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.