Resistance to Acetylsalicylic Acid in Patients with Coronary Heart Disease Is the Result of Metabolic Activity of Platelets.

Sensitivity to acetylsalicylic acid (ASA) is important in the treatment of patients with coronary heart disease (CHD) after coronary artery bypass grafting (CABG). Patients were divided into ASA sensitive (sASA) and ASA resistant (rASA) by the activity of platelet aggregation induced arachidonic acid (ARA) together with ASA. Induced platelet aggregation activity was studied in sASA and rASA patients with CHD before and after CABG. The level of synthesis of primary and secondary reactive oxygen species (ROS) by platelets was determined using chemiluminescent analysis. The activity of NAD- and NADP-dependent dehydrogenases in platelets was determined by the bioluminescent method. It was found that the aggregation activity of platelets depended on the sensitivity of CHD patients to ASA and decreased during postoperative ASA therapy. The most pronounced differences in metabolic parameters of platelets in sASA and rASA patients were detected by Nox2 activity. The synthesis of secondary ROS by platelets of CHD patients did not depend on the sensitivity of patients to ASA but increased during postoperative treatment with ASA. The activity of NAD(P)-dependent dehydrogenases in platelets did not differ in sASA and rASA patients with CHD.

Acetylsalicylic acid resistance after renal transplantation.

BACKGROUND: Cardiovascular diseases are a leading cause of mortality after kidney transplantation. According to guidelines, acetylsalicylic acid (ASA) must be given as preventive antiplatelet therapy, but resistance to this drug is also well-known. PATIENTS AND METHODS: A total of 214 renal transplant patients were included in our study and took 100 mg of ASA q.d. Aggregometry was performed to determine resistance. Twenty-four variables were examined using logistic regression analysis as possible causes of resistance. RESULTS: ASA resistance was observed in 40.18% of the patients. Resistance reduced concomitant statin therapy and significantly increased simultaneous cyclosporine therapy. CONCLUSION: Our study assessed the post-transplant ASA resistance in a large population. Clarification of this matter is crutial, since one of the major preventive pharmacological therapies of cardiovascular mortality is not effective in a significant number of patients.

Acetylsalicylic Acid resistance in patients with type 2 diabetes mellitus, prediabetes & non-diabetic coronary artery disease.

UNLABELLED: Objective : Several studies have demonstrated the beneficial role of antiplatelet therapy with acetylsalicylic acid (ASA) at atherosclerotic vascular disease. Antiaggregant effect of ASA is not uniform in all patients. Purpose of the present study is to evaluate the prevalence of ASA resistance in patients with type 2 diabetes mellitus (T2DM), pre-diabetes and non-diabetic coronary artery disease (CAD). METHODS: Effect of ASA was assessed using the platelet function analyzer (PFA-100) system. Resistance to ASA was defined as a normal collagen/epinephrine induced closure time after one week of ASA therapy. Patients with non-diabetic CAD, pre-diabetes and T2DM were compared. RESULTS: ASA resistance was found in 26 (37.1%), 6 (17.6%) and 41 (26.5%) patients in the groups, respectively (p=0.154). ASA resistance was found to be significantly higher in men, smokers and insulin users, besides this it was found to be significantly lower in beta blocker (BB) users, angiotensin converting enzyme inhibitor (ACEI) users with univariate analysis. However insulin usage was found to be the single effective parameter on ASA resistance in multivariate analysis. CONCLUSION: There was no difference with regard to ASA resistance between groups. While ASA resistance was higher in men, smokers and insulin users, it was lower in patients using BBs and ACEIs.