Right Ventricle Dependent Coronary Circulation: Location of Obstruction is Associated with Survival.

Pulmonary atresia with intact ventricular septum (PAIVS) with right ventricle dependent coronary circulation (RVDCC) carries suboptimal outcomes primarily due to cardiac ischemia. We hypothesize clinical outcomes are affected by the level of coronary obstruction, a surrogate for vulnerable myocardium.We conducted a single-institution retrospective analysis of all neonates with PAIVS with RVDCC from 1995-2017. RVDCC was defined as the presence of any coronary-cameral fistula with coronary obstruction proximal to the fistula and angiographic evidence of RV perfusion of the myocardium through the fistulous communication. Location of coronary obstruction was categorized as either proximal or distal segments using the SYNTAX score criteria. Transplant-free survival was compared between those with proximal and distal obstruction, then these groups were compared to those without RVDCC.Of 103 neonates with PAIVS, 28 (27%) had RVDCC: 18 proximal (64%), 10 distal (36%). Median age at last follow-up for RVDCC patients was 1.8 years (interquartile range 0.3-8.1). All deaths (10/28, 36%) occurred at six months old or earlier. Proximal coronary artery obstruction was associated with decreased transplant-free survival relative to distal obstruction (HR 3.63, 95%CI 1.01 - 13.00, p=0.048). Transplant-free survival at 1 year was 33% and 70% in the proximal and distal obstruction groups, respectively. Compared to patients without RVDCC, patients with proximal obstruction had significantly lower transplant-free survival (p<0.0001), while those with distal obstruction did not (p=0.22).The location of coronary artery obstruction impacts clinical outcome and may represent a potential branch point in the management for PAIVS with RVDCC.