Critical Limb IschemiaNCT02094755

Aspirin and Clopidogrel Reactivity in Patients With Critical Limb Ischemia (CLI)

An observational study of Critical Limb Ischemia, run by University of Southern California at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

Who is it for?: Ages 18 to 80 yearsHealthy volunteers can take part
Conditions the study is for: Critical Limb Ischemia
What is being tested?: Blood draw only
How many people: 100 participants
Where: 1 siteUnited States
Study dates: 19 Jun 2013to 31 Jan 2017
Phase: Observational
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 80 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Study population: The patient population will include one-hundred patients with a diagnosis of CLI. We will only include in the study CLI patients who as part of their standard of care medical treatment are receiving dual antiplatelet therapy with aspirin 81 mg and clopidogrel 75 mg daily for at least one week.

Who may be able to join

EXPERIMENTAL GROUP: Patients with a diagnosis of critical limb ischemia (CLI) and uninterrupted treatment with aspirin and/or clopidogrel for at least one week before testing.
CONTROL GROUP: 10 normal volunteers without any known co-morbidities

Who cannot join

Chronic use of nonsteroidal anti-inflammatory drugs, thrombocytopenia (platelet count <100 × 103/μl), use of an oral anticoagulant (warfarin), glycoprotein (GP) IIb/IIIa inhibitors, or fibrinolytic drugs within 30 days before testing. Any documented history of hypercoaguable states or history of medication non-compliance.

Trial locations and contacts

1 site in 1 country.

United States1 site

University of Southern California
Los Angeles, California, 90033

Other trials in United States

About this study

Official title: Prevalence of High On-Treatment (Aspirin and Clopidogrel) Platelet Reactivity in Patients With Critical Limb Ischemia

Critical Limb Ischemia (CLI) is defined as limb pain that occurs at rest, or impending limb loss that is caused by severe compromise of blood flow to the affected extremity. CLI is a major cause of death and disability (secondary to myocardial infarction, stroke and amputation). The mortality in patients with CLI approaches 25% and 50% at one and five years respectively. High on-treatment platelet reactivity (HPR) in patients treated with aspirin and clopidogrel (previously referred to as "resistance") is associated with an increased risk of recurrent cardiovascular events after percutaneous coronary interventions and acute coronary syndromes. The prevalence and significance of High on-treatment Platelet Reactivity (HPR) in patients with critical limb ischemia treated with aspirin and/or clopidogrel is not known.

The investigators project aims to investigate the prevalence of HPR (to aspirin and clopidogrel) in one hundred patients with diagnosis of critical limb ischemia encountered at University of Southern California (USC) affiliated hospitals (Los Angeles County Hospital and Keck Hospital of University of Southern California).

Read the detailed description

This prospective clinical study will investigate the prevalence of high on- treatment platelet reactivity (HPR) in one hundred patients with critical limb ischemia (CLI), at the Keck Hospital of USC and Los Angeles County Medical Center (LAC+USC). Platelet inhibition to aspirin will be evaluated with the VerifyNow® aspirin (ASA) test. Clopidogrel platelet inhibition will be evaluated with two different tests: the vasodilator-stimulated phosphoprotein (VASP) and the VerifyNow® purigenic receptor P2Y12 (VN-P2Y12) assays. All platelet function analyses will be performed once after a minimum of one week of uninterrupted dual antiplatelet therapy with aspirin and clopidogrel. High on-treatment Platelet Reactivity on aspirin treatment (HPRA) group will be defined as aspirin reaction units (ARU) ≥550 by the VerifyNow® ASA assay. High on-treatment Platelet Reactivity on clopidogrel (HPRC) group will be defined as P2Y12 reaction units (PRU) ≥208 by the VerifyNow® assay and Vasodilator-stimulated phosphoprotein-platelet reactivity index (VASP-PRI) ≥50% by the vasodilator-stimulated phosphoprotein (VASP) assay. All other patients will be assigned to the adequate platelet reactivity on therapy (APR) group. Prevalence of high on-treatment platelet reactivity will then be calculated for aspirin and/or clopidogrel

Conditions: Critical Limb Ischemia
Being tested: Blood draw only
Keywords: ASA-PLAVIX Reactivity in CLI
Medical subject headings: Chronic Limb-Threatening Ischemia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Blood draw onlyOther
Blood draw only

Study groups in NCT02094755
Study group	Role	What they receive
Single cohort		Single cohort will receive Blood draw only. Receives: Other: Blood draw only

What is being measured

The primary outcome is the main question the study is designed to answer.

Asses the Prevalence of High On-treatment Platelet Reactivity in Critical Limb Ischemia Patients Treated With Aspirin and Clopidogrel.
Platelet inhibition to aspirin will be evaluated with the VerifyNow® aspirin (ASA) test. Clopidogrel platelet inhibition will be evaluated with two different tests: the vasodilator-stimulated phosphoprotein (VASP) and the VerifyNow® purinergic receptor P2Y12 (VN-P2Y12) assays.
Measured: Single measurment after a minimum of one week of uninterrupted dual antiplatelet therapy with aspirin and clopidogrel

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

19 Jun 201331 Jan 2017

First posted24 Mar 2014 (estimated)
Study start19 Jun 2013
Primary completion21 Nov 2016
Study completion31 Jan 2017

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Critical Limb IschemiaStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Observational
Observational model: Cohort
Time perspective: Prospective
Enrolment: 100 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT02094755
Sponsor's protocol ID: D5130L00047/ISSBRIL0152
Status last verified: Apr 2019
First submitted: 19 Mar 2014
Last updated: 28 Jun 2019
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Critical Limb Ischemia trials

