Study On The Role Of NT-pro-BNP (Brain Natriuretic Peptide) And Troponin I In The Detection Of Anthracycline Induced Cardiotoxicity

IntroductionAnthracyclines are commonly used anticancer drugs because of their proven potency but cardiotoxicity represents their most devastating effect .The present study was undertaken to explore the role of biomarkers (NT pro BNP & troponin I) for the detection of chemotherapy induced cardiotoxicity. MethodsTwenty two patients of malignancy who previously underwent anthracycline chemotherapy were enrolled after informed and written consent. Detailed two-dimensional echocardiography was done to detect left ventricular dysfunction. A single point estimation of either plasma NT pro BNP or troponin I was done. Fourteen age and sex matched healthy controls were taken for analysis too. Results Although all patients were clinically asymptomatic, echocardiographic evidence of Left Ventricular Dysfunction (LVD) was present in 20 (91%) study subjects. LV diastolic dysfunction was prevalent (77%) from where as systolic dysfunction was present only in 14% subjects. There was a statistically significant decline in echocardiographic parameters (E/A ratio, IVRT and LVEF) following anthracycline chemotherapy vis-à-vis controls. In patients who developed LV dysfunction the mean dose of anthracycline was higher as compared to those who did not. The mean level of NT-pro BNP was higher in the study population as compared to controls , though not statistically significant (431 + 597.13 pg/ml vs. 68.28 + 28.39 pg/ml, p=0.11).However, the level of troponin I in study population was significantly higher as compared to controls (0.16 + 0.27 ng/ml vs. 0.02 + 0.01 ng/ml, p=0.02). There was a negative correlation of NT pro BNP levels with LVEF (r=-0.11) and peak E velocity (r=0.35). A similar positive correlation between NT pro BNP & IVRT (r= .006) was also seen. As regards to Troponin I, similar positive and negative correlation with IVRT (r= +0.08) and LVEF (r= -0.2) were seen respectively. The mean levels of NT pro BNP and troponin I were higher in patients who were co-administered additional chemotherapy. In the study, both plasma NT pro BNP and troponin I had a low Sensitivity of (40% & 10% respectively) but high Specificity (100%) in predicting LV dysfunction on echocardiography. ConclusionsThere is high prevalence of left ventricular dysfunction on echocardiography after anthracycline chemotherapy. LV diastolic dysfunction is more common than LV systolic dysfunction. Plasma NT pro BNP and Troponin-I levels are higher in patients who developed LV dysfunction following Chemotherapy. Both NT pro BNP and Troponin-I levels have low sensitivity and high specificity for detecting LV dysfunction following anthracycline chemotherapy. Biomarker levels showed a significant correlation with various echocardiographic parameters too.