The statement from the American Heart Association on cardio-oncology rehabilitation includes steps to identify cancer patients at high risk for cardiac dysfunction and also gives an overview of the cardiac rehabilitation infrastructure needed to address the complications related to cancer care.

Cancer patients are at increased risk of morbidity and mortality from noncancerous causes, such as cardiovascular disease (CVD). The elevated CVD risk can occur from the direct effects of cancer therapies as well as the presence of concomitant risk factors such as hypertension, weight gain, cigarette smoking, and loss of cardiorespiratory fitness.

Effective strategies to tackle cardiovascular disease risk in cancer patients are the need of the hour. Cardiac rehabilitation (CR) programs may prove to be a potential solution to this problem. CR is defined as “the provision of comprehensive long-term services involving medical evaluation, prescriptive exercise, cardiac risk factor modification, and education, counseling, and behavioral interventions.”

The American Heart Association has proposed a comprehensive model termed cardio-oncology rehabilitation (CORE) to identify patients at high risk of CVD including cardiotoxicity related to cancer therapies. CORE encompasses the use of a multimodality approach of CR (eg, exercise plus nutritional counseling and cardiovascular risk factor assessment) to prevent or mitigate cardiovascular events.

Role of structured exercise training in cardiac rehabilitation for patients with cancer

Cardiorespiratory fitness or CRF includes an integrative assessment of global cardiovascular function. CRF is known to decline during exposure to various systemic anticancer therapeutics; furthermore CRF may not recover after treatment cessation

Exercise training is the mainstay of contemporary CR and is a well-known therapy to improve CRF. In those with pre-existing CVD, exercise training leads to reductions in cardiovascular morbidity and its accompanying symptoms.

Current evidence demonstrates that exercise may attenuate the cancer treatment–induced declines in CRF; exercise training may also improve CRF after the completion of cancer therapy.

As per current investigations, CR models are a feasible option and can improve CRF, muscular strength, and quality of life in cancer survivors. As cancer therapy can result in increased risk of morbidity and mortality, identifications of survivors at greatest risk and delivering individualised interventions should be the main focus.

Apart from the therapy-related decline in CRF, preexisting and treatment-related modifiers may also elevate CVD risk. Due to the shared pathways of CVD and cancer, risk factors for CVD such as smoking, hypertension, diabetes mellitus, dyslipidaemia, and obesity may be higher in cancer survivors.

The CORE algorithm: A targeted approach to identify patients who may benefit from multimodal cardiac rehabilitation

The American Heart Association has presented a targeted approach to identify cancer patients who may derive the greatest benefit from multimodal cardiac rehabilitation.

The CORE algorithm is based on a patient’s underlying risk of cardiac dysfunction (based on the American Society of Clinical Oncology clinical practice guideline), cardiac symptoms, or CVD history.

• In patients eligible for CORE, cardiopulmonary safety should be assessed (before initiating CORE) with cardiopulmonary exercise testing.
• The protocol used should consider age, habitual physical activity, and the anticipated functional capacity of the patient.
• Cardiorespiratory fitness can be assessed using a modified Balke protocol (treadmill test). A 6-minute walk test can also be used to evaluate the functional capacity of patients with cancer before they begin an exercise routine.
• Cancer rehabilitation such as physical therapy, occupational therapy should be initiated before CORE in patients where exercise may be limited or unsafe. Such group includes patients with treatment-related frailty, musculoskeletal, neurological, or cognitive issues, bone loss, and ongoing treatment.
• If patients with cancer demonstrate functional impairments during or after active CORE, a cancer rehabilitation consultation should be done before or in concert with CORE.

The type and duration of treatment with CORE, as well as the optimal time to initiate a patient-specific rehabilitation program are highly individualised. As per the CORE algorithm, referral to CORE should be based on exposures and symptoms, not timing after a cancer diagnosis.

Both centre-based and home-based exercise programs can be initiated in cancer patients; patient preference, safety, and efficacy should be considered while choosing the best option.

Center-based CORE programs is apt for patients with cancer who are preparing for or have completed their most intensive surgical, chemotherapy, and radiation therapy interventions and thus have fewer structured medical appointments. On the other hand, home-based CORE programs may be advantageous for those who are deemed safe to exercise due to its lower-cost and convenience.