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World J Cardiol. Dec 26, 2015; 7(12): 912-921
Published online Dec 26, 2015. doi: 10.4330/wjc.v7.i12.912
Current status of high on-treatment platelet reactivity in patients with coronary or peripheral arterial disease: Mechanisms, evaluation and clinical implications
Stavros Spiliopoulos, Georgios Pastromas
Stavros Spiliopoulos, Georgios Pastromas, Department of Interventional Radiology, Patras University Hospital, 26504 Rio, Greece
Author contributions: Spiliopoulos S performed the majority of the writing, designed the outline and coordinated the writing of the paper; Pastromas G prepared the tables, performed data accusation and wrote the paper.
Conflict-of-interest statement: There is no conflict of interest associated with any of the authors contributed their efforts in this manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Stavros Spiliopoulos, MD, PhD, EBIR, Department of Interventional Radiology, Patras University Hospital, Ippokratous Avenue, 26504 Rio, Greece. stavspiliop@upatras.gr
Telephone: +30-261-3603219
Received: May 31, 2015
Peer-review started: June 4, 2015
First decision: June 18, 2015
Revised: July 16, 2015
Accepted: September 29, 2015
Article in press: September 30, 2015
Published online: December 26, 2015
Processing time: 206 Days and 23.2 Hours
Abstract

Antiplatelet therapy with aspirin or clopidogrel or both is the standard care for patients with proven coronary or peripheral arterial disease, especially those undergoing endovascular revascularization procedures. However, despite the administration of the antiplatelet regiments, some patients still experience recurrent cardiovascular ischemic events. So far, it is well documented by several studies that in vitro response of platelets may be extremely variable. Poor antiplatelet effect of clopidogrel or high on-treatment platelet reactivity (HTPR) is under investigation by numerous recent studies. This review article focuses on methods used for the ex vivo evaluation of HTPR, as well as on the possible underlying mechanisms and the clinical consequences of this entity. Alternative therapeutic options and future directions are also addressed.

Keywords: Coronary disease; Clopidogrel; Aspirin; High on treatment platelet reactivity; Peripheral arterial disease; Antiplatelet therapy; Ticagrelor; Prasugrel

Core tip: Recent data related high on-treatment platelet reactivity (HTPR) with adverse clinical outcomes, such as stent thrombosis and repeat procedures, following coronary or peripheral endovascular revascularization procedures. Notably, the incidence of patients suffering from peripheral arterial disease demonstrating inadequate response to clopidogrel is around 50%, which is much higher than the approximately 30% reported for patients suffering from coronary artery disease. Novel more potent antiplatelet P2Y12 agents seem to overcome the phenomenon of HTPR decreasing ischemic events with the cost of increased bleeding risk. Until today no major trial demonstrated clinical improvement for patients undergoing platelet function test-guided individualized antiplatelet therapy. Prescription of new antithrombotic agents aims in avoiding major cardiovascular adverse events, as well as sustaining vessel patency following revascularization. Therefore, improving antiplatelet therapy, considering the risk/benefit ratio, is imperative especially in HTPR patients. Further large-scale studies are awaited to elucidate the role of individualized therapy.