Class of Recommendation and Level of Evidence The Class of Recommendation (COR) and Level of Evi- dence (LOE) are derived independently of one another according to established criteria. The COR indicates the strength of recommendation, encompassing the esti- mated magnitude and certainty of bene t of a clinical action in proportion to risk. The LOE rates the quality of scienti c evidence supporting the intervention on the basis of the type, quantity, and consistency of data from clinical trials and other sources (Table 1) (1,7,8). Relationships With Industry and Other Entities The ACC and AHA sponsor the guidelines without com- mercial support, and members volunteer their time. The Task Force zealously avoids actual, potential, or perceived con icts of interest that might arise through relationships with industry or other entities (RWI). All Guideline Writing Committee (GWC) members and re- viewers are required to disclose current industry re- lationships or personal interests from 12 months before initiation of the writing effort. Management of RWI in- volves selecting a balanced GWC and assuring that the chair and a majority of committee members have no relevant RWI (Appendixes 1 and 2). Members are restricted with regard to writing or voting on sections to which their RWI apply. For transparency, members comprehensive disclosure information is available online. Comprehensive disclosure information for the Task Force is also available online. The Task Force strives to avoid bias by selecting experts from a broad array of back- grounds representing different geographic regions, sexes, ethnicities, intellectual perspectives/biases, and scopes of clinical practice, and by inviting organizations and pro- fessional societies with related interests and expertise to participate as partners or collaborators. 