Global Longitudinal Strain Monitoring to Guide Cardioprotective Medications During Anthracycline Treatment

Supervised exercise training in patients with cancer during anthracycline-based chemotherapy to mitigate cardiotoxicity: a randomized-controlled-trial

Background

Exercise training (ET) has been shown to mitigate cardiotoxicity of anthracycline-based chemotherapies (AC) in animal models. Data from randomized controlled trials in patients with cancer are sparse.

Methods

Patients with breast cancer or lymphoma receiving AC were recruited from four cancer centres and randomly assigned to 3 months supervised ET. Primary outcome was change in left ventricular global longitudinal strain (GLS) from baseline (before AC) to post AC (AC-end) compared between the EXduringAC group, who participated in an exercise intervention during AC including the provision of an activity tracker, and the control group EXpostAC, who received an activity tracker only. Secondary outcome parameters were changes in high sensitivity Troponin T (hsTnT), NT-pro-brain natriuretic peptide (NT-proBNP), peak oxygen consumption (peak VO2) and objectively measured physical activity (PA) during this same time-period. All assessments were repeated at a 12-week follow-up from AC-end, when also the EXpostAC group had completed the ET, that started after AC. In exploratory analyses, robust linear models were performed to assess the association of PA with changes in echocardiographic parameters and biomarkers of LV function.

Results

Fifty-seven patients (median age 47 years; 95% women) were randomized to EXduringAC (n = 28) and EXpostAC (n = 29) group. At AC-end, GLS deteriorated in both study groups (albeit insignificantly) with 7.4% and 1.0% in EXduringAC (n = 18) and EXpostAC (n = 18), respectively, and hsTnT and NT-proBNP significantly increased in both groups, without difference between groups for any parameter. Change in peak VO2 (-1.0 and -1.1 ml/kg/min) at AC-end was also similar between groups as was duration of moderate-to-vigorous PA (MVPA) with a median of 33 [26, 47] min/day and 32 [21, 59] min/day in the EXduringAC and EXpostAC group, respectively. In the robust linear model including the pooled patient population, MVPA was significantly associated with a more negative GLS and lesser increase in hsTnT at AC-end.

Conclusion

In this small scale RCT, supervised ET during AC was not superior to wearing a PA tracker to mitigate cardiotoxicity. The dose-response relationship between PA and cardioprotective effects during AC found in our and previous data supports the notion that PA should be recommended to patients undergoing AC.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03850171.

Echocardiographic evaluation of cardiac reserve to detect subtle cardiac dysfunction in mice

AIMS

Cardiac reserve is a sensitive tool for early detection of cardiac dysfunction. However, cardiac reserve assessment by catecholamine stress echocardiography in mice varied in the doses of β-adrenergic agonists and the time point for measurements, which may lead to inaccurate readouts. This study aims to establish a standardized protocol for assessing cardiac reserve in mice.

MAIN METHODS

C57BL/6J mice under isoflurane anesthesia were intraperitoneally injected with varying doses of isoproterenol (Iso), and subjected to echocardiographic measurements.

KEY FINDINGS

Heart rate (HR), ejection fraction (EF), fractional shortening (FS), global longitudinal strain (GLS) and strain rate all reached peak values within 1-3 min after Iso injection at doses higher than 0.2 mg/kg. Compared with 0.1 mg/kg Iso, 0.2 mg/kg Iso resulted in higher HR, EF, FS and GLS, whereas doses higher than 0.2 mg/kg did not yield further increase. Cardiac response of female mice recapitulated main characteristics of those of male mice except that female mice displayed higher maximum HR and were more sensitive to higher doses of Iso. Furthermore, the advantages of present stress protocol over conventional baseline echocardiographic measurements were verified in comparisons of exercised vs. sedentary and aged vs. young mice for cardiac function evaluation.

SIGNIFICANCE

We developed a reproducible and sensitive approach to evaluate cardiac reserve by continuously monitoring cardiac function every minute for 3 min after 0.2 mg/kg Iso injection. This approach will enable detection of subtle cardiac dysfunction and accelerate innovative research in cardiac pathophysiology.

