โ—† ClinicalMetric Research Team ยท Last Reviewed: September 2026 ยท Sources: ClinicalTrials.gov ยท FDA ยท NIH
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Cardiology Last Reviewed: May 2026 CM-INS-065 // MARCH 2026

Heart Disease Clinical Trials 2026: Cardiovascular Studies and Recruiting Research

Cardiovascular disease remains the leading cause of death globally, and the research pace has not just kept up โ€” it's accelerated. The most structurally interesting change in 2026 isn't a new drug molecule; it's the transformation of lipid management from a daily adherence problem into a twice-yearly injection. Inclisiran gives you 50% LDL-C reduction from two injections per year. Its cardiovascular outcomes trial is enrolling 22,000 patients. Meanwhile, Lp(a) โ€” which until recently was a risk factor you could identify but couldn't treat โ€” finally has multiple siRNA agents in Phase 3 outcomes trials. For a field that spent decades mostly refining statins, this is a genuinely different era.

Medical Notice

This article is for informational purposes only and does not constitute medical advice. Clinical trial eligibility and availability vary. Always consult a qualified healthcare professional before making any medical decisions or considering participation in a clinical trial.

Summary

In 2026, cardiovascular trial data is changing standards of care across multiple fronts simultaneously. SELECT trial: semaglutide 2.4mg reduced MACE by 20% in CVD patients without diabetes, establishing GLP-1 agonists as cardiovascular drugs independent of weight loss. SUMMIT trial: tirzepatide reduced HFpEF events by 38% in obese patients. ORION-4 (22,000 patients): testing whether inclisiran's 50% LDL-C reduction from twice-yearly injections translates to hard cardiovascular endpoints. CRISPR base editing (NTLA-2001) achieved 90% TTR knockdown from a single dose in ATTR-CM Phase 1/2 โ€” potentially a single-treatment cure. This is the cardiovascular research landscape patients should understand before deciding whether to enroll.

ClinicalMetric Analysis

  • SELECT's 20% MACE reduction was too fast to be explained entirely by weight loss. The cardiovascular event benefit in semaglutide's SELECT trial emerged within months โ€” before sustained weight change could account for it. Anti-inflammatory effects, direct attenuation of atherosclerotic plaque inflammation, and improvements in endothelial function are likely parallel mechanisms. Framing GLP-1 agonists as "weight loss drugs with cardiovascular benefits" inverts the pharmacology โ€” they are cardiovascular drugs that also reduce weight.
  • Lp(a) siRNA trials are addressing a risk factor that 25% of the population carries and nobody could previously treat. Elevated Lp(a) is entirely genetically determined, unaffected by statins or lifestyle, and independently increases cardiovascular risk. Olpasiran and lepodisiran reduce Lp(a) by 90%+ with quarterly or twice-yearly dosing. The outstanding question is whether Lp(a) reduction translates to MACE reduction โ€” which is what the ongoing OCEAN(a) and AMPLITUDE outcomes trials will answer.
  • In vivo CRISPR for ATTR cardiomyopathy has the highest potential upside of any intervention in cardiology right now. NTLA-2001 achieved ~90% TTR knockdown from a single infusion in Phase 1 โ€” meaning near-elimination of the misfolded transthyretin protein that causes cardiac and neurological ATTR disease. If durability holds at 5+ years, the implications are transformative: a single treatment that halts an otherwise progressive and fatal disease. The timing question โ€” how early in the ATTR course to treat to preserve cardiac function โ€” is where Phase 3 design needs to get it right.

GLP-1 Agonists: Cardiovascular Drugs That Also Cause Weight Loss

The framing matters here. Semaglutide and tirzepatide are not weight loss drugs that happen to have cardiovascular benefits โ€” they are cardiovascular drugs with substantial metabolic effects. The SELECT trial (NCT03574597) enrolled patients with established cardiovascular disease but without diabetes and randomized them to semaglutide 2.4mg weekly versus placebo. The primary composite endpoint โ€” non-fatal MI, non-fatal stroke, cardiovascular death โ€” was reduced by 20% (HR 0.80, 95% CI 0.72โ€“0.90) over ~3 years of follow-up. Weight loss contributed to some of the benefit, but analyses show the cardiovascular protection exceeds what weight change alone would predict, suggesting direct cardiac and vascular effects.

