Commentary: Associations are not enough the explain causality: Multifactorial interactions are the key

The quest to improve hypoplastic left heart syndrome outcomes has evolved over the years, from a focus on operative details and perioperative management to identification of nonmodifiable patient-related factors like prematurity, genetic abnormalities, and anatomic subtype. Based on a few retrospective single-institution reports, the presence of aortic atresia and mitral stenosis (aa/ms) has been associated with higher operative mortality and worse late outcomes.1,2 Much like in the case of pulmonary atresia with intact ventricular septum, coronary-ventricular fistulae have been indicted as the culprit for the worse outcomes, despite the fact that ventricular decompression is never a factor, which could increase the propensity for perfusion abnormalities.