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. …