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Ischemic heart disease — clinical trials landscape

TL;DR — The IHD pipeline is shifting from “another stent versus another drug” toward unresolved selection problems: PCI versus CABG in ischemic LV dysfunction, CTO revascularization versus medical therapy, Lp(a) lowering, IL-6 inhibition, vulnerable-plaque treatment, INOCA endotyping, and delivery/adherence. Sham-controlled trials are now central where symptoms are the primary endpoint: ORBITA-2 proved PCI relieves angina, and ORBITA-COSMIC tested a coronary sinus reducer against placebo (Rajkumar 2023, PMID 38015442; Foley 2024, PMID 38604209). Outcome-scale programs are large—ARTEMIS estimates 10,000 participants and OCEAN(a)-Outcomes enrolled 7,297—while mechanistic enrichment trials may enroll only 100–300. Trial status and enrollment below were verified live from ClinicalTrials.gov API v2 on 2026-09-02; registry status is not proof of data quality, completion, or publication. REVIVED showed that viability-selected patients with severe ischemic LV dysfunction did not gain a death/HF-hospitalization benefit from routine PCI, but it did not test CABG or every possible viability-guided strategy (Perera 2022, PMID 36027563).

Active and recently completed registry landscape

Domain Trial NCT Status on 2026-09-02 Enrollment Design question
Ischemic cardiomyopathy STICH3C NCT05427370 Recruiting 754 estimated CABG versus PCI
CTO ISCHEMIA-CTO NCT03563417 Recruiting 1,560 estimated CTO revascularization versus OMT
Lp(a) Lp(a)HORIZON NCT04023552 Completed 8,323 actual Pelacarsen and MACE
Lp(a) OCEAN(a)-Outcomes NCT05581303 Active, not recruiting 7,297 actual Olpasiran and events
Inclisiran V-DIFFERENCE NCT05192941 Completed 1,770 actual Placebo-controlled phase 4 test of inclisiran added to individually optimized lipid-lowering therapy (LDL-C and quality-of-life endpoints, not events)
IL-6 ZEUS NCT05021835 Completed 6,385 actual Ziltivekimab in CVD + CKD + inflammation
IL-6 ARTEMIS NCT06118281 Recruiting 10,000 estimated Ziltivekimab after MI
IL-6/plaque Post-MI plaque study NCT07301034 Recruiting 332 estimated Ziltivekimab effect on coronary plaque
Precision inflammation TET2 colchicine NCT07362966 Recruiting 120 estimated Colchicine in TET2 clonal hematopoiesis
Precision inflammation RIGHT NCT06025071 Unknown; last known not yet recruiting 800 estimated hsCRP-enriched colchicine versus control
Vulnerable plaque PREVENT NCT02316886 Completed 1,608 actual Preventive PCI versus medical therapy
DAPT OPT-CAD de-escalation NCT06216821 Recruiting 3,490 estimated Score-guided DAPT de-escalation
INOCA CorMicA NCT03193294 Completed 151 actual Endotype-guided care
Microvascular angina COSIMA NCT04606459 Recruiting 144 estimated Coronary sinus reducer
INOCA/CMD Reducer CMD study NCT05492110 Active, not recruiting 54 actual Reducer in non-obstructive CMD
INOCA rehabilitation ExINOCA NCT06529848 Recruiting 100 estimated Exercise training
Polygenic risk PRS subclinical CAD NCT05819814 Active, not recruiting 200 estimated PRS-guided detection/health change
STEMI mechanism Ischemic postconditioning NCT03787745 Recruiting 1,800 estimated Reperfusion-injury modification

RIGHT's record has not been updated since September 2023 and has no posted results; it therefore demonstrates that an hsCRP-enriched strategy was registered, not that recruitment or completion occurred (NCT06025071).

