Management of STEMI Patient with PCI Restenosis Who Cannot Tolerate Prasugrel or Afford Rivaroxaban
For a STEMI patient with PCI restenosis on clopidogrel who cannot tolerate prasugrel and cannot afford rivaroxaban 2.5 mg, ticagrelor 60 mg twice daily should be considered as the next antiplatelet agent of choice.
Antiplatelet Options After PCI Restenosis
Current Situation Assessment
- Patient has experienced restenosis while on clopidogrel therapy
- Prasugrel is not tolerated
- Rivaroxaban 2.5 mg is not affordable
- Need for more effective antiplatelet therapy is evident 1
Recommended Alternative Therapy
- Ticagrelor 60 mg twice daily is the recommended next option for this patient 1
- Provides more potent platelet inhibition than clopidogrel
- Has different chemical structure than prasugrel (may avoid cross-reactivity)
- Shown to reduce ischemic events in high-risk post-MI patients 1
Evidence-Based Rationale
Limitations of Current Therapy
- Clopidogrel resistance occurs in up to 25% of STEMI patients undergoing PCI and is associated with increased risk of recurrent cardiovascular events 2
- Patient's restenosis while on clopidogrel suggests inadequate platelet inhibition 1
Benefits of Ticagrelor
- More rapid, potent, and predictable antiplatelet effect compared to clopidogrel 3
- Belongs to a different chemical class (cyclopentyltriazolopyrimidine) than thienopyridines (clopidogrel and prasugrel), reducing risk of cross-reactivity 4, 5
- The PEGASUS-TIMI 54 trial demonstrated efficacy of ticagrelor 60 mg BID in post-MI patients for secondary prevention 1
Implementation Plan
Dosing and Administration
- Loading dose: 180 mg (if switching directly from clopidogrel)
- Maintenance dose: 60 mg twice daily
- Must be used with low-dose aspirin (75-100 mg daily) 1
Monitoring Considerations
- Assess for dyspnea, which occurs in approximately 14% of patients on ticagrelor
- Monitor for bleeding complications
- Evaluate for bradyarrhythmias, especially in first week of therapy 1
Important Precautions
Contraindications
- History of intracranial hemorrhage
- Active pathological bleeding
- Severe hepatic impairment 1
Drug Interactions
- Avoid concomitant use with strong CYP3A4 inhibitors or inducers
- Unlike clopidogrel, ticagrelor does not require hepatic activation, reducing variability in response 3
- No dose adjustment needed for patients taking proton pump inhibitors 1
Duration of Therapy
- Continue dual antiplatelet therapy for at least 12 months after DES placement 1
- Consider extended therapy beyond 12 months given the patient's high-risk status (restenosis) 1
Alternative Options if Ticagrelor Not Suitable
- Consider cilostazol as add-on therapy to clopidogrel and aspirin 4
- Genetic testing for CYP2C19 polymorphisms to assess clopidogrel metabolism if available 1
- Consider platelet function testing to guide therapy 2
Follow-up Recommendations
- Regular clinical evaluation for signs of ischemia
- Assess compliance with dual antiplatelet therapy
- Periodic monitoring of complete blood count 1