(CCSP120) THE USE OF PRE-OPERATIVE NT-PROBNP/B-TYPE NATRIURETIC PEPTIDE FOR RISK STRATIFICATION IN CARDIAC SURGERY PATIENTS

Background: Brain/B-type natriuretic peptide (BNP) and NT-proBNP are released by ventricular myocytes during cardiac stress. Elevated NT-proBNP has been associated with adverse outcomes in patients with heart failure, acute coronary syndrome, and undergoing major non-cardiac surgery. Few studies have looked at the prognostic value of NT-proBNP in cardiac surgery patients. The purpose of the study was to determine if preoperative NT-proBNP could be used to risk stratify patients undergoing cardiac surgery.

METHODS AND RESULTS: All patients undergoing first time, non-emergent CABG and/or valve surgery between November 2021 and July 2022 were considered. Patients were excluded if a preoperative NT-proBNP value could not be obtained. Receiver operating characteristic (ROC) curve analysis was used to evaluate preoperative NT-proBNP as a predictor of an in-hospital composite outcome. Youden’s index was used to determine optimal cut point and define two groups: “elevated” and “low” preoperative NT-proBNP. Unadjusted comparisons were made on the basis of baseline and intraoperative variables, and in-hospital outcomes. The independent effect of preoperative NT-proBNP on the composite outcome was determined using multivariable regression modeling.

A total of 324 patients were included. NT-proBNP, as a predictor of the composite outcome, exhibited an AUC of 0.65 (95% CI: 0.60–0.71). 153 ng/l was determined as the optimal cut point and used to stratify patients into two groups: low (n=110) and elevated (n=214) (Figure 1). Preoperatively, elevated patients had increased rates of atrial fibrillation (1.8% vs. 8.4%, p= 0.026), cerebrovascular disease (1.8 vs. 8.4, p=0.026), NYHA class IV symptoms (35.5 vs. 47.7, p=0.048), and ejection fraction (LVEF) < 40% (2.7 vs. 17.8, p < 0.0001). Patients with elevated NT-proBNP underwent more isolated valve procedures (12.7 vs. 32.7, p=0.001) and had increased inotropic support following surgery (5.5 vs. 17.3, p=0.003). Rate of in-hospital outcomes were significantly higher in elevated NT-pro BNP patients (Table 1). Following risk adjustment, elevated preoperative NT-proBNP was found to be an independent predictor of the composite outcome (OR 2.60, 95% CI 1.53-4.44, p= 0.0004).

Conclusion: Elevated pre-operative NT-proBNP, as determined by optimal cut point, was associated with increased likelihood of adverse events following cardiac surgery. This suggests that preoperative NT-proBNP may be used to help risk stratify cardiac surgery patients.