A universal definition of bleeding has been proposed to assist clinicians.547,719 721 The incidence of major bleeding in patients with ACS varies widely (0.4% to owing to differing definitions of major bleeding, patient populations, anticoagulation regimens, and PCI or CABG. Factors in patients with ACS related to an increased bleeding risk include older age, female sex, lower body weight, history of prior bleeding and/or invasive procedures, anemia, use of GP IIb/IIIa inhibitors or thrombolytics, and Non weight-based dosing of anticoagu- lants and dosing of antithrombin and antiplatelet medications that are not adjusted for CKD are associated with an increased risk of bleeding.522,697,698 Bleeding is related to adverse out- comes because it may be a marker of underlying disease, such as occult malignancy; leads to cessation of antithrombin and antiplatelet therapy; may prompt transfusion, which itself may have adverse effects; can cause hypotension; and, if intracra- nial, can be fatal.724 Proton pump inhibitors decrease the risk of upper GI bleeding, including in patients treated with DAPT. Proton pump inhibitors are used in patients with a history of prior GI bleeding who require DAPT and are an option in patients at increased risk of GI bleeding.26,430 Evaluation of the risk of bleeding includes a focused his- tory of bleeding symptoms, identification of predisposing comorbidities, evaluation of laboratory data, and calculation of a bleeding risk score.688,716,725 Approximately 15% of all patients with NSTE-ACS and 3% to 12% of those not under- going CABG receive blood transfusion.702 Rates vary widely and are closer to the lower figure but increase in association with factors such as coronary intervention, anticoagulant/ antithrombotic therapy, older age, female sex, anemia, renal insufficiency, and frailty. 