Biomarkers of myocardial injury in surgical treatment of lung cancer: perioperative dynamics and prognostic value

Aim. To study the perioperative dynamics of myocardial injury biomarkers and determine their significance in assessing the postoperative mortality risk in patients with nonsmall cell lung cancer. Methods. The study included 82 male patients with non-small cell lung cancer undergoing pneumonectomy. The median age was 64 (59; 67) years. The blood levels of cardiac troponin I (cTnI), N-terminal pro b-type natriuretic peptide (NT-proBNP) and fatty acid-binding protein (FABP) were noted before and after surgery. The rate of myocardial injury after non-cardiac surgery (MINS) was determined. The postoperative cTnI level above 0.023 μg/L was considered as MINS criterion. The significance of the studied biomarkers in predicting the total mortality within 6 months after surgery was assessed using the univariate and multivariate Cox regression and ROC analysis. Results. Compared to baseline levels, all myocardial injury biomarkers increased in 24 and 48h after surgery: cTnI by 120 and 85%, NT-proBNP by 128 and 129%, FABP by 207 and 31%, respectively. The postoperative cTnI levels met the MINS criterion in 45.1% of patients. During the follow-up period 12 patients died, 9 (75%) of those were diagnosed with MINS. Based on the results of the univariate Cox regression overall postoperative mortality was associated with NTproBNP levels before and after the surgery, cTnI growth rate after the surgery and MINS. According to the multivariate Cox regression (adjusted for age and other clinical parameters), preoperative NT-proBNP and atrial fibrillation proved to be the independent predictors of postoperative mortality. The cut-off value of preoperative NT-proBNP was 225 pg/mL; relative risk of death above that value was 5.9 and 95% confidence interval of 1.74–20.0. Conclusion. In patients with non-small cell lung cancer the increase of cTnI, NT-proBNP and FABP mean levels was observed in 24 and 48 hours after pneumonectomy. MINS was diagnosed in 45.1% of patients. According to the univariate regression analysis, MINS and preoperative and postoperative NT-proBNP levels were associated with the risk of total six-month postoperative mortality. The preoperative NT-proBNP was proved to be an independent predictor of adverse outcome.