Left ventricular dysfunction before chemotherapy: Did we miss something?

Abstract

We have read with a great interest the article by Akam-Venkata et al regarding left ventricular (LV) function and mechanics in pediatric patients who still did not receive chemotherapy. 1 The investigators included pediatric patients with various malignancies and compared them with healthy children. The results showed that LV longitudinal strain was significantly lower in chemotherapy-naïve young patients than in healthy children despite similar values of LV ejection fraction, myocardial performance index, and shortening fraction. 1 The data were same for solid and hematological tumors. LV circumferential and radial strains were not assessed in this study. This is very important topic, which has not been sufficiently investigated so far. Mavinkurve-Groothuis et al reported a significant reduction in LV longitudinal, circumferential, and radial strains in the children with acute lymphoblastic leukemia after anthracycline therapy than before treatment. 2 Even though the researchers did not make statistical comparison in LV mechanics between healthy controls and cancer patients before chemotherapy, it was clear that LV longitudinal and circumferential strains were remarkably lower and that LV radial strain was remarkably higher, in the children with leukemia before chemotherapy than in healthy children. 2 In the adult population were obtained similar results. Assuncao et al in the adult patients with acute leukemia found significantly lower values of LV longitudinal strain than in healthy controls. 3 Our research group recently published studies in which it was shown not only that LV multidirectional strain (longitudinal, circumferential, and radial) was significantly decreased in chemotherapy-and radiotherapy-naïve patients with solid cancer, but also that right ventricular (RV) longitudinal strain was significantly reduced in the cancer patients in comparison with controls. 4,5 The difference existed not only in the global values of LV and RV strains, but also in layer-specific strain, which further implies transmural myocardial and not endocardial impairment, as it was usually presumed.The most important question that has been imposed from these studies is the potential mechanism(s) of this relationship. Why and how cancer could interfere cardiac function? All mentioned investigations showed that conventional parameters of LV and RV systolic function were similar between cancer patients and controls. On the other hand, all researches agree that mechanical function was deteriorated in the cancer patients independently of their age. There are several speculations on this topic: increased inflammation, elevated vasoactive peptides (endothelin, copeptin), pro-BNP, pro-ANP, and troponin T, impaired oxidative stress, or even direct infiltration of the myocardium by circulating cancer cells. To our knowledge, there are no studies designed to answer the questions regarding mechanisms responsible for cardiac dysfunction in the cancer patients. Considering the fact that most of the cancer patients are treated with cardioto...