Landmark completed programs that define present questions

Program Finding New question created
COURAGE No death/MI benefit from routine PCI in stable CAD (PMID 17387127) Which patients gain symptoms, and does any subgroup gain survival?
ORBITA Sham control exposed placebo/context effect (PMID 29103656) Which physiologic/symptom features predict true PCI response?
ORBITA-2 PCI improved angina versus sham (PMID 38015442) Durability and individualized prediction
ISCHEMIA No overall event benefit from initial invasive strategy (PMID 32227755) Cause-specific mortality split and excluded anatomy
REVIVED PCI neutral in ischemic LV dysfunction (PMID 36027563) CABG-versus-PCI route and viability concept
CANTOS IL-1β blockade reduced MACE without lipid change (PMID 28845751) Safer, cheaper pathway targeting
COLCOT/LoDoCo2 Colchicine benefit (Tardif 2019, PMID 31733140; Nidorf 2020, PMID 32865380) Who benefits and when?
CLEAR SYNERGY Routine post-MI colchicine neutral (PMID 39555823) Why did efficacy not replicate universally?
PREVENT Preventive PCI of non-flow-limiting vulnerable plaque lowered the 2-year target-vessel composite (0.4% vs 3.4%) (Park 2024, PMID 38604213) Generalizability, durability beyond 2 years, and patient-level rather than target-vessel benefit
CorMicA Endotype-guided care improved symptoms (PMID 30266608) Hard outcomes and scalable noninvasive endotyping

Sham control as a design standard

Procedures can create large nonspecific effects through expectation, intensified attention, peri-procedural medication, and reporting. Where the endpoint is pain, function, or quality of life and equipoise permits, sham control separates device biology from treatment context (Al-Lamee 2018, PMID 29103656).

Trial NCT Control Primary scientific contribution
ORBITA-2 NCT03742050 Placebo procedure PCI angina efficacy without background antianginal escalation
ORBITA-COSMIC NCT04892537 Placebo procedure Fewer angina episodes; no benefit on the primary myocardial-perfusion endpoint
COSIRA NCT01205893 Sham procedure Earlier reducer efficacy in refractory angina

Sham control is not always ethical or feasible for mortality endpoints or emergencies. It is most valuable when subjective outcomes dominate and procedure risk is acceptable.

Revascularization frontier

STICHES and REVIVED studied different procedures and populations; STICH3C directly compares CABG and PCI in ischemic cardiomyopathy (NCT05427370; Velazquez 2016, PMID 27040723; Perera 2022, PMID 36027563).

ISCHEMIA-CTO addresses a common extrapolation problem: CTO PCI is technically distinct, symptom-driven, and underrepresented in general stable-CAD strategy trials (NCT03563417).

PREVENT operationalized imaging-defined vulnerable plaque and tested prophylactic PCI, reporting a lower 2-year target-vessel composite (0.4% versus 3.4%) with no significant difference in death or myocardial infarction (Ahn 2023, PMID 37271356; Park 2024, PMID 38604213). Follow-up must separate target-lesion events, patient-level systemic events, procedure harm, and background prevention.

Lipid and inflammation frontier

Target Why compelling What outcome trial must prove
Lp(a) Strong inherited risk; large selective reductions now possible Fewer hard events and safe long-term treatment; Lp(a)HORIZON is completed but no primary outcome report was found in live PubMed searches repeated on 2026-09-02 (NCT04023552)
IL-6 Downstream of IL-1β; strong hsCRP suppression Net event benefit without infection/competing harm
Clonal hematopoiesis Mechanistic inflammatory enrichment Predictive treatment interaction
Inclisiran delivery Twice-yearly LDL lowering Better sustained exposure and fewer events

Biomarker reduction cannot replace outcome data. CIRT is the cautionary example: an “anti-inflammatory” drug that did not suppress the relevant pathway did not reduce events (Ridker 2019, PMID 30415610).

INOCA trial-design problems

INOCA trials must define endotype, avoid mixing structural CMD with epicardial spasm, use validated symptom instruments, measure medication changes, and include physiologic and patient-reported outcomes. CorMicA supports endotyping but not mortality benefit (Ford 2018, PMID 30266608).

Reducer and exercise trials verified above extend the field beyond antianginal pills, but small samples and subjective endpoints make blinding and standardized background care critical.

How to interpret registry entries

  • “Recruiting” may lag real site activity.
  • Estimated enrollment can change and does not equal completed follow-up.
  • A registered primary endpoint can be amended; compare versions at publication.
  • Completion without publication creates outcome-reporting uncertainty.
  • Multiple NCT records may cover mechanistic substudies of one program.
  • Registry titles are not peer-reviewed claims.

