Underlying heart disease affects preoperative NT-proBNP levels
In patients admitted for cardiac surgery, preoperative levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) are affected by underlying heart diseases which, in turn, affect its predictive value for severe postoperative heart failure (SPHF), a recent study has shown.
Researchers performed a prospective cohort study on 2,978 adults (median age 70 years; 24 percent female) undergoing first-time surgery for coronary artery disease (CAD; n=2,226), mitral regurgitation (MR; n=346) or aortic stenosis (AS; n=406).
Relative to CAD patients (290 ng/L), median levels of preoperative NT-probNP were 1.67 times higher in the AS group (595 ng/L; p<0.0001) and 1.47 times higher in the MR patients (400 ng/L; p<0.0001). The overall median preoperative NT-proBNP concentration was 330 ng/L.
Median levels of preoperative NT-proBNP were significantly higher in participants who eventually developed SPHF (2,060 vs 310 ng/L; p<0.0001). This trend remained significant even in the patient subgroups of CAD (2,345 vs 280 ng/L; p<0.0001), AS (1,290 vs 585 ng/L; p=0.047) and MR (1,650 vs 345 ng/L; p<0.0001).
Preoperative NT-proBNP also had significant discriminatory power for SPHF in patients with CAD (area under the curve [AUC], 0.79; 95 percent CI, 0.73–0.85; p<0.0001) and MR (AUC, 0.80; 0.72–0.87; p<0.0001), but less so for AS (AUC, 0.66; 0.51–0.81; p=0.047). Only in CAD patients was preoperative NT-proBNP an independent risk factor for SPHF (adjusted odds ratio [OR], 2.87; 1.56–5.30; p=0.001).
The predictive value of preoperative NT-proBNP for postoperative mortality was confirmed only in patients with CAD (AUC, 0.78; 0.71–0.85; p<0.0001). The number of cases was too few in the other patient subgroups.