To the Editor We read with interest the report by Smith et al1 titled “Long-term Outcomes of Tetralogy of Fallot: A Study From the Pediatric Cardiac Care Consortium.” In a retrospective multicenter cohort of 3283 participants, the authors aimed to determine the transplant-free survival of patients with tetralogy of Fallot (TOF) and the predictors of survival. The study showed excellent long-term survival following TOF surgical repair (94.5% at 25 years). Surgical era, operative strategy, and presence of genetic abnormality were independent predictors of survival. We want to congratulate the authors on completing this study that informs the management of patients with TOF where evidence is lacking. Low prevalence, broad spectrum of presentation, and heterogeneity in management make clinical research on congenital heart disease challenging. A retrospective study design and registry data overcome these challenges; however, they impose limitations that warrant highlighting.