Effect of Physical Exercise on Platelet Reactivity in Patients with Dual Antiplatelet Therapy

It is known that physical exercise may increase platelet activity. However, the effect of exercise on platelet reactivity in patients on dual antiplatelet therapy has not been investigated yet. In our study, 21 patients with coronary artery disease on dual antiplatelet therapy and 10 controls were enrolled. We performed an exercise test using a cycle ergometer and determined the adenosine diphosphate-induced platelet reactivity before and immediately after exercise testing. Additionally, we analysed maximal exercise capacity and an electrocardiogram. Further, we assessed chromogranin A and P-selectin levels and platelet counts. In patients on dual antiplatelet therapy, adenosine diphosphate-induced platelet reactivity was significantly increased after exercise (48.8 +/- 6.1 U versus 38.4 +/- 6.0 U; p < 0.001). This was associated with significantly increased platelet counts and increased chromogranin A levels. Adenosine diphosphate-induced platelet reactivity was significantly higher in patients on aspirin plus clopidogrel compared to patients on aspirin plus prasugrel. The increase of platelet reactivity (Delta U) did not correlate with the maximal exercise capacity or the duration of exercise testing. Our findings show that physical exercise results in significantly increased adenosine diphosphate-induced platelet reactivity in patients on dual antiplatelet therapy. This may contribute to acute stent thrombosis occurring after physical exercise.