictive cubic splines, along with multivariable logistic and Cox regression models, were used to examine the association between NT-proBNP and the outcomes. The study endpoints were early postoperative complications (postoperative atrial fibrillation, need for blood transfusion, intensive care unit [ICU] length of stay [LOS], total hospital LOS), and long-term all-cause mortality.

Results

A total of 834 patients were included in the study (median age, 58 [interquartile range (IQR), 48-65] years; 41.8% females). The median NT-proBNP concentration was 698 (IQR, 265-1446) pg/mL. Maximal septal thickness and maximal left ventricular outflow tract gradient, among other echocardiographic parameters, were linearly associated with NT-proBNP concentration (P < .001). Two patients died in the hospital (0.2%). On multivariable analysis, each 1000 pg/mL increase in NT-proBNP was independently associated with a 13% increase in blood transfusions (odds ratio, 1.13; 95% confidence interval [CI], 1.02-1.26), a 2-hour increase in ICU LOS (P < .001), and a 4-hour increase in total hospital LOS. Additionally, every 100 pg/mL increase in NT-proBNP within the range of 0 to 800 pg/mL was independently correlated with a 10% increase in the odds of postoperative atrial fibrillation. NT-proBNP also was associated with long-term mortality (hazard ratio, 1.1; 95% CI 1.04-1.14; P < .001).

Conclusions

Preoperative NT-proBNP has strong, independent associations with early and late outcomes and may be useful in stratifying, managing, and monitoring oHCM patients.