High-sensitivity troponin T as a biomarker of exercise tolerance impairment assessed in CPET and left ventricular function 3 months after adjuvant therapy for breast cancer

Purpose The aim of the study was to assess the biochemical biomarkers of left ventricular ejection fraction (LVEF) decrease and/or functional capacity decrease in CPAP three months after adjuvant breast cancer therapy. Methods The 55 breast cancer females (50±9.5) treated with anthracyclines or anthracyclines and trastuzumab and 50 control females (52±7.2) were assessed before and three months after adjuvant therapy. Clinical examination, laboratory results, selected biochemical biomarkers: [C-reactive protein (CRP), haemoglobin, N-terminal probrain natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), fatty acid binding protein 3 (FABP3) (pg/ml), galectin -3 (ng/ml), high-sensitivity cardiac troponin T (hs-cTnT) (pg/ml), creatynine], echocardiography with Vivid E95-GE Healthcare, cardiopulmonary exercise testing (CPET) with MetaSoft® Studio application and body mass compartments in Tanita system. Results After follow-up in cancer group we observed significantly lower LVEF (62% vs 64%, p=0.03), lower E’ (10cm/s vs 11 cm/s, p<0.001), compared to values before adjuvant therapy. Furthermore, the maximal oxygen uptake (VO2max) ( 17ml/min/kg vs 19 ml/min/kg, p<0.001) and V'O2 peak (1,4 l/min vs 1,3 l/min, p=0.001) and oxygen uptake at the anaerobic threshold (V02AT)(12 vs 11 ml/min/kg, p=0.005) were lower and ECW/TBW was higher (45 vs 44 %, p=0.02) in the breast cancer females assessed after follow-up compared to the values before adjuvant treatment. The level of hs-cTnT (6,4 pg/ml vs 3,5 pg/ml (hs-cTnT) (p<0,0001), the level of ferritin (96 ng/ml vs 35 ng/ml, p<0.0001) and the level of NT-proBNP (71 vs 78 pg/ml, p=0.03) were significantly elevated while the level of galectin-3 was lower after therapy (6 vs 9,3 ng/ml, p<0.0001). None of the biochemical biomarkers were associated with the decrease of exercise capacity in CPET 3 months after adjuvant treatment. In a multivariate analysis, hs-cTnT was the independent predictor of LVEF decrease 3 months after chemotherapy (OR=5.6; 95%CI 1.35-23.23, p=0.02). For the hs-cTnT the receiver-operating characteristic curve (ROC) was created to determine the cut point for LVEF decrease – Figure 1. Conclusion The breast cancer adjuvant therapy negatively affects not only LVEF but also exercise tolerance in spiroergometry. The hs-cTnT increase above 3.7 pg/ml is related to almost 6 times greater chance of a decrease in LVEF three months after breast cancer chemotherapy.