Clinical Trials Logo

Clinical Trial Summary

Aspirin resistance is the persistent platelet activation, demonstrated by platelet function tests (1).

The hypothesis is that:LDL lowering by statin in patients with aspirin resistance can improve the effect of aspirin due to the potential decreasing of cholesterol content in the platelet membranes.

Patients and methods:Forty hypercholesterolemic patients with aspirin resistance after 5 days of treatment with aspirin and high LDL and triglycerides<300 mg/dL, will be enrolled.

Ten healthy volunteers will be the control group.


Clinical Trial Description

The patients will be treated by aspirin loading dose of 500mg and then 100 mg/day for other 4 days. For patients that will be entrolled in the regular working hours, platelet aggregation test and cholesterol content in platelet membranes will be done at baseline.

Blood tests for lipids, liver (ALT,AST,GGT,Alkaline phosphatase and bilirubin) and renal function tests (blood urea nitrogen and creatinine), complete blood count, general urine test and serum homocysteine will be done on the second day.

On the fifth day optical platelet aggregation test, cholesterol content in platelet membranes, platelet function in the PFA-100 system and soluble p-selectin in the plasma will be done If the patient has aspirin resistance (platelet aggregation 20% with epinephrine or 70% with ADP), LDL will be lowered in the plasma of 20 patients by hypolipidemic drugs (statin alone or combined with ezetimibe). Other 20 patients will continue to be treated by aspirin alone.

One month later, blood tests for lipids, liver (ALT,AST,GGT,Alkaline phosphatase and bilirubin) and renal function tests (blood urea nitrogen and creatinine), complete blood count, general urine test and serum homocysteine will be done for the second time and platelet activity will be tested again for all patients.

Platelet separation:

For platelet studies, venous blood (30 ml) will be collected through siliconized syringes into acid citrate dextrose solution(1.4% citric acid, 2.5% sodium citrate, and 2% dextrose) at a ratio of 9:1 (v:v) for washed platelets (WP)preparation.WP will be prepared by centrifugation at 240g for 20 min. The platelet bellet will be washed twice in 5 mmol Hepes buffer, pH 7.4 (140 mmol NaCl, 2 mmol KCL, 1 mmol MgCl2, 5 mmol Hepes, 12 mmol NaHCO3 and 5.5 mmol of glucose). For the preparation of WP suspension, 15 uL of acetic acid (1mmol) will be added to 1 ml of platelet suspension throughout WP preparation in order to ensure acidic conditions which are required for platelet resuspension. This procedure will reduce the medium pH to 6.5 and it does not influence the aggregation response of the WP.

Platelet aggregation:

Collagen (Nycomed, germany) will be used as the aggregating agent at a concentration of 4 ug/ml (this concentration can cause up to 60% aggregation amplitude in WP). Platelet aggregation will be perfomed at 37ºC in aggregometer using hepes as a reference system. Results will be expressed as the extent of maximal aggregation (% of maximal amplitude) and also as the slope of the aggregation curve (cm/min).

Cholesterol content in platelet membranes:

Platelets will be washed three times with Hepes buffer, and then sonicated twice for 20 seconds at 80 watt. Platelet lipids will be extracted with hexane:isopropanolol (3:2, v:v). The cholesterol content will be measured in the dried hexane phase by the method of Chiamori et al (12). Platelet protein will be determined using the method of Lowry (13). ;


Study Design

Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment


Related Conditions & MeSH terms


NCT number NCT00466154
Study type Interventional
Source Ziv Hospital
Contact
Status Completed
Phase N/A
Start date July 2005
Completion date January 2007

See also
  Status Clinical Trial Phase
Completed NCT04998695 - Health Effects of Consuming Olive Pomace Oil N/A
Recruiting NCT03947866 - Ezetimibe-Rosuvastatin Evaluation Study
Completed NCT01709513 - Study of Alirocumab (REGN727/SAR236553) in Patients With Primary Hypercholesterolemia and Moderate, High, or Very High Cardiovascular (CV) Risk, Who Are Intolerant to Statins (ODYSSEY ALTERNATIVE) Phase 3
Completed NCT01212900 - Randomized Trial of Imaging Versus Risk Factor-Based Therapy for Plaque Regression Phase 4
Completed NCT00001154 - Lipoprotein Metabolism in Normal Volunteers and Patients With High Levels of Lipoproteins
Completed NCT02550288 - A Clinical Trial to Assess the Efficacy and Safety of MK-0653C in Japanese Participants With Hypercholesterolemia (MK-0653C-383) Phase 3
Completed NCT03929198 - Translation of Pritikin Program to the Community N/A
Completed NCT04485793 - Effect of a Dietary Supplement on Lipid Pattern and Liver Parameters in Hypercholesterolemia N/A
Completed NCT02341924 - Validating the "Foods for Health" Portfolio of Functional Food Products N/A
Active, not recruiting NCT02223793 - Vascular Lifestyle-Intervention and Screening in Pharmacy N/A
Completed NCT01941836 - Evaluation of ETC-1002, Ezetimibe, and the Combination in Hypercholesterolemic Patients Phase 2
Completed NCT01934608 - The Effect of Synching Prescription Refills on Adherence N/A
Recruiting NCT01705873 - Analysis on the Risk of Cardiovascular Events in HIV- Infected Subjects Treated With LPV/r Based HAART Regimen vs. an EFV Based Regimen N/A
Completed NCT01678521 - Effect of LDL-apheresis on PTX3 Plasma Levels in Hypercholesterolemic Patients N/A
Completed NCT01670734 - Pharmacokinetic and Tolerability of Alirocumab SAR236553 (REGN727) in Patients With Hepatic Impairment and in Healthy Subjects Phase 1
Completed NCT01370603 - A Study to Evaluate the Effectiveness of Ezetimibe/Atorvastatin 10 mg/40 mg Combination Tablet Compared to Marketed Ezetimibe 10 mg and Atorvastatin 40 mg Tablets in Participants With High Cholesterol (MK-0653C-190 AM1) Phase 3
Completed NCT01370590 - A Study to Evaluate the Effectiveness of Ezetimibe/Atorvastatin 10 mg/20 mg Combination Tablet Compared to Marketed Ezetimibe 10 mg and Atorvastatin 20 mg Tablets in Participants With High Cholesterol (MK-0653C-185 AM1) Phase 3
Completed NCT01575171 - Using Nudges to Implement Comparative Effectiveness N/A
Completed NCT01768403 - Centralised Pan-Algerian Survey on the Undertreatment of Hypercholesterolemia N/A
Completed NCT01446679 - Special Drug Use-Results Survey of Lipitor Tablets N/A