The Early Valve Replacement in Severe ASYmptomatic Aortic Stenosis Study

Aortic stenosis (AS) affects approximately 5% of individuals \>65 years old, with \~3% of people \>75 years having moderate to severe disease. The prevalence of AS is rising rapidly due to an ageing population and is projected to double in the next two decades. Increasingly clinicians face the dilemma of how to best manage this growing population of mainly elderly patients, many of whom are asymptomatic but have been identified as having severe AS, often as an incidental finding. Reduced aortic valve opening progresses over decades without any apparent symptoms because the heart compensates for the AS. Ultimately, compensatory mechanisms fail resulting in angina, syncope or heart failure. If these symptomatic patients with severe AS remain untreated, they have a dire prognosis. In this situation the only effective treatment is AVR, either surgically or using TAVI. Conversely, conventional teaching and clinical practice in cardiology has been that, in the absence of symptoms, the prognosis is usually excellent and, except in a few very specific circumstances, conservative management and regular review (expectant management) is recommended. This advice is reflected in current international guidelines but is based largely on historical precedent. There has never been a randomised controlled trial to address the relative benefits of early AVR versus expectant management in patients with severe asymptomatic AS. The relative benefits of a strategy of early AVR/TAVI versus expectant management in patients with asymptomatic severe AS are unclear. There is clinical equipoise but it remains one of the few areas of cardiovascular medicine where no randomised controlled trials (RCT) have been performed. The EASY-AS study will provide crucial data on the relative merits of these differing approaches to management, in terms of important patient orientated outcomes, conventional cardiovascular end-points and cost effectiveness.