From the Guidelines
For a 56-year-old male with a history of STEMI who has been on dual antiplatelet therapy (DAPT) with Aspirin 81 mg and Prasugrel (Effient) for 12 months without side effects, I recommend transitioning to Aspirin 81 mg alone indefinitely while discontinuing Effient. The standard recommendation for DAPT following a STEMI is typically 12 months, after which the bleeding risk generally outweighs the additional benefit of continued dual therapy, as suggested by the 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease 1. For secondary prevention, single antiplatelet therapy with low-dose Aspirin (81 mg daily) is the preferred long-term strategy, with the recommendation to continue aspirin indefinitely 1. However, certain high-risk patients might benefit from extended DAPT beyond 12 months, particularly those with complex coronary disease, multiple stents, or recurrent events. If the patient has remained asymptomatic and has no additional risk factors like diabetes or hypertension, the benefit-risk ratio favors Aspirin monotherapy. This approach balances effective prevention of future cardiovascular events while minimizing bleeding complications, as supported by the guidelines that recommend a daily aspirin dose of 81 mg for patients treated with DAPT 1. Should any new cardiac symptoms develop or if the patient undergoes additional coronary interventions, the antiplatelet regimen should be reassessed. Key considerations include:
- The patient's lack of side effects on current DAPT regimen
- The absence of high-risk features for bleeding or recurrent events
- The importance of indefinite aspirin therapy for secondary prevention, as emphasized in the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention 1. Given these factors, transitioning to Aspirin monotherapy is the most appropriate next step for this patient, aligning with the most recent and highest quality evidence available 1.
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) for Secondary Prevention
- The patient has been taking Aspirin 81 and Effient (prasugrel) for 12 months without any side effects, and is asymptomatic.
- According to the study 3, DAPT with prasugrel or ticagrelor prolonged beyond 12 months markedly reduces fatal and non-fatal ischemic events, offsetting the increased risk deriving from the higher bleeding risk.
- However, this benefit may not apply to patients older than 75 years or female patients, due to an increased risk of bleeding 3.
Aspirin Dosing for Secondary Prevention
- The study 4 found that the relative effectiveness and safety of high- versus low-dose aspirin was not modified by baseline P2Y12 inhibitor use, such as prasugrel.
- Another study 5 found no significant sex-specific differences in the effectiveness and safety of 2 aspirin doses for secondary prevention of atherosclerotic cardiovascular disease events.
Recommendations for DAPT Regimen
- Based on the studies 3 and 6, it appears that continuing both Aspirin and Effient (prasugrel) may be beneficial for secondary prevention, as long as the patient is not at high risk of bleeding.
- However, the decision to continue or stop Effient should be made on an individual patient basis, taking into account the patient's risk factors and medical history.
- The study 7 suggests that short-course DAPT may be effective for secondary stroke prevention, but this may not be directly applicable to the patient's condition, as they have had a STEMI rather than a stroke or TIA.