Perioperative Prognostic Value of N-Terminal Pro-Brain Natriuretic Peptide (NT- proBNP) Level in Patients Undergoing Open Heart Surgery

Abstract
Background: In this article, we examined the relationship between the pre- and postoperative N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and occurance of complications in patients undergoing open heart surgery.
Aim of Study: To find out the prognostic value of NT-proBNP as a valuable marker in predicting postoperative myocardial insult, short term outcome in patients undergoing open heart surgery and evaluate the independency of this biomarker.
Patients and Methods: It was carried out on 105 patients who had cardiac surgery in our department from April 2016 to August 2017. All patients had preoperative and postoperative ECG, Echocardiography and full investigations. Venous blood samples were drawn for estimation of serum level NT-pro BNP by ELISA one hour prior to the operation and 24 hours after the operation. Intraoperative and postoperative data include cardiopulmonary bypass time, aortic cross clamping time, requirement for cardiac support immediately after the operation, ICU and hospital stay and occurance of postoperative complications.
Results: There was highly statistically significant differ-ence between preoperative and postoperative NT-proBNP (p<0.001). Also, we found a significant relation between postoperative NT-proBNP and need of inotropes immediately after operation (p=0.035). Patients who had prolonged ICU stay and hospitalization had significantly higher postoperative NT-proBNP levels with (p<0.001) and (p=0.009) respectively. Our results showed that there was a significant relationship between postoperative NT-proBNP and most of postoperative complications (p<0.001).
Conclusion: NT-proBNP levels strongly correlated with postoperative complications, suggesting its value as a useful prognostic predictor after cardiac surgery which can predict early outcome after cardiac surgery. NT-proBNP levels may be an option when an echocardiogram is not feasible and inotropes may be needed, especially if these levels can be measured in the patient's bed. So, NT-proBNP may become a clinical routine biomarker capable of predicting patients' perioperative and early postoperative risk because of it is convenient, quick and not expensive. The quantitative cut-off values may be used by physicians in their decision to delay heart surgery in order to further ameliorate the patient.