Hypoplastic Left Heart Syndrome with Restrictive Atrial Septal Defect: Influence on Cardiac Transplantation

Excerpt

In their paper on the influence of restrictive atrial septal defect (rASD) on pulmonary vascular morphology in patients with hypoplastic left heart syndrome (HLHS), Graziano and colleagues [3] mention that the study by Canter et al. [1] showed that patients with HLHS and rASD are at significantly higher risk for death following transplantation compared to infants with HLHS without rASD. I believe that this is a misinterpretation of Canter et al.’s study, which claims that rASD is a significant negative risk factor for death primarily before transplantation. In this study, of the 20 patients listed for transplant, 7 had a rASD (35%). Four of these 7 infants with rASD died (3 pretransplant and 1 posttransplant due to pulmonary vascular disease), whereas only 1 of 13 infants without rASD died (pretransplant due to necrotizing enterocolitis and septic shock). The authors calculate a relative risk of death for those listed for transplant with a rASD of 7.4 (p = 0.01) compared to those without a rASD. If one carefully examines the numbers, it becomes clear that among the 12 infants with nonrestrictive ASD who were transplanted, all 12 are alive, whereas among the 4 with rASD who received a transplant, 3 are alive. Although it seems quite plausible that posttransplant survival may be affected by the pulmonary vascular disease that has been shown to be associated with rASD in HLHS [2, 5], one posttransplant death in this group with rASD does not allow a meaningful conclusion that these patients are at higher risk for death following transplantation as mentioned by Graziano et al. [3]. In fact, in their paper on the intermediate outcome of cardiac transplantation for HLHS in 142 infants, Razzouk et al. [4] attribute only 1 early death out of 13 early and 22 late deaths to pulmonary vascular disease. …