Mitral Stenosis and Aortic Atresia—A Risk Factor for Mortality After the Modified Norwood Operation in Hypoplastic Left Heart Syndrome

Background There are conflicting reports regarding the importance of mitral stenosis and aortic atresia as a risk factor for Norwood mortality. This study reviews outcomes of this anatomic subgroup at our institution and examines the utility of preoperative cardiac catheterization and its correlation with clinical outcomes and pathology findings. Methods This is a single-center, retrospective review of hypoplastic left heart syndrome patients who underwent modified Norwood operation between October 2005 and May 2013. Results Fourteen of 74 hypoplastic left heart syndrome patients (19%) had mitral stenosis and aortic atresia. Operative mortality for MS/AA was 29% versus 7% for all other hypoplastic left heart syndrome anatomic subgroups ( p = 0.04). Although only 19% of the entire cohort, the mitral stenosis and aortic atresia subgroup constituted 50% of the total operative mortality and the only interstage deaths. Autopsies support myocardial ischemia as the mechanism of death. Although preoperative angiography defined the presence of ventriculo-coronary connections, it did not clearly risk stratify patients in regard to operative mortality. Conclusions Mitral stenosis and aortic atresia is a risk factor for perioperative myocardial ischemia and mortality. Further exploration of myocardial reserve is warranted.