Abstract
Despite the application of new antiplatelet drugs (prasugrel and ticagrelor), dual
antiplatelet therapy with clopidogrel and aspirin remains the standard for patients
with acute coronary syndrome undergoing percutaneous coronary intervention, especially
in countries of low socioeconomic status. Regardless of the proven benefits, numerous
studies have shown that certain groups of patients who receive standard doses of clopidogrel
and aspirin do not respond adequately, and many of them also exhibit adverse cardiovascular
events. Studies have shown that the risk of stent thrombosis and ischemic complications
is higher in patients with: acute coronary syndrome, diabetes mellitus, thrombocytosis,
reduced systolic function of the left ventricle with ejection fraction less than 30%,
presence of multiple stents, longer and thinner stents, and renal failure. In these
patients it is particularly important to assess the response to clopidogrel and selecting
adequate antiplatelet therapy; this provides an impetus for platelet function tests.
The second especially significant group to target for laboratory evaluation includes
patients with increased risk of bleeding, such as elderly patients, patients with
low body weight, anemia, thrombocytopenia, renal failure, past or current ventricular
or duodenal ulcer, coagulopathy, or liver disease. The third important application
of platelet function tests entails the preparation and evaluation of the time for
surgical interventions or invasive diagnostic procedures in patients on antiplatelet
therapy. These tests can also be helpful for monitoring the effects of therapy of
bleeding due to platelet dysfunction. For high-risk patients the careful selection
of optimal antiplatelet drug(s) on the basis of estimated individual risk of thrombosis
and bleeding, pharmacodynamic characteristics of each drug, and patient̀s comorbidity
remains essential.
Keywords
acute coronary syndrome - percutaneous coronary intervention - high risk patients
- antiplatelet therapy
