Platelet aggregability and anticoagulant proteins activity during dobutamine stress echocardiography in asymptomatic patients four months after percutaneous coronary intervention

Abstract

Introduction: Platelets aggregability (PA) and the activation of hemostasis, during myocardial ischemia within physical or mental stress, can be one of many factors that influence the process of stent thrombosis after percutaneous coronary intervention (PCI). Objective: The aim of the study is to investigate the relationship between PA and activity of anticoagulant proteins with myocardial ischemia during dobutamine stress echocardiography (DSE) in asymptomatic patients four months after PCI. Methods: The study population included 74 asymptomatic patients who had successful PCI four months before high-dose dobutamine stress echocardiography (DSE).PA on epinephrine (EPI) and adenosine diphosphate (ADP) were determined by Light Transmission Aggregometry (LTA), together with plasma activity of protein C (PC) and antithrombin (AT) before DSE and at the peak stage of the stress test. Patients were divided into several groups whether they have baseline or induced disturbance of segmental myocardial kinetics or not. All patients were on clopidogrel and aspirin therapy at the time of DSE. Results: There were no statistically significant difference in PA on ADP (47.50% vs. 50.20%; p=0.970) as well as on EPI (59.30% vs. 60.30%, p=0.600) before and at the peak DSE. A statistically significant difference was found in the anticoagulant activity of the AT (84.85% vs. 74.75%, p=0.001) and PC (77.75% vs. 67.60%, p<0.001). Significance of differences in antithrombin and the protein C, refers to the result before and at the peak levels of the test. There was no significant difference in PA and plasma activity of anticoagulant proteins in patients with or without induced myocardial ischemia at the peak of DSE. Patients who had increased wall motion score index (WMSI) at the peak of DSE had higher EPI induced PA (68.60% vs. 54.70% p=0.017) than patients with normal myocardial contractility. Conclusion: There are no changes in the PA before and after DSE, however, plasma activity of anticoagulant proteins decreased at the peak level of the test. Platelet aggregability on EPI significantly increases at the peak of DSE in patients with segmental myocardium hypocontractility.

Keywords

• antithrombins
• echocardiography, stress
• percutaneous coronary intervention
• platelet aggregation