These included 8 of cial reviewers jointly nominated by the ACC and AHA, 4 of cial/organizational reviewers nominated by SCAI, and 25 individual content reviewers. Reviewers RWI information was distributed to the GWC and is published in this document (Appendix 3). Applying Class of Recommendation and Level of Evidence to Clinical Strategies, Interventions, Treatments, or Diagnostic Testing in Patient Care* (Updated August 2015) Levine et al. J A C C V O L . 6 7 , N O . 1 0 , 2 0 1 6 This document was approved for publication by the governing bodies of the ACC, the AHA, and the SCAI and was endorsed by the Latin American Society of Interven- tional Cardiology. 2. CULPRIT ARTERY ONLY VERSUS MULTIVESSEL PCI (See Section 5.2.2.2 of 2011 PCI guideline and Section 4.1.1 of 2013 STEMI guideline for additional recommendations.) Approximately 50% of patients with STEMI have mul- tivessel disease (25,26). PCI options for patients with STEMI and multivessel disease include: 1) culprit artery only primary PCI, with PCI of nonculprit arteries only for spontaneous ischemia or intermediate- or high-risk nd- ings on predischarge noninvasive testing; 2) multivessel PCI at the time of primary PCI; or 3) culprit artery only primary PCI followed by staged PCI of nonculprit arteries. Observational studies, randomized controlled trials (RCTs), and meta-analyses comparing culprit artery only PCI with multivessel PCI have reported con icting results (11,12,14 24,27,28), likely because of differing in- clusion criteria, study protocols, timing of multivessel PCI, statistical heterogeneity, and variable endpoints (Data Supplement). Previous clinical practice guidelines recommended against PCI of nonculprit artery stenoses at the time of primary PCI in hemodynamically stable patients with STEMI (9,10). 