Exercise Testing and Stress Imaging in Aortic Valve Disease.

Aortic valve disease and especially aortic stenosis (AS) is a growing cardiac pathology. Aortic valve replacement (AVR) is still the only treatment with proven benefit on survival in symptomatic patients and in patients with a left ventricular ejection fraction (LVEF) <50%. The benefit of prophylactic AVR in asymptomatic patients is still unproven. Once symptoms develop, the prognosis worsens. Exercise testing has emerged as a tool to unmask the "pseudo-asymptomatic" patients with AS (those without self-reporting symptoms), to link "exercise induced dyspnea" more confidently and more objectively to aortic valve disease and to allow for a safe "watchful waiting strategy" in "pseudo-symptomatic" patients (those with dyspnea unrelated to aortic valve disease). In cases in which exercise testing is unable to link dyspnea to aortic valve disease, exercise stress echocardiography and cardiopulmonary exercise testing may be helpful. Whatever the results of exercise testing with regard to symptom development, an increase in mean aortic valve pressure gradient >18-20 mmHg was associated with an increased risk of cardiac related events in severe AS patients (class IIb indication for AVR in the ESC guidelines). The decrease in LVEF during exercise as well as the development of exercise induced pulmonary hypertension, as revealed by exercise stress echocardiography, may be also useful in the risk stratification of these asymptomatic patients with severe AS. Data on the role of exercise echocardiography in asymptomatic severe aortic regurgitation patients is still scarce and further studies are needed. It seems that an exercise induced decrease in LVEF by 5% may be a better predictor of LV systolic dysfunction after AVR in asymptomatic patients or in patients with minimal symptoms. Exercise testing and exercise echocardiography are safe in the asymptomatic patients with aortic disease, provide useful clinical information that may help in risk assessment of these complicated patients and their use should be encouraged especially in heart valve clinics.