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Platelet Acetyl Coenzyme A Carboxylase Phosphorylation in Coronary Artery Disease (ACCTHEROMA)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03034148
Recruitment Status : Completed
First Posted : January 27, 2017
Last Update Posted : February 17, 2017
Information provided by (Responsible Party):
Cliniques universitaires Saint-Luc- Université Catholique de Louvain

Brief Summary:

In human purified platelets, only thrombin, and not the other platelet agonists, leads to a transient activation of the protein kinase activated by AMP (AMPK) and to phosphorylation of its "bona fide" substrate, ACC on its Ser79. ACC phosphorylation (P-ACC) can be an interesting marker of thrombin action on platelets. Indeed platelet and coagulation interplay, though undoubtedly present in atherosclerosis and atherothrombosis, remains difficult to assess. Our group showed that atherosclerotic mice (SRBI/Apolipoprotein E knock-out) had higher platelet P-ACC compared to corresponding control mice (C57BL6). In agreement with these data, preliminary results showed increased platelet P-ACC in a small cohort of patients admitted for coronary angiogram, with demonstrated coronary artery disease (CAD).

In the light of our preliminary results, we sought to analyze platelet P-ACC in a large prospective clinical trial (ACCTHEROMA) in patients admitted for coronary angiogram. The aim of the study is to compare platelet P-ACC in platelets of patients with CAD and more particularly in unstable CAD patients to non-CAD patients. This study could potentially identify patients at high risk of future ischemic cardiovascular events, because of a higher level of thrombin generation.

Condition or disease Intervention/treatment Phase
Coronary Artery Disease Acute Coronary Syndrome Coronary Thrombosis Diagnostic Test: Platelet Acetyl Coenzyme A Carboxylase analysis in CAD Not Applicable

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Detailed Description:

Consecutive patients with planned coronary angiogram at the Cliniques Universitaires Saint Luc, Brussels, whatever the indication, will be included between March 2015 and February 2016. Informed consent will be obtained before angiogram.

A. Blood Sampling Routine veinous blood sample will be done under fasting condition in the cardiology ward before the angiogram (standard of care for patients undergoing coronary angiogram).

In order to avoid additional puncture for blood sampling and to limit platelet activation, blood samples are withdrawn after sheath insertion at the Cath lab before any drug administration. The following measurements will be done:

  • Routine coagulation tests including international rationalize ratio, activated cephaline time, thrombin time, prothrombin time, Fibrinogen, DDimers.
  • Platelet reactivity testing by the Multiple Electrode Aggregometer (Multiplate Analysis)
  • Platelet isolation and lysates will be stocked frozen for phospho-protein analysis by immunoblotting and electrochemiluminescence (ECLIA)
  • Aliquots of poor platelet plasma stocked frozen for inflammation (HsCRP), thrombin generation tests (thrombin-antithrombin complex, prothrombin fragment F1.2, endogenous thrombin generation potential-ETP), platelet activation markers (platelet factor 4, soluble CD40ligand, soluble P-selectin) and circulating micro-RNA extraction.
  • Platelet isolation and further purification for platelet specific micro-RNA extraction.

B. Atherosclerosis evaluation All patients underwent coronary angiogram. Significant coronary artery lesion is defined as a luminal stenosis above 50%. Syntax score will be calculated for all patients.

Global atherosclerotic plaque burden on coronary and extracoronary arteries will be evaluated by measuring calcium score on thoraco-abdominal scanner with prospective ECG-gating in a randomly selected subgroup of patients. Coronary artery calcification (CAC) is expressed as Agatston score using calcium scoring software (Philips Healthcare) with a threshold of 130 Hounsfield units. The degree of atherosclerotic burden on coronary arteries is classified as mild (Agatston score <100), moderate (Agatston score 100-400) or severe (Agatston score >400). Aortic calcification (AoC score) was measured from aortic arch to iliac arteries in all patients.

C. Data collection Baseline characteristics of patients will be collected from the medical database of the Cliniques Universitaires Saint Luc. All coronary angiogram will be reviewed by 2 different investigators and syntax score will be calculated with the online syntax score calculator. CAC Agatston and AoC score will also be assessed by 2 different investigators.

