New ACC/AHA valve guidelines: aligning definitions of aortic stenosis severity with treatment recommendations

This editorial is the first of many which will address key issues in new guidelines, providing a quick overview of major changes, comparing guidelines on the same topic from different professional societies and providing additional explanation of new concepts or controversial issues. In the 2014 American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for Management of Patients with Valvular Heart Disease, a new approach to writing and presenting guidelines has been implemented.1 First we started with the evidence, summarising the published data in 28 detailed evidence tables which can be found in the online supplement to the guidelines. Next, we focused on the specific recommendations, ensuring that the level of evidence, with the key references indicated, supported the strength of the recommendation, using the standard classification from class I to class III. The precise wording of each recommendation was extensively discussed by the committee and underwent rigorous external review. The text that accompanies each recommendation provides additional details and references to ensure clinicians have the information needed to follow these guidelines. Each recommendation is presented in a modular format with the recommendation, references, text and evidence tables linked to allow easy presentation of the information across digital platforms and to allow updating of individual recommendations in the future, without updating the entire document. Several new concepts are introduced in these guidelines. We recommend a paradigm shift in the descriptions of the severity of valve disease with the introduction of disease stages, ranging from the patient-at-risk (stage A) to severe symptomatic disease (stage D). Valve disease stages are based on an integrative approach that includes patient symptoms, valve anatomy, valve haemodynamics and LV function. The example of aortic stenosis (AS) is shown in table 1. This patient centred approach to defining disease severity allows alignment of treatment recommendations with …