Conditions: Coronary Artery Disease Acute Coronary Syndrome
Keywords: platelet reactivity ticagrelor prasugrel
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 82
Healthy volunteers: no

Brief summary:
Recently, two new oral P2Y12 antagonists have been approved for clinical use: prasugrel, a third generation thienopyridine, and ticagrelor, a first in class cyclopentyltriazolopyrimidine (CPTP). These agents have been shown to be associated with more potent platelet inhibitory effects compared with clopidogrel. In addition, both agents have shown to be superior to clopidogrel in preventing recurrent ischemic events in the setting of acute coronary syndromes (ACS). Understanding how to switch patients from prasugrel to ticagrelor is an unmet need of clinical interest. The proposed PD investigation will have a prospective, randomized, parallel design aimed to show that switching patients from prasugrel to ticagrelor provides similar levels of platelet inhibition.

Detailed description:
Dual antiplatelet therapy consisting of aspirin and a P2Y12 receptor antagonist is the cornerstone of treatment for secondary prevention of thrombotic events in patients with coronary artery disease. Recently, two new oral P2Y12 antagonists have been approved for clinical use: prasugrel, a third generation thienopyridine, and ticagrelor, a first in class cyclopentyltriazolopyrimidine (CPTP). These agents have been shown to be associated with more potent platelet inhibitory effects compared with clopidogrel. In addition, both agents have shown to be superior to clopidogrel in preventing recurrent ischemic events in the setting of acute coronary syndromes (ACS). Therefore, current guidelines recommend prasugrel or ticagrelor (as first line therapy according to European Society of Cardiology) in ACS patients undergoing percutaneous coronary intervention (PCI). Despite the broader indication for ticagrelor (also medically managed ACS) and its mortality benefit, prasugrel has a higher uptake than ticagrelor in the US market, likely due to its earlier approval. Further, implementation of prasugrel into institutional protocols, particularly for ST elevation myocardial infarction (STEMI) patients undergoing primary PCI, may also be a reason for the slow uptake of ticagrelor. However, many clinicians would indeed consider ticagrelor as the long-term treatment of choice for a variety of reasons. Therefore, understanding how to switch patients from prasugrel to ticagrelor is an unmet need of clinical interest. However, currently, there are no data on the pharmacodynamic (PD) effects of switching from prasugrel to ticagrelor. The proposed PD investigation will have a prospective, randomized, parallel design aimed to show that switching patients from prasugrel to ticagrelor provides similar levels of platelet inhibition. This study will provide insights on the PD effects of switching and will help clinicians to choose the most appropriate schema to avoid complications related to inadequate antiplatelet therapy in patients with coronary artery disease if switching from prasugrel to ticagrelor is desired.

Arms:
arm 1: Patients on prasugrel will switch to ticagrelor with a 180mg loading dose arm 2: Patients on prasugrel will switch to ticagrelor with a 90mg maintenance dose arm 3: Patients already on prasugrel, will maintain prasugrel

Interventions: intervention 1: Ticagrelor 180mg intervention 2: Prasugrel 10mg intervention 3: Ticagrelor 90mg
Intervention descriptions: intervention 1: After providing written informed consent, eligible patients on maintenance prasugrel meeting inclusion and exclusion criteria will be randomized in a 1:1:1 fashion to one of the following treatment arms:

A. Ticagrelor 180 mg loading dose (two 90mg ticagrelor tablets) followed by 90 mg BID maintenance dose for 7±2 days.

B. Ticagrelor 90 mg (one 90mg ticagrelor tablet) followed by 90 mg BID maintenance dose for 7±2 days C. Prasugrel 10 mg once daily maintenance dose for 7±2 days intervention 2: After providing written informed consent, eligible patients on maintenance prasugrel therapy meeting inclusion and exclusion criteria will be randomized in a 1:1:1 fashion to one of the following treatment arms:

A. Ticagrelor 180 mg loading dose (two 90mg ticagrelor tablets) followed by 90 mg BID maintenance dose for 7±2 days.

B. Ticagrelor 90 mg (one 90mg ticagrelor tablet) followed by 90 mg BID maintenance dose for 7±2 days C. Prasugrel 10 mg once daily MD for 7±2 days intervention 3: After providing written informed consent, eligible patients on maintenance prasugrel therapy meeting inclusion and exclusion criteria will be randomized in a 1:1:1 fashion to one of the following treatment arms:

A. Ticagrelor 180 mg loading dose (two 90mg ticagrelor tablets) followed by 90 mg BID maintenance dose for 7±2 days.

B. Ticagrelor 90 mg (one 90mg ticagrelor tablet) followed by 90 mg BID maintenance dose for 7±2 days C. Prasugrel 10 mg once daily MD for 7±2 days

Protocol document: