The Task Force recognizes the need for objective, indepen- dent Evidence Review Committees (ERCs) that include meth- odologists, epidemiologists, clinicians, and biostatisticians who systematically survey, abstract, and assess the evidence to address key clinical questions posed in the PICOTS format (P=population, I=intervention, C=comparator, O=outcome, Practical considerations, including time and resource constraints, limit the ERCs to evidence that is relevant to key clinical questions and lends itself to sys- tematic review and analysis that could affect the strength of corresponding recommendations. Recommendations devel- oped by the GWC on the basis of the systematic review are marked SR . Guideline-Directed Medical Therapy The term guideline-directed medical therapy refers to care defined mainly by ACC/AHA Class I recommendations. For these and all recommended drug treatment regimens, the reader should confirm dosage with product insert mate- rial and carefully evaluate for contraindications and interac- tions. Recommendations are limited to treatments, drugs, and devices approved for clinical use in the United States. Class of Recommendation and Level of Evidence The Class of Recommendation (COR; ie, the strength of the rec- ommendation) encompasses the anticipated magnitude and cer- taintyofbenefitinproportiontorisk.TheLevelofEvidence(LOE) rates evidence supporting the effect of the intervention on the basis of the type, quality, quantity, and consistency of data from clinical trials and other reports (Table 1).5,7 Unless otherwise stated, recom- mendations are sequenced by COR and then by LOE.Where com- parative data exist, preferred strategies take precedence. When >1 drug, strategy, or therapy exists within the same COR and LOE and no comparative data are available, options are listed alphabetically. Each recommendation is followed by supplemental text linked to supporting references and evidence tables. Relationships With Industry and Other Entities The ACC and AHA sponsor the guidelines without com- mercial support, and members volunteer their time. 