Heart disease remains the number one killer of men and women in the US, claiming more lives than all forms of cancer combined, according to the American Heart Association.
Cancer treatments can cause cardiac toxicity that can lead to a poor quality of life long after the cancer has been treated, and even premature death. According to American Heart Association Scientific Statement on Cardiovascular Disease and Breast Cancer, issued in February 2018, the risk of mortality attributable to CVD is higher in breast cancer survivors than in women without the disease. The increased risk is evident approximately seven years after the breast cancer diagnosis.
Chemotherapy drugs with the potential to harm the heart remain in use because they’re effective cancer fighters. They include anthracycline (AC)-based chemotherapeutic agents, such as doxorubicin, daunorubicin, epirubicin, and idarubicin, a class of drug commonly used to treat breast and lymphoma and HER2-targeted agents such as Herceptin (trastuzumab, pertuzumab and lapatinib).
The early or delayed cardiotoxicity that can result from oncology treatment includes left ventricular dysfunction leading to heart failure, thromboembolic disease, hypertension, arrhythmias, myocardial ischemia, valvular disease, pulmonary hypertension, and pericarditis. AC-induced cardiotoxicity isn’t reversible and may require medication to help the heart work efficiently.
It is estimated that of treated patients, 2 to 4% will experience clinically symptomatic heart failure, 9-11% will experience an asymptomatic fall in LVEF, arrhythmia will occur in 12% or more, and cardiac biomarkers rise in 30–35%, according to a study in Cardiovascular Drugs and Therapy. Predictors of cardiotoxicity include cardiovascular risk factors, age at treatment, and cumulative dose of therapy.
The authors suggested that continuing to investigate ways to protect the heart during cancer therapy is necessary. This may include prescribing cardioprotective agents that are not routinely used prophylactically, such as IV dexrazoxane, which is given concurrently for anthracycline patients with chemotherapy, to help counteract cardiotoxic side effects, ACE-inhibitors, ARBs, and beta-blockers.
The AHA also recommends heart monitoring strategies for patients with breast cancer, such as echocardiography and/or strain imaging, MUGA scans, cardiac MRI, and/or feature tracking (FT-MRI) and biomarkers — such as troponins and B-type natriuretic peptide. If scans indicate that a patient’s cardiac function is declining over time, it may be necessary to switch to a different, more cardio-friendly chemotherapy drug, even if it is less effective at preventing cancer recurrence.
A systematic review in the American Journal of Physiology-Heart and Circulatory Physiology also found that it may be important to encourage patients undergoing cancer treatment to get plenty of aerobic exercise, such as walking, running, biking, and rowing. “Although AC treatment can decrease exercise capacity, aerobic exercise prescription before, concomitant, and after AC treatment provides cardioprotective benefits, which can mitigate or even prevent AC-induced cardiotoxicity,” the authors wrote.
For more information on how to help patients undergoing cancer treatment exercise safely, visit the American Cancer Society.
Last updated on 9/25/19.