What are the consequences of not taking dual antiplatelet therapy (DAPT) after coronary stent placement?

From the Guidelines

Not taking dual antiplatelet therapy (DAPT) after stent placement significantly increases your risk of developing life-threatening blood clots in the stent, which can lead to heart attack, stroke, or death. DAPT typically consists of aspirin (81-325 mg daily) plus a P2Y12 inhibitor such as clopidogrel (75 mg daily), ticagrelor (90 mg twice daily), or prasugrel (10 mg daily) 1. The duration of therapy depends on your stent type and individual risk factors, but generally ranges from 1-12 months for bare metal stents and 6-12 months for drug-eluting stents, with aspirin continued indefinitely.

Key Considerations

• The stent itself is a foreign object in your artery that can trigger platelet activation and clotting, and the healing process after placement creates a thrombogenic environment 1.
• If you're experiencing side effects from these medications, don't stop taking them without consulting your cardiologist, as alternative regimens may be available.
• Missing even a few doses can be dangerous, so establish a consistent routine for taking your medications and always have enough supply, especially when traveling.
• The American College of Cardiology (ACC)/American Heart Association (AHA) guideline for percutaneous coronary intervention (PCI) recommends a minimum DAPT duration of at least 12 months after drug-eluting stents (DES) implantation, irrespective of clinical presentation 1.

Recommendations

• In patients receiving a stent (bare metal stent or DES) during PCI for acute coronary syndrome, P2Y12 inhibitor therapy should be given for at least 12 months 1.
• In patients receiving DES for a non–acute coronary syndrome indication, clopidogrel 75 mg daily should be given for at least 12 months if patients are not at high risk of bleeding 1.
• The recommendation of at least 12 months of DAPT after DES implantation for acute coronary syndrome (ACS) was supported by a subgroup analysis of a randomized trial and several observational studies 1.

From the FDA Drug Label

In patients who are managed with PCI and stent placement, premature discontinuation of any antiplatelet medication, including thienopyridines, conveys an increased risk of stent thrombosis, myocardial infarction, and death. Patients who require premature discontinuation of a thienopyridine will be at increased risk for cardiac events Lapses in therapy should be avoided, and if thienopyridines must be temporarily discontinued because of an adverse event(s), they should be restarted as soon as possible

The risk of stent thrombosis, myocardial infarction, and death is increased if dual anti-treatment is not taken after stent placement. It is essential to continue antiplatelet medication as prescribed by the doctor to minimize the risk of these cardiac events. If the medication needs to be discontinued due to an adverse event, it should be restarted as soon as possible 2.

From the Research

Risks of Not Taking Dual Antiplatelet Therapy After Stent Placement

• Stent thrombosis is a major risk if dual antiplatelet therapy is not taken after stent placement, with a hazard ratio of 13.74 (95% CI, 4.04-46.68; P < 0.001) for early discontinuation of clopidogrel within the first 6 months after drug-eluting stent placement 3.
• Early discontinuation of clopidogrel is associated with significantly higher rates of long-term clinical events, including death and myocardial infarction (MI) 3.
• The risk of major adverse cardiac events increases many fold if dual antiplatelet therapy is stopped in a patient with a drug-eluting stent within 1 year of implantation 4.

Benefits of Dual Antiplatelet Therapy

• Dual antiplatelet therapy reduces the risk of late stent thrombosis and complications, including myocardial infarction and death, after placement of a drug-eluting stent 3.
• The combination of clopidogrel and low-dose aspirin for 12 months is the preferred regimen for the prevention of stent thrombosis and cardiac complications after drug-eluting stent placement 3.
• Extended duration of antiplatelet therapy beyond 6-12 months may aid in the prevention of spontaneous MI and cardiac mortality, particularly in higher risk anatomic or clinical subgroups 5.

Duration of Dual Antiplatelet Therapy

• The optimal duration of dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stents remains uncertain 5, 6, 7.
• Short-term dual antiplatelet therapy followed by P2Y12 inhibitor monotherapy may be associated with lower major bleeding and similar stent thrombosis, all-cause death, myocardial infarction, and stroke compared with prolonged dual antiplatelet therapy 6.
• Extended-term dual antiplatelet therapy may be associated with a reduced risk of myocardial infarction, but at the expense of more bleeding events 7.