Routine Prophylactic Cardioprotective Therapy Should Be Given to All Recipients at Risk of Cardiotoxicity From Cancer Chemotherapy

Oxidative Stress Biomarkers Predict Myocardial Dysfunction in a Chemotherapy-Induced Rat Model

Objectives: Chemotherapy improves survival in breast cancer patients but increases the risk of myocardial dysfunction and heart failure. Since early prediction of cardiomyopathy remains difficult, biomarkers are needed for detecting myocardial damage before heart failure develops. This study examines the association between oxidative stress biomarkers and myocardial dysfunction in a chemotherapy-induced rat model. Methods: Forty-two rats were randomized into four groups: control (n = 7), doxorubicin only (n = 7), doxorubicin plus trastuzumab (n = 7), and doxorubicin plus trastuzumab with cardioprotective intervention (n = 21). Doxorubicin and trastuzumab were administered sequentially over 28 days. Echocardiography with speckle-tracking was utilized to measure longitudinal strain (LS, -%). Reduced LS was defined by a LS with a median value less than 23% on day 28. Blood samples were collected for biomarker analysis, focusing on superoxide dismutase (SOD) and glutathione (GSH). Myocardium fibrosis was assessed using Masson's trichrome staining. Results: Thirty-four rats survived and underwent LS analysis. All rats treated with doxorubicin and trastuzumab exhibited reduced LS, while those receiving cardioprotective intervention maintained preserved LS on day 28. The reduced LS group had significantly lower SOD and higher GSH levels compared to the preserved LS group. SOD and GSH correlated strongly with LS (SOD, r = 0.590, p = 0.001; GSH, r = -0.590, p = 0.003), and LS correlated with fibrosis area (r = -0.660, p < 0.001). SOD and GSH effectively predicted reduced LS. Conclusions: In a rat model of chemotherapy-induced cardiomyopathy, oxidative stress biomarkers correlated with myocardial dysfunction, as indicated by LS. These findings highlight the potential of biomarker monitoring to improve early detection and prevention strategies for chemotherapy-induced cardiomyopathy.

Statins to prevent early cardiac dysfunction in cancer patients at increased cardiotoxicity risk receiving anthracyclines

BACKGROUND AND AIMS

Anthracyclines can cause cancer therapy-related cardiac dysfunction (CTRCD). We aimed to assess whether statins prevent decline in left ventricular ejection fraction (LVEF) in anthracycline-treated patients at increased risk for CTRCD.

METHODS

In this multicenter double-blinded, placebo-controlled trial, patients with cancer at increased risk of anthracycline-related CTRCD (per ASCO guidelines) were randomly assigned to atorvastatin 40 mg or placebo once-daily. Cardiovascular magnetic resonance (CMR) imaging was performed before and within 4 weeks after anthracyclines. Blood biomarkers were measured at every cycle. The primary outcome was post-anthracycline LVEF, adjusted for baseline. CTRCD was defined as a fall in LVEF by >10% to <53%. Secondary endpoints included left ventricular (LV) volumes, CTRCD, CMR tissue characterization, high sensitivity troponin I (hsTnI), and B-type natriuretic peptide (BNP).

RESULTS

We randomized 112 patients (56.9 ± 13.6 years, 87 female, and 73 with breast cancer): 54 to atorvastatin and 58 to placebo. Post-anthracycline CMR was performed 22 (13-27) days from last anthracycline dose. Post-anthracycline LVEF did not differ between the atorvastatin and placebo groups (57.3 ± 5.8% and 55.9 ± 7.4%, respectively) when adjusted for baseline LVEF (P = 0.34). There were no significant between-group differences in post-anthracycline LV end-diastolic (P = 0.20) or end-systolic volume (P = 0.12), CMR myocardial edema and/or fibrosis (P = 0.06-0.47), or peak hsTnI (P ≥ 0.99) and BNP (P = 0.23). CTRCD incidence was similar (4% versus 4%, P ≥ 0.99). There was no difference in adverse events.

CONCLUSIONS

In patients at increased risk of CTRCD, primary prevention with atorvastatin during anthracycline therapy did not ameliorate early LVEF decline, LV remodeling, CTRCD, change in serum cardiac biomarkers, or CMR myocardial tissue changes.

TRIAL REGISTRATION

NCT03186404.

Strategies for Cardio-Oncology Care During the COVID-19 Pandemic

Purpose of review

The COVID-19 pandemic has disrupted healthcare and has disproportionately affected the marginalized populations. Patients with cancer and cardiovascular disease (cardio-oncology population) are uniquely affected. In this review, we explore the current data on COVID-19 vulnerability and outcomes in these patients and discuss strategies for cardio-oncology care with a focus on healthcare innovation, health equity, and inclusion.