D.Patients Classification for platelet P-ACC analysis Platelet ACC phosphorylation (P-ACC) analysis will be done by immunoblotting with a specific antibody probing for phosphorylated (Ser 79) ACC. Purified washed platelets stimulated with 0.5 units/ml thrombin will be used as positive internal controls.

Patients will first be classified in non-CAD and CAD groups based on the results of coronary angiogram and CAC Agatston score: Non-CAD (absence of lesion on angiogram and/or CAC Agatston score<100) and CAD (presence of at least 1 lesion on angiogram and/or CAC Agatston score>100).

In a second analysis, based on clinical presentation, the CAD group will further be divided into Stable CAD or Unstable CAD [acute coronary syndrome (ACS)]. Platelet P-ACC will be compared in both subgroups. This detailed classification will outline high-risk patients with ongoing acute coronary syndrome.

E. Sample size and statistical analysis. Based on our preliminary data, we determined that enrolment of 102 patients would provide a power of 80% at a significance level of 5% to detect a difference of 0.15 (A.U.) in the phosphorylation of ACC in atherosclerotic patients, compared to non CAD patients.

Continuous variables will be expressed as mean +/- one standard deviation, categoric variables as counts and percentages. Patients will separated in four groups depending on the level of P-ACC (quartiles). Clinical presentation, thrombin generation markers and calcium scoring will be compared in all these groups, based on ANOVA analysis. Variables will be submitted to logistic regression test in order to identify independent predictors of high ACC phosphorylation state. The role of high platelets P-ACC in assessing the risk of the patients will be then studied.

F.Follow-up A follow-up period of 3 years is planned. Events recorded during the follow-up period will be obtained from the medical database and a phone call will be done in case of missing data.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 188 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Screening
Official Title: Prospective Evaluation of Acetyl-Coenzyme A Carboxylase Phosphorylation State in Platelets in Atherothrombotic Coronary Artery Disease.
Study Start Date : March 2015
Actual Primary Completion Date : February 2016
Actual Study Completion Date : February 2016

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Coronary artery disease
blood sampling for biomarkers assessment in a population undergoing coronary angiogram
Diagnostic Test: Platelet Acetyl Coenzyme A Carboxylase analysis in CAD

Primary Outcome Measures :
  1. an increase in platelet ACC phosphorylation state in patients with coronary artery disease [ Time Frame: 2 years ]

Secondary Outcome Measures :
  1. a correlation between thrombin generation markers and platelet P-ACC in overall population. [ Time Frame: 2 years ]
  2. platelet ACC phosphorylation state according clinical severity of CAD (stable versus unstable patients) [ Time Frame: 2 years ]
  3. the role of platelet P-ACC in predicting the risk of the patient for future cardiovascular events (death, myocardial infarction, stroke) [ Time Frame: 3 years ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Signed informed consent
  • Planned angiography within the next 3 days, whatever the indication.

Exclusion Criteria:

  • Not able to sign informed consent
  • Patients on anticoagulation therapy (oral or parenteral) including heparins, fondaparinux, vitamin K antagonist, novel oral anticoagulants, for any reasons.
  • Active neoplasia
  • Active inflammatory disease
  • Patients with life expectancy lower than 3 years
  • Haemophilia and other coagulopathy
  • Abnormal platelet count
  • Heart transplanted patients
  • Active hepatitis B or C or HIV patients
  • Any contra-indication for coronary angiography.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03034148

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Cliniques Universitaires Saint Luc
Brussels, Belgium, 1200
Sponsors and Collaborators
Cliniques universitaires Saint-Luc- Université Catholique de Louvain
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Principal Investigator: Christophe Beauloye, MD, PhD Cliniques universitaires Saint-Luc- Université Catholique de Louvain

Publications of Results:
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Responsible Party: Cliniques universitaires Saint-Luc- Université Catholique de Louvain Identifier: NCT03034148     History of Changes
Other Study ID Numbers: cb07012015
First Posted: January 27, 2017    Key Record Dates
Last Update Posted: February 17, 2017
Last Verified: February 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Cliniques universitaires Saint-Luc- Université Catholique de Louvain:
Coronary artery disease
Thrombin generation
Platelet Acetyl Coenzyme A carboxylase phosphorylation
Additional relevant MeSH terms:
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Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Acute Coronary Syndrome
Coronary Thrombosis
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases
Embolism and Thrombosis