Established Cardiovascular Disease: Finding the Right Clinical Trial

What "Established Cardiovascular Disease" Means for Trial Eligibility

Established CVD is a regulatory and clinical designation covering four core diagnoses: prior myocardial infarction, prior ischemic stroke, peripheral arterial disease (PAD) with ankle-brachial index <0.9 or prior revascularization, and symptomatic coronary artery disease confirmed by angiography or stress imaging. This matters because trial protocols use these categories as inclusion criteria, not a general label like "heart disease."

The ACC/AHA 2019 Guideline on the Primary Prevention of Cardiovascular Disease defines secondary prevention as care delivered to patients who have already experienced an atherosclerotic event, and states that "high-intensity statin therapy is recommended for patients with clinical ASCVD" as the baseline against which trial interventions are layered. [1]

Why the Distinction Between Primary and Secondary Prevention Matters

Sponsors design secondary-prevention trials for higher-risk populations. Event rates are faster, so sample sizes can be smaller and trial durations shorter while still reaching statistical power. A patient with a single episode of hypertension but no prior event almost certainly does not qualify for an established-CVD trial.

Confirm your category before approaching any site. Ask your cardiologist for documentation of your index event, the date, and the imaging or lab evidence. Registrars check this at screening.

The Four Diagnosis Categories That Reveal Trial Access

• Prior MI: Documented by troponin elevation, ECG changes, or coronary angiography.
• Prior ischemic stroke: MRI- or CT-confirmed infarct, distinct from hemorrhagic stroke, which typically triggers exclusion.
• PAD: ABI <0.9 on resting Doppler, or prior peripheral revascularization (angioplasty, bypass, or endarterectomy).
• Symptomatic CAD: Stable angina with ≥50% stenosis on angiography, or a history of coronary revascularization (PCI or CABG).

Having more than one qualifying diagnosis does not disqualify you. It may, however, move you into a subgroup of interest for sponsors studying polyvascular disease.

The SELECT Trial: What It Means for Patients Looking for GLP-1 Trials

The SELECT trial is the most clinically relevant recent cardiovascular outcomes trial for patients with established CVD and overweight or obesity. Published in the New England Journal of Medicine in 2023, SELECT enrolled 17,604 adults aged ≥45 years with BMI ≥27, established CVD, and no history of type 2 diabetes. [2]

Participants received subcutaneous semaglutide 2.4 mg once weekly (Wegovy) or placebo on top of standard care.

Primary Endpoint Results

At a mean follow-up of 39.8 months, the primary MACE endpoint (cardiovascular death, non-fatal MI, or non-fatal stroke) occurred in 6.5% of the semaglutide group vs. 8.0% of the placebo group. That is a 20% relative risk reduction (HR 0.80, 95% CI 0.72 to 0.90, P<0.001). [2]

The number needed to treat to prevent one MACE event over approximately 3.3 years was 67.

What SELECT Means for Current Trial Enrollment

The SELECT trial is closed to enrollment. Its results did, however, trigger an FDA approval in March 2024 for semaglutide 2.4 mg to reduce the risk of serious cardiovascular events in adults with established CVD and BMI ≥27. [3] That approval now forms the backbone of several active follow-on trials examining:

• Long-term outcomes beyond 5 years in SELECT participants
• GLP-1 plus SGLT2 inhibitor combination in polyvascular disease
• Semaglutide dose escalation strategies in post-MI populations
• Biomarker substudies (NT-proBNP, hsCRP) within ongoing CVOT extensions

Patients who qualify for the SELECT phenotype (CVD, overweight, no T2D) should ask their cardiologist whether any of these extension or successor protocols are recruiting locally.

How to Search ClinicalTrials.gov for Established CVD Trials

ClinicalTrials.gov is the mandatory federal registry for all interventional trials conducted in the United States. Searching it efficiently requires knowing the right MeSH terms and filters.

Step-by-Step Search Strategy

1. Go to clinicaltrials.gov and select "Find a Study."
2. In the Condition field, enter "cardiovascular diseases" or the specific diagnosis (e.g., "myocardial infarction").
3. Set Status to "Recruiting" only. Open but not-yet-recruiting studies rarely need patients for 6 to 18 months.
4. Set Age to your age band and Phase to "Phase 3" for the most enrollment-ready trials.
5. Add your ZIP code and a 100-mile radius to surface sites near you.
6. Filter by Intervention Type: Drug for pharmacotherapy trials, Device for catheter-based or implantable studies.

Common search terms that return established-CVD secondary-prevention results:

• "Secondary prevention atherosclerosis"
• "MACE cardiovascular outcomes"
• "GLP-1 cardiovascular"
• "PCSK9 inhibitor secondary prevention"
• "Anti-inflammatory cardiovascular" (for colchicine and IL-6 pathway trials)

Reading the Eligibility Criteria

Every registered trial lists Inclusion Criteria and Exclusion Criteria. Print both before calling a site coordinator. Common exclusion criteria in CVD trials include:

• eGFR <30 mL/min/1.73m² (renal impairment threshold varies by trial)
• Recent ACS within 60 days (some trials require event stability)
• Active malignancy within 5 years
• Concurrent participation in another interventional trial
• HbA1c ≥6.5% in trials that exclude type 2 diabetes (as in SELECT)

Identifying a disqualifying exclusion before traveling to a site saves time for you and the investigator.

