Current concept of transcatheter closure of atrial septal defect in adults

Authors, Journal, Affiliations, Type, DOI

• Teiji Akagi (MD, PhD, FJCC, FACC, FSCAI, FAHA)
• Journal of Cardiology, 2015;65(1):17–25
• Adult Congenital Heart Disease Center, Okayama University Hospital, Okayama, Japan
• Review article
• DOI: https://doi.org/10.1016/j.jjcc.2014.09.002

Overview

Single-centre expert review from Okayama University Hospital summarising the state of transcatheter ASD closure in adults and the elderly, with emphasis on morphological and hemodynamic features that make closure difficult. The article introduces atrial septal malalignment as a novel mechanism contributing to cardiac erosion, describes procedural techniques for challenging anatomy, and provides actionable hemodynamic monitoring protocols and AF management strategies for geriatric ASD patients.

Keywords

Atrial septal defect, Three-dimensional imaging, Atrial arrhythmia, Congestive heart failure

Key Takeaways

Introduction

• ASD accounts for 7% of all congenital heart disease; secundum is the most common subtype
• If untreated: right-sided heart failure, arrhythmia, and pulmonary hypertension
• Transcatheter closure provides significant symptom improvement without thoracotomy or cardiopulmonary bypass

Clinical Features of ASD in Various Aged Populations

• ASD <6 mm: spontaneous closure can be expected during the newborn-to-pediatric period
• Adult ASD: predominantly symptomatic; common presenting triggers are palpitation, arrhythmia, congestive heart failure, and stroke; majority diagnosed within 3 years of intervention
• Murphy 1990 (historical cohort): survival significantly worse without surgical closure by age 24 or if complicated by pulmonary hypertension
• Elderly ASD patients represent a distinct population with multiple comorbidities (arrhythmia, hypertension, renal disease, COPD, etc.) and may have survived by virtue of inherently milder physiology or superior resilience — extrapolation from younger patients is inappropriate

Transcatheter Closure of ASD

• Low complication rates, short anaesthetic times, and short hospitalisation; treatment of choice in eligible patients
• Amplatzer Septal Occluder (ASO; St. Jude Medical): widely used; can close defects up to 38 mm
• Occlutech (Helsingborg, Sweden) and Lifetech Cera (Shenzhen, China): available for larger defects
• ASD subtypes for catheter closure: secundum only (involves fossa ovalis region)
• Primum and sinus venosus defects: surgical repair indicated
• Coronary sinus septal defect: surgery is standard; isolated catheter case reports successful
• Procedural difficulties persist due to morphological or hemodynamic features

Morphological Features of Difficult Transcatheter ASD Closure

• Two crucial assessment parameters for secundum ASD: (1) maximum ASD diameter, (2) surrounding rim dimensions
• Maximum defect diameter must be <38 mm; ASDs have ellipsoidal shape that varies through the cardiac cycle
• Major axis diameter measured at ventricular end systole (especially without balloon sizing)
• Large ASD (>30 mm): challenging; alternative special deployment techniques routinely required
• Rim classification — distances from ASD to: aorta (superoanterior rim), SVC (superoposterior rim), right upper pulmonary vein (posterior rim), IVC (inferoposterior rim), coronary sinus, AV valve (inferoanterior rim)
• Rim deficiency defined as <5 mm
• Difficult morphology categories: (1) large ASD ≥30 mm, (2) wide rim deficiency, (3) multiple defects

Cardiac Erosion and Its Mechanism

• Cardiac erosion: a serious, potentially life-threatening device complication; definite mechanism not fully established
• Established risk factors: aortic (superoanterior) rim deficiency + oversized device
• Novel risk factor: atrial septal malalignment — surfaces of septum primum and secundum are offset in opposite vertical planes, causing tight impingement of the right atrial disk toward the aortic root; changes device axis angle → increased erosion risk after cable release
• Many cases with aortic rim deficiency do NOT develop erosion → additional morphological factors (malalignment) required
• Assessment of malalignment before device deployment is difficult; both disk surfaces must be observed pre- and post-release
• Updated ASO Instructions for Use (IFU): now adds IVC rim <5 mm as additional contraindication (in addition to aortic rim deficiency), because such anatomy tends to cause oversized device selection

Imaging Modality for Transcatheter ASD Closure

• 2D TTE (± colour Doppler): first-line; detects ASD, chamber dilatation, estimated PA pressure, shunt ratio, tissue Doppler for diastolic function; limited for detailed rim morphology in adults
• 2D TEE: necessary for precise morphological evaluation in most adult ASD patients
• 3D TTE: promising for en face ASD imaging; limitations in adults — operator-dependent, restricted echo windows in elderly, echo dropout (can simulate larger defects), lower temporal and spatial resolution than 2D TTE
• Real-time 3D TEE (matrix array probe): superior spatial resolution; allows high-quality en face imaging; essential for complex ASD shapes including multiple defects; preferred modality for intraprocedural guidance

Various Closure Techniques for Difficult ASD

• Rotation or remolding of delivery sheath outside the body: improves alignment at septum
• Left or right upper pulmonary vein (LUPV/RUPV) technique: left atrial disk deployed inside LUPV or RUPV, then pulled back into left atrium; concerns exist for pulmonary vein injury; enables delivery of large devices (up to 38 mm demonstrated)
• Hausdorf sheath (Cook, Bloomington, IN): specially designed; aligns left atrial disk parallel to atrial septum; favourable for interatrial septum approach in large defects
• Straight side-hole delivery sheath (Kutty modification of Mullins transseptal sheath): enhanced delivery; exit orifice on side of distal sheath
• Balloon assist technique: partially inflated Amplatzer sizing balloon holds left atrial disk inside left atrium, preventing prolapse into right atrium; requires additional venous access; relatively simple and less traumatic; high procedural success expected even for large ASD
• Operators should master one or two techniques for difficult anatomy; familiarisation with all not required

