Long-Term Outcomes of Unrepaired Isolated Partial Anomalous Pulmonary Venous Connection With an Intact Atrial Septum.

The natural history of an unrepaired isolated partial anomalous pulmonary venous connection(s) (PAPVC) and the absence of other congenital anomalies remains unclear. This study aimed to expand the understanding of the clinical outcomes in this population. Isolated PAPVC with an intact atrial septum is a relatively uncommon condition. There is the perception that patients with isolated PAPVC are usually asymptomatic, that the lesion generally has a limited hemodynamic impact, and that surgical repair is rarely justified. For this retrospective study, we reviewed our institutional database to identify patients with either 1 or 2 anomalous pulmonary veins that drain a portion of but not the complete ipsilateral lung. Patients with previous surgical cardiac repair, coexistence of other congenital cardiac anomalies that would result in either pretricuspid or post-tricuspid loading of the right ventricle (RV), or scimitar syndrome were excluded. We reviewed their clinical course over the follow-up period. We identified 53 patients; 41 with a single and 12 with 2 anomalous PAPVC. A total of 30 patients (57%) were men, with a mean age at the latest clinic visit of 47 ± 19 years (18 to 84 years). Turner syndrome (6 of 53, 11.3%), bicuspid aortic valve (6 of 53, 11.3%), and coarctation of the aorta (5 of 53, 9.4%) were commonly associated anomalies. A single anomalous left upper lobe vein was the most commonly identified variation. More than half of the patients were asymptomatic. Cardiopulmonary exercise test demonstrated a maximal oxygen consumption of 73 ± 20% expected (36 to 120). Transthoracic echocardiography demonstrated a mean RV basal diameter of 4.4 ± 0.8 cm, RV systolic pressure of 38 ± 13 (16 to 84) mm Hg. A total of 8 patients (14.8%) had ≥moderate tricuspid regurgitation. Cardiac magnetic resonance in 42 patients demonstrated a mean RV end-diastolic volume index of 122 ±3 0 ml/m2 (66 to 188 ml/m2), of which in 8 (14.8%), it was >150 ml/m2. Magnetic resonance imaging-based Qp:Qs was 1.6 ± 0.3. A total of 5 patients (9.3%) had established pulmonary hypertension (mean pulmonary artery pressure ≥25 mm Hg). In conclusion, isolated single or dual anomalous pulmonary venous connection is not necessarily a benign congenital anomaly because a proportion of patients develop pulmonary hypertension and/or RV dilation. Regular follow-up and on-going patient surveillance with cardiac imaging is advised.