Switch to Ticagrelor in Critical Limb Ischemia Anti-platelet Study
| Status: | Unknown status |
|---|---|
| Conditions: | Peripheral Vascular Disease, Cardiology |
| Therapuetic Areas: | Cardiology / Vascular Diseases |
| Healthy: | No |
| Age Range: | 18 - 80 |
| Updated: | 10/14/2017 |
| Start Date: | February 2014 |
| End Date: | September 2016 |
| Contact: | Christine Tam, RN |
| Email: | christine.tam@med.usc.edu |
| Phone: | 323-442-6863 |
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 13-25% and 50% at one and five
years respectively. High on-treatment platelet reactivity (HPR) in patients treated with
aspirin and clopidogrel is associated with increased risk of recurrent cardiovascular events
after percutaneous coronary interventions and coronary syndromes. Preliminary studies suggest
that the prevalence of HPR in patients with critical limb ischemia treated with aspirin and
clopidogrel is as high a 78.5%. In patients with coronary artery disease ticagrelor overcomes
non-responsiveness to clopidogrel. However, the antiplatelet effect of ticagrelor in patients
with critical limb ischemia is unknown.
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 13-25% and 50% at one and five
years respectively. High on-treatment platelet reactivity (HPR) in patients treated with
aspirin and clopidogrel is associated with increased risk of recurrent cardiovascular events
after percutaneous coronary interventions and coronary syndromes. Preliminary studies suggest
that the prevalence of HPR in patients with critical limb ischemia treated with aspirin and
clopidogrel is as high a 78.5%. In patients with coronary artery disease ticagrelor overcomes
non-responsiveness to clopidogrel. However, the antiplatelet effect of ticagrelor in patients
with critical limb ischemia is unknown.
Study Aim: This pilot study aims to investigate platelet function after switching from
clopidogrel to ticagrelor in patients with critical limb ischemia.
Fifty patients with diagnosis of CLI (Rutherford class IV-VI) treated with clopidogrel 75 mg
and aspirin 81 mg daily will be tested for inhibition of platelet aggregation using the
VerifyNow P2Y12 and VASP assays before and 6±1 hours after their daily clopidogrel dose. All
patients will then be switched from clopidogrel to ticagrelor 90 mg twice daily for two weeks
and the VerifyNow and VASP platelet reactivity assays repeated, samples will be collected
before and 6±1 hours after the last ticagrelor dose. For exploratory analysis, patients will
be divided in two groups based on the P2Y12 reaction units (PRU): Group 1. High on treatment
platelet reactivity on clopidogrel (HPR), defined as P2Y12 reaction units (PRU) ≥235 and
Group 2. Appropriate platelet inhibition on clopidogrel (API), defined as P2Y12 reaction
units (PRU) <235.
clopidogrel to ticagrelor in patients with critical limb ischemia.
Fifty patients with diagnosis of CLI (Rutherford class IV-VI) treated with clopidogrel 75 mg
and aspirin 81 mg daily will be tested for inhibition of platelet aggregation using the
VerifyNow P2Y12 and VASP assays before and 6±1 hours after their daily clopidogrel dose. All
patients will then be switched from clopidogrel to ticagrelor 90 mg twice daily for two weeks
and the VerifyNow and VASP platelet reactivity assays repeated, samples will be collected
before and 6±1 hours after the last ticagrelor dose. For exploratory analysis, patients will
be divided in two groups based on the P2Y12 reaction units (PRU): Group 1. High on treatment
platelet reactivity on clopidogrel (HPR), defined as P2Y12 reaction units (PRU) ≥235 and
Group 2. Appropriate platelet inhibition on clopidogrel (API), defined as P2Y12 reaction
units (PRU) <235.
Inclusion Criteria:
- Patients with diagnosis of CLI (Rutherford class IV, V and VI) on continuous dual
antiplatelet therapy with aspirin 81 mg and clopidogrel 75 mg daily for at least 14+2
days .
Exclusion Criteria:
- Chronic use of nonsteroidal anti-inflammatory drugs, thrombocytopenia (platelet count
<100 × 103/μl), hemoglobin <10 g/dL, use of an oral anticoagulant (warfarin) or low
molecular weight heparin within 14 days, GPIIb/IIIa inhibitors, or fibrinolytic drugs
within 30 days. Pregnancy, <18 or >80 years of age, current smoking (>1 pack per day),
concomitant therapy with strong cytochrome P450 3A inhibitors or inducers within 14
days, concomitant antithrombotic therapy other than aspirin within 14 days,
hypercoaguable states. History of medication non-compliance, drug or alcohol abuse
within 2 years. Acute coronary syndrome or coronary drug-eluting stenting within 1
year. Peripheral vascular revascularization procedures (surgical or endovascular)
and/or amputation within one month. Contraindications for ticagrelor including:
hypersensitivity to ticagrelor or any of the excipients, Active pathological bleeding,
History of intracranial hemorrhage and Severe hepatic impairment.
We found this trial at
1
site
Los Angeles, California 90033
213) 740-2311
Principal Investigator: Leonardo Clavijo, MD, PhD
Phone: 323-442-6863
University of Southern California The University of Southern California is one of the world’s leading...
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