Recent findings

The growing evidence suggest increased morbidity and mortality from COVID-19 in patients with comorbid cancer and cardiovascular disease. Additionally, de novo cardiovascular complications such as myocarditis, myocardial infarction, arrhythmia, heart failure, and thromboembolic events have increasingly emerged, possibly due to an accentuated host immune response and cytokine release syndrome.

Summary

Patient-centric policies are helpful for cardio-oncology surveillance like remote monitoring, increased use of biomarker-based surveillance, imaging modalities like CT scan, and point-of-care ultrasound to minimize the exposure for high-risk patients. Abundant prior experience in cancer therapy scaffolded the repurposed use of corticosteroids, IL-6 inhibitors, and Janus kinase inhibitors in the treatment of COVID-19 infection. COVID-19 vaccine timing and dose frequency present a challenge due to overlapping toxicities and immune cell depletion in patients receiving cancer therapies. The SARS-CoV-2 pandemic laid bare social and ethnic disparities in healthcare but also steered in innovation to combat problems of patient outreach, particularly with virtual care. In the recovery phase, the backlog in cardio-oncology care, interplay of cancer therapy-related side effects, and long COVID-19 syndrome are crucial issues to address.

Anthracycline-induced cardiomyopathy: cellular and molecular mechanisms

Despite the known risk of cardiotoxicity, anthracyclines are widely prescribed chemotherapeutic agents. They are broadly characterized as being a robust effector of cellular apoptosis in rapidly proliferating cells through its actions in the nucleus and formation of reactive oxygen species (ROS). And, despite the early use of dexrazoxane, no effective treatment strategy has emerged to prevent the development of cardiomyopathy, despite decades of study, suggesting that much more insight into the underlying mechanism of the development of cardiomyopathy is needed. In this review, we detail the specific intracellular activities of anthracyclines, from the cell membrane to the sarcoplasmic reticulum, and highlight potential therapeutic windows that represent the forefront of research into the underlying causes of anthracycline-induced cardiomyopathy.

Protective Effects of Statin and Angiotensin Receptor Blocker in a Rat Model of Doxorubicin- and Trastuzumab-Induced Cardiomyopathy

BACKGROUND

Chemotherapy has led to improved survival in patients with breast cancer; however, it is associated with an increased risk of cardiac dysfunction and heart failure. We investigated the protective effects of rosuvastatin and candesartan, alone and in combination, in a doxorubicin- and trastuzumab-induced rat model of cardiomyopathy.

METHODS

Forty-two rats were allocated into six groups (G1-G6): G1, control; G2, doxorubicin only; G3, doxorubicin + trastuzumab; G4, doxorubicin + trastuzumab + rosuvastatin; G5, doxorubicin + trastuzumab + candesartan; and G6, doxorubicin + trastuzumab + rosuvastatin + candesartan. Doxorubicin and trastuzumab were sequentially administered for 28 days. Left ventricular end-systolic dimension and longitudinal strain (LS) were assessed via echocardiography. Left ventricular (LV) performance was evaluated using a microcatheter in the LV apex on day 28. Blood for biomarker analysis was collected from the inferior vena cava before sacrifice.

RESULTS

Doxorubicin in combination with trastuzumab increased the LV end-systolic dimension but worsened LS compared with the control group (all P < .05). The level of C-reactive protein was lower in the rosuvastatin treatment group (P = .007) than in the controls but not in the candesartan treatment group. Both rosuvastatin and candesartan attenuated the increase in glutathione. Candesartan treatment improved +dP/dt (P = .011), whereas rosuvastatin did not. In the combination treatment group, the worsening of LS was significantly attenuated compared with that in either the rosuvastatin or candesartan group (all P < .05).

CONCLUSIONS

In a rat model of doxorubicin- and trastuzumab-induced cardiomyopathy, rosuvastatin alleviated systemic inflammation, while candesartan improved LV performance. Combination therapy with rosuvastatin and candesartan demonstrated additional preventive effects on myocardial strain. The protective mechanisms of rosuvastatin and candesartan appear to be different but complementary in chemotherapy-induced cardiomyopathy.

