Right Ventricular Remodeling after Veno-Venous Extracorporeal Membrane Oxygenation Bridge to Lung Transplantation in Adults with Severe Lung Disease

Background Right ventricular (RV) dysfunction is a common complication of advanced lung disease, yet data on RV remodeling and long-term outcomes following veno-venous extracorporeal membrane oxygenation (VV-ECMO) as a bridge to lung transplantation remain limited. Methods We conducted a retrospective cohort study of consecutive adult patients bridged to lung transplant on VV-ECMO from January 1, 2015, to December 31, 2022. Transthoracic echocardiograms were analyzed pre-transplant (on VV-ECMO) and post-transplant in the ‘early' ( ≤ 3 months) and ‘late' (3-12 months) phases. Within-patient changes in echocardiographic parameters were assessed using paired nonparametric tests. The association between pre-transplant RV systolic function, quantified by RV fractional area of change (RVFAC), and 3-year post-transplant survival was evaluated using Cox proportional hazards modeling. Results Twenty patients were included (65.0% male, median age 47.5 [IQR: 41.5 – 56.4]) with primary etiologies of interstitial lung disease (50.0%) and COVID-19 (30.0%). In the ‘early' post-transplant phase, median RV systolic pressure decreased from 70.0 to 31.2mmHg (p<0.001) and RVFAC increased from 25.9 to 31.9% (p=0.004), whereas tricuspid annular plane systolic excursion decreased from 15.0 to 10.3mm (p<0.001). RV and right atrial dilation improved, while RV free-wall thickness remained unchanged (5.4 to 5.8mm, p=0.601). Among patients with greater baseline RV dysfunction, substantial functional and structural recovery was observed at 1-year. Three-year survival was 85.0% and preoperative RV dysfunction was not associated with mortality (HR: 0.96 [95% CI: 0.14 – 6.87]). Conclusions Meaningful RV recovery and favorable 3-year survival appear achievable after VV-ECMO bridge to transplantation, even among patients with moderate-to-severe pre-transplant RV dysfunction.