Abstract 16913: Cardiac Magnetic Resonance Versus Routine Catheterization Prior to Bidirectional Glenn Operation: Long-Term Follow-Up of a Randomized Clinical Trial

Abstract

Background: A previously published randomized clinical trial of cardiac magnetic resonance (CMR) versus routine catheterization in patients with functional single ventricle (SV) prior to Glenn operation (BDG) demonstrated similar short-term post-operative outcomes. We sought to evaluate late outcomes in this cohort to ascertain any long-term effects of this management strategy. Methods: Retrospective review of enrolled patients through most recent follow-up. Results: Follow-up was available on all 82 patients in the original cohort, median age 6.5 years at most recent follow-up. Of these, 76 (93%) underwent Fontan operation; 2 died prior to Fontan. Baseline demographics, anatomic factors, and age at BDG did not differ between those randomized to CMR versus catheterization. Although CMR patients were slightly younger at Fontan operation (2.4 vs 2.7 years, p=0.02), baseline weight, body surface area, and oxygen saturation at time of Fontan were similar. Echocardiographic data prior to Fontan were similar, with 2 patients in each group having ≥ moderate ventricular dysfunction, and only 1 patient with ≥ moderate atrioventricular valve regurgitation. Catheterizations were performed in all patients prior to Fontan (n=76). Although age at catheterization was younger in the CMR group (2.3 vs 2.7 years, p=0.003), hemodynamic parameters were not significantly different, including pulmonary vascular resistance, mean pulmonary artery, atrial, and ventricular end-diastolic pressures. Prevalence of coarctation and pulmonary artery stenoses were similar. Patients in the CMR group had a similar rates of transcatheter interventions (71 vs. 79%, p=0.6) including similar rate of coil occlusion of aorto-pulmonary collaterals (66 vs. 61%, p=0.29). At time of Fontan, short-term complications, hospital length of stay, and the percent of patients meeting a 5-part definition of a successful Fontan operation were not significantly different (71 vs 55%, p=0.23). Conclusions: The CMR and catheterization groups had equivalent clinical and hemodynamic profiles prior to Fontan, and similar post-Fontan outcomes at a median follow-up of 6 years post BDG. For selected patients, a pre-BDG evaluation with CMR is an acceptable alternative to catheterization.