Secundum ASD with pulmonary arterial hypertension — case discussion

Presentation

Practice case (not a real patient). A 56-year-old woman in Brisbane has 3 years of declining exercise tolerance, exertional breathlessness and palpitations.^[1] She has fixed splitting of the second heart sound and a systolic pulmonary flow murmur; the ECG shows incomplete right bundle branch block and right-axis deviation.^[1] Transthoracic echocardiography shows a secundum ASD with RV enlargement and increased stroke volume, normal LV function with no LV disease, and a calculated systolic pulmonary artery pressure of 62 mmHg.^[1]

Step 1 — Define the defect and the pulmonary circulation

Discussion:

• ESC 2020 requires catheterisation to determine PVR when the calculated systolic pulmonary artery pressure is over 40 mmHg, and makes invasive PVR measurement mandatory with non-invasive signs of raised pressure (Class I, Level C).^[1]
• ACC/AHA 2025 recommends CMR, TOE or cardiac CT to define defect size, morphology, rim anatomy and pulmonary venous connections (COR 1, LOE B-NR), and assessment for PAH to guide therapy and suitability for repair (COR 1, LOE C-EO).^[2]
• Catheterisation shows mean pulmonary artery pressure 34 mmHg, wedge pressure 10 mmHg, PVR 6.2 WU and Qp:Qs 1.9; she has PAH by the ACC/AHA definition (mean PA pressure over 20 mmHg, PVR over 2 Wood units, wedge 15 mmHg or less).^[2]
• Six-minute walk testing shows no desaturation; ESC 2020 says exercise testing should be done in PAH to exclude it.^[1]

Step 2 — Close now?

Discussion:

• Not now. ESC 2020 says that with PVR of 5 WU or more improvement is unlikely and complete closure is likely to make the outcome worse; vasoreactivity testing is not recommended for the decision.^[1]
• ACC/AHA 2025 recommends that adults with an unrepaired ASD and PAH undergo risk assessment and management in consultation with pulmonary hypertension specialists, to improve outcomes (COR 1, LOE B-NR).^[2]
• Her profile matches the ACC/AHA row in which, with Qp:Qs of 1.5 or more, RV dilation, PVR 5–8 Wood units and no significant LV disease, closure can be beneficial if PVR under 5 Wood units can be achieved with targeted PAH therapy (COR 2a, LOE B-NR).^[2]
• Targeted PAH therapy is started; ESC 2020 says it appears safer to treat PAH, re-evaluate haemodynamics and consider fenestrated closure only if PVR falls below 5 WU with a significant left-to-right shunt.^[1]

Step 3 — Reassessment

Discussion:

• After treatment, repeat catheterisation shows PVR 4.1 WU with Qp:Qs still over 1.5.^[1]
• ESC 2020: with PVR of 5 WU or more that falls below 5 WU after targeted PAH treatment and a significant left-to-right shunt (Qp:Qs over 1.5), fenestrated closure may be considered (Class IIb, Level C).^[1]
• The newer ESC/ERS 2022 row (Recommendation Table 18, for a pulmonary-to-systemic flow ratio over 1.5:1): with ASD and PVR over 5 WU that declines to under 5 WU with PAH treatment, shunt closure may be considered (Class IIb, Level C), with a multiparametric decision rather than numbers alone.^[3]
• Under ACC/AHA 2025, the condition of its COR 2a row is now met: PVR under 5 Wood units has been achieved with targeted PAH therapy, so closure can be beneficial to improve medium-term functional status.^[2]
• ACC/AHA 2025: for an adult with ASD and PAH for whom closure is indicated, fenestrated repair can be considered to improve functional class and clinical outcomes (COR 2b, LOE B-NR); closure with raised PVR does not remove the need for continued PAH therapy and specialised care.^[2]

Step 4 — After closure

Discussion:

• Follow-up should assess residual shunt, RV size and function, TR and pulmonary pressure by echocardiography, and arrhythmias by history, ECG and, only if indicated, Holter monitoring (ESC 2020).^[1]
• Repair at adult age, particularly over 40, and raised pulmonary pressure call for regular follow-up, including in specialised ACHD centres (ESC 2020).^[1]
• ESC 2020 reports that in patients who undergo ASD closure aged over 40, as she would, the prevalence of atrial arrhythmias is up to 40–60%.^[1]