Atrial septal defect and PFO — viva

Stem

Practice viva. The examiner shows a report of an adult with a secundum ASD and asks how you decide whether, when and how to close it, then moves to a young patient with a stroke and a PFO.^[1][6]

Branch A — Physiology

Examiner: Why does an ASD shunt left to right, and why might it matter more with age?^[1]

Strong answer:

• ESC 2020: shunt volume depends on RV and LV compliance, defect size and LA and RA pressure; because the RV is more compliant than the LV, a simple ASD shunts left to right, causing RV volume overload and pulmonary overcirculation.^[1]
• Reduced LV compliance or raised LA pressure (hypertension, ischaemic heart disease, cardiomyopathy, aortic and mitral valve disease) increases the shunt, so the ASD may become more important with age.^[1]
• Reduced RV compliance or tricuspid valve disease may reduce the shunt or eventually reverse it, causing cyanosis.^[1]

Follow-up: Which single echocardiographic finding best tells you the defect matters?^[1]

• ESC 2020: RV volume overload is the key finding and best characterises the haemodynamic relevance of the defect, better than the shunt ratio.^[1]

Branch B — Who to close

Examiner: Give me the ESC and ACC/AHA criteria for closure.^[1][2]

Strong answer:

• ESC 2020: RV volume overload and no PAH (no non-invasive signs of raised PAP, or invasive PVR under 3 WU when such signs exist) or LV disease: closure is recommended regardless of symptoms (Class I, Level B).^[1]
• ACC/AHA 2025: unrepaired ASD, Qp:Qs of 1.5 or more and RV dilation, no PAH (PVR of 2 Wood units or less) and no significant LV disease: closure is recommended to improve functional class and clinical outcomes (COR 1, LOE B-R).^[2]
• ACC/AHA defines significant LV disease as any condition causing a chronically raised left atrial pressure of 15 mmHg or more.^[2]

Follow-up: What about raised PVR?^[1]

• ESC 2020 (the older ESC statement): PVR 3–5 WU with a significant left-to-right shunt (Qp:Qs over 1.5): closure should be considered (Class IIa, Level C); PVR of 5 WU or more: fenestrated closure may be considered when PVR falls below 5 WU after targeted PAH treatment with a significant shunt (Class IIb, Level C).^[1]
• The newer ESC/ERS 2022 Recommendation Table 18, for a pulmonary-to-systemic flow ratio over 1.5:1, uses PVR under 3 WU (I C), 3–5 WU (IIa C), over 5 WU falling below 5 WU with PAH treatment (IIb C) and over 5 WU despite treatment (III C), and says the decision should not rest on numbers alone.^[3]
• ESC 2020 does not recommend vasoreactivity testing for the closure decision when PVR is 5 WU or more.^[1]

Branch C — Who not to close

Examiner: When is closure harmful?^[1][2]

Strong answer:

• ESC 2020 does not recommend closure with Eisenmenger physiology, with PAH and PVR of 5 WU or more despite targeted PAH treatment, or with desaturation on exercise (Class III, Level C); by clinical experience, desaturation means a fall in arterial saturation below 90%.^[1]
• ACC/AHA 2025: closure should not be performed with Eisenmenger physiology, to avoid increasing morbidity and mortality (COR 3: Harm, LOE C-LD).^[2]
• With LV disease, ESC 2020 recommends balloon testing and weighing closure, fenestrated closure or no closure against a rise in filling pressure (Class I, Level C); ACC/AHA 2025 rates balloon test occlusion 2b (LOE C-LD).^[1][2]

Branch D — Device or surgery

Examiner: How would you close it?^[1]

Strong answer:

• Device closure is the ESC 2020 method of choice for secundum ASD when technically suitable (Class I, Level C), and ACC/AHA 2025 says transcatheter closure is usually preferred for an isolated secundum ASD (COR 1, LOE B-NR).^[1][2]
• ESC 2020: device suitability depends on morphology, which includes a stretched diameter of 38 mm or less and a sufficient rim of 5 mm except towards the aorta; this is the case in about 80% of patients.^[1]
• ACC/AHA 2025 says surgery may be preferable for anatomic reasons or comorbid disease, such as other concomitant cardiac surgery.^[2]
• For a superior sinus venosus defect, ACC/AHA 2025 says transcatheter closure, when technically feasible, may be a reasonable alternative to surgery (COR 2b, LOE B-NR).^[2]

Branch E — PFO and stroke

Examiner: A 40-year-old has a cortical stroke and a PFO. Do you close it?^[6][7]

Strong answer:

• First a thorough evaluation for other mechanisms (AAN 2020, level B) and a joint decision with the patient, a cardiologist and a neurologist (AHA/ASA 2021, COR 1, LOE C-EO).^[9][6]
• AHA/ASA 2021: age 18 to 60 with a nonlacunar stroke of undetermined cause despite a thorough evaluation and a PFO with high-risk anatomic features: transcatheter closure plus long-term antiplatelet therapy over antiplatelet therapy alone is reasonable (COR 2a, LOE B-R); without high-risk features the benefit is not well established (COR 2b, LOE C-LD).^[6]
• ESO 2024 recommends closure plus antiplatelet therapy in selected patients aged 18–60 with PFO-associated stroke (strong; high-quality evidence), adds that PASCAL can be used to select such candidates, and suggests against closure when PASCAL rates the stroke unlikely, unless there is a high probability of clinical causality (weak against; low quality).^[7]

Follow-up: And if he were 68?^[6]

• AHA/ASA 2021 says closure should rarely be done in older patients, and only in very unusual clinical circumstances; ESO 2024 makes no evidence-based recommendation above 60, and its expert consensus (vote 8/9) encourages enrolment in trials or at least a registry and otherwise suggests using PASCAL and clinical judgement to guide therapy; SCAI 2022 suggests PFO closure rather than long-term antiplatelet therapy alone at 60 or older after a prior PFO-associated stroke (conditional, very low certainty).^[6][7][8]