SPIRO-First: A Pragmatic Primary Care-Embedded Pilot Trial of Renin-Guided First-Line Antihyperte… (NCT07687160) | Clinical Trial Compass
Not Yet RecruitingPhase 4
SPIRO-First: A Pragmatic Primary Care-Embedded Pilot Trial of Renin-Guided First-Line Antihypertensive Therapy
Canada30 participantsStarted 2026-09-01
Plain-language summary
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.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Age ≥18 years.
. Under the care of a primary care clinician in Ontario.
. 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:
. 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.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1This trial is described as a 'pilot' study that's primarily measuring how quickly they can recruit participants rather than whether the treatment works — does that mean we won't get a clear answer about whether renin-guided therapy is better for my blood pressure, and should that affect whether I consider joining?
2The trial uses renin levels to guide which blood pressure medication is chosen first — can you explain what a renin test involves, whether I'd need one before enrolling, and whether my renin level has ever been checked?
3Since this trial is embedded in primary care and not yet recruiting, how long might I wait before it even starts, and would it make more sense for us to just begin a standard first-line blood pressure medication now rather than waiting?
4This is a Phase 4 trial, which means the medications being tested are already approved — but can you help me understand what is still unknown about using renin to guide the choice between them, and what the potential downsides of that approach might be for someone in my situation?
5Because this is a pragmatic pilot trial focused on enrollment feasibility, what would happen to my care if the trial doesn't recruit enough people or gets discontinued — would I be able to stay on whatever medication I was started on?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
PRIMARY OUTCOME: Recruitment Rate of Randomized Participants per Month
Timeframe: 12 months following activation of all participating study sites