Trial portfolio balance

Portfolio question Current imbalance Corrective design
Symptoms versus events Many small symptom/device studies; few outcome-scale INOCA trials Common PROs plus pragmatic hard outcomes
Efficacy versus delivery Drug/device RCT density exceeds implementation RCTs Cluster and health-system randomization
Average versus enriched effect Broad syndromes can dilute mechanism-specific benefit Prespecified biomarker/endotype enrichment
Procedure versus systemic care Lesion trials may under-specify prevention Standardized LDL/BP/smoking run-in
High versus low resource Cath-lab trials dominate LMIC delivery questions Essential-medicine and network trials
Publication versus registry Completed records may lack results Automated results and publication linkage

Minimum registry-to-publication reconciliation

  1. Match NCT ID, title, sponsor and protocol version.
  2. Compare planned and analyzed enrollment.
  3. Compare primary endpoint definition and time point.
  4. Record changes in status, arms, eligibility and analysis.
  5. Link main paper, substudies and negative/unpublished results.
  6. Preserve registry date when reporting “active” status.

This is especially important for symptom/device trials, in which analysis populations and blinded phases can differ from total registered enrollment. ClinicalTrials.gov still returns UNKNOWN with 50 estimated participants for ORBITA-COSMIC, whereas the completed paper reports 61 enrolled, 51 randomized, and 50 analyzed by intention to treat; the registry–publication discordance was live-verified again on 2026-09-02 (NCT04892537; Foley 2024, PMID 38604209).

What the completed portfolio has taught trial design

Design lesson Paired evidence Consequence for new trials
Strategy and procedure are different interventions COURAGE tested PCI+OMT; ISCHEMIA tested an initial invasive strategy allowing CABG/PCI and later crossover (Boden 2007, PMID 17387127; Maron 2020, PMID 32227755). Name the randomized strategy and report actual treatment received without replacing intention-to-treat inference.
Symptoms require blinding ORBITA and ORBITA-2 produced different symptom estimates under different medication states, while ORBITA-COSMIC separated symptoms from perfusion (Al-Lamee 2018, PMID 29103656; Rajkumar 2023, PMID 38015442; Foley 2024, PMID 38604209). Use sham control when feasible, daily symptom capture, unblinding rules, and medication exposure.
Route matters in LV dysfunction STICH supports CABG; REVIVED does not support prognostic PCI, and viability did not select benefit (Velazquez 2016, PMID 27040723; Perera 2022, PMID 36027563; Perera 2023, PMID 37878295). Do not pool CABG and PCI as one revascularization exposure.
Biomarker change is not clinical benefit Ziltivekimab markedly lowers hsCRP, but event and infection outcomes remain necessary; inclisiran strongly lowers LDL-C while outcome confirmation remains distinct (Ridker 2021, PMID 34015342; Ray 2020, PMID 32187462). Phase 2 target engagement should unlock, not substitute for, event trials.
A positive class narrative can fail CANTOS/COLCOT/LoDoCo2 were positive in selected contexts, CIRT and CLEAR SYNERGY were neutral (Ridker 2017, PMID 28845751; Tardif 2019, PMID 31733140; Nidorf 2020, PMID 32865380; Ridker 2019, PMID 30415610; Jolly 2025, PMID 39555823). Prespecify disease phase, inflammatory enrichment, adherence, and competing infection/non-CV death.
Lesion prediction is not strategy validation PROSPECT predicted events; PREVENT randomized treatment of vulnerable non-flow-limiting lesions and reported a lower 2-year target-vessel composite (Stone 2011, PMID 21247313; Park 2024, PMID 38604213; Kim 2025, PMID 40439104). Report target-lesion and patient-level events separately and preserve systemic therapy in both arms.
Implementation can be the active ingredient SECURE showed a polypill strategy reduced MACE, and CR meta-analysis supports structured delivery (Castellano 2022, PMID 36018037; Dibben 2023, PMID 36746187). Randomize delivery bundles and measure reach, adherence, completion, equity, and clinical outcomes.
Heterogeneous syndromes need endotypes CorMicA improved symptoms by linking function-testing results to therapy; reduced CFR predicts risk (Ford 2018, PMID 30266608; Kelshiker 2022, PMID 34849697). ANOCA/INOCA/MINOCA trials should require mechanism-specific entry and outcome definitions.