Usefulness of Longitudinal Strain to Assess Cancer Therapy-Related Cardiac Dysfunction and Immune Checkpoint Inhibitor-Induced Myocarditis

Longitudinal strain (LS) measured by echocardiography has been reported to be useful not only for the diagnosis and risk stratification of various cardiac diseases, but also in cardio-oncology. Most previous studies have been conducted on patients undergoing treatment with anthracyclines and human epidermal growth factor receptor 2-targeted therapies. Existing guidelines recommend that global LS (GLS) should be measured before and after the administration of cancer drugs. This recommendation is based on many reports showing that a decline in GLS is indicative of early or mild cancer therapy-related cardiac dysfunction. The main purpose of this article is to provide insight into the importance of LS in patients undergoing cancer treatment and highlight the role of LS evaluation in patients undergoing immune checkpoint inhibitor (ICI) treatment, which is being used with increasing frequency. Among cancer drug therapies, immune checkpoint inhibitors (ICIs) have an important place in cancer treatment and are used for the treatment of many types of cancer. Although the efficacy of ICIs in cancer treatment has been reported, immune-related adverse events (irAEs) have also been reported. Among these irAEs, cardiovascular complications, although rare, are recognized as important adverse events that may result in ICI treatment discontinuation. Myocarditis is one severe adverse event associated with ICIs, and it is important to standardize diagnostic and therapeutic approaches to it. Several studies have reported a relationship between LS and cardiac complications associated with ICIs which may contribute to the early diagnosis of ICI-induced cardiac complications.

Racial Disparity in Anthracycline-induced Cardiotoxicity in Breast Cancer Patients

Breast cancer has become the most common cancer in the US and worldwide. While advances in early detection and treatment have resulted in a 40% reduction in breast cancer mortality, this reduction has not been achieved uniformly among racial groups. A large percentage of non-metastatic breast cancer mortality is related to the cardiovascular effects of breast cancer therapies. These effects appear to be more prevalent among patients from historically marginalized racial/ethnic backgrounds, such as African American and Hispanic individuals. Anthracyclines, particularly doxorubicin and daunorubicin, are the first-line treatments for breast cancer patients. However, their use is limited by their dose-dependent and cumulative cardiotoxicity, manifested by cardiomyopathy, ischemic heart disease, arrhythmias, hypertension, thromboembolic disorders, and heart failure. Cardiotoxicity risk factors, such as genetic predisposition and preexisting obesity, diabetes, hypertension, and heart diseases, are more prevalent in racial/ethnic minorities and undoubtedly contribute to the risk. Yet, beyond these risk factors, racial/ethnic minorities also face unique challenges that contribute to disparities in the emerging field of cardio-oncology, including socioeconomic factors, food insecurity, and the inability to access healthcare providers, among others. The current review will address genetic, clinical, and social determinants that potentially contribute to this disparity.

Speckle tracking echocardiography in early disease stages: a therapy modifier?

Echocardiography has been included as a first-line tool in several international guidelines for the management of patients with various cardiac diseases. Beyond diagnosis, echocardiographic examination helps in characterizing the severity of the condition since the very first stages. In particular, the application of second-level techniques, speckle tracking echocardiography in particular, can also reveal a subclinical dysfunction, while the standard parameters are in the normality range. The present review describes the potentialities of advanced echocardiography in different settings, including arterial hypertension, atrial fibrillation, diastolic dysfunction, and oncological patients, thus opening up potential starting points for its application as a clinical routine changer.

Global Longitudinal Strain in Cardio-Oncology: A Review

Several therapies used in cancer treatment are potentially cardiotoxic and may cause left ventricular (LV) dysfunction and heart failure. For decades, echocardiography has been the main modality for cardiac assessment in cancer patients, and the parameter examined in the context of cardiotoxicity was the left ventricular ejection fraction (LVEF). The assessment of the global longitudinal strain (GLS) using speckle tracking echocardiography (STE) is an emerging method for detecting and quantifying subtle disturbances in the global long-axis LV systolic function. In the latest ESC guidelines on cardio-oncology, GLS is an important element in diagnosing the cardiotoxicity of oncological therapy. A relative decrease in GLS of >15% during cancer treatment is the recommended cut-off point for suspecting subclinical cardiac dysfunction. An early diagnosis of asymptomatic cardiotoxicity allows the initiation of a cardioprotective treatment and reduces the risk of interruptions or changes in the oncological treatment in the event of LVEF deterioration, which may affect survival.