Preoperative plasma N-terminal pro-brain natriuretic peptide as a marker of cardiac risk in patients undergoing elective non-cardiac surgery

Background: Plasma N-terminal pro-brain natriuretic peptide (NTproBNP) is a sensitive marker for heart failure. This study tested whether the preoperative plasma level of NTproBNT could predict cardiac complications in patients undergoing non-cardiac surgery. Methods: A total of 190 consecutive patients who underwent elective non-cardiac surgery that required general anaesthesia were studied. In addition to routine preoperative evaluation, a blood sample was taken for estimation of plasma NTproBNP concentration. Postoperative cardiac complications were defined as cardiac death, acute coronary syndrome, heart failure and haemodynamic compromise from cardiac arrhythmias. Results: Fifteen of the 190 patients had a cardiac complication: four had acute coronary syndrome and 13 had congestive heart failure. NTproBNP concentration was significantly higher in patients with a cardiac complication; a level greater than 450 ng/l was predictive of cardiac complications with a sensitivity of 100 per cent and a specificity of 82.9 per cent. Other factors associated with cardiac complications were a higher American Society of Anesthesiologists grade, age and clinical cardiac impairment, but in a multivariate analysis NTproBNP level was the only independent factor. Conclusion: Preoperative plasma NTproBNP concentration may be an independent predictor of cardiac complications in patients undergoing non-cardiac surgery.