Resolution of Severe PAH After Late VSD Closure in an 8‐Year‐Old: Clinical Prudence or Adventurism?

Ventricular septal defect (VSD) is one of the most common congenital heart defects. Large, uncorrected VSDs can lead to significant left-to-right shunting, resulting in pulmonary arterial hypertension (PAH) and progressive pulmonary vascular disease. Early surgical intervention is recommended but is not always possible due to various socioeconomic and health infrastructure-related issues, especially in countries like India [1]. This report highlights the long-term successful outcome of a girl child who underwent surgery for a large VSD, severe PAH, and severely elevated pulmonary vascular resistance (PVR) at 8 years of age. At 8 years of age, the child presented with a history of dyspnea on exertion. She has had a history of recurrent respiratory infections in early childhood and poor weight gain. She was severely malnourished, with a body mass index of 12.4 kg/m2. She had normal oxygen saturation at rest and on exertion. On cardiac examination, S1 was normal, while S2 had a narrow split and a loud P2. There was no LVS3. A grade 2/6 systolic murmur was audible at the left lower sternal border. Chest radiograph showed cardiomegaly with mildly increased pulmonary blood flow. The electrocardiogram showed biventricular hypertrophy. Echocardiography revealed a large non-restrictive perimembranous VSD with a left-to-right gradient of 16 mmHg, thus indicating severe PAH. The left ventricle was dilated with end-diastolic and systolic dimensions of 39 (z score 1.9) and 26 mm (z score 2.4), respectively. She also had a tiny PDA and moderate tricuspid regurgitation (TR). Cardiac catheterization confirmed high pulmonary blood flow with a pulmonary-to-systemic blood flow (Qp/Qs) ratio of 1.8, with a high indexed PVR (PVRI) of 11.7 WU.m2 and PVR to SVR ratio of 0.45 (Table 1). Following oxygen administration for vasoreactivity, Qp/Qs increased to 2, with PVRI of 11.1 WU.m2 and PVR to SVR ratio of 0.39. Despite PVRI being well beyond the usual consensus-based cut-off of 8 WU.m2 [2, 3], considering clinical, X-ray, and hemodynamic evidence of high pulmonary blood flow, surgical VSD closure with PDA ligation and tricuspid valve repair was performed. She had an uneventful postoperative period but had mild TR. The right ventricular systolic pressure predicted by TR was 55 mmHg, so she was started on dual pulmonary vasodilator therapy (Sildenafil and Bosentan). She was asymptomatic and discontinued pulmonary vasodilators 1 year after the surgery. Thereafter, she did not come for follow-up until this time at 19 years of age, when she was referred for cardiac evaluation in view of prior cardiac surgery. She was asymptomatic and had a normal cardiac examination. Her echocardiography confirmed no residual VSD and mild TR. TR predicted right ventricular systolic pressure was 30 mmHg. Considering significantly elevated PVRI before VSD closure, cardiac catheterization was performed for better hemodynamic assessment, which revealed a mean pulmonary artery pressure of 24 mmHg (Table 1). Operability decisions in left-to-right shunts with raised PVRI are difficult. It is generally believed that the risks of conversion of potential Eisenmenger syndrome to pulmonary hypertension with a closed intracardiac shunt outweigh the benefits accrued from surgery [4]. More recently, there has been a shift in the guidelines regarding operability towards a lower PVRI than in the past. Nevertheless, there is a paucity of well-conducted studies, and most recommendations are based on expert consensus [2, 3, 5, 6]. (Table 2) The role of vasodilator testing in deciding operability and the “treat and repair” or “treat-repair-treat” strategy has not been adequately validated [7]. Empirical clinical decisions based on the total clinical picture are encouraged but require experience and might not always be reliable [8]. Favorable outcomes have been reported despite the high PVRI in many patients [9, 10]. Kannan et al., in a retrospective study, reported good long-term outcomes at a mean follow-up of 8.7 years in 30 out of 38 (79%) patients with shunts and raised PVRI. Although the pulmonary artery pressure did not normalize at follow-up, it was acceptably low to permit survival with good functional capacity in the long term, including a few successful pregnancies [9]. < 4 WU·m2 (< 2.3 WU) < 6 WU·m2 PVR/SVR < 0.3 < 4 WU·m2 (< 2.3 WU) 4–8 WU·m2 (2.3–4.6 WU) 6–8 WU·m2 PVR/SVR 0.3–0.5 4–8 WU·m2 (2.3–4.6 WU) > 8 WU·m2 (> 4.6 WU) > 8 WU·m2 PVR/SVR > 0.5 If AVT positive > 8 WU·m2 (> 4.6 WU) This communication highlights concerns regarding the recently proposed PVRI cut-off of 4 WU·m² or 3 WU to define operability in cases with large VSD presenting late [2, 6]. While this threshold prioritizes safety, it may not always be the best clinical decision for certain patients. The increasing tendency among young physicians to strictly adhere to this conservative cut-off could, over time, lower operability thresholds without sufficient justification, thereby missing the opportunity for timely and effective treatment. Although a single case cannot establish a general principle, physicians must acknowledge the biological variability in pulmonary vascular disease progression. Rather than rigidly adhering to an overly cautious PVRI threshold, clinical decisions in this subset of patients should be individualized. Saurabh Kumar Gupta prepared the manuscript. Saurabh Kumar Gupta and Shyam S. Kothari finalized the manuscript. The authors have nothing to report. Consent for publication was obtained from the patient. The authors declare no conflicts of interest.