Late Pulmonary Hypertension In Surgically Palliated D-Transposition Of The Great Arteries: A 55-Year Review

Introduction: Pulmonary hypertension (PH) has been described following surgical palliation for transposition of the great arteries (D-TGA). While early pulmonary vascular disease is associated with late repair, the increasing prevalence of late PH has been observed following the intra-atrial baffle procedure (ABP), Mustard/Senning. A previous study from our institution identified patients with precapillary PH. More recent studies have described predominately postcapillary PH, suggesting multiple, differing mechanisms for this complication. Hypothesis: While heart failure is a common complication following ABP and is associated with postcapillary PH, we hypothesize that precapillary PH can be identified in a subset of patients. Methods: A retrospective descriptive study was performed at a single institution. Using 6 th World Symposium on Pulmonary Hypertension definitions. PH was defined as a mean pulmonary artery pressure >20mmHg. Etiology of PH was defined as precapillary (≥3 Wood units) versus postcapillary (pulmonary artery wedge pressure >15 mmHg). Results: We reviewed 157 D-TGA patients following ABP, finding 33 patients with PH. Mean age at last evaluation was 36.6 (14-54) years. Current condition: 22 alive, 7 dead, and 4 lost to follow-up. Etiology of PH: 10 precapillary, 8 postcapillary, 8 mixed, 2 borderline PH, and 2 did not undergo catherization. Additionally, 2 patients had pulmonary venous baffle obstruction and 1 had left lung hypoplasia. Of patients with recent imaging, 21 of 25 had systemic RV systolic dysfunction on echocardiogram or MRI. Conclusions: Late-onset PH in D-TGA following ABP is a significant long-term complication and warrants vigilant surveillance. This highlights the limitations of imaging and need for catheterization for complete evaluation. In this study, we observed precapillary PH in a majority of patients with PH, which differs from some previous studies. Identifying the etiology of PH could drastically alter treatment strategies and has implications for transplant consideration. Further studies are needed to identify the clinical attributes that contribute to this process.