What is the recommended aspirin (acetylsalicylic acid) regimen after device closure?

Aspirin After Device Closure

For device closure of atrial septal defects (ASD) or ventricular septal defects (VSD), administer low-dose aspirin (75-100 mg daily) for at least 6 months after implantation. 1, 2

Immediate Periprocedural Management

• All patients must receive unfractionated heparin (UFH) 100 U/kg (maximum 5000 units) at the time of device implantation (Class I recommendation). 1, 2
• This applies to both ASD and VSD device closures. 1

Standard Post-Procedure Aspirin Regimen

For Children with ASD Device Closure

• Initiate oral low-dose aspirin immediately post-procedure and continue for at least 6 months (Class I, Level of Evidence C). 1, 2
• The recommended dose is aspirin 5 mg/kg/day, which typically translates to 75-100 mg daily depending on weight. 1
• This 6-month duration aligns with the time required for complete device endothelialization. 1, 2

For Children with VSD Device Closure

• Low-dose aspirin for at least 6 months is reasonable (Class IIa, Level of Evidence C). 1, 2
• The same dosing strategy applies: 75-100 mg daily or 5 mg/kg/day. 1
• Device-related thrombosis has not been reported as a procedural complication in published VSD closure series when this regimen is followed. 1

Enhanced Therapy for Older Children and Adults

• For older children and adults undergoing ASD device closure, consider adding another anticoagulant (such as clopidogrel 75 mg daily) in addition to aspirin for 3-6 months (Class IIb, Level of Evidence C). 1, 2
• This dual antiplatelet approach is particularly relevant for adults, as device-related thrombotic complications are reported more frequently in adult series compared to pediatric populations. 1

Extended Duration Considerations

If complete defect closure is not achieved (residual shunt persists), continue aspirin beyond 6 months indefinitely because incomplete endothelialization creates ongoing risk of paradoxical embolus. 1, 2

High-Risk Patient Modifications

• In patients with history of stroke or cryptogenic events, screen for inherited thrombophilic disorders before device implantation to appropriately tailor antithrombotic prophylaxis. 1, 2
• These high-risk patients may warrant extended dual antiplatelet therapy or therapeutic anticoagulation based on individual thrombophilic findings. 1

Dosing Nuances

The European Society of Cardiology specifies a minimum of 100 mg daily aspirin after device closure. 2 However, the American Heart Association guidelines support doses as low as 75 mg daily (or 5 mg/kg/day in children), which has proven effective in large pediatric series. 1 For practical purposes, 81-100 mg daily represents an optimal balance that satisfies both guideline recommendations and minimizes bleeding risk while maintaining efficacy. 2

Critical Pitfalls to Avoid

• Never omit aspirin therapy entirely after device closure, even though device thrombosis rates are extremely low (approximately 0.2% in pediatric series). 1, 2 The standard of care mandates antiplatelet prophylaxis. 1
• Do not discontinue aspirin before 6 months without compelling contraindications, as this is the minimum duration required for device endothelialization. 1, 2
• Do not forget the procedural UFH bolus at implantation, which is a Class I recommendation separate from the post-procedure aspirin regimen. 1, 2
• Do not use higher aspirin doses (>100 mg) routinely, as doses of 75-100 mg provide equivalent thrombotic protection with lower bleeding risk compared to 325 mg doses. 2

Evidence Quality Context

These recommendations are based on Class I and IIa evidence, though the level of evidence is C (expert consensus and observational data). 1 No randomized controlled trials have definitively established the optimal anticoagulation strategy or whether any prophylaxis is necessary. 1 However, the extremely low incidence of device thrombosis when aspirin is used (1 event among 417 patients in the largest series) supports current practice. 1 The therapy remains empirical but represents established standard of care with excellent safety outcomes. 1