OFDI-Quantified Intracoronary Thrombus, Antiplatelet Pretreatment Effect and Myocardial Reperfusion

The management of ST-elevation myocardial infarction in the acute phase requires an optimal antiaggregation combining aspirin and a P2Y12 inhibitor (clopidogrel, prasugrel or ticagrelor). Primary percutaneous coronary intervention must be performed within 2 hours of first medical contact. However, even with the new P2Y12 inhibitors, effective platelet inhibition which is required to inhibit the progression of intracoronary thrombus, is present only in half of the patients at 2 hours.

Optical coherence tomography (OCT) is the reference method for visualizing and quantifying intracoronary thrombus. The post-stenting intracoronary residual mass evaluated in OCT was associated with altered myocardial reperfusion indices, which were themselves associated with the prognosis of the patient. However, the determinants of this post-stenting residual mass -mostly thrombotic- remain unknown.

Measurement of platelet reactivity (expressed as P2Y12 Reaction Unit and Aspirin Reaction Unit) by simple turbidimetric tests (VerifyNow) is available in the cathlab. Enhanced platelet reactivity is reported in patients with acute coronary syndrome and represents a high-risk situation for recurrent coronary events in this setting.

The study aims to:

1. to evaluate the relationship between the post-stenting residual intracoronary mass evaluated in OCT and the platelet response at the time of the PCI evaluated by Verify Now 2. to confirm the impact of the residual mass measured by OCT on the EKG and angiographic myocardial reperfusion indices 3. identify patients with high thrombotic risk who may require more intensive antithrombotic therapy 4. identify simple biological markers associated with the residual mass measured by OCT