From the Guidelines
Aspirin is recommended for the first 6 months after atrial septal defect (ASD) closure, usually in combination with clopidogrel, to prevent thrombosis. This recommendation is based on the guidelines from the American Heart Association, as stated in the 2013 scientific statement on prevention and treatment of thrombosis in pediatric and congenital heart disease 1. The use of aspirin and clopidogrel for 6 months after device closure is a common practice for patients with ASD closure devices.
- Key considerations for aspirin therapy in this context include:
- Dose: Although the exact dose is not specified in the provided evidence, typical recommendations are 3-5 mg/kg/day for children or 81-325 mg daily for adults.
- Duration: The standard duration is 6 months, but this may be adjusted based on the size of the defect and the patient's individual risk factors for thromboembolism.
- Combination therapy: Aspirin is usually recommended in combination with clopidogrel for the first 6 months after device closure, as stated in the guidelines 1.
- Alternative therapy: For patients with aspirin allergy, clopidogrel may be used as an alternative, at a dose of 75 mg daily (or 0.2-1 mg/kg/day in children).
- It is essential to note that patients should be advised to avoid other NSAIDs during this period to prevent increased bleeding risk.
- The rationale for aspirin therapy is to prevent thrombus formation on the closure device while it undergoes endothelialization, which typically takes 3-6 months.
From the Research
Aspirin in Post ASD Closure
- The use of aspirin in post atrial septal defect (ASD) closure has been studied to determine its safety and effectiveness in preventing device thrombosis and major bleedings 2.
- A study published in the European journal of internal medicine found that a regimen of 100 mg of aspirin for six months after ASD closure appeared to be both safe and effective in preventing device thrombosis and major bleedings 2.
- Another study published in Platelets found that high on-treatment platelet reactivity to clopidogrel was detected in 71% of patients, while high on-treatment platelet reactivity to aspirin was detected in only 4% of patients 3.
- The incidence of high on-treatment platelet reactivity to clopidogrel in ASD closure patients is very high, but despite this, no stroke or thrombus formation on the occluder occurred 3.
Comparison of Single and Dual Antiplatelet Therapy
- A study published in the Journal of Nepal Health Research Council compared the safety and efficacy of single vs dual antiplatelet therapy after ASD device closure 4.
- The study found that single antiplatelet therapy with aspirin was as safe and effective as aspirin and clopidogrel after device closure 4.
- There was no significant difference between the two groups in terms of transient ischemic attack, stroke, myocardial infarction, thrombus, major bleeding, and minor bleeding 4.
Aspirin Resistance
- Aspirin resistance, also known as high on-treatment platelet reactivity, is a phenomenon where patients taking aspirin are still at risk for re-occurring cardiovascular events 5, 6.
- The phenomenon of aspirin resistance has been reported in patients after stroke, atherosclerosis of the lower limbs, stable coronary disease, and patients immediately after myocardial infarction 6.
- Despite studies conducted for several years, there are no clear guidelines for monitoring platelet function in patients taking aspirin, both in primary and secondary stroke prevention 6.