Registration and reporting controversies

A registry record proves that a study was registered, not that recruitment occurred as planned, the primary endpoint remained unchanged, or results were published. For each tracked NCT, curation should compare original and current enrollment, status, completion date, primary outcomes, analysis population, and linked publications. Trials stopped early, delayed, or reported only in conference form should remain labeled accordingly rather than silently treated as negative.

Composite endpoints create a second portfolio-level bias. Revascularization, biomarker-defined procedural MI, spontaneous MI, stroke, CV death, and all-cause death are not interchangeable. ISCHEMIA's early procedural and later spontaneous MI pattern, CANTOS's infection signal, and antithrombotic trials' bleeding tradeoffs show why components, confidence intervals, and competing events must accompany the headline composite (Maron 2020, PMID 32227755; Ridker 2017, PMID 28845751; Chew 2020, PMID 32646566).

The same separation applies to lipid programs: FOURIER and CLEAR Outcomes are completed event trials, whereas inclisiran outcome inference cannot be replaced by its approximately 50% LDL-C reduction (Sabatine 2017, PMID 28304224; Nissen 2023, PMID 36876740; Ray 2020, PMID 32187462). Trial-landscape tables should therefore label phase, endpoint type, and whether an outcome paper exists rather than placing biomarker and event trials in one undifferentiated pipeline.

Trial architecture can change the apparent answer

Endpoint definitions are part of the intervention's apparent net benefit. In PRODIGY, BARC 2/3/5 bleeding occurred in 7.1%, versus 2.5% by TIMI minor/major and 3.1% by GUSTO moderate/severe definitions; BARC 3/5 bleeding carried adjusted 2-year mortality HR 7.72 (95% CI 4.75–12.54), similar to the other severe-bleeding scales (Vranckx 2014, PMID 24755007). A trial portfolio should therefore prespecify severity, timing, adjudication, and whether recurrent bleeds count, rather than report an undifferentiated “safety” composite.

Representativeness remains measurable and inadequate. Across 598 major cardiovascular RCTs published from 1986–2015, women's enrollment rose from 21% to 33%, but women comprised only 30% of coronary-disease trial participants and remained below their expected disease share (Gong 2019, PMID 31030866). An updated analysis of 799 trials and 4,071,921 participants through 2023 found women comprised 25.0% of coronary-disease trials; improvement over calendar time therefore did not eliminate the coronary-specific gap (Sheikh 2024, PMID 38487060).

Outcome selection has also not standardized reliably. Among 115 late-phase PCI RCTs published in 2014–2022, all core-outcome-set domains were reported in 55% after the set became available versus 40% beforehand (P=0.121), and patient/public involvement did not increase (Duncan 2024, PMID 38688715). Registry compliance, population representativeness, core outcomes, and publication reconciliation should be reported as separate trial-quality axes.

Open questions

  • Will STICH3C show a route-specific benefit in ischemic LV dysfunction? (NCT05427370)
  • Do pelacarsen or olpasiran reduce events enough to justify broad Lp(a) screening? (NCT04023552; NCT05581303)
  • Can ARTEMIS reproduce pathway benefit without CANTOS-like safety trade-offs? (NCT06118281)
  • Is vulnerable-plaque PCI additive to maximal lipid and inflammation control? (NCT02316886)
  • Can sham-controlled device standards become routine for refractory-angina interventions? (NCT04892537)

References

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  2. Foley MJ, et al. Coronary sinus reducer for the treatment of refractory angina (ORBITA-COSMIC): a randomised, placebo-controlled trial. Lancet. 2024;403:1543-1553. PMID 38604209
  3. Perera D, et al. Percutaneous Revascularization for Ischemic Left Ventricular Dysfunction. N Engl J Med. 2022;387:1351-1360. PMID 36027563
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