Hemodynamic Features of Difficult Transcatheter ASD Closure

Pulmonary Arterial Hypertension and ASD

• Candidates for closure: hemodynamically significant atrial shunt OR RV volume overload AND/OR clinical symptoms (dyspnoea, reduced exercise capacity, paradoxical embolism)
• Hemodynamic criteria for closure: PVR <5 WU/m² AND peak PA pressure ≤70% systemic blood pressure
• PAH incidence significantly increases with age in ASD patients; natural course with PAH significantly worse
• Transcatheter closure (without CPB) feasible even in high-risk patients: several studies demonstrate efficacy and safety; greater PA pressure reduction achievable even in severe PAH
• Treat-and-repair strategy: ASD closure may be performed if pulmonary vascular resistance responds to PAH-specific vasodilators (prostanoids, ERA, PDE5i); even initially contraindicated hemodynamics may become operable after medical optimisation
• Long-term follow-up mandatory in high-risk populations; further PAH improvement confirmed post-closure in responders (Fig. 9)

Specific Issues for Management of Elderly Patients with ASD

• ~10% of transcatheter ASD cases at author's institution were aged >70 years; majority had ≥1 major comorbidity (HTN, stroke, CAD, AF)

• 50% were on diuretics for CHF; 30% had prior CHF hospitalisation; majority NYHA class >II

• Common hemodynamic abnormalities in elderly: PAH, atrial arrhythmias, valvular regurgitation → CHF
• LV diastolic dysfunction: masked by the left-to-right shunt (unloads LV); after closure, abrupt elevation in LV preload can trigger acute CHF — risk especially in elderly with impaired systolic or diastolic function
• LV dysfunction assessment: tissue Doppler (decreased e', increased E/e'); pre-conditioning with anti-congestive medication
• Pre- and peri-procedural anti-congestive medication: key to preventing post-closure CHF in elderly; series showed no acute CHF despite impaired diastolic function
• PCWP monitoring protocol during procedure:
  • Mean PCWP rise >10 mmHg from baseline during balloon test occlusion → procedure should be abandoned
  • Mean PCWP >20 mmHg → procedure should be abandoned (pulmonary oedema risk)
  • PCWP continuously monitored during device deployment
• Fenestrated device: may moderate abrupt hemodynamic change; optimal fenestration size not yet evaluated; limited experience
• Outcomes: high procedural success rate in elderly; significant NYHA functional class improvement; no additional CHF hospitalisation during follow-up (despite 30% prior CHF history)
• Atrial arrhythmias in elderly ASD:
  • ~1/3 of patients aged >60 years have AF; ~1/2 of patients aged >70 years have AF
  • Permanent AF: ASD closure still beneficial (resolves L→R shunt → symptom improvement); strict anticoagulation required post-closure; no age limitation for closure
  • Symptomatic paroxysmal or persistent AF: PVI (pulmonary vein isolation) indicated BEFORE ASD closure
  • PVI criteria (author's institution): age <75 years + symptomatic paroxysmal/persistent AF + LA dimension <50 mm
  • ASD closure scheduled when sinus rhythm persists >3 months after ablation

Future Directions

• Transcatheter ASD closure established as safe and effective for most patients
• Cardiac erosion: mechanism not fully clarified; late erosion occurs → longitudinal follow-up essential
• Other concerns requiring long-term data: device-induced late arrhythmias, AV valve regurgitation, myocardial tissue reaction
• Multidisciplinary ACHD teams (pediatric + adult cardiologists, cardiac surgeons, anaesthesiologists) essential for optimal outcomes
• ACHD specialist in each institution performing these procedures is most desirable

Limitations of the Document

• Single-centre review (Okayama University Hospital); limited generalisability
• Review article — not a systematic review or meta-analysis; no pooled outcome data
• Optimal fenestrated device size not studied
• Mechanism of cardiac erosion not fully established; malalignment as risk factor based on mechanistic reasoning and case series (not prospective study)
• No randomised data comparing techniques for difficult ASD anatomy
• PVI-before-closure strategy criteria (age <75, LA <50 mm) are institution-specific and not guideline-derived

Key Concepts Mentioned

• concepts/Atrial-Septal-Defect — primary focus; adult and elderly closure, morphological and hemodynamic challenges
• concepts/Pulmonary-Hypertension — PAH as key determinant of closure candidacy; treat-and-repair strategy
• concepts/LV-Diastolic-Function — masked diastolic dysfunction; post-closure CHF risk; PCWP monitoring
• concepts/Right-Heart-Catheterization — PCWP monitoring protocol during ASD closure
• concepts/Catheter-Ablation-AF — PVI before ASD closure strategy in AF

Key Entities Mentioned

• entities/Atrial-Fibrillation — most common comorbidity in elderly ASD; permanent AF not a contraindication to closure; PVI before closure for paroxysmal/persistent AF

Wiki Pages Updated

• wiki/concepts/Atrial-Septal-Defect.md — added cardiac erosion mechanism (malalignment), PCWP protocol, LUPV/RUPV/balloon-assist techniques, elderly outcomes, AF prevalence by age, PVI-first strategy details; source_count 2→3
• wiki/sourceindex.md — added new entry
• wiki/wikiindex.md — updated ASD concept description and date