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Pharmacogenomics of Antiplatelet Response - II (PARes-II)

Pharmacogenomics of Antiplatelet Response - II

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01894555
Acronym
PARes-II
Enrollment
33
Registered
2013-07-10
Start date
2013-01-31
Completion date
2014-08-31
Last updated
2017-01-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Atherothrombosis

Keywords

Platelet Transcriptome, Coronary Artery Disease, Myocardial Ischemia, Coronary Disease, Heart Diseases, Cardiovascular Diseases, Arteriosclerosis, Arterial Occlusive Diseases, Vascular Diseases, Aspirin

Brief summary

This clinical trial is examining the effect of 4-week aspirin therapy on platelet transcriptome in persons at high-risk for myocardial infarction or stroke due to family history of early-onset coronary artery disease.

Detailed description

Platelet aggregation can initiate thrombosis on ulcerated arterial plaques resulting in acute coronary syndrome (ACS). There is large variation in platelet aggregation between individuals. As the genetic message to the cell machinery is conveyed through its transcriptome, we hypothesize that much of the variability in platelet function can be explained by transcriptome changes including differences in gene or isoform expression, altered splicing events, or allele-specific expression. Moreover, aspirin modifies gene expression in several cells, but whether it also affects platelet transcriptome has not yet been studied. Our goal is to characterize the platelet transcriptome and identify genes that are up- or down-regulated after 4-week aspirin therapy. A major strength of our study is that it enrolls individuals from European Americans and African Americans and thus will have the ability to study similarities and differences between the two. The study will produce innovative comparative genomic/platelet phenotype data and will provide a potential pharmacogenomic and diagnostic template for the future discovery of novel antiplatelet regimens to prevent thrombosis-related cardiovascular disease events.

Interventions

DRUGAspirin

81 mg daily for 4 weeks

Sponsors

Johns Hopkins University
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
45 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

* Participants from the GeneSTAR cohort * Unaffected with no overt coronary artery disease or serious vascular event (stroke or peripheral vascular disease diagnosis * Women who are postmenopausal. * Women who use a reliable contraceptive method; a reliable contraceptive method will be defined as personal history of tubal ligation, ongoing use of intra-uterine device, or ongoing use of oral contraceptive pills.

Exclusion criteria

* Presence of any CAD or stroke, transient ischemic attacks, peripheral arterial disease * Persons taking aspirin, NSAIDS, or any anti-coagulants who are medically unable to stop them for a two week pre-trial * A history of allergy to aspirin or clopidogrel * Weight \< 60kg * Age \< 45 and \> 75 years of age * A history of recent or any active bleeding * Serious or current co-morbidity (AIDS, cancer) * Pregnant women as determined by urine dipstick pregnancy test * Any aneurysms on cranial magnetic resonance imaging/magnetic resonance angiography (obtained recently in the GeneSTAR participants) * Blood pressure above \>=159/95mmHg * History of a gastric or duodenal ulcer, or significant gastrointestinal disease, like regional enteritis * Mental incompetence to make a decision to participate (developmentally disabled, and persons with diagnosed psychiatric disorders-documented in primary care records).

Design outcomes

Primary

MeasureTime frameDescription
Changes in Platelet Transcriptome4 weeksComparison of platelet transcriptome before aspirin therapy with platelet transcriptome after aspirin therapy. The expression levels of genes before aspirin therapy was compared with the expression level of the genes after aspirin therapy. The expression levels were measured using the FPKM unit (Fragments Per Kilobase of transcript per Million mapped reads). The gene with the highest difference (pre vs. post) in FPKM is being reported with name in the units area and the actual difference in the number area

Countries

United States

Participant flow

Participants by arm

ArmCount
Aspirin
Participants treated with aspirin - there is no control group. Participant's baseline will act as their control. Aspirin: 81 mg daily for 4 weeks
33
Total33

Baseline characteristics

CharacteristicAspirin
Age, Continuous50.6 years
STANDARD_DEVIATION 8
Gender
Female
15 Participants
Gender
Male
18 Participants
Race/Ethnicity, Customized
African Americans
22 participants
Race/Ethnicity, Customized
Caucasians
11 participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
0 / 33
serious
Total, serious adverse events
0 / 33

Outcome results

Primary

Changes in Platelet Transcriptome

Comparison of platelet transcriptome before aspirin therapy with platelet transcriptome after aspirin therapy. The expression levels of genes before aspirin therapy was compared with the expression level of the genes after aspirin therapy. The expression levels were measured using the FPKM unit (Fragments Per Kilobase of transcript per Million mapped reads). The gene with the highest difference (pre vs. post) in FPKM is being reported with name in the units area and the actual difference in the number area

Time frame: 4 weeks

Population: The data were analyzed combining results from two studies (33 from this study and additional 24 individuals from study NCT02234427; total population size = 57) to improve the power to detect a difference. Same results are reported for the two studies. Note that the top most gene (HBG1) with the lowest p-value is being reported.

ArmMeasureValue (MEAN)Dispersion
AspirinChanges in Platelet Transcriptome77.1 FPKM difference for HBG1 GeneStandard Error 19.8

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026