A Novel Predictor of Chemotherapeutic Cardiotoxicity in Patients with Non-Hodgkin Lymphoma

BACKGROUND: It is known that chemotherapeutic agents cause myocardial cell damage leading to left ventricular dysfunction and heart failure. Fragmented QRS is an indication of fibrosis developing as a result of myocardial cell damage. The aim of this study is to assess whether there is a relationship between the chemotherapeutic treatment and the development of the fragmented QRS complex in electrocardiography (ECG). PATIENTS AND METHODS: Among 130 patients who were diagnosed with non-Hodgkin lymphoma and received an R-CHOP treatment regimen, the potential emergence of fragmented QRS on ECG as well as the changes in the left ventricular ejection fraction (LVEF) (on transthoracic echocardiography) in response to various chemotherapeutic regimens were sought. RESULTS: New development of a fragmented QRS pattern was observed in 53 of the 130 patients (40.8%). These patients were found to have lower LVEF values along with higher numbers of chemotherapy courses and cumulative doses. In the logistic regression analysis, age (OR = 1.042; 95% CI 1.009-1.076; p = 0.012) and number of courses (OR = 1.848; 95% CI 1.409-2.423; p < 0.001) were found to be the most important predictors of fragmented QRS development. In subjects with a fragmented QRS pattern, there was a significant difference between the initial and repeat LVEF values (p < 0.001). Importantly the emergence of a fragmentation pattern occurred much earlier compared to the drop in LVEF values (10.62 ± 4.04 vs. 15.24 ± 7.49 months). CONCLUSION: Development of a fragmented QRS pattern in response to cancer therapy emerges as a new parameter potentially predictive of chemotherapy-induced cardiotoxicity.