Background: Early diagnosis, referral, and timely surgical intervention can significantly improve outcomes in children with congenital cardiac disease. Ventricular septal defect (VSD) closure is recommended before 9 months of age. In Guatemala, patients with congenital heart defects referral is often delayed therefore jeopardizing care. We report short and mid-term follow up of patients with right cardiac catheterization (RCC) diagnosis of pulmonary hypertension (PHT) that underwent late VSD closure at Unidad de Cirugía Cardiovascular de Guatemala (UNICAR).

Methods: We reviewed charts of patients with preoperative-RCC diagnosis of PHT who underwent late closure of isolated VSD between January 2010 to December 2018. Those whose preoperative-RCC didn’t include a vasoreactivity test with 100% FiO2 and inhaled nitric oxide, extracardiac comorbidities, and syndromes, were excluded. Demographics, hemodynamic data, surgical findings, and echocardiographic data were collected. Patients were asked to visit UNICAR for follow-up clinical evaluation, post-operative RCC, and 6-minute-walk-test. Primary endpoints were pulmonary pressure and vascular resistance (PVR) ≥2 years after surgery. Paired t-test was used for statistical analysis.

Results: Twelve patients, 7 female (58%), were analyzed. Median age 7.5 years (interquartile-range [IQR] 3–17 years). Most VSD (10, 83%) were subaortic and 2 (17%) inlet type, all were non-restrictive. Mean preoperative pulse oximetry saturation (PulOxSat) was 93±2%. On preoperative RCC, median pulmonary artery pressure (MPAP) was 55mmHg (IQR 42-60mmHg), PVR was >6 Wood-Units/m2 in 50% of patients, median 5.3 (IQR 3.8-6.3) Wood-Units/m2, median pulmonary-to-systemic vascular resistance index (PSVRi) was 0.45 (interquartile range 0.27-0.55:1). Vasoreactivity-test was positive in 2 (17%) patients (Sitbon-criteria) and in 5 (41%) patients (Barst-criteria). Mean time of follow-up was 4.5 years. Mean postoperative PulOxSat increased to 97±2% (p=0.0001). On follow-up RCC, MPAP with 21% FiO2 was <25mmHg in 83% of patients, median decreased to 20 mmHg (IQR 17-22mmHg, p<0.05). PVR was <3 Wood-Units/m2 in 92% of patients, median decrease of 2.23 (IQR 1.76-2.51, p=0.03) Wood-Units/m2, PSVRi was <0.25:1 in 92% of patients, median decrease of 0.12 (IQR 0.1-0.14:1, p=0.0222). Vasoreactivity-test of the one patient with elevated MPAP and PSVRi was negative. Ten patients (83%) completed a 6-minute-walk-test (2 were not eligible due to age), 1 patient failed to walk >500 meters.

Conclusions: In this study, patients with isolated VSD and PHT successfully underwent late VSD closure, even if pulmonary-to-systemic vascular resistance index was high. Moreover, VSD closure resulted in resolution of PHT. Despite our sample size, VSD closure appears to be beneficial independently of patient age. Vasoreactivity test does not predict the evolution of pulmonary pressure neither of the PVR. Therefore, we recommend that this test be used exclusively to decide regarding the use of calcium channel blocker as the primary treatment of PHT.