Semaglutide received expanded FDA approval for cardiovascular risk reduction in 2024, making it the first obesity drug with a labeled MACE indication. The SOUL trial confirmed the same 14% MACE reduction with oral semaglutide in T2D patients with high CV risk, validating cardiovascular benefit across delivery routes. Now the trials are pushing into new populations: FLOW-HF is examining semaglutide in HFpEF; tirzepatide's SURPASS-CVOT is fully enrolled; and EVOKE-2 is investigating GLP-1 cardiovascular and neurovascular protection in patients without current GLP-1 indications.

Lipid Lowering: RNA Therapies and the Lp(a) Problem

PCSK9 inhibitors (evolocumab/Repatha, alirocumab/Praluent) achieve 50โ€“60% additional LDL-C reduction on top of statins, but require injections every 2โ€“4 weeks and face cost and adherence barriers that have limited real-world uptake despite compelling trial data. Inclisiran (Leqvio) solves the adherence problem with a different mechanism: it's an siRNA that silences PCSK9 production in hepatocytes directly, requiring only two injections per year after an initial dose โ€” at months 0 and 3, then every 6 months thereafter. The ORION program demonstrated 50% sustained LDL-C reduction. What remains unknown is whether this translates to MACE reduction; the ORION-4 Phase 3 outcomes trial (22,000 patients, primary MACE endpoint) is the pivotal study, with results expected 2026โ€“2027.

Lp(a) reduction is the emerging frontier. Elevated Lp(a) affects approximately 20% of the global population and confers cardiovascular risk that statins don't touch โ€” but until recently, no approved agent reduced it meaningfully. Pelacarsen (an antisense oligonucleotide targeting Lp(a) synthesis) is in the HORIZON Phase 3 outcomes trial. Olpasiran (siRNA, AMG 890) and lepodisiran (Eli Lilly) are in OCEAN(a)-OUTCOMES and ACCLAIM trials respectively. These are the first large randomized trials to test Lp(a) reduction as a cardiovascular endpoint โ€” we don't yet know whether lowering Lp(a) reduces events, and these trials will answer that definitively.

HFpEF: Finally Getting Some Answers

Heart failure with preserved ejection fraction (HFpEF) โ€” where the ventricles are stiff and don't fill normally despite normal contractility โ€” accounts for roughly half of all heart failure and had essentially no proven pharmacological treatment until 2022. SGLT2 inhibitors empagliflozin and dapagliflozin changed that with EMPEROR-Preserved and DELIVER, demonstrating significant reductions in heart failure hospitalization. Modest reductions, to be clear โ€” not the kind of mortality data that transformed HFrEF management โ€” but real and guideline-recommended.

The SUMMIT trial (tirzepatide in HFpEF patients with obesity) produced something more striking: a 38% reduction in heart failure events and significant improvements in KCCQ score (symptom burden) and 6-minute walk distance. The effect was large enough that many HFpEF specialists consider tirzepatide the most promising new therapy in the phenotype, though the patient population (HFpEF with obesity) is specific. FINEARTS-HF is evaluating finerenone (non-steroidal mineralocorticoid receptor antagonist) in HFpEF with top-line results expected in 2026. Anti-inflammatory approaches โ€” colchicine for post-MI cardioprotection, ziltivekimab (anti-IL-6 ligand) for HF with elevated inflammatory markers in ZEUS โ€” are expanding the portfolio of mechanistically distinct approaches.

