In a patient with thrombus‑laden ST‑elevation myocardial infarction who underwent plain‑old‑balloon angioplasty and received a tirofiban (glycoprotein IIb/IIIa inhibitor) infusion, should unfractionated heparin anticoagulation be continued after the tirofiban drip is stopped while awaiting staged drug‑eluting stent placement?

Anticoagulation Management After POBA in Thrombus-Laden STEMI

Yes, unfractionated heparin anticoagulation should be continued after tirofiban is stopped in patients awaiting staged DES placement, as the ACC/AHA guidelines provide a Class I recommendation to continue UFH through PCI with additional boluses as needed to maintain therapeutic ACT. 1

Guideline-Based Anticoagulation Strategy

During the Interim Period (Post-POBA, Pre-Stenting)

• Continue UFH anticoagulation with IV boluses as needed to maintain therapeutic activated clotting time (ACT) until the staged DES procedure is performed. 1

• The target ACT depends on whether GP IIb/IIIa inhibitors are still being used:

  • Without GP IIb/IIIa inhibitor: Target ACT 250-300 seconds (HemoTec device) or 300-350 seconds (Hemochron device). 1
  • With GP IIb/IIIa inhibitor: Target ACT less than 300 seconds. 1

• Tirofiban should be discontinued 2-4 hours before the staged PCI if urgent surgery becomes necessary, though this is not your scenario since you're proceeding to staged stenting. 1

Rationale for Continued Anticoagulation

• High thrombotic risk: Your patient has a thrombus-laden STEMI with only balloon angioplasty performed—no definitive stent placement yet. This creates an unstable coronary lesion with exposed endothelium and residual thrombus burden that requires ongoing anticoagulation to prevent acute vessel closure or propagation of thrombus. 2

• Bridging to definitive therapy: The interval between POBA and staged DES placement represents a vulnerable period where the disrupted plaque and vessel wall injury create a prothrombotic substrate. 2

• Post-heparin infusions are NOT recommended after uncomplicated PCI with stent placement, but your patient has not yet received definitive stenting—only temporizing balloon angioplasty. 1

Critical Timing Considerations

• If tirofiban was discontinued: The short-acting GP IIb/IIIa inhibitor tirofiban has a plasma half-life of approximately 2 hours, with platelet function recovering within 4-8 hours after discontinuation. 3

• During this recovery period, maintaining therapeutic anticoagulation with UFH is essential to prevent acute thrombotic complications before platelet inhibition from oral agents (aspirin and P2Y12 inhibitor) becomes fully effective. 3

Antiplatelet Therapy Concurrent with Anticoagulation

• Continue aspirin 81-325 mg daily throughout the interim period. 1

• Ensure adequate P2Y12 inhibitor loading has occurred:

  • If clopidogrel was given with initial presentation: Continue 75 mg daily without additional loading. 1
  • If no prior P2Y12 loading: Administer clopidogrel 600 mg loading dose (or prasugrel 60 mg if >24 hours from any fibrinolytic therapy and no prior stroke/TIA). 1

At Time of Staged DES Placement

• Continue UFH through the staged PCI procedure, administering additional IV boluses as needed to maintain therapeutic ACT. 1

• After successful DES placement: Discontinue UFH—routine post-PCI heparin infusions are not recommended and may increase bleeding risk. 1

• Initiate or continue dual antiplatelet therapy for at least 12 months:

  • Aspirin 81 mg daily (preferred maintenance dose) indefinitely. 1
  • Clopidogrel 75 mg daily OR prasugrel 10 mg daily for minimum 1 year. 1

Common Pitfalls to Avoid

• Do not discontinue anticoagulation in the interim period between POBA and staged stenting—this is NOT an "uncomplicated PCI" scenario where post-procedural heparin can be safely omitted. 1

• Do not "cross over" between different anticoagulants (e.g., switching from UFH to enoxaparin or vice versa) during this period, as this increases bleeding risk without improving efficacy. 1

• Do not rely on ACT monitoring if you switch to low-molecular-weight heparin, as LMWHs have minimal effect on ACT measurements. 1

• Monitor for tirofiban-induced thrombocytopenia: Check platelet count within 24 hours of tirofiban administration, as severe thrombocytopenia can occur and requires immediate drug discontinuation. 4