In this prospective study with a single group pre-test post-test design, a 6-month comprehensive CVD risk reduction program involving structured cardio-oncology evaluation with regular motivational interviewing counseling for improved nutrition and adherence to individualized physical fitness prescriptions resulted in improvement in patient-reported mental health despite breast cancer diagnosis and exposure to potentially cardiotoxic cancer treatments. Although patient-reported physical health declined, numerous measures of health-related fitness, dietary habits, and CV health were maintained or improved.
Although breast cancer and CVD remain common causes of morbidity and mortality in the United States, survival has improved significantly for both diseases due to improved screening and treatment [12]. There is also increasing recognition that both CVD and breast cancer share common risk factors, such as age, diet, and family history [6]. Around 80% of CVD can be prevented with interventions such as healthy diet, tobacco cessation, blood pressure and diabetes mellitus control and physical activity [13]. Similar interventions can also improve breast cancer outcomes yet there are no standard recommendations for the management and monitoring of CVD in cancer patients and survivors [14].
While much of the attention from cardio-oncology interventions has focused on the prevention of disease development such as heart failure or ischemic heart disease, there is an increasing body of literature demonstrating the positive impact of patient reported psychosocial outcomes on the long-term health of breast cancer patients [15, 16]. To assess the mental well-being of our patients, we used the mental component of the well-validated SF-36 [17]. The mental component score of the survey improved in our patients after the intervention, highlighting the potential psychological impact of a multidisciplinary approach to improving the cardiovascular health of breast cancer patients.
Despite the patient-reported improvement in mental well-being, participants in our study reported lower perceived physical health post-intervention. Nevertheless, objective markers of health-related fitness were maintained or improved over the course of the study. For example, both systolic and diastolic blood pressure significantly improved after the intervention. Systolic blood pressure reduced by 12 points, while diastolic blood pressure reduced by 6 points. This decline in blood pressure is similar to what has been reported with certain heart-healthy diets, such as the DASH (Dietary Approach to Stop Hypertension) eating plan [18, 19]. Similarly, we observed a statistically significant improvement in muscular endurance as assessed by arm curl repetitions after the intervention. The arm-curl test is a common and validated field test to assess for upper extremity strength via repetitions of elbow flexion and extension performed with a dumbbell over 30 seconds [20]. We hypothesize that this decline in the patient-reported perception of physical health is related to the challenges faced with cancer treatments such as chemotherapy, radiotherapy, and breast surgery. It is possible that this decline may have been more pronounced in a control group and the intervention in this study may have attenuated the overall decline.
It is important to motivate cancer patients to maintain physical activity during and after treatment. Women in their 40 s with breast cancer have a mean cardiorespiratory fitness level 30–32% lower than age-matched controls [21]. Exercise training is the primary modality used to improved cardiorespiratory fitness within an increasing body of literature demonstrating its benefit in the breast cancer population. For example, a meta-analysis of 27 studies demonstrated a significant improvement in cardiorespiratory fitness after adjuvant therapy among women actively engaged in exercise training [22].
This is also one of a relatively small number of studies to objectively evaluate changes in CV nutrition habits in breast cancer patients. We utilized The Rapid Eating and Activity Assessment for Patients (REAP), a brief validated questionnaire designed to evaluate dietary and physical activity patterns with higher scores indicating healthier eating behaviors [10]. The REAP scores significantly increased indicating improved dietary habits as a result of our motivational interventions. This is consistent with recommendations from the American Heart Association to tailor nutritional counseling to the unique needs of cancer patients [7].
Our findings underscore the results from other studies that have aimed to identify non-pharmacological interventions to decrease CVD events in breast cancer patients. Jones and colleagues found exercise was associated with substantial reductions in the incidence of cardiovascular events in women with nonmetastatic breast cancer [23]. Similarly a recent retrospective study by Okwuosa and colleagues demonstrated that exercise exposure prior to breast cancer diagnosis was associated with a significant reduction in CVD events in long-term survivors [24]. Although our study was not designed to assess long-term CVD outcomes, the impact on quality of life and markers of health-related fitness may translate into improved and enduring health effects.