Landmark Trials Shaping the Current Trial Field

Understanding prior CVOTs helps you ask better questions when evaluating a new trial. Each landmark study below defined a therapeutic category now generating second-generation trials.

FOURIER (Evolocumab) and ODYSSEY OUTCOMES (Alirocumab)

FOURIER enrolled 27,564 patients with established ASCVD on maximally tolerated statin therapy and randomized them to evolocumab (a PCSK9 inhibitor) or placebo. At 2.2 years, evolocumab reduced LDL-C by 59% from a median baseline of 92 mg/dL and reduced the primary composite endpoint (CV death, MI, stroke, hospitalization for unstable angina, or coronary revascularization) by 15% (HR 0.85, 95% CI 0.79 to 0.92, P<0.001). [4]

ODYSSEY OUTCOMES (N=18,924) tested alirocumab vs. Placebo in post-ACS patients and found a 15% reduction in MACE at a median 2.8 years (HR 0.85, 95% CI 0.78 to 0.93, P<0.001). [5]

Both trials are now generating follow-on work on inclisiran (a small-interfering RNA targeting PCSK9), with the ORION-4 trial (N=15,000) ongoing and enrolling.

COLCOT and LoDoCo2 (Colchicine)

The inflammatory hypothesis for atherosclerosis produced two important colchicine trials. COLCOT (N=4,745) randomized post-MI patients to colchicine 0.5 mg daily vs. Placebo and found a 23% reduction in the primary composite endpoint (cardiovascular death, resuscitated cardiac arrest, MI, stroke, or urgent coronary revascularization) at 22.6 months (HR 0.77, 95% CI 0.61 to 0.96, P=0.02). [6]

LoDoCo2 (N=5,522) extended this finding to stable CAD: colchicine 0.5 mg daily reduced the primary endpoint of MI, ischemic stroke, ischemia-driven revascularization, or cardiovascular death by 31% over a median 28.6 months (HR 0.69, 95% CI 0.57 to 0.83, P<0.001). [7]

Active trials are now examining colchicine in post-PCI populations and in heart failure with preserved ejection fraction (HFpEF), which broadens eligibility for established-CVD patients with concurrent HF.

EMPEROR-Reduced and DAPA-HF (SGLT2 Inhibitors in Heart Failure)

For patients whose established CVD includes heart failure with reduced ejection fraction (HFrEF), SGLT2 inhibitor trials are the most active enrollment category. EMPEROR-Reduced (N=3,730) found empagliflozin reduced the primary endpoint of cardiovascular death or hospitalization for heart failure by 25% over a median 16 months (HR 0.75, 95% CI 0.65 to 0.86, P<0.001). [8] DAPA-HF (N=4,744) showed a nearly identical result for dapagliflozin (HR 0.74, 95% CI 0.65 to 0.85, P<0.001). [9]

Second-generation SGLT2 trials now focus on dose optimization, combination with GLP-1 agonists, and populations with HFpEF (EF ≥50%).

Matching Your CVD Subtype to the Right Trial Category

Not all established CVD is the same. Your specific diagnosis profile should guide which trial category you pursue.

Post-MI or Post-ACS Patients

Your best-matched categories:

• PCSK9 inhibitor trials (if LDL-C ≥70 mg/dL on maximally tolerated statin)
• Anti-inflammatory trials (colchicine, IL-6 inhibitors, lipoprotein-associated phospholipase A2 inhibitors)
• GLP-1 trials if BMI ≥27 and HbA1c <6.5%
• Omega-3 fatty acid trials (icosapentaenoic acid analogs following REDUCE-IT data)

Patients with Stroke or TIA History

Stroke and TIA open eligibility for trials targeting:

• Dual antiplatelet therapy duration studies
• Factor XI inhibitors (a growing trial category for AF-related stroke)
• Inclisiran and PCSK9 RNA interference studies that include cerebrovascular disease as a qualifying event

The AHA/ASA 2021 Guideline for the Prevention of Stroke in Patients with Stroke and Transient Ischemic Attack specifies that "high-intensity statin therapy is recommended for patients with atherosclerotic ischemic stroke or TIA." [10] Confirm your statin status before screening, as most secondary-prevention trials require at least moderate-intensity statin use as an inclusion criterion.

PAD Patients

Peripheral arterial disease is systematically underrepresented in CVD trials despite conferring mortality risk equivalent to prior MI. [11] PAD-specific trials include:

• Vorapaxar (PAR-1 antagonist) extension studies
• Rivaroxaban plus aspirin trials (building on COMPASS, which showed a 24% relative risk reduction with the combination vs. Aspirin alone, HR 0.76, P<0.001) [12]
• GLP-1 trials that include PAD as a qualifying CVD event (SELECT did include PAD)

Patients with Symptomatic CAD but No Prior Acute Event

Stable CAD patients often have the broadest eligibility windows because exclusion criteria for "recent ACS" do not apply. LoDoCo2 was built around this population. Active trials in this category focus on high-sensitivity CRP reduction, triglyceride lowering, and novel lipid-lowering agents targeting remnant cholesterol.

