Analysis of 2,097 children undergoing the Ross procedure—a complex heart valve replacement—found that discharge antihypertensive medications reduced combined reintervention and mortality rates from 13.9% to 8.9% over five years. Beta-blockers showed the strongest protective effect, with benefits most pronounced in children aged 1-12 years. The protective mechanism likely involves reducing mechanical stress on the neo-aortic valve created during surgery, as elevated blood pressure can accelerate structural deterioration of the transplanted valve. This finding challenges conventional pediatric cardiology practice, where antihypertensive use post-Ross procedure varies widely without clear guidelines. The 37% relative risk reduction represents clinically meaningful protection for these vulnerable patients. However, this observational study from administrative data cannot establish causation—children receiving antihypertensives may have differed in unmeasured ways from controls. The research also lacks hemodynamic data to determine optimal blood pressure targets. As a preprint awaiting peer review, these results require validation through randomized trials. Nevertheless, the findings suggest systematic antihypertensive protocols could substantially improve outcomes for pediatric Ross patients, potentially transforming post-operative care standards.