Should a 56-year-old male with a history of ST-Elevation Myocardial Infarction (STEMI), currently asymptomatic and taking Aspirin (acetylsalicylic acid) 81mg and Effient (prasugrel) for 12 months, continue both medications or discontinue Effient (prasugrel) and continue Aspirin (acetylsalicylic acid) indefinitely for secondary prevention?

From the Guidelines

For a 56-year-old male with a history of STEMI who has been on dual antiplatelet therapy (DAPT) with Aspirin 81mg and Effient (prasugrel) for 12 months without side effects, I recommend continuing both Aspirin and Effient as long as the patient remains asymptomatic and without bleeding complications, as the benefits of extended DAPT may outweigh the risks in certain patients. The 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease 1 suggests that in patients with STEMI treated with DAPT, a daily aspirin dose of 81 mg is recommended, and P2Y12 inhibitor therapy should be continued for at least 12 months. Some key points to consider in this decision include:

• The patient's lack of high bleeding risk factors, such as prior bleeding on DAPT, coagulopathy, or oral anticoagulant use, which makes extended DAPT a more reasonable option 1.
• The patient's current asymptomatic status and tolerance of the medications without side effects, which suggests that the benefits of continued DAPT may outweigh the risks.
• The potential for extended DAPT to provide additional protection against ischemic events, particularly in patients with high ischemic risk features, although this must be balanced against the individual patient's bleeding risk. It is essential to weigh the patient's individual bleeding risk against ischemic risk and consider factors such as complex coronary anatomy, multiple stents, or prior stent thrombosis when deciding on the duration of DAPT. In this case, since the patient has been on DAPT for 12 months without complications and is asymptomatic, continuing both Aspirin and Effient may be a reasonable approach, as suggested by the guideline 1, which states that continuation of DAPT for longer than 12 months may be reasonable in patients who have tolerated DAPT without bleeding complications and are not at high bleeding risk.

From the FDA Drug Label

Prasugrel tablets are used to lower your chance of having another serious problem with your heart or blood vessels, such as another heart attack, a stroke, blood clots in your stent, or death. Do not stop taking prasugrel tablets without talking to the doctor who prescribes them for you. People who are treated with angioplasty and have a stent, and stop taking prasugrel tablets too soon, have a higher risk of a blood clot in the stent, having a heart attack, or dying. Your doctor will decide how long you should take prasugrel tablets.

The patient can continue both aspirin and prasugrel as long as he feels fine, since the drug label states that prasugrel tablets should be taken with aspirin as instructed by the doctor, and the doctor will decide how long the patient should take prasugrel tablets 2, 2.

• The patient should not stop taking prasugrel without first talking to the doctor who prescribed them.
• Aspirin should be continued indefinitely as part of the dual antiplatelet therapy (DAPT) regimen.
• Prasugrel can be continued as part of the DAPT regimen, as it has been shown to be effective in reducing the risk of another heart attack, stroke, or death in patients with a history of heart attack or severe chest pain.

From the Research

Dual Antiplatelet Therapy (DAPT) in STEMI Patients

• The patient in question has been taking Aspirin 81 and Effient (prasugrel) for 12 months without any side effects after a STEMI event.
• The decision to continue or stop Effient and keep Aspirin indefinitely depends on the risk-benefit ratio of DAPT in this patient population.
• According to the study by 3, long-term DAPT with prasugrel or ticagrelor beyond 12 months reduces fatal and non-fatal ischemic events, offsetting the increased risk of bleeding in unselected real-world acute coronary syndrome patients treated with percutaneous coronary intervention.

Risk-Benefit Ratio of DAPT

• The study by 4 found that short-course clopidogrel plus aspirin immediately following an ischemic stroke or transient ischemic attack appears to be more effective than and as safe as monotherapy for secondary stroke prevention.
• However, the study by 3 suggests that prolonged DAPT beyond 12 months may be beneficial in reducing ischemic events, despite an increased risk of bleeding.
• The patient's age (56 years) and lack of bleeding complications during the initial 12 months of DAPT suggest that continued DAPT may be beneficial.

Aspirin Therapy in Primary and Secondary Prevention

• Aspirin therapy is widely accepted for secondary prevention of atherosclerotic cardiovascular disease (ASCVD) in all patient populations, as the benefits linked to the reduction of clinical events outweigh the risk of major bleeding 5.
• However, the use of aspirin in primary prevention is more debated, and a personalized therapeutic approach is recommended, taking into account the individual's estimated ASCVD risk and potential benefits and harms of aspirin therapy 5, 6.

Recommendations for DAPT in this Patient

• Based on the available evidence, it is reasonable to continue DAPT with Aspirin and Effient (prasugrel) beyond 12 months, given the patient's low risk of bleeding complications and the potential benefits of reducing ischemic events.
• However, regular monitoring of the patient's bleeding risk and ischemic event risk is necessary to adjust the DAPT regimen as needed.
• The decision to continue or modify DAPT should be individualized, taking into account the patient's preferences, bleeding risk, and ischemic event risk, as well as the potential benefits and harms of continued DAPT 3, 7.