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.

Inclusion criteria

• Diagnosis of ADPKD.
• Age 15-49 (Study A); Age 18-64 (Study B).
• GFR >60 mL/min/1.73 m2 (Study A); GFR 25-60 mL/min/1.73 m2 (Study B).
• BP ≥130/80 or receiving treatment for hypertension.
• Informed Consent.

Exclusion criteria

• Pregnant/intention to become pregnant in 4-6 yrs.
• Documented renal vascular disease.
• Spot urine albumin-to-creatinine ratio of >0.5 (Study A) or ≥1.0 (Study B) and/or findings suggestive of kidney disease other than ADPKD.
• Diabetes requiring insulin or oral hypoglycemic agents / fasting serum glucose of >126 mg/dl / random non-fasting glucose of >200 mg/dl.
• Serum potassium >5.5 milliequivalent per liter (mEq/L) for participants currently on ACE-I or ARB; >5.0 mEq/L for participants not currently on ACE-I or ARB.
• History of angioneurotic edema or other absolute contraindication for ACE-I or ARB. Intolerable cough associated with ACE-I is defined as a cough developing within six months of initiation of ACE-I in the absence of other causes and resolving upon discontinuation of the ACE-I.
• Indication (other than hypertension) for β-blocker or calcium channel blocker therapy (e.g. angina, past myocardial infarction, arrhythmia), unless approved by the site principal investigator. (PI may choose to accept an individual who is on only a small dose of one of these agents and would otherwise be eligible.)
• Systemic illness necessitating nonsteroidal antiinflammatory drugs (NSAIDs), immunosuppressant or immunomodulatory medications.
• Systemic illness with renal involvement.
• Hospitalized for acute illness in past 2 months.
• Life expectancy <2 years.
• History of non-compliance.
• Unclipped cerebral aneurysm >7mm diameter.
• Creatine supplements within 3 months of screening visit.
• Congenital absence of a kidney (also total nephrectomy for Study B).
• Known allergy to sorbitol or sodium polystyrene sulfonate.
• Exclusions specific to magnetic resonance imaging (Study A).