What to Expect During the Screening Process

The screening visit is not treatment. It determines whether you qualify, and roughly 30 to 50% of interested patients are screen-failed for one or more criteria.

What Sites Assess at Screening

• Review of medical records confirming your qualifying CVD event
• Fasting lipid panel and HbA1c
• Renal function (creatinine and eGFR)
• Liver function tests (required for most lipid-lowering trials)
• 12-lead ECG
• Blood pressure and weight
• Medication reconciliation to confirm background therapy

Bring a complete medication list, including supplements, to the first contact call. Fish oil supplements at doses above 2 g/day may confound triglyceride endpoints and trigger exclusion in lipid trials.

Randomization and Follow-Up Expectations

Most Phase 3 CVD trials randomize in a 1:1 ratio (active drug vs. Placebo) under double-blind conditions. Follow-up visits are typically every 3 to 6 months for the first year, then every 6 months for the duration of the trial. Endpoint-driven trials (those that continue until a pre-specified number of MACE events occur) may run longer than originally planned if event rates are lower than projected.

Compensation varies by site and protocol. Typically, trial participation covers all study-related procedures and medications at no cost.

Society Guidelines That Define Standard of Care (and Why That Matters for Trials)

Clinical trials for established CVD are almost always add-on to guideline-directed medical therapy (GDMT). Understanding what GDMT requires helps you confirm you are on the right background regimen before enrolling.

ACC/AHA 2019 and 2022 Updates

The 2019 ACC/AHA Guideline on Primary Prevention and the 2022 AHA/ACC Guideline for Coronary Artery Disease Management both define GDMT for established CVD as:

• High-intensity statin (atorvastatin 40 to 80 mg or rosuvastatin 20 to 40 mg)
• Antiplatelet therapy (aspirin 81 mg for most; P2Y12 inhibitor post-ACS for 12 months)
• ACE inhibitor or ARB for patients with EF <40% or diabetes
• Beta-blocker post-MI for at least 12 months
• SGLT2 inhibitor for patients with HFrEF or type 2 diabetes [1]

Most trial protocols require that participants be on stable doses of background medications for 4 to 8 weeks prior to randomization.

ESC 2021 CVD Prevention Guidelines

The European Society of Cardiology 2021 Guidelines on Cardiovascular Disease Prevention in Clinical Practice recommend a target LDL-C of <55 mg/dL (<1.4 mmol/L) for very-high-risk patients, which includes all established CVD. [13] Many PCSK9 inhibitor and inclisiran trials use a baseline LDL-C ≥70 mg/dL as an inclusion criterion, meaning patients already at ESC target may not qualify.

Knowing your current LDL-C before applying to a lipid trial prevents a wasted screening visit.

Practical Steps to Enroll in a Cardiovascular Clinical Trial

The process from interest to randomization typically takes 4 to 12 weeks.

Step 1: Gather Your Clinical Documentation

Collect the following before contacting any trial site:

• Discharge summary or catheterization report documenting your qualifying event
• Current medication list with doses and start dates
• Most recent lipid panel, HbA1c, eGFR, and BMI
• Cardiology or vascular surgery follow-up notes from the past 12 months

Step 2: Search and Shortlist Trials

Use ClinicalTrials.gov (method described above) to identify 3 to 5 recruiting trials for which you appear to meet the basic inclusion criteria. Note the NCT number for each.

Step 3: Contact the Site Coordinator

Call or email the listed contact at the nearest recruiting site. Site coordinators perform a brief pre-screen by phone (10 to 15 minutes) to eliminate obvious disqualifiers before scheduling an in-person visit.

Step 4: Attend the Screening Visit

Bring all documentation. The informed consent process must occur before any study procedures, and you have the right to ask questions, take the form home, and decide without pressure.

Step 5: Confirm Compatibility with Your Treating Physician

Your cardiologist should know about any trial you are considering. Randomization to a blinded study drug does not replace GDMT, but potential drug-drug interactions need review.

Red Flags: When a Trial May Not Be Appropriate

Some offers of trial participation deserve careful scrutiny.

• No ClinicalTrials.gov registration: All legitimate U.S. Interventional trials must be registered. Verify the NCT number before proceeding.
• Pressure to discontinue GDMT: No reputable CVOT trial asks patients to stop their statin or antiplatelet as a condition of enrollment without a clinical rationale documented in the protocol.
• Compensation that seems extraordinarily high: FDA regulations allow reasonable compensation for time and travel, not amounts that constitute undue inducement. Offers exceeding $500 per visit for a routine outpatient trial warrant a question.
• Phase 1 trials for established CVD: Phase 1 trials test safety in healthy volunteers or very small patient groups. They are not appropriate vehicles for secondary-prevention therapy and rarely recruit established-CVD patients.

The FDA guidance on informed consent in clinical investigations specifies that subjects must be told of "any reasonably foreseeable risks or discomforts" before enrollment. [14]