Global longitudinal strain: an early marker for cardiotoxicity in patients treated for breast cancer

Detection of Cardiotoxicity Using Right Ventricular Free Wall Longitudinal Strain in Low Cardiovascular Risk Breast Cancer Patients Receiving Low-Dose Anthracycline Treatment

Objective Breast cancer patients who receive chemotherapy may develop cancer therapy-related cardiovascular toxicity, particularly if they have pre-existing cardiovascular risk factors. Notably, right ventricle dysfunction may manifest before the left ventricle. Our study aims to compare conventional echocardiography with global longitudinal strain (GLS) in low cardiovascular risk patients on low-dose anthracycline, focusing on early cardiotoxicity detection. Additionally, we explore the predictive role of right ventricular free wall longitudinal strain (RVFWLS) in cardiotoxicity. Methods In a recent study, 28 women with low cardiovascular risk who underwent low-dose anthracycline chemotherapy for breast cancer were assessed for cardiac function using two-dimensional echocardiography and speckle-tracking echocardiography. The measurements included left ventricular ejection fraction (LVEF), right ventricular systolic function (RVS'), tricuspid annular plane systolic excursion (TAPSE), left ventricular global longitudinal strain (LVGLS), and RVFWLS. All patients had normal LVEF at the beginning of the study. Cardiotoxicity was defined as a new decrease in LVEF by 10% or below 53% and/or changes in LVGLS/RVFWLS by 15%. Results In our study, no significant changes were observed in the LVEF following chemotherapy treatment. The LVEF values remained stable, changing slightly from 63 ± 3.7 to 65.0 ± 3.4, with a t-test value of 1.790 and a p-value of 0.079. Similarly, the analysis found no significant changes in RVS' and TAPSE values following chemotherapy treatment. However, significant changes were observed in strain measurements. LVGLS decreased from -21.2 ± 2.1 to -18.6 ± 2.6 (t-test = -4.116; df = 54, p=0.001), and RVFWLS decreased from -25.2 ± 2.9 to -21.4 ± 4.4 (t-test = -3.82; df = 54, p=0.001). Notably, 35% of participants showed changes in RVFWLS greater than 15%, whereas LVGLS changed by less than 15%. This indicates that RVFWLS is more sensitive to the treatment compared to LVGLS. Conclusions The study results indicate that during the initial phases of chemotherapy treatment in low cardiovascular risk patients, early changes in strain measures reveal subclinical cardiotoxicity. This suggests that GLS measurements are more effective at detecting early signs of myocardial damage and potential deterioration in cardiac function than traditional echocardiographic parameters. Additionally, it is noteworthy that RVFWLS exhibits greater sensitivity to these changes, regardless of the chemotherapy dosage and regimen.

HER2-Targeted Therapy-From Pathophysiology to Clinical Manifestation: A Narrative Review

Trastuzumab is the primary treatment for all stages of HER2-overexpressing breast cancer in patients. Though discovered over 20 years ago, trastuzumab-induced cardiotoxicity (TIC) remains a research topic in cardio-oncology. This review explores the pathophysiological basis of TIC and its clinical manifestations. Their understanding is paramount for early detection and cardioprotective treatment. Trastuzumab renders cardiomyocytes susceptible by inhibiting the cardioprotective NRG-1/HER2/HER4 signaling pathway. The drug acts on HER2-receptor-expressing cardiomyocytes, endothelium, and cardiac progenitor cells (see the Graphical Abstract). The activation of immune cells, fibroblasts, inflammation, and neurohormonal systems all contribute to the evolution of TIC. A substantial amount of research demonstrates that trastuzumab induces overt and subclinical left ventricular (LV) systolic failure. Data suggest the development of right ventricular damage, LV diastolic dysfunction, and heart failure with preserved ejection fraction. Further research is needed to define a chronological sequence of cardiac impairments to guide the proper timing of cardioprotection implementation.

Correlation of Speckle-Tracking Echocardiography with Traditional Biomarkers in Predicting Cardiotoxicity among Pediatric Hemato-Oncology Patients: A Comprehensive Evaluation of Anthracycline Dosages and Treatment Protocols

Speckle tracking-echocardiography (STE) is a novel non-invasive imaging tool capable of quantifying myocardial deformation, and thus holds promise in detecting early subclinical myocardial injury. This study aimed to evaluate the correlation of STE with traditional biomarkers in predicting anthracycline-induced cardiotoxicity in the context of varying dosages and treatment protocols in pediatric hemato-oncology patients. We conducted a retrospective study involving pediatric hemato-oncology patients undergoing anthracycline-based chemotherapy. A total of 99 patients were included in the final analysis, with 82 receiving Doxorubicin, of which 58.5% were males, and 17 receiving Epirubicin, of which 70.6% were males, with a median of 10 years old. Traditional biomarkers, such as Troponin I (cTnI) and B-type natriuretic peptide (BNP), were compared with STE parameters, including the global longitudinal strain (GLS), Simpson method of discs (SMOD), and myocardial performance index (MPI). A comprehensive evaluation was conducted based on different dosages of anthracyclines and different treatment protocols, with a follow-up period of one year post-chemotherapy. It was observed that the cTnI levels in the Doxorubicin group were significantly higher (3.2 ng/mL, p = 0.002) than in the Epirubicin group (2.7 ng/mL). However, BNP and NT-proBNP levels were not significantly different between the two groups (p = 0.096 and p = 0.172, respectively). Regarding STE parameters, a significant negative correlation was observed between the anthracycline dose and GLS (Rho = -0.411, p = 0.001), indicating increased cardiotoxicity with dose elevation. The SMOD and MPI gave significantly better values in the Epirubicin group (59.2 and 0.41 vs. 54.4 and 0.36, respectively). However, the ROC analysis did not find GLS, SMOD, or MPI to be significant independent predictors of cardiotoxicity (p > 0.05). There was also considerable variation in cardiotoxicity between the Doxorubicin and Epirubicin study groups, suggesting that the risk of cardiotoxicity is not solely determined by dose. Our study underlines the potential of STE as a sensitive tool for the early detection and prediction of anthracycline-induced cardiotoxicity in pediatric hemato-oncology patients, but only in association with the clinical findings and cardiac biomarkers. While traditional biomarkers still play a role, STE can offer a more accurate prediction of cardiac risk, potentially leading to better management and outcomes for these patients.