Myocardial Infarctions, Stroke
Conditions
Brief summary
The purpose of this study is to determine if PFA results correlate with ischemic event outcomes as well as bleeding complications. Hypothesis is antiplatelet agents will be more efficacious if they are administered in a dose-adjusted manner using PFA results as a guide.
Detailed description
Atherothrombotic disease is a leading killer of adults throughout the world. The current mainstay for the prevention of ischemic vascular events is the use of aspirin Antiplatelet agents are used routinely for the primary and secondary prevention of vascular events in patients with a prior history of stroke, TIA, or at high risk for the development of cerebrovascular disease. Numberous individual studies and meta-analyses have shown that essentially all of the oral antiplatelet agents have limited efficacy, with relative risk reductions in the range of 20-35%. The purpose of this study is to perform serial platelet function assays (PFAs) on patients with cerebrovascular disease who are taking antiplatelet agents and perform a pilot study to determine the feasibility of administering ASA as a dose adjusted medication using PFA. The long term goal of this study is to determine whether antiplatelet therapy will be more efficacious and/or safer if it is administered in a dose-adjusted manner.
Interventions
DRUGClopidogrel
Clopidogrel 75 mg QD
DRUGAspirin 81 mg
Aspirin 81mg QD
DRUGAspirin >300 mg
Aspirin \>300 mg QD
Sponsors
Northwestern University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patient must be taking Aspirin or Plavix * Patient must have had a stroke, TIA or cerebrovascular disease
Exclusion criteria
-None
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| PFA1 | 3-6 months (Collected once between regulalary scheduled follow-up visit between 3-6 months) | Platelet Function Analysis (PFA) lab results: PFA was performed using the PFA 100 device (Dade-Behring), which uses a higher sheer stress flow cytometry paradigm to measure the time in seconds to closing of an aperture. Normal is defined as \<172 seconds. |
Countries
United States
Participant flow
Recruitment details
Patients with cerebrovascular disease and taking one or more antiplatelet medication were consented for study participation from 2007 though 2010. Patients were recruiting on the inpatient stroke unit at Northwestern Memorial Hospital and seen in the outpatient stroke clinic.
Participants by arm
| Arm | Count |
|---|---|
| Clopidogrel 75 mg Clopidogrel 75 mg QD | 15 |
| Aspirin 81 mg Aspirin 81 mg QD | 32 |
| Aspiring >300 mg Aspirin \>300 mg QD | 46 |
| Total | 93 |
Baseline characteristics
| Characteristic | Total | Aspirin 81 mg | Aspiring >300 mg | Clopidogrel 75 mg |
|---|---|---|---|---|
| Age, Customized | 60.7 years | 67.4 years | 56.2 years | 60.6 years |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 4 Participants | 2 Participants | 2 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 13 Participants | 4 Participants | 7 Participants | 2 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants | 1 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 75 Participants | 25 Participants | 37 Participants | 13 Participants |
| Region of Enrollment United States | 93 participants | 32 participants | 46 participants | 15 participants |
| Sex: Female, Male Female | 51 Participants | 16 Participants | 26 Participants | 9 Participants |
| Sex: Female, Male Male | 42 Participants | 16 Participants | 20 Participants | 6 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 2 / 15 | 3 / 32 | 2 / 46 |
| serious Total, serious adverse events | 0 / 15 | 1 / 32 | 2 / 46 |
Outcome results
Primary
PFA1
Platelet Function Analysis (PFA) lab results: PFA was performed using the PFA 100 device (Dade-Behring), which uses a higher sheer stress flow cytometry paradigm to measure the time in seconds to closing of an aperture. Normal is defined as \<172 seconds.
Time frame: 3-6 months (Collected once between regulalary scheduled follow-up visit between 3-6 months)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Clopidogrel 75 mg | PFA1 | 202.0 seconds | Standard Error 27.1 |
| Aspirin 81 mg | PFA1 | 271.1 seconds | Standard Error 14.9 |
| Aspirin > 300 mg | PFA1 | 234.7 seconds | Standard Error 13.4 |
Comparison: Kruskal-Wallis non-parametric ANOVA testp-value: 0.0742Kruskal-Wallis