Abstract 2210: Randomized Clinical Trial Comparing Cardiac MRI with Routine Cardiac Catheterization Prior to Superior Cavopulmonary Anastomosis
Background: Routine preoperative catheterization (CATH) is often performed in patients with single ventricle physiology prior to superior cavopulmonary anastomosis (SCPA) to evaluate candidacy for this procedure. We hypothesized that cardiac magnetic resonance (CMR) can safely and effectively evaluate such patients with similar outcomes following SCPA.
Methods: Single center, prospective, randomized clinical trial comparing CMR to CATH in patients considered for SPCA from 1/2003 to 5/2006. Patients were followed from pre-operative evaluation to 3 months after SPCA.
Results: Of 91 eligible patients, 81 were enrolled based on screening echocardiogram, fulfillment of inclusion criteria, and informed consent. Patients were randomized to CATH (n = 41) or CMR (n = 40). There were no differences between groups in demographics (mean age 5.2 months), ventricular type (52% hypoplastic left heart syndrome), prior operation, oxygen saturation, ventricular function, and AV valve regurgitation. Four patients crossed over, 3 from CMR to CATH and 1 from CATH to CMR. Interventions were performed at CATH in 17 patients (41%). CATH patients had more blood transfusions (66% v. 5%), minor complications (78% v. 5%, P < 0.001), longer hospital stays (median 2 v. 1 day, p 0.001), and higher hospital charges ($34,479 v. $14,781, p < 0.001). There was one major complication in the CMR group (p = 0.49). At time of SPCA, other operative procedures, cardiopulmonary bypass times, superior vena cava and atrial pressures, and rate of intraoperative complications were similar. Length of mechanical ventilation (17 v. 11 hours, p < 0.001), length of ICU stay (3 v. 2 days, p = 0.003), and length of hospital stay (6 v. 5 days, p = 0.04) were longer in the CATH group. The proportion who met a 4-part clinical definition of a successful SPCA was similar (71% v. 83%, p = 0.30) as were duration of thoracostomy tube drainage and oxygen saturation at hospital discharge. At 3-month follow-up (n = 63), the groups did not differ in terms of clinical well-being, oxygen saturation, or frequency of re-intervention.
Conclusions: Preliminary results from this randomized trial show that CMR is a safe, effective, and less costly alternative to routine CATH in the evaluation of selected patients prior to SCPA.