Anticoagulant Therapy

For NSTEMI

UFH: 60 U/kg IVB (max 4000 U) then 12 U/kg/h (max 1000 U/h initially) × 48 h or until end of PCI

24% ↓ D/MI (JAMA 1996;276:811)

Titrate to aPTT 1.5–2× control (~50–70 sec)

Hold until INR <2 if already on warfarin

Enoxaparin (low-molec-wt heparin) 1 mg/kg SC bid (± 30 mg IVB) (qd if CrCl <30) × 2–8 d or until PCI

~10% ↓ D/MI vs. UFH (JAMA 2004;292:45,89). Can perform PCI on enox (Circ 2001;103:658), but ↑ -bleeding if switch b/w enox and UFH.

Bivalirudin (direct thrombin inhibitor) 0.75 mg/kg IVB at PCI → 1.75 mg/kg/h

No diff in bleeding, MI, or death c/w UFH (NEJM 2017;377:1132). Use instead of UFH if HIT.

Fondaparinux (Xa inh) 2.5 mg SC qd

Rarely used; must supplement w/ UFH if PCI.

For STEMI

UFH

60 U/kg IVB (max 4000 U) 12 U/kg/h (max 1000 U/h initially) No demonstrated mortality benefit ↑ patency with fibrin-specific lytics Titrate to aPTT 1.5–2× control (~50–70 sec)

Enoxaparin

| Lysis: 30 mg IVB → 1 mg/kg SC bid (adjust for age >75 & CrCl) | Lysis: 17% ↓ D/MI w/ ENOX × 7 d vs. UFH × 2 d (NEJM 2006;354:1477) | | PCI: 0.5 mg/kg IVB | PCI: ↓ D/MI/revasc and ≈ bleeding vs. UFH (Lancet 2011;378:693) |

Bivalirudin

0.75 mg/kg IVB → 1.75 mg/kg/hr IV PCI: similar bleeding, ± ↑ MI, ↑ stent thromb, ↓ mortality in some but not all trials (Lancet 2014;384:599; JAMA 2015;313:1336; NEJM 2015;373:997)

Fondaparinux can be used (if CrCl >30 mL/min) in setting of lysis, where superior to UFH w/ less bleeding (JAMA 2006;295:1519). Adapted from ACC/AHA 2013 STEMI Guidelines (Circ 2013;127:529; Lancet 2013;382:633).