Study at a glance

From the registry record, last updated by the sponsor on 28 Jun 2019. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Prevalence of High On-Treatment (Aspirin and Clopidogrel) Platelet Reactivity in Patients With Critical Limb Ischemia
ClinicalTrials.gov ID: NCT02094755
Acronym / sponsor ID: D5130L00047/ISSBRIL0152
Conditions: Critical Limb Ischemia
Keywords: ASA-PLAVIX Reactivity in CLI
Study type: Observational
Recruitment status: Completed
Enrolment: 100 participants (actual)
Lead sponsor: University of Southern CaliforniaUniversity, hospital or other
Study start: 19 Jun 2013 (actual)
Primary completion: 21 Nov 2016 (actual)
Study completion: 31 Jan 2017 (actual)
First posted: 24 Mar 2014 (estimated)
Results: Posted 28 Jun 2019

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Observational model: Cohort
Time perspective: Prospective
Number of arms: 1

Arm	Type	Receives
Single cohort	–	Other: Blood draw onlySingle cohort will receive Blood draw only.

Who may qualify

Ages: 18 to 80 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult
Study population: The patient population will include one-hundred patients with a diagnosis of CLI. We will only include in the study CLI patients who as part of their standard of care medical treatment are receiving dual antiplatelet therapy with aspirin 81 mg and clopidogrel 75 mg daily for at least one week.

Key inclusion criteria (2 listed)

EXPERIMENTAL GROUP: Patients with a diagnosis of critical limb ischemia (CLI) and uninterrupted treatment with aspirin and/or clopidogrel for at least one week before testing.
CONTROL GROUP: 10 normal volunteers without any known co-morbidities

Key exclusion criteria (1 listed)

Chronic use of nonsteroidal anti-inflammatory drugs, thrombocytopenia (platelet count <100 × 103/μl), use of an oral anticoagulant (warfarin), glycoprotein (GP) IIb/IIIa inhibitors, or fibrinolytic drugs within 30 days before testing. Any documented history of hypercoaguable states or history of medication non-compliance.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Blood draw onlyBlood draw only	Other	Single cohort

Primary outcome

Asses the Prevalence of High On-treatment Platelet Reactivity in Critical Limb Ischemia Patients Treated With Aspirin and Clopidogrel.
Time frame: Single measurment after a minimum of one week of uninterrupted dual antiplatelet therapy with aspirin and clopidogrel
Platelet inhibition to aspirin will be evaluated with the VerifyNow® aspirin (ASA) test. Clopidogrel platelet inhibition will be evaluated with two different tests: the vasodilator-stimulated phosphoprotein (VASP) and the VerifyNow® purinergic receptor P2Y12 (VN-P2Y12) assays.

Results and safety

Results posted to the registry on 28 Jun 2019, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Single Cohort	100	100

Primary outcome: Asses the Prevalence of High On-treatment Platelet Reactivity in Critical Limb Ischemia Patients Treated With Aspirin and Clopidogrel.

Time frame: Single measurment after a minimum of one week of uninterrupted dual antiplatelet therapy with aspirin and clopidogrel. Count of participants. Unit: Participants

Measure	Single Cohort n = 100
HPR on Clopidogrel	18
HPR on Aspirin	17
HPR on Both	8
API on Both	57

Population analysed: High on-treatment platelet reactivity on clopidigrel (HPRC) was defined as VerifyNow®P2Y12 reactive units (PRU) \>208 and VASP-platelet reactivity index (VASP-PRI) \>50%. Thromboxane A2 (TXA2) inhibition was measured with the VerifyNow®aspirin test and High on-treatment reactivity on aspirin (HPRA) was defined as aspirin reaction units (ARU) \>550.

Adverse events

Time frame: Critical limb ischemia patients with clinical indication of aspirin and clopidogrel dual antiplatelet therapy with for at least 1 week as standard of care, were monitored for adverse events for the length of study participation which was 1 day from study enrollment to the last study intervention.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Single Cohort	0 of 100 (0%)	0 of 100 (0%)	0 of 100

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 28 Jun 2019.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Critical Limb Ischemia

Recruiting
Radiotracer-Based Perfusion Imaging of Patients With Peripheral Arterial Disease
Peripheral Artery Disease, Diabetes Mellitus
RecruitingObservational study
Vessel Recoil in Specific CLTI Populations
Chronic Limb Threatening Ischemia
Not yet recruiting
DCB Outcomes After Non-Compliant Balloon Vessel Preparation With or Without Scoring in Patients With Femoropopliteal Arterial Disease
Femoropopliteal Disease, Drug Coated Balloon
Active, not recruitingObservational study
Laser Atherectomy and Sirolimus-coated Balloon Angioplasty for CLTI
Chronic Limb Threatening Ischemia
RecruitingEarly Phase 1
Nutrition in Patient With Critical Limb Ischemia
Critical Limb Ischemia, Malnutrition

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Leonardo Clavijo, MD, PhD principal investigator

University of Southern California

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of Critical Limb Ischemia, run by University of Southern California at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 28 Jun 2019. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 28 Jun 2019). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Asses the Prevalence of High On-treatment Platelet Reactivity in Critical Limb Ischemia Patients Treated With Aspirin and Clopidogrel. (time frame: Single measurment after a minimum of one week of uninterrupted dual antiplatelet therapy with aspirin and clopidogrel). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02094755.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jun 2019.