Autosomal dominant polycystic kidney disease (PKD) is a slowly progressive kidney disease, and the effect of interventions on hard outcomes such as onset of end-stage kidney disease (ESKD) may be challenging to ascertain given the short duration of most clinical trials, where the statistical power may be low.1 We previously demonstrated a “legacy effect” of target blood pressure (BP) interventions in patients with CKD in the Modification of Diet in Renal Disease and African American Study of Kidney Disease and Hypertension trials (which had null effects during the parent trial) after 2 decades of post-trial follow-up facilitated by linkage to the US Renal Data System (USRDS) and National Death Index.