The 2009 STEMI/PCI guidelines update10 listed the rec- ommendation if the risk of morbidity because of bleeding outweighs the anticipated benefit afforded by thienopyridine therapy, earlier discontinuation should be considered as a Class I recommendation, although the language used, in part, was consistent with a Class IIa recommendation. To clarify the intent of the recommendation, as well as to acknowledge the inherent difficulties in weighing bleeding and stent thrombosis risks, the recommendation is designated a Class IIa recommendation, using the phrase earlier discontinuation is reasonable. Recommendations regarding P2Y12 inhibitor discontinuation before elective or urgent CABG are provided in the 2011 ACCF/AHA Guideline for Coronary Artery Bypass Graft Surgery. 824 6.1.1. PPIs and Antiplatelet Therapy: Recommendations Class I 1. PPIs should be used in patients with a history of prior gastrointestinal (GI) bleeding who require DAPT.794 (Level of Evidence: C) Class IIa 1. Use of PPIs is reasonable in patients with an in- creased risk of GI bleeding (eg, advanced age, concomitant use of warfarin, steroids, nonsteroidal anti-inflammatory drugs, Helicobacter pylori infec- tion) who require DAPT.794 (Level of Evidence: C) Class III: NO BENEFIT 1. Routine use of a PPI is not recommended for pa- tients at low risk of GI bleeding, who have much less potential to benefit from prophylactic therapy.794 (Level of Evidence: C) See Online Data Supplement 31 for additional data regarding the clopidogrel PPI interaction. PPIs are often prescribed prophylactically when clopidogrel is started to prevent GI complications such as ulceration and bleeding due to DAPT.825 There is pharmacodynamic evidence that omeprazole interferes with clopidogrel metabolism,826,827 but there is no clear evidence implicating other PPIs. 