Performance of PCI with enoxaparin may be reason- able in patients treated with upstream subcutaneous enoxaparin for NSTE-ACS.26,309,399 402,405,406 (Level of Evidence: B) Class III: Harm 1. Fondaparinux should not be used as the sole an- ticoagulant to support PCI in patients with NSTE- ACS due to an increased risk of catheter thrombo- (Level of Evidence: B) Anticoagulant therapy prevents thrombus formation at the site of arterial injury, on the coronary guide wire, and in the catheters used for PCI.26,407 With rare exceptions, all PCI studies have used some form of anticoagulant at the time Intravenous UFH and bivalirudin both have Class I recommendations in patients undergoing PCI in the 2011 Patients who have received multiple doses of subcutaneously-administered enoxaparin who undergo PCI within 8 hours of the last subcutaneous dose generally have received adequate anticoagulation to undergo PCI, but the degree of anticoagulation may diminish 8 to 12 hours after the last subcutaneous dose. In such patients, as well as in patients who have received fewer than 2 subcutaneous doses of enoxaparin, the addition of enoxaparin (0.3 mg/kg IV) at the time of PCI provides additional anticoagulation and has become standard practice.26,309,399 403 Patients who undergo PCI >12 hours after the last subcutaneous dose of enoxa- parin are usually treated with full-dose de novo anticoagu- lation with an established regimen (eg, full-dose UFH or bivalirudin). Fondaparinux as the sole anticoagulant during PCI has been associated with catheter thrombosis, and use of an anticoagulant with anti-IIa activity is recommended when patients treated with fondaparinux undergo PCI.313 315 One suggested regimen is UFH 85 IU/kg IV if no GP IIb/IIIa inhibitor is used and 60 IU/kg IV if a GP IIb/IIIa inhibitor is used with UFH dosing based on the target-activated clotting Amsterdam et al 2014 AHA/ACC NSTE-ACS Guideline e375 5.2. 