From the Guidelines
Patients with an interatrial septal aneurysm (IASA) should undergo a comprehensive cardiac evaluation to rule out associated defects like patent foramen ovale (PFO) or atrial septal defect (ASD), and if associated with a PFO and a history of cryptogenic stroke, PFO closure may be considered to prevent recurrent strokes, as suggested by the as-treated analysis of patients who actually received the assigned treatment in trials like RESPECT, which showed a significant difference in the rate of recurrent events (odds ratio, 0.62; 95% confidence interval, 0.41–0.94) 1.
Key Considerations
- Most cases of IASA are asymptomatic and discovered incidentally during cardiac imaging.
- No specific treatment is required for an isolated IASA without associated conditions.
- Patients with IASA have a slightly increased risk of atrial arrhythmias, particularly atrial fibrillation, so monitoring for symptoms like palpitations, dizziness, or shortness of breath is important.
- The exact cause of IASA is not fully understood, but it likely results from abnormal development of the septum primum during embryonic heart formation or from increased pressure differences between the atria.
Management and Monitoring
- Regular follow-up with a cardiologist is advised, typically with annual echocardiograms to monitor the aneurysm.
- Patients with a history of cryptogenic stroke and PFO may benefit from PFO closure, as the intention-to-treat analysis of trials like CLOSURE I, RESPECT, and PC showed a trend toward device-related AF inducibility, but the as-treated analysis suggested a significant reduction in recurrent events with PFO closure 1.
- High-volume divers, compressed-air tunnel workers, high-altitude aviators, and astronauts may suffer from decompression sickness and asymptomatic neurological events regardless of the presence of PFO, and multiple recurrences in individuals who wish to continue diving or to continue their high-risk jobs may warrant PFO closure in centers maintaining closure registries or participating in trials 1.
From the Research
Interatrial Septal Aneurysm Characteristics
- Interatrial septal aneurysm (IASA) is a potential cardiac source of embolism, with a strong association between IASA and stroke 2.
- IASA are often found to overlap the fossa ovalis region, protrude into the right atrium, and appear thin and highly mobile 2.
- A history of systemic embolic events is common in patients with IASA, with 58% of patients having such a history 2.
- Atrial septal shunt is detected in 61% of patients with IASA 2.
Treatment and Management
- Long-term oral anticoagulant therapy with warfarin is the treatment of choice for secondary stroke prevention following transient ischaemic attack (TIA) or minor ischaemic stroke in association with persistent or paroxysmal non-valvular atrial fibrillation or atrial flutter 3.
- For patients with interatrial septal defects, percutaneous transcatheter closure of a patent foramen ovale (PFO) has been utilized to prevent thromboembolic events 4.
- The use of anticoagulants such as bivalirudin, unfractionated heparin, and enoxaparin has been explored in patients undergoing closure of interatrial septal defects, with bivalirudin showing a trend toward fewer minor complications 5.
Recurrent Cerebrovascular Events
- The risk of recurrent ischaemic cerebrovascular events is significant in patients with patent foramen ovale (PFO) or atrial septal aneurysm (ASA), with a cumulative risk of 1.2% at 2 years, 5.5% at 4 years, 7.6% at 6 years, and 23.6% at 8 years 6.
- The risk of recurrent events is similar in patients with PFO alone versus those with PFO plus ASA 6.
- Treatment with antiplatelet drugs or oral anticoagulants may reduce the risk of recurrent events, while transcatheteral closure may be an effective option for preventing further events 6.