Gene Therapy: ATTR Cardiomyopathy and Beyond

Transthyretin amyloid cardiomyopathy (ATTR-CM) affects an estimated 500,000 Americans โ€” predominantly older adults and those of West African descent carrying the Val122Ile variant โ€” and was historically difficult to diagnose and impossible to cure. RNA interference therapies have changed the trajectory. Vutrisiran (HELIOS-B trial) demonstrated significant cardiovascular event reduction. Eplontersen (NEURO-TTRansform) showed deep TTR knockdown with meaningful cardiovascular and neurological benefits.

What makes the ATTR story particularly remarkable in 2026 is the gene editing data. NTLA-2001 (Intellia Therapeutics) is a CRISPR base editing construct that targets TTR-producing hepatocytes with a single IV infusion. Phase 1/2 data showed ~90% TTR knockdown that has persisted at 18+ months follow-up without any return of protein. A single treatment that durably eliminates the source of the misfolded protein โ€” if this holds in larger trials, it would be a functional cure. Phase 2 enrollment is ongoing.

For AAV-based cardiac gene therapy, the PRECISION trial is evaluating SERCA2a gene delivery in heart failure with reduced ejection fraction โ€” restoring calcium handling function to dysfunctional cardiomyocytes. This was a concept proposed in the 1990s based on understanding of cardiac physiology; it's taken this long to have a delivery vector safe enough and efficient enough to test clinically.

How to Access Cardiovascular Trials

Cardiovascular trials are more geographically distributed than most specialties โ€” they're conducted at community cardiology practices, regional hospitals, and academic medical centers across the country, not only at NCI-designated centers. Key eligibility data to have ready before contacting any trial: most recent echocardiogram with ejection fraction documented, BNP or NT-proBNP level, LDL-C value on current therapy, eGFR, and a complete medication list including dose. For ATTR-CM trials specifically, TTR gene testing and a recent cardiac MRI are typically required. ClinicalTrials.gov searches by condition ("Heart Failure," "Coronary Artery Disease," "Transthyretin Amyloid") filtered to "Recruiting" reveal the full landscape; the American Heart Association's Patient Pages provide condition-specific context.

Key Trial Data Points

  • SELECT trial: semaglutide 2.4mg reduced MACE by 20% (HR 0.80) in patients with CVD but no diabetes โ€” GLP-1 agonists now carry a labeled cardiovascular risk reduction indication.
  • SUMMIT trial: tirzepatide reduced HFpEF cardiovascular events by 38% in obese patients, with significant KCCQ and 6-minute walk improvements โ€” strongest HFpEF signal since SGLT2 inhibitor data.
  • ORION-4 (22,000 patients): the pivotal inclisiran cardiovascular outcomes trial; results expected 2026โ€“2027 will determine whether twice-yearly siRNA LDL lowering reduces hard events.
  • NTLA-2001 CRISPR base editing: ~90% TTR knockdown persisting 18+ months from a single dose in ATTR-CM Phase 1/2 โ€” Phase 2 enrollment ongoing.
  • Lp(a) outcomes trials (HORIZON, OCEAN(a)-OUTCOMES): first large randomized trials testing whether Lp(a) reduction prevents CV events โ€” results will determine whether elevated Lp(a) is a treatable risk factor or merely a marker.

Frequently Asked Questions

What cardiovascular conditions have the most active trials?

Most active areas in 2026: heart failure with reduced ejection fraction (HFrEF) โ€” continuing to expand on SGLT2i and sacubitril/valsartan; heart failure with preserved ejection fraction (HFpEF) โ€” still a high-unmet-need area with SGLT2i showing modest benefit; atrial fibrillation ablation and rhythm control; coronary artery disease revascularization vs. medical therapy comparative effectiveness; and lipid-lowering beyond statins (PCSK9 inhibitors, bempedoic acid, inclisiran, small-interference RNA targeting ANGPTL3 and apoC-III for specific dyslipidemias). Inflammation as a CV risk target (colchicine post-MI, ziltivekimab anti-IL-6 in CKD patients) is a growing area following COLCOT and LoDoCo2.

