Updated standardized endpoint definitions for transcatheter aortic valve implantation: The Valve Academic Research Consortium-2 consensus document

Objectives: The aim of the current Valvular Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI)- clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand understanding of patient risk stratification and case selection. Background: A recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous. Methods and results: Two in-person meetings (held in September 2011 in Washington, DC, USA, and in February 2012 in Rotterdam, The Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and non-interventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the United States Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document also provides an overview of risk assessment and patient stratification that needed to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding, acute kidney injury, vascular complications, conduction disturbances & arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiographic recommendations are provided for evaluation of prosthetic valve (dys)function. Definitions for quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints. Conclusions: This VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of study results, supplying an increasingly growing body of evidence with respect to transcatheter aortic valve implantation and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavors of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).