NT-proBNP Level as a Substitute for Myocardial Perfusion Scan in Preoperative Cardiovascular Risk Assessment in Noncardiac Surgery

Background: Preoperative cardiovascular risk assessment is one of the main principles before noncardiac surgeries. Cardiac stress imaging, such as myocardial perfusion scan (MPI), is one of the proposed cardiac risk evaluation methods according to the latest guidelines. Yet, its efficacy, along with the cost-effectiveness of the method, has been questioned in previous studies. Our study aims to evaluate the utility of NT-proBNP level measurement in predicting postoperative cardiovascular complications in candidates who have undergone an MPI scan before surgery and compare the results. Methods A cohort of 78 patients with an RCRI score of one or more who were scheduled for high to moderate-risk noncardiac surgeries and met the criteria to undergo an MPI scan for risk assessment were included in the study. All patients underwent an MPI scan one week before surgery. Their preoperative NT-proBNP, troponin levels, and ECGs were obtained one day before surgery. The predictive efficacy of NT-proBNP levels and MPI scans were compared. Results Seventy-eight patients underwent surgery, of which three patients exhibited a rise in troponin level, six showed ECG changes, and pulmonary edema was detected in one patient three days after surgery. There was no mortality. The sensitivity and specificity of the MPI scan for predicting postoperative adverse cardiovascular outcomes were 100% and 66%, respectively. MPI scan also had a positive predictive value (PPV) of 20% and a negative predictive value (NPV) of 100%. A 332.5 pg/ml cut-off value for NT-proBNP level yielded a sensitivity of 100%, specificity of 79.2%, PPV of 40%, and NPV of 100%. Conclusions This study reveals the incremental prognostic value of NT-proBNP level measurement in preoperative cardiac risk evaluation compared to an MPI scan. Given the low feasibility, high costs, and disappointing predictive value of MPI scans, preoperative NT-proBNP level assessment can be substituted. This method can assist anesthesiologists and surgeons with detecting at-risk patients resulting in taking proper measures to reduce morbidity and mortality in the preoperative period.