What key tests are needed before a cardiovascular trial?

Standard cardiovascular trial baseline workup includes: echocardiography (LVEF required for HF trials, defining HFrEF <40% vs. HFmrEF 40-49% vs. HFpEF >=50%), ECG (QTc evaluation for any agent with cardiac electrophysiology effects), cardiac biomarkers (NT-proBNP or BNP in HF trials; troponin in ACS trials), comprehensive metabolic panel (renal function is critical โ€” eGFR thresholds define eligibility for SGLT2i and renin-angiotensin system-modifying trials), lipid panel, and NYHA functional class assessment. Coronary CTA or invasive coronary angiography is required for revascularization trials. Holter monitoring for AF burden characterization in rhythm control trials.

Can I join a heart disease trial if I have diabetes or CKD?

Yes โ€” and for some trials, diabetes and CKD make you the target population. SGLT2 inhibitor trials (DAPA-HF, EMPEROR-Reduced, and their successors) specifically enrolled patients with both HF and diabetes. Renal protection trials (DAPA-CKD, CREDENCE) enrolled patients with T2D and CKD as the primary population. Cardiorenal syndrome trials specifically study patients with combined cardiac and kidney dysfunction. For most other cardiovascular trials, stable diabetes (HbA1c below a defined threshold) and CKD (eGFR above a minimum threshold) are permitted but subject to washout or dose adjustment requirements for diabetes medications that interact with the trial drug.

What is the MACE endpoint in cardiovascular outcomes trials?

MACE (Major Adverse Cardiovascular Events) is the composite primary endpoint in most cardiovascular outcomes trials. The standard 3-point MACE includes: cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. Some trials use 4-point MACE adding hospitalization for unstable angina or heart failure. The MACE composite is used because individual CV events are uncommon enough that statistical power would require impractical sample sizes to detect differences on single endpoints. Understanding whether you will be followed for MACE in a trial means understanding a trial that may require 3-5 years of follow-up to accumulate sufficient events for the primary analysis.

โ—† Primary Sources & Further Reading
โ†’ ClinicalTrials.gov โ€” Recruiting Heart Disease Trials โ†’ NHLBI โ€” Heart Disease Research

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Researched and reviewed by the ClinicalMetric editorial team
Written from primary registry sources and checked for medical accuracy before publication. See our contributors and three-stage editorial process ยท last reviewed 2026-03-18.
Medical disclaimer: ClinicalMetric provides research intelligence only. Always consult a qualified healthcare provider before making clinical decisions or participating in a trial.
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Clinical Trial Research & Analysis ยท Last updated September 2026
Analysis compiled from ClinicalTrials.gov (NIH/NLM), FDA trial registry data, and peer-reviewed clinical research. ClinicalMetric tracks 400,000+ active clinical trials worldwide, updated daily from the ClinicalTrials.gov AACT database.
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โ—† ClinicalMetric original analysis

Why heart disease trials fail

We classified the sponsor-stated reason for every heart diseasestudy on ClinicalTrials.gov that was terminated or withdrawn โ€” 1,433 in total, 1,285 of which gave a reason.

40.8%
died from recruitment failure
944
terminated after enrolling
489
withdrawn before anyone joined
40
median participants at termination
Leading stated causes
Recruitment failure
40.8%
Funding
11.8%
Business decision
4.8%
Investigator / site
4.5%

Percentages are of heart disease studies that stated a reason. Free-text reasons were classified by keyword; roughly a quarter site-wide resist classification and are excluded from the causes above. Studies are matched on their primary registered condition, so trials filed under a broader or related term are not counted. Source: ClinicalTrials.gov (NIH/NLM), retrieved 16 July 2026. Full methodology โ†’

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ClinicalMetric โ€” Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here โ€” always consult a qualified healthcare professional. Full Disclaimer  ยท  Last Reviewed: September 2026  ยท  Data Methodology