Definition of hidden drug cardiotoxicity: paradigm change in cardiac safety testing and its clinical implications

Unexpected cardiac adverse effects are the leading causes of discontinuation of clinical trials and withdrawal of drugs from the market. Since the original observations in the mid-90s, it has been well established that cardiovascular risk factors and comorbidities (such as ageing, hyperlipidaemia, and diabetes) and their medications (e.g. nitrate tolerance, adenosine triphosphate-dependent potassium inhibitor antidiabetic drugs, statins, etc.) may interfere with cardiac ischaemic tolerance and endogenous cardioprotective signalling pathways. Indeed drugs may exert unwanted effects on the diseased and treated heart that is hidden in the healthy myocardium. Hidden cardiotoxic effects may be due to (i) drug-induced enhancement of deleterious signalling due to ischaemia/reperfusion injury and/or the presence of risk factors and/or (ii) inhibition of cardioprotective survival signalling pathways, both of which may lead to ischaemia-related cell death and/or pro-arrhythmic effects. This led to a novel concept of 'hidden cardiotoxicity', defined as cardiotoxity of a drug that manifests only in the diseased heart with e.g. ischaemia/reperfusion injury and/or in the presence of its major comorbidities. Little is known on the mechanism of hidden cardiotoxocity, moreover, hidden cardiotoxicity cannot be revealed by the routinely used non-clinical cardiac safety testing methods on healthy animals or tissues. Therefore, here, we emphasize the need for development of novel cardiac safety testing platform involving combined experimental models of cardiac diseases (especially myocardial ischaemia/reperfusion and ischaemic conditioning) in the presence and absence of major cardiovascular comorbidities and/or cotreatments.

Upfront dexrazoxane for the reduction of anthracycline-induced cardiotoxicity in adults with preexisting cardiomyopathy and cancer: a consecutive case series

BACKGROUND

Cardiotoxicity associated with anthracycline-based chemotherapies has limited their use in patients with preexisting cardiomyopathy or heart failure. Dexrazoxane protects against the cardiotoxic effects of anthracyclines, but in the USA and some European countries, its use had been restricted to adults with advanced breast cancer receiving a cumulative doxorubicin (an anthracycline) dose > 300 mg/m2. We evaluated the off-label use of dexrazoxane as a cardioprotectant in adult patients with preexisting cardiomyopathy, undergoing anthracycline chemotherapy.

METHODS

Between July 2015 and June 2017, five consecutive patients, with preexisting, asymptomatic, systolic left ventricular (LV) dysfunction who required anthracycline-based chemotherapy, were concomitantly treated with off-label dexrazoxane, administered 30 min before each anthracycline dose, regardless of cancer type or stage. Demographic, cardiovascular, and cancer-related outcomes were compared to those of three consecutive patients with asymptomatic cardiomyopathy treated earlier at the same hospital without dexrazoxane.

RESULTS

Mean age of the five dexrazoxane-treated patients and three patients treated without dexrazoxane was 70.6 and 72.6 years, respectively. All five dexrazoxane-treated patients successfully completed their planned chemotherapy (doxorubicin, 280 to 300 mg/m2). With dexrazoxane therapy, changes in LV systolic function were minimal with mean left ventricular ejection fraction (LVEF) decreasing from 39% at baseline to 34% after chemotherapy. None of the dexrazoxane-treated patients experienced symptomatic heart failure or elevated biomarkers (cardiac troponin I or brain natriuretic peptide). Of the three patients treated without dexrazoxane, two received doxorubicin (mean dose, 210 mg/m2), and one received daunorubicin (540 mg/m2). Anthracycline therapy resulted in a marked reduction in LVEF from 42.5% at baseline to 18%. All three developed symptomatic heart failure requiring hospitalization and intravenous diuretic therapy. Two of them died from cardiogenic shock and multi-organ failure.

CONCLUSION

The concomitant administration of dexrazoxane in patients with preexisting cardiomyopathy permitted successful delivery of anthracycline-based chemotherapy without cardiac decompensation. Larger prospective trials are warranted to examine the use of dexrazoxane as a cardioprotectant in patients with preexisting cardiomyopathy who require anthracyclines.

An emerging epidemic: cancer and heart failure

Heart disease and cancer are the two leading causes of mortality globally. Cardiovascular complications of cancer therapy significantly contribute to the global burden of cardiovascular disease. Heart failure (HF) in particular is a relatively common and life-threatening complication. The increased risk is driven by the shared risk factors for cancer and HF, the direct impact of cancer therapy on the heart, an existing care gap in the cardiac care of patients with cancer and the increasing population of adult cancer survivors. The clear relationship between cancer treatment initiation and the potential for myocardial injury makes this population attractive for prevention strategies, targeted cardiovascular monitoring and treatment. However, there is currently no consensus on the optimal strategy for managing this at-risk population. Uniform treatment using cardioprotective medications may reduce the incidence of HF, but would impose frequently unnecessary and burdensome side effects. Ideally we could use validated risk-prediction models to target HF-preventive strategies, but currently no such models exist. In the present review, we focus on evidence and rationales for contemporary clinical decision-making in this novel field and discuss issues, including the burden of HF in patients with cancer, the reasons for the elevated risk and potential prevention strategies.