The relationship between widespread coronary artery disease or episodes of recurrent percutaneous coronary i̇nterventi̇on and aspirin resistance

Introduction: Atherothrombosis, which is the primary cause of acute ischaemic syndromes in vascular bed, comprises more than 35% of all the mortality in the world and is characterized by rupture of atherothrombotic lesion which is associated with thrombotic complications. Aspirin is an antithrombotic drug that is used in the primary and secondary protection against atherothrombotic diseases and their complications. Aspirin inhibits cyclooxygenase-1 (COX-1) enzyme by acetylating the serine residues and thus, prevents the synthesis of thromboxane-A2 and other eicosanoids from arachidonic acid. According to contemporary guidelines, the usage of aspirin alone or combined with clopidogrel in atherosclerotic diseases and acute coronary syndromes is the standard treatment modality. Despite all the positive effects of aspirin, it is known that aspirin using atherosclerosis patients experience recurrent vascular events in their long term follow ups. The occurence of new cardiovascular events in the patients who are using aspirin is defined as "clinical resistance" and incomplete blockage of thrombocyte activity in vitro is defined as "laboratory resistance" against aspirin. Studies show that, in patients with documented laboratory resistance to aspirin, there are increases in the incidence of myocardial infarction, stroke, cardiovascular mortality and reocclusion rate in patients with percutaneous coronary intervention. Purpose: To investigate the relation of aspirin resistance with coronary artery disease severity, risc factors and stent thrombosis related repetitive percutaneous coronary interventions. Method: Our study included 100 patients who are followed with CAD diagnosis and under therapeutic dose aspirin treatment, among the patients, 70 are aspirin non resistant and 30 are aspirin resistant, which is determined by Verify Now© system. In the study, the thrombocyte inhibition level of aspirin is measured with Verify Now© system, the patients with ARU>550 are defined as aspirin resistant and with ARU<550 are defined as aspirin non-resistant. Demographic variables, cardiovascular risk factors, body mass indexes, usage of drugs with the possible interaction with aspirin, biochemical parameters, coronary angiographic features are compared between the groups that are aspirin resistant and aspirin non-resistant. Results: In our study, the relation of coronary artery disease severity with aspirin resistance is found to be significant. The disease severity which is calculated with Gensini score is found 85,96±29,70 in aspirin resistant group and 55,28±29,70 in aspirin non-resistant group (p=0,041). Furthermore, in aspirin resistant group, the increase of stent thrombosis and repetitive percutaneous coronary interventions is also found to be significant (84,6% vs. 38,5%; p=0,001). Conclusion: There is increased level of coronary artery disease severity and increased frequency of repetitive percutaneous coronary interventions in the patients with aspirin resistance.