Trial Outcomes & Findings for Efficacy and Safety of Low-dose Ticagrelor (NCT NCT03381742)

3,737 CAD patients who received either clopidogrel or ticagrelor therapy and underwent TEG test from 11 medical centers. Among these patients, 1,725 subjects were treated with clopidogrel and 2,012 subjects were treated with different ticagrelor regimens.

Efficacy and Safety of Low-dose Ticagrelor

The venous blood samples for platelet function test were drawn after an overnight fast, at 12 hours post-last study-drug dose for subjects receiving twice-daily administrations, and at 24 hours post-last study-drug dose for subjects treated with once-daily regimens. The blood was collected in an evacuated vacuum tube containing 3.2% trisodium citrate and lithium heparin. Then the samples were processed within two hours of blood draw according to standard operating procedure. The physical properties of samples were analyzed using Thromboelastography (TEG) Hemostasis Analyzer (CFMS LEPU-8800, Lepu Medical Technology Co., Ltd, Beijing, China) and automated analytical software. TEG test used four channels to detect the effects of anti-platelet therapy via the arachidonic acid (AA) and ADP pathways. TEG test results were expressed in terms of ADP-induced inhibition of platelet aggregation (IPA, range 0% - 100%), with higher values indicating greater platelet inhibition.

Major bleeding was defined as type ≥ 3 and minor bleeding as types 1 and 2, in accordance to the Bleeding Academic Research Consortium classification. (Mehran R et al. Standardized bleeding definitions for cardiovascular clinical trials: a consensus report from the Bleeding Academic Research Consortium. Circulation. 2011 Jun 14;123(23):2736-47. doi: 10.1161/CIRCULATIONAHA.110.009449.)

The physical properties of samples were analyzed using Thromboelastography (TEG) Hemostasis Analyzer (CFMS LEPU-8800, Lepu Medical Technology Co., Ltd, Beijing, China) and automated analytical software. TEG test used four channels to detect the effects of anti-platelet therapy via the arachidonic acid (AA) and ADP pathways. TEG test results were expressed in terms of ADP-induced platelet-fibrin clot strength (MA). A MA\>47mm was shown to have a high predictive value for 3-year post-PCI ischemic events during dual antiplatelet therapy. Moreover, ROC curve and quartile analysis suggested MA\<31 mm as a predictive value for post-PCI bleeding events (J Am Coll Cardiol. 2013;62(24):2261-73. doi: 10.1016/j.jacc.2013.07.101.).

HTPR was defined as IPA ≤ 30% and MA ≥ 47 mm.

Cardiovascular death was defined as sudden cardiac death, fatal myocardial infarction, death due to heart failure, or death due to other cardiovascular causes. Stroke was defined as the focal loss of neurologic function caused by an ischemic or a hemorrhagic event with residual symptoms lasting at least 24 hours or eventually leading to death.

New-onset dyspnea in patients without previous history of dyspnea