Post-treatment platelet reactivity predicts long-term adverse events better than the response to clopidogrel in patients with non-ST-segment elevation acute coronary syndrome.
OBJECTIVE
Poor response to antiplatelet therapy has been associated with adverse long-term outcomes. The objective of this study is to assess the relationship between response to clopidogrel and post-treatment platelet reactivity (PPR) and 1-year major adverse cardiovascular events (MACE) in patients with non-ST segment elevation acute coronary syndrome (NSTEACS).


METHODS
Patients with NSTEACS undergoing early coronary angiography were enrolled in this prospective, observational study. The VerifyNow analyzer was used to measure clopidogrel response and PPR immediately before coronary angiography.


RESULTS
Of the 179 patients included (97 percutaneous coronary intervention, 21 coronary artery bypass graft), 161 (90%) completed 1-year follow-up and 18 (11%) incurred MACE: 10 deaths, 6 myocardial infarctions, 2 strokes, 5 revascularizations. Lower response to clopidogrel (31 +/- 21% vs. 43 +/- 21%; P.049) and higher PPR (204 +/- 60 vs. 155 +/- 67 platelet reaction units [PRU]; p= 0.006) were significantly associated with MACE occurrence. Multivariate analysis confirmed PPR (OR per 10-unit increase