Prevention Using Exercise Rehabilitation to Offset Cardiac Toxicities Induced Via Chemotherapy

With more than 14 million cancer survivors in the United States, more patients than ever are living well beyond their initial cancer diagnosis. However despite the tremendous progress, cancer treatments often come with adverse side-effects, perhaps none are more serious or devastating than chemotherapy induced heart failure.

In many patients, the clinical manifestation of heart failure may not appear until a year, or several years, after completion of chemotherapy. While an echocardiogram is part of standardized surveillance for patients on these drugs, current echocardiogram parameters may not be sensitive enough to quickly detect early heart damage which, in some cases, is irreversible.

Unfortunately, even if detected early, there is no uniformity in terms of how to best treat patients with subclinical cardiac dysfunction who are at risk for heart failure. The use of certain blood pressure drugs show promise, especially in patients with hypertension. However, in addition to drug side-effects (e.g. dizziness/lightheadedness), they do not target the underlying mechanism of chemotherapy induced cardiotoxicity.

Exercise, in various forms, has shown promise in animal studies as a potential cardio-protective therapy to counteract drug toxicity. In general, exercise has many pleiotropic effects for patients receiving chemotherapy (e.g. reduces fatigue, improves endurance, reduces frailty, and enhances quality of life). Relative to DOX toxicity, research involving animals has also shown that exercise protects against deleterious heart dysfunction while showing an enhancement of potential mechanisms involved in chemotherapy induced heart failure (i.e. anti-oxidant and anti-apoptosis pathways).

Patients with cancer who receive either doxorubicin (DOX) or trastuzumab will be screened by one of two methods: 1) a strain echo or 2) a high sensitivity troponin. If either test is positive, patients will meet with a board-certified cardiologist who will determine if the patient may participate in the exercise trial. Under the supervision of a trained clinical exercise physiologist patients will undergo baseline testing, which includes: a quality of life assessment via questionaires, a body composition test, cardiopulmonary stress test and a muscle strength test. These assessment will be performed at baseline and at 12 weeks. Also performed at 12 weeks will be a repeat strain echo and high sensitivity troponin.