NCT07687160Not yet recruitingPhase 4
SPIRO-First: A Pragmatic Primary Care-Embedded Pilot Trial of Renin-Guided First-Line Antihypertensive Therapy
Source: ClinicalTrials.gov · Last updated 14 Oct 2026
Brief summary (registry, in English)
The goal of this clinical trial is to determine whether a renin-guided antihypertensive treatment strategy is feasible to implement in community primary care clinics and to explore whether spironolactone improves blood pressure control in adults with low-renin hypertension. The main questions it aims to answer are: Is it feasible to identify, recruit, randomize, and follow adults with low-renin hypertension in a pragmatic primary care-based clinical trial? Does first-line treatment with spironolactone result in greater reductions in ambulatory blood pressure compared with standard first-line antihypertensive therapy among adults with low-renin hypertension? Researchers will compare spironolactone 25 mg daily with standard first-line antihypertensive therapy (candesartan, hydrochlorothiazide, or amlodipine) to determine whether spironolactone provides better blood pressure control in adults with low-renin hypertension. Participants will: Undergo blood pressure assessments, blood tests, and ambulatory blood pressure monitoring (ABPM) to determine eligibility. Be randomly assigned to receive either spironolactone or a standard first-line antihypertensive medication for 12 weeks. Complete follow-up visits and laboratory testing to monitor blood pressure response, kidney function, electrolyte levels, medication adherence, and side effects. Undergo repeat blood pressure measurements and ABPM at the end of the study.
- Status (registry)
- Not yet recruiting
- Phase (registry)
- Phase 4
- Study type
- Interventional
- Enrollment
- 30 (estimated)
- First submitted
- 12 Jun 2026
- Start date
- 1 Jan 2027
- Primary completion date
- Aug 2028
- Lead sponsor
- Ottawa Hospital Research Institute
- Diseases
- High blood pressure
- NCT number
- NCT07687160
What you commit to
- Study type: Interventional · Phase 4
- Planned participants: 30
- From 1 Jan 2027 to the primary completion date, Aug 2028
- 4 sites in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Standardized office systolic blood pressure \>170 mmHg if untreated OR \>150 mmHg if receiving one antihypertensive medication.
- Pregnancy, breastfeeding, or intention to become pregnant during the study period. Women of childbearing potential must have a negative pregnancy test prior to randomization.
Other illness
- Known secondary hypertension requiring disease-specific therapy.
Lab values
- eGFR \<30 mL/min/1.73 m2.
- Serum potassium ≥5.0 mmol/L.
- Serum sodium \<135 mmol/L.
Other
- Known diagnosis of PA requiring specialist-directed management.
- Current use of MR antagonists.
- Known intolerance or contraindication to spironolactone, candesartan, hydrochlorothiazide, or amlodipine.
- Participation in another interventional study likely to affect blood pressure.
- Inability to provide consent
Who the study is looking for
- Age ≥18 years.
- Under the care of a primary care clinician in Ontario.
- Standardized office systolic blood pressure ≥130 mmHg or diastolic blood pressure ≥80 mmHg.
- Mean daytime baseline ABPM systolic blood pressure ≥130 mmHg or diastolic blood pressure ≥80 mmHg.
- Treating primary care clinician has independently determined that initiation of antihypertensive pharmacotherapy is clinically indicated.
- Either:
- Not currently receiving antihypertensive therapy, OR
- Receiving a single antihypertensive medication (ACE inhibitor, ARB, thiazide/thiazide-like diuretic, or calcium channel blocker) which the treating primary care clinician considers safe to discontinue for a 2-week washout period.
- Suppressed renin defined as direct renin concentration \<6 ng/L (\<10 mU/L) measured under routine outpatient conditions. Suppressed renin was selected as the primary biologic enrichment criterion because it is the physiologic hallmark of sodium-retaining, aldosterone-mediated hypertension and is more pragmatically scalable in primary care than complex biochemical primary aldosteronism (PA) definitions.
- In the opinion of the treating primary care clinician, outpatient participation in the study is appropriate.
Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers
Sites (4)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| GMF Universitaire Laval Coordinator of this site? Confirm its status | Laval | Canada | Unknown status |
| Ottawa Nurse Practitioner-Led Clinic Coordinator of this site? Confirm its status | Ottawa | Canada | Unknown status |
| The Ottawa Hospital Coordinator of this site? Confirm its status | Ottawa | Canada | Unknown status |
| St-Isidore Médical Coordinator of this site? Confirm its status | Saint Isidore | Canada | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.