Hypertension Clinical Trials — A Patient's Guide

What is hypertension?

Hypertension is the medical term for high blood pressure. Blood pressure is the force of blood pushing on the walls of your arteries. When that force stays too high for too long, it wears on the heart, brain, kidneys, and blood vessels.

Doctors use the American College of Cardiology / American Heart Association (ACC/AHA) categories:

• Normal — less than 120/80 mmHg
• Elevated — 120-129 systolic and less than 80 diastolic
• Stage 1 hypertension — 130-139 systolic or 80-89 diastolic
• Stage 2 hypertension — 140 or higher systolic, or 90 or higher diastolic
• Hypertensive crisis — higher than 180/120 mmHg (call your doctor or seek urgent care)

Hypertension also has sub-categories that matter for trial eligibility:

• Uncontrolled hypertension — your blood pressure stays above goal even though you are taking medication.
• Resistant hypertension — your blood pressure is still above goal despite three or more blood pressure medications at full doses, including a diuretic. This is the population most active 2026 hypertension trials are designed for.
• Refractory hypertension — blood pressure remains uncontrolled despite five or more medications. This is a smaller, harder-to-treat group.
• Isolated systolic hypertension — the top number is high (≥130) but the bottom number is normal. Common in older adults.

Why this matters for trials: many hypertension studies enroll only specific sub-groups (for example, only patients with resistant hypertension on at least three medications). The screening visit checks which group you fall into.

If you do not know your numbers off the top of your head, that is fine. We will check during screening, and a few home blood pressure readings ahead of your visit are helpful if you have a cuff at home.

What hypertension trials are testing in 2026

The hypertension space has moved well beyond "another pill once a day." Current trials are exploring several directions at once:

• Long-duration medications. RNAi (RNA-interference) therapeutics are designed to lower blood pressure for months at a time from a single subcutaneous injection given every few months. The goal is to make the daily-pill problem go away for patients who struggle with adherence or side effects.
• Mechanism-novel drugs. New oral medicines targeting pathways like aldosterone synthase, the endothelin system, and other non-traditional mechanisms are in active Phase 2 and Phase 3 trials, especially for resistant hypertension.
• Device-based renal denervation. Catheter-based procedures that calm the nerves around the kidney arteries continue to be studied as add-on therapy for patients whose blood pressure stays high despite medications.
• Combination therapies. Some trials test fixed-dose combinations that pair two or three blood pressure medications in a single tablet to simplify the regimen and improve control.
• Personalized medicine trials. A smaller but growing group of studies use genetic, hormonal, or biomarker-based criteria to match patients to the treatment most likely to work for them.

Resistant hypertension is a particularly active area in 2026. If your cardiologist has used the words "resistant" or "hard to control," there are more trial options open to you than there were even a few years ago.

A trial is not a guess. By the time a treatment reaches a Phase 2 or Phase 3 hypertension study, it has already gone through earlier safety testing. The trial is asking a more specific question: does this lower blood pressure in real patients, and is the risk reasonable for the potential benefit?

Who might be eligible

Every hypertension trial has its own eligibility list. Some are narrow, some are broader. A few common requirements come up again and again:

• Documented hypertension — usually with office blood pressure readings, home readings, or 24-hour Ambulatory Blood Pressure Monitoring (ABPM) confirming the diagnosis.
• Blood pressure within a trial-specific range. Some trials need your BP to be above a certain number (for example, ≥140/90 despite medications) to enroll. Others have an upper limit too.
• On (or off) specific medications. A trial may require that you are already on three blood pressure drugs at stable doses, or that you are willing to wash out a specific medication for a defined period before starting. The protocol spells this out.
• Stable comorbidities. Conditions like diabetes, heart failure, or kidney disease are often allowed if they are stable and well-managed; uncontrolled comorbidities may exclude you.
• Age range. Most adult hypertension trials enroll ages 18-80 or so; some have a higher upper age limit.
• Kidney function above a cutoff — measured by eGFR. Severely reduced kidney function may exclude you from some trials.
• Ability to commit to the visit schedule.
• Not pregnant or planning pregnancy during the study, for relevant patients.

You may also be excluded for things like a recent cardiovascular event, secondary causes of hypertension that need a different work-up, or being enrolled in another investigational study. None of these are personal — they are study-design decisions made to keep results clear and participants safe.

The honest reality: most patients who screen for any one trial do not end up enrolling in that specific trial. If you are not eligible for one, you may be eligible for another.

What participation involves

Every hypertension trial is structured a little differently, but the general arc looks like this:

Screening (1-3 hours)

You meet the trial team. The Principal Investigator — a practicing cardiologist — reviews your history with you. You go through informed consent: a detailed document explaining what the trial is studying, what is involved, the known risks, and your right to leave at any time. (For a section-by-section walkthrough, see our consent-form reading guide.) Screening usually includes:

• Multiple seated blood pressure readings, spaced minutes apart, to confirm your average BP
• Sometimes 24-hour Ambulatory Blood Pressure Monitoring (ABPM) — a small cuff and recorder you wear for a day so we can see how your BP behaves overnight and during normal activity
• ECG, blood draw, urine sample
• A review of all your current medications and supplements

Baseline visit

If screening confirms eligibility, the baseline visit collects the starting measurements the trial uses to track change: office BP, home BP averages, sometimes a repeat ABPM, baseline labs, and quality-of-life questionnaires. You receive instructions for the study treatment.

