ASD Creation/Fenestration is NOT Indicated in Your Case
With a PVR/SVR ratio of 0.03 and mPAP of 42 mmHg, you do not meet criteria for fenestrated closure or ASD creation—your hemodynamics are well within the range for standard complete closure without fenestration. 1
Why Your Hemodynamics Favor Standard Closure
Your PVR/SVR ratio of 0.03 is dramatically below the threshold that would raise concerns about operability or require fenestration:
- Guideline thresholds for operability: The AHA/ATS pediatric pulmonary hypertension guidelines specify that PVR/SVR ratio <0.3 with PVRI <6-8 WU·m² predicts good surgical outcomes 1
- Your ratio is 10-fold lower than the 0.3 threshold, indicating minimal pulmonary vascular resistance relative to systemic resistance 1
- The 2018 AHA/ACC adult CHD guidelines recommend closure when "pulmonary vascular resistance is less than one third of systemic resistance" (i.e., PVR/SVR <0.33), which you easily meet 1
When Fenestration IS Actually Indicated
Fenestration or ASD creation is reserved for patients with markedly elevated PVR, not your situation:
- Pediatric guidelines: "Many programs advocate for a fenestration at the atrial or ventricular level in patients with higher PVR" 1
- Specific criteria from research: Fenestrated closure has been studied in patients with baseline PVR >6 U·m² and PVR/SVR ratio >0.3 1, or those with systolic PAP >60-70 mmHg with PVRI >7-9 WU·m² 2, 3
- Recent ATS guidelines (2025): ASD creation is suggested specifically for "children with progressive PH and RV failure despite optimal therapy"—a palliative intervention for end-stage disease 1
Your mPAP of 42 mmHg in Context
While your mPAP is elevated, it does not contraindicate standard closure:
- Contraindication thresholds: ASD closure should NOT be performed when "PA systolic pressure is greater than two thirds systemic" or "pulmonary vascular resistance is greater than two thirds systemic" 1
- Your PVR/SVR of 0.03 indicates PVR is only 3% of systemic resistance, nowhere near the two-thirds threshold 1
- Studies show successful outcomes with mPAP in the 40s when PVR/SVR ratio remains favorable 2, 3
The Role of Vasoreactivity Testing
If there were any concern about your pulmonary vascular bed (which your ratio suggests there should not be), acute vasoreactivity testing would clarify:
- Positive AVT response: Defined as ≥20% decrease in mPAP and PVRI, or achieving PVR/SVR <0.3 after vasodilator challenge 1
- Given your baseline ratio is already 0.03, you would not require AVT to demonstrate operability 1
- Pretreatment with PAH therapies showing >20% reduction in pulmonary arterial resistance predicts favorable prognosis after closure 1, but this applies to patients with elevated baseline PVR, not your case
Critical Pitfall to Avoid
Do not create unnecessary fenestration based solely on mPAP elevation without considering the PVR/SVR ratio. The ratio is the critical determinant of right ventricular afterload and operability 1. Your extremely low ratio indicates that despite moderate PAP elevation, the pulmonary vascular bed is not significantly diseased and will tolerate complete closure 1.
Recommended Approach
- Proceed with standard complete ASD closure (surgical or device-based depending on anatomy) 1
- Ensure accurate invasive hemodynamic measurements confirm your reported values 1
- Standard post-closure antiplatelet therapy with aspirin 100 mg daily for at least 6 months 4
- No need for pulmonary vasodilator therapy given favorable hemodynamics 2, 3