HALT Progression of Polycystic Kidney Disease Study A

\* Specific Aims of Study A To study the efficacy of angiotensin-converting-enzyme inhibitor (ACE-I) and angiotensin-receptor blockade (ARB) combination therapy as compared to ACE-I monotherapy and usual vs. low blood pressure targets on the percent change in kidney volume in participants with preserved renal function (GFR \>60 mL/min/1.73m2)and high-normal blood pressure or hypertension (\>130/80 mm Hg). \* Hypotheses to be tested in Study A In ADPKD individuals with hypertension or high-normal blood pressure and relatively preserved renal function (GFR \>60 mL/min/1.73 m2), multi-level blockade of the RAAS using ACE-I/ARB combination therapy will delay progression of cystic disease as compared to ACE-I monotherapy, and a low blood pressure goal will delay progression as compared with standard control.