Treatment phase

This is the bulk of the trial. Visits typically happen every 1-3 months and last 1-3 hours. The study treatment is given in one of three ways depending on the protocol:

• A daily pill you take at home
• A subcutaneous injection given in the clinic every few months (for example, RNAi therapies)
• An in-office procedure (for example, renal denervation)

Between visits you may be asked to:

• Take home blood pressure readings on a fixed schedule (often morning and evening)
• Log your readings in a paper diary or app
• Take your study medication consistently and report any missed doses
• Continue your regular blood pressure medications unless the protocol tells you otherwise

24-hour ABPM is often repeated at key time points (for example, baseline, 3 months, 6 months) so the team can compare full-day BP profiles, not just office readings.

End-of-study and follow-up

At the end of the treatment phase, you have a final visit with closing assessments. Many trials add a follow-up period (3, 6, or 12 months) where the site stays in touch to monitor longer-term outcomes. After that, you return to your regular cardiologist or primary care doctor for ongoing care.

What you might gain

Patients have different reasons for considering a trial. Common ones:

• Access to investigational treatments that are not yet available outside research — for example, a long-acting therapy that may simplify a complex pill regimen.
• Better blood pressure monitoring than routine care typically provides — multiple office readings, home readings, and 24-hour ABPM at several time points.
• Closer cardiology follow-up than many patients receive in routine practice.
• Possible improved blood pressure control for some participants, depending on which group you are randomized to and how the treatment performs.
• A meaningful contribution to research that may help future patients with hypertension.

We want to be honest here: a trial may help you, may not change your blood pressure much, or in some cases may cause side effects. No one — not your cardiologist, not the trial team, not the sponsor — can promise benefit. That is exactly why the trial is being done: to find out.

What the risks are

Hypertension trials are highly regulated, but participation does carry real risks. Patients should know about:

• Side effects from the study treatment. These are listed in the consent form. Some are common, some rare, some serious. Common BP-related side effects can include dizziness, fatigue, swelling, or changes in kidney function or potassium levels.
• Randomization to placebo or a comparison treatment. Many trials are designed so that some participants receive the new treatment and some receive a placebo or current standard care, on top of their usual blood pressure medications. You may not get the investigational treatment.
• Blood pressure too high or too low. This is monitored very closely with frequent readings. The trial team adjusts your management or stops the study treatment if needed.
• Procedural risks for trials that include a procedure such as renal denervation — bleeding, vessel injury, kidney-artery complications — described in detail in the consent form for those studies.
• Time commitment. Visits, ABPM, labs, and study procedures take time and energy.
• Inconvenience and travel. Trial visits are at the research site, not at your regular clinic.

You can withdraw at any time, for any reason, without it affecting your future medical care.

How to find out if you are eligible

There are three easy ways to start the conversation:

• Call (786) 703-5941. A 15-minute eligibility screening is free and does not commit you to anything.
• Use our patient contact form at /contact-patient.
• Have your cardiologist or primary care doctor refer you. We coordinate with most Miami-area cardiology and primary care practices.

Bring or be ready to share: a list of your current blood pressure medications and doses, recent home BP readings if you take them, your most recent labs if available, and any prior cardiology notes.

Active hypertension trials at Amavita Research

We currently have hypertension protocols open at Amavita Research. As of the date on this page, an active study is:

• ZENITH (zilebesiran) — a Phase 3 evaluation of zilebesiran, an investigational RNAi therapeutic targeting AGT, in adults with hypertension and elevated cardiovascular risk. Sponsored by Alnylam and coordinated with Duke Clinical Research Institute. The study aims to find out whether zilebesiran lowers blood pressure and cardiovascular risk in adults whose hypertension is not controlled by multiple medications. See /trials/zenith-zilebesiran for details.

For the current list of trials and contact information, see /therapeutic-areas/hypertension. Trial availability changes — call us for the most current status.

Questions worth asking before you join

The trial team welcomes these questions. If yours is not on the list, ask anyway.

• What is the chance I will receive the investigational treatment versus placebo? This is set by the trial design and the team can tell you.
• Can I stay on my current blood pressure medications? Most hypertension trials are designed so you continue your existing regimen, sometimes with specific adjustments. The protocol spells out which drugs are allowed, restricted, or required.
• What happens if my blood pressure goes too low or too high during the study? The team adjusts your management, and your safety comes first. You may have your study treatment paused or stopped if needed.
• How will my regular cardiologist or PCP be kept in the loop? With your permission, we send updates to your regular team so your care stays coordinated.
• What happens at the end of the study? Can I keep the treatment? Sometimes, depending on the program. Ask about post-trial access if it matters to you.
• Are there any costs to me? For most cardiovascular trials at Amavita Research, study-related care is paid for by the sponsor. Routine medical care is still billed to your insurance as usual.

A note for patients with resistant hypertension

If you have been told your blood pressure is "resistant" or "hard to control," 2026 is an unusually active year for trials in your population. RNAi therapies, aldosterone synthase inhibitors, and renal denervation are all in active Phase 2 and Phase 3 development specifically for patients like you. If you are on three or more blood pressure medications and still above goal, it is worth a call.

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About the author: Amavita Research is a cardiovascular clinical trial site embedded inside amavita Heart and Vascular Health® in North Miami Beach, FL. Our PIs are practicing cardiologists. We see patients in English, Spanish, Haitian Creole, and Brazilian Portuguese. Call (786) 703-5941 or visit /contact-patient.