Ticagrelor versus prasugrel in acute coronary syndrome patients with high on-clopidogrel platelet reactivity following percutaneous coronary intervention: a pharmacodynamic study.
OBJECTIVE
The study aimed to compare the antiplatelet action of ticagrelor with prasugrel in acute coronary syndrome (ACS) patients with high on-treatment platelet reactivity (HTPR) while on clopidogrel after percutaneous coronary intervention (PCI).


BACKGROUND
Newer P2Y12 inhibitors like prasugrel and ticagrelor provide stronger platelet inhibition compared with clopidogrel. Both agents are efficacious in patients with HTPR while on clopidogrel, but direct comparison between them has not yet been reported.


METHODS
In a prospective, single-center, single-blind study, 44 (of 139 screened, 31.7%) ACS patients with HTPR while on clopidogrel 24 h post-PCI were randomized to either ticagrelor 90 mg twice daily or prasugrel 10 mg once daily for 15 days with a crossover directly to the alternate treatment for another 15 days. HTPR was defined as platelet reactivity units (PRU) ≥ 235 as assessed by the VerifyNow P2Y12 function assay.


RESULTS
The primary endpoint of platelet reactivity at the end of the 2 treatment periods was lower for ticagrelor (32.9 PRU, 95% confidence interval [CI]: 18.7 to 47.2) compared with prasugrel (101.3 PRU, 95% CI: 86.8 to 115.7) with a least squares mean difference of -68.3 PRU (95% CI: -88.6 to -48.1; p < 0.001). The secondary endpoint of HTPR rate was 0% for ticagrelor and 2.4% for prasugrel (1 of 42, p = 0.5). No patient exhibited a major bleeding event at either treatment group.


CONCLUSIONS
In patients with ACS exhibiting HTPR while on clopidogrel 24 h post-PCI, ticagrelor produces a significantly higher platelet inhibition compared with prasugrel. (Ticagrelor Versus Prasugrel in Acute Coronary Syndromes After Percutaneous Coronary Intervention; NCT01360437).
Department of Cardiology, Patras University Hospital, Rion, Patras, Greece. dalex@med.upatras.gr
Dimitrios
D
Alexopoulos
Anastasia
A
Galati
Ioanna
I
Xanthopoulou
Eleni
E
Mavronasiou
George
G
Kassimis
Konstantinos C
KC
Theodoropoulos
George
G
Makris
Anastasia
A
Damelou
Grigorios
G
Tsigkas
George
G
Hahalis
Periklis
P
Davlouros
D054058:Acute Coronary Syndrome / Q000628:therapy; D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D000077144:Clopidogrel; D003328:Coronary Thrombosis / Q000209:etiology / Q000517:prevention & control*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000494:pharmacology* / Q000627:therapeutic use; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D000068799:Prasugrel Hydrochloride; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D013876:Thiophenes / Q000494:pharmacology* / Q000627:therapeutic use; D000077486:Ticagrelor; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use
D010879:Piperazines; D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D013876:Thiophenes; D000077144:Clopidogrel; D000068799:Prasugrel Hydrochloride; D000077486:Ticagrelor; D000241:Adenosine; D013988:Ticlopidine