What medications are typically prescribed after device closure of a heart defect, considering factors such as prevention of thromboembolic complications and patient's overall cardiovascular risk profile, including history of coronary artery disease, atrial fibrillation, or venous thromboembolism?

Medications Following Device Closure of Heart Defects

All patients undergoing device closure of heart defects must receive unfractionated heparin (UFH) at 100 U/kg (maximum 5000 U) during the procedure, followed by low-dose aspirin for at least 6 months postoperatively to prevent device thrombosis until complete endothelialization occurs. 1

Periprocedural Anticoagulation (During Device Implantation)

Unfractionated heparin is mandatory at the time of device placement:

• Dosing: 100 U/kg intravenously (maximum 5000 U) administered during implantation 1, 2, 3
• Rationale: Prevents acute thrombus formation on the device during and immediately after deployment 1
• Evidence strength: Class I recommendation (must be done) for both atrial septal defect (ASD) and ventricular septal defect (VSD) closures 1, 3

Postprocedural Antiplatelet Therapy

Standard Regimen for Children

Low-dose aspirin monotherapy is the standard approach:

• Duration: Minimum 6 months after implantation 1, 2, 3
• Dosing: 5 mg/kg/day in children 1; 100 mg daily minimum in adults 3
• Evidence strength: Class I recommendation for ASD closure; Class IIa for VSD closure 1, 3
• Rationale: The 6-month duration corresponds to the time required for complete device endothelialization, after which the thrombotic risk becomes negligible 1, 3

Enhanced Regimen for Higher-Risk Patients

Dual antiplatelet therapy or anticoagulation may be considered in specific circumstances:

• Patient populations: Older children, adults, or those with history of stroke 1
• Regimen: Aspirin plus clopidogrel 75 mg, OR warfarin/LMWH with or without aspirin 1
• Duration: 3-6 months, then transition to aspirin monotherapy to complete 6 months total 1
• Evidence strength: Class IIb recommendation (may be considered) 1

High-Risk Lesion Considerations

More aggressive anticoagulation is reasonable for higher thrombotic risk scenarios:

• Risk factors: Nonpulsatile flow, previous complete vessel occlusion, known thrombophilic disorder 1
• Regimen: Warfarin or LMWH with or without antiplatelet therapy for 3-6 months 1
• Evidence strength: Class IIa recommendation 1
• Screening: Inherited thrombophilic disorders should be excluded before device implantation in patients with prior stroke history to guide appropriate prophylaxis intensity 1, 3

Device-Specific Protocols

Atrial Septal Defect Closure

• Procedural: UFH 100 U/kg (Class I) 1, 2
• Postprocedural: Aspirin for 6 months minimum (Class I in children) 1, 2, 3
• Device thrombosis incidence: Extremely rare when this protocol is followed—only 1 in 417 patients in large series 1

Ventricular Septal Defect Closure

• Procedural: UFH 100 U/kg (Class I) 1, 3
• Postprocedural: Aspirin for 6 months (Class IIa) 1, 3
• Device thrombosis incidence: Not reported as a complication in published series when aspirin is used 1

Patent Ductus Arteriosus Closure

• Procedural anticoagulation: Variable practice; many centers use 50-100 U/kg UFH 1
• Postprocedural: No specific thromboprophylaxis typically recommended 1
• Rationale: Device thrombotic complications have not been reported with Amplatzer occluder or coil closure 1

Critical Clinical Pitfalls to Avoid

Never omit procedural UFH anticoagulation:

• This is a Class I (mandatory) recommendation with specific dosing of 100 U/kg 1, 2, 3
• Failure to anticoagulate during implantation risks acute device thrombosis 1

Never discontinue aspirin before 6 months without compelling contraindication:

• Complete endothelialization requires this full duration 1, 3
• Early discontinuation leaves exposed device material that can serve as a nidus for thrombus 1

Extend thromboprophylaxis beyond 6 months if residual shunt persists:

• Incomplete defect closure prevents complete endothelialization 1, 3
• Ongoing risk of paradoxical embolus necessitates continued antiplatelet therapy 1, 3

Screen for thrombophilic disorders in stroke patients before device placement:

• Allows adaptation of antithrombotic prophylaxis intensity 1, 3
• Particularly important in patients with cryptogenic stroke undergoing PFO closure 1

Rationale for Medication Protocols

The primary goal is prevention of device thrombosis during the endothelialization period:

• Device surfaces remain thrombogenic until covered by endothelium 1, 3
• Limited human explantation data suggest this process takes approximately 6 months 1
• Device thrombosis can lead to systemic embolization, stroke, or device dysfunction 1

Current practice is based on empirical data and standard-of-care rather than randomized trials:

• No randomized studies have assessed optimal anticoagulation strategy 1
• The extremely low incidence of device thrombosis with current protocols (essentially zero in pediatric series) supports their effectiveness 1
• Adult series show higher complication rates, particularly in PFO closure post-cryptogenic stroke, justifying more aggressive anticoagulation in this population 1