English

Abstract

BACKGROUND: The preferred choice of treatment for malignant tumours is chemotherapy, which carries equal risk of cardiotoxicity. These drugs are dose dependent, hence worsen cardiac function from treatment completion to follow-up. Late effects of anthracyclines include subclinical cardiac abnormalities like systolic and diastolic dysfunction that are usually masked in the routine conventional echocardiography. With the regular use of tissue Doppler imaging, 2D derived strain and strain rate besides conventional Doppler techniques helps in early diagnosis of myocardial systolic and diastolic dysfunction, thereby reducing cardiac disease progression.MATERIALS AND METHODS: A prospective cohort study was employed to establish diastolic dysfunction in cancer patients undergoing anthracycline-based chemotherapy in the Department of Cardiology, Kasturba Medical College (Affiliated to MAHE), Manipal. The study group consisted of patients with no past history of anticancer treatment, baseline left ventricular EF > 50% and normal levels of renal and hepatic enzymes. This study was performed on 190 patients, 70 males and 120 females with mean age of 38±16 years. The subjects undergoing first and second dose of chemotherapy were named as first follow-up (F1) and second follow-up (F2). Among these, only 70 subjects could complete two follow-ups of chemotherapy. Parameters of conventional echocardiography were recorded and integrated with TDI parameters such as LVEF, transmitral E and A velocity and TDI (e’/a’ = ratio between early diastolic velocity of myocardium and late diastolic velocity a’ and systolic myocardial velocity (Sm). LV systolic function in terms of EF was measured by modified biplane Simpson’s method. Newer parameters like 2D derived strain and strain rate imaging were included that consisted of Peak Systolic Strain Rate (SSR), Early Diastolic Strain Rate (EDSR) and Late Diastolic Strain Rate (LDSR).RESULTS :This study was performed on 190 patients, 70 males and 120 females with mean age of 38±16 years. The subjects undergoing first and second dose of chemotherapy were named as first follow-up (F1) and second follow-up (F2). Among these, only 70 subjects could complete two follow-ups of chemotherapy. Among the conventional 2D echocardiographic parameters representing LV systolic and diastolic function assessed from the baseline to first follow-up showed no statistically significant changes. TDI and strain values were not found to be significant at the early doses of chemotherapy (4 weeks from the baseline), though an increase in systolic strain rate in anterior wall of LV (-1.29±0.42 vs -1.8±0.78, p < 0.001) was noted during first follow-up. TDI performed in the inter follow-up group was significantly reduced in basal IVS in terms of early myocardial tissue velocity (0.09±0.02 vs 0.07±0.02). Pairwise comparison between baseline study and second follow-up (F2) showed statistically significant decrease in early diastolic strain rate in two segments of LV, LW (1.58±0.49 and 1.34±0.49, p < 0.001) and AS (1.78±2.15 and 1.33±0.45, p<0.001). The inter follow-up group when compared for systolic strain rate showed a decline in systolic strain rate and early diastolic strain rate (1.93±0.68 and 1.34±0.49, p < 0.001).CONCLUSION:Patients exposed to anthracycline treatment previously show subtle abnormalities (both systolic and diastolic), though the convention 2D echocardiography shows a normal ejection fraction. The cardiac function deteriorates over time leading to CHF which can be reduced by early diagnosis through newer Doppler independent techniques like strain and strain rate. Hence, 2D derived strain rate imaging with its ease of use and reproducibility over TDI should be utilised as potential non-invasive tool for the early detection of subclinical longitudinal myocardial abnormalities in chemotherapy patients.