Exercise in Specific Diseases: Valvular Heart Disease

Abstract

While the beneficial effects of exercise in coronary artery disease and heart failure are established as an evidence-based therapeutic strategy, valvular heart disease (VHD) shows a more complex relationship with physical activity. Evidence on beneficial effects of exercise as a conservative medical management in VHD patients is scarce, and patients with moderate to severe VHD are often discouraged from exercise. Preclinical and clinical studies support a potential beneficial role of limited exercise training programs in counteracting deconditioning and frailty and in delaying the natural history in selected cases. Following cardiac surgery, cardiac rehabilitation is effective in increasing cardiorespiratory fitness alongside an improved circulatory response to exercise, particularly after years of physical activity restriction. It further reduces cardiovascular mortality and hospital readmissions and improves quality of life. In contrast, hemodynamic improvements after valve surgery are impaired by the type of valve lesion, the degree of preoperative ventricular impairment, the extent of frailty and the presence of surgical complications. Therefore, exercise training should be part of a multidisciplinary rehabilitation approach. Prior to inclusion, patients should undergo cardiopulmonary exercise testing and echocardiography. More recently, minimally invasive cardiac surgery and percutaneous approaches facilitate an early initiation of exercise training, reducing muscular atrophy, anxiety and fatigue. Most studies focused on cardiovascular rehabilitation after transcatheter aortic valve implantation and demonstrated improvements in quality of life, 6-min walking distance and perceived physical function, whereas only few studies evaluated cardiorespiratory fitness by assessing peak oxygen uptake. The increasing significance of cardiac rehabilitation thus requires support from randomized trials to establish evidence-based exercise regimens in the growing population of surgically or interventionally treated VHD patients.

Review

1.1 Questions

• 1. A 66-year-old male patient is referred to your outpatient clinic for the evaluation of continued eligibility to perform regular and partly intensive exercise after a moderate aortic stenosis had been incidentally diagnosed during a preventive examination. His non-indexed valve orifice area was 1.1 cm² due to valve calcification, but even during more intense activities such as mountain-biking (which he loves to perform) no symptoms had occurred so far. What would be your next steps and your final advice?

• 2. When performing exercise stress echocardiography in valvular heart disease, which of the following markers indicate an increased risk of symptoms or adverse outcomes during intensive exercise (more than one answer is correct)?

  • (a) Increase of pressure gradient over mitral valve of 10 mmHg at peak exercise

  • (b) Increase of pressure gradient over mitral valve of 20 mmHg at peak exercise

  • (c) Increase of systolic pulmonary artery pressure of 30 mmHg at peak exercise

  • (d) Increase of systolic pulmonary artery pressure of 70 mmHg at peak exercise

  • (e) Increase of systolic pulmonary artery pressure of >90% of the baseline value early during exercise

• 3. A 91-year-old female patient has undergone transcatheter aortic valve implantation 1 week earlier and is now referred to a 3-week inpatient cardiac rehabilitation program. What would be your assessments and how would you start an exercise program?

1.2 Answers

• 1. Prior to any exercise recommendation, an extensive work-up of medical history, risk factors and concomitant diseases such as coronary artery disease (CAD) is required, involving cardiopulmonary exercise testing to evaluate ECG and blood pressure responses during exercise and stress echocardiography to assess the pressure gradient. Coronary angiography may also be indicated in case of signs of ischemia to rule out additional CAD and to invasively assess the severity of aortic stenosis in case of equivocal findings during echocardiography. If the aortic stenosis remains the sole finding, the decision on participating in intensive sport such as mountain-biking depends on the presence of symptoms and signs of ischemia due to relatively reduced coronary blood supply. If an ischemia threshold is detectable by ECG, the patient should be advised to remain at least 10 bpm below this threshold which might preclude more intense efforts. In case of completely unremarkable findings the patient may be cleared for exercise at higher intensities but should be advised to carefully observe symptoms during exercise and to undergo echocardiography and exercise testing follow-ups every 6 months.

• 2. The correct answers are (b), (c) and (e). These values indicate severe mitral valve stenosis and that exercise-induced dyspnea may readily be explained by hemodynamic compromises induced by valvular heart disease.

• 3. In this patient, assessments depend on the presence of any physical disabilities. Usually an evaluation of functional capacity should be performed at the beginning of a CR intervention. If possible, this patient should thus at least undergo a 6-min walking test; moreover, assessment of frailty status using one of the established methods (see text for details) and a questionnaire on health-related quality of life would be reasonable. If the patient is able to use a bicycle adequately, cardiopulmonary exercise testing should be performed in order to provide baseline parameters and to calculate exercise intensities from peak oxygen uptake. The program should then start with sessions of 10–20 min daily or even less, at an intensity of 30–50% VO₂peak or according to subjective exhaustion if not available, which often means very low, but still effective workloads of only about 20–30 Watts. A gradual increase in duration and intensity during CR should be aimed at. Strength training should also be conducted twice a week at very low intensities, e.g. 30–50% of the 1-repetition maximum, and consist of 1–2 sets with 10–15 repetitions. Although CR starts very early after the intervention there is no evidence that this might cause any harm to the newly implanted prosthesis.