Chemotherapy-related cardiac dysfunction: grey area in type I and type II classification

Quantification of Extracellular Volume in CT in Neoadjuvant Chemotherapy in Breast Cancer: New Frontiers in Assessing the Cardiotoxicity of Anthracyclines and Trastuzumab

Breast cancer patients undergoing neoadjuvant chemotherapy with anthracyclines or trastuzumab can suffer cardiotoxic issues. Nowadays, the markers of cardiac damage are still not reliable, and extracellular volume (ECV) calculated from CT could be a promising cardiotoxic marker. Eighty-two patients, treated with two different chemotherapy regimens based on doxorubicin (DOX) or epirubicin-trastuzumab (EPI-TRAS), were retrospectively selected and the variations in extracellular volume (ECV) values were measured and analyzed. Whole Body CT (WB-CT) scans were acquired after 1 min, in the portal phase (PP), and after 5 min, in the delayed phases (DP), at the baseline (T₀), after one year (T₁) and after five years (T₅) from the end of chemotherapies. The values measured by two radiologists with different levels of experience were evaluated in order to assess the inter-reader reproducibility assessment (ICC = 0.52 for PP and DP). Further, we performed a population-based analysis and a drug-oriented subgroup analysis in 54 DOX-treated and 28 EPI-TRAS-treated patients. In the general cohort of women treated with any of the two drugs, we observed in the lapse T₀-T₁ a relative increase (RI) of 25% vs. 20% (PP vs. DP, p < 0.001) as well as in the lapse T₀-T₅ an RI of 17% vs. 15% (PP vs. DP, p < 0.01). The DOX-treated patients reported in the lapse T₀-T₁ an RI of 22% (p < 0.0001) in PP and an RI of 16% (p = 0.018) in the DP, with ECV values remaining stably high at T₅ both in PP (RI 14.0%, p < 0.0001) and in DP (RI 17%, p = 0.005) highlighting a possible hallmark of a persisting CTX sub-damage. On the other hand, ECV measured in EPI-TRAS-treated women showed an RI in T₀-T₁ of 18% (p = 0.001) and 29% (p = 0.006) in PP and DP, respectively, but the values returned to basal levels in T₅ both in the PP (p = 0.12) and in DP setting (p = 0.13), suggesting damage in the first-year post-treatment and a possible recovery over time. For the 82 patients, an echocardiography was performed at T₀, T₁= 12 m + 3 m and T₅ = 60 m + 6 m with LVEF values at T₀ (64% ± 5%), T₁ (54% ± 6%) and T₅ (53% ± 8%). WB-CT-derived ECV values could provide a valid imaging marker for the early diagnosis of cardiotoxic damage in BC patients undergoing oncological treatments. We detected different patterns during the follow-up, with stably high values for DOX, whereas EPI-TRAS showed a peak within the first year, suggesting different mechanisms of cardiac damage.

Indole Alkaloid Derivative B, a Novel Bifunctional Agent That Mitigates 5-Fluorouracil-Induced Cardiotoxicity

Clinically approved therapeutics that mitigate chemotherapy-induced cardiotoxicity, a serious adverse effect of chemotherapy, are lacking. The aim of this study was to determine the putative protective capacity of a novel indole alkaloid derivative B (IADB) against 5-fluorouracil (5-FU)-induced cardiotoxicity. To assess the free-radical scavenging activities of IADB, the acetylcholine-induced relaxation assay in rat thoracic aorta was used. Further, IADB was tested in normal and cancer cell lines with assays gauging autophagy induction. We further examined whether IADB could attenuate cardiotoxicity in 5-FU-treated male ICR mice. We found that IADB could serve as a novel bifunctional agent (displaying both antioxidant and autophagy-modulating activities). Further, we demonstrated that IADB induced production of cytosolic autophagy-associated structures in both cancer and normal cell lines. We observed that IADB cytotoxicity was much lower in normal versus cancer cell lines, suggesting an enhanced potency toward cancer cells. The cardiotoxicity induced by 5-FU was significantly relieved in animals pretreated with IADB. Taken together, IADB treatment, in combination with chemotherapy, may lead to reduced cardiotoxicity, as well as the reduction of anticancer drug dosages that may further improve chemotherapeutic efficacy with decreased off-target effects. Our data suggest that the use of IADB may be therapeutically beneficial in minimizing cardiotoxicity associated with high-dose chemotherapy. On the basis of the redox status difference between normal and tumor cells, IADB selectively induces autophagic cell death, mediated by reactive oxygen species overproduction, in cancer cells. This novel mechanism could reveal novel therapeutic targets in chemotherapy-induced cardiotoxicity.

Chemotherapy-induced cardiomyopathy caused by Pemetrexed

Chemotherapy-related cardiac toxicity is a rare but serious adverse event in patients with cancer. Thus far, no case of serious cardiac toxicity of pemetrexed has been reported. We describe the case of a patient with advanced lung cancer and cardiomyopathy due to pemetrexed. A 59-year-old woman visited our hospital, and we found abnormal findings on a chest radiograph. She was diagnosed as having stage IV lung adenocarcinoma. Chemotherapy with cisplatin and pemetrexed every 3 weeks was initiated. After four cycles of chemotherapy, maintenance chemotherapy with pemetrexed was administered every 3 weeks. During the seventeenth cycle of pemetrexed, she had shortness of breath in her daily life. A chest radiograph showed an enlarged cardiothoracic ratio (66%), and the transthoracic echocardiogram demonstrated expansion of the left ventricle (diastolic diameter, 67 mm), severe global hypokinesis, and reduced left ventricular ejection fraction (28%). The coronary angiogram showed no coronary constriction. There was no delayed accumulation on the contrast-enhanced cardiac magnetic resonance imaging scan. After right heart catheterization, pathological results of a myocardial biopsy from the ventricular septum indicated no cardiac muscle hypertrophy, cardiac fibrosis, inflammatory cell infiltration, or myocyte disarray. Eventually, she was diagnosed as having pemetrexed-induced cardiomyopathy. Pemetrexed was discontinued, and furosemide, enalapril, and carvedilol were started. Then her symptoms and cardiac function improved. Early detection and discontinuation of causative agents are the most important treatment strategies in similar patients. Diuretics, angiotensin-conversion enzyme inhibitors, and beta-blockers may be effective for treating heart failure.