Cardiac magnetic resonance versus routine cardiac catheterization before bidirectional Glenn anastomosis: Long-term follow-up of a prospective randomized trial

ObjectivesA previously published randomized clinical trial comparing cardiac magnetic resonance (CMR) versus routine catheterization in patients with functional single ventricle before bidirectional Glenn (BDG) operation demonstrated similar short-term post-BDG outcomes. We sought to assess late outcomes in this cohort to ascertain any long-term effects of this evaluation strategy.MethodsRetrospective review of enrolled patients through most recent follow-up was performed on all 82 patients in the original cohort, at a median age of 8.8 years.ResultsOf these, 76 (93%) underwent Fontan operation; 2 died before Fontan. Baseline demographics, anatomic factors, and age at BDG did not differ between those randomized to CMR versus catheterization. Although pre-BDG CMR patients were younger at Fontan (2.4 vs 2.7 years; P = .02), baseline weight, body surface area, oxygen saturation, ventricular function, and degree of atrioventricular valve regurgitation were similar. Catheterization before Fontan (n = 76) demonstrated similar hemodynamic parameters including pulmonary vascular resistance and mean pulmonary artery, atrial, and ventricular end-diastolic pressures. CMR patients had comparable rates of transcatheter interventions (71% vs 79%; P = .6), including coil occlusion of systemic–pulmonary collaterals (66% vs 61%; P = .29). At Fontan surgery, short-term complications, hospital length of stay, and the percent meeting a 5-part definition of successful Fontan operation were not different (71% vs 55%; P = .23).ConclusionsPre-BDG CMR and catheterization groups had equivalent clinical and hemodynamic profiles before Fontan and similar post-Fontan outcomes at a median follow-up of 8 years after BDG. For selected patients, a pre-BDG evaluation with CMR is an acceptable alternative to catheterization.