Partial anomalous pulmonary venous return in adults: Insight into pulmonary hypertension

Background: Partial anomalous pulmonary venous return (PAPVR) is a rare condition that may lead to pulmonary arterial hypertension (PAH). We sought to determine the prevalence of PAPVR, the follow-up rate of incidentally discovered PAPVR, the repercussions of volume and pressure overload on the right ventricle (RV), and the prevalence and predictors of PAH. Methods and results: Fifty PAPVR patients aged ≥18 years were included. All underwent transthoracic echocardiography and multislice imaging. PAPVR prevalence was 0.2% (23/13,606 chest computed tomography reports). Of the 26 incidentally diagnosed patients, 14 (54%) did not have a cardiac follow-up. Seven (14%) patients had PAH, of whom one third (28%) had Eisenmenger syndrome. The left-to-right shunt ratio (Qp/Qs) was the only predictor of PAH. PAPVR-induced volume overload led to increased right chamber volumes (RV basal diameter 45±8 mm, RV mid-diameter 38±9 mm, RV/left ventricle ratio 1.2 ± 0.2, indexed RV end-diastolic area 14±4 cm2/m2, indexed RV end-systolic area 8.6 ± 3.2 cm2/m2) and increased RV functional parameters (tricuspid annular plane systolic excursion 27±5 mm, fractional area change [FAC] 42 ± 10%, global longitudinal strain [GLS] −22 ± 5). In contrast, PAH-induced pressure overload had no impact on right heart volumes, but on RV functional parameters, which were decreased compared to non-PAH patients (FAC 35 ± 13% vs. 43 ± 10%, p = 0.049; GLS -18 ± 5 vs. −23 ± 4%, p = 0.01). Conclusions: PAPVR prevalence was 0.2%. When incidentally diagnosed, its management was often neglected despite potentially serious consequences (14% PAH). Only the Qp/Qs ratio was predictive of PAH. PAPVR-induced volume overload was shown to increase right heart volumes, while PAH-induced pressure overload caused alterations of RV functional parameters.