Myeloperoxidase as a novel biomarker for prediction of cardiotoxicity: results from a prospective cohort study

Background Myeloperoxidase (MPO) is considered a potential biomarker for prediction of cardiotoxicity in patients undergoing anticancer treatment. However, data regarding its prognostic value remain limited and inconsistent. Purpose To assess whether baseline MPO predicts early cardiotoxicity and short-term mortality in patients receiving antineoplastic therapy, and to compare its predictive value with hsTroponin and NT-proBNP. Methods A total of 477 patients receiving antineoplastic therapy were followed up, with measurements of MPO, troponin, NT-proBNP, and comprehensive echocardiographic evaluation performed at baseline, 3 months, and 6 months. We evaluated and compared the association between these biomarkers and the development of a >10% decline in left ventricular ejection fraction (EF) to values <55%, a >15% reduction in global longitudinal strain (GLS) from baseline, and mortality. Results By the third month, 181 patients had been followed up. 54 of them had died (29.83%). Early cardiotoxicity incidence was low (significant EF decline: n=6; significant GLS decline: n=15). Baseline elevation of MPO (>94 ng/ml) did not show a statistically significant association with an EF decline of >10% to <55%, nor with a GLS reduction of >15%. However, elevated MPO was significantly associated with higher 3-month mortality (40% vs. 20%; p-value=0.0287), indicating nearly doubled risk. A trend was also observed toward an association between elevated MPO and reduced TAPSE, indicating possible early right ventricular dysfunction (p-value = 0.17). Another trend was noted between elevated MPO and development of new pericardial effusion (p-value = 0.19). Patients with simultaneous baseline elevation of troponin, NT-proBNP, and MPO (22 patients, 12.2% of the 181 followed up at month 3) represented a high-risk group, but they did not develop typical cardiotoxicity (EF/GLS decline), rather die early, which dominated the composite endpoint (OR = 5.21, p < 0.001). Interpretation of the results at the six-month follow-up remained limited due to the still small number of patients (n=99) and high mortality rate (64.6%). Conclusions Although MPO did not demonstrate statistically significant predictive value for early changes in EF or GLS, the results highlighted its independent prognostic significance for early mortality in patients undergoing anticancer treatment. The lack of statistical significance for some parameters is likely due to the small number of patients followed up to date, as well as the low incidence of cardiotoxicity. Patients with triple positive baseline biomarkers represented a particularly high-risk group; such patients should be monitored more closely and receive earlier or more aggressive cardioprotective therapy.Comparison of Biomarkers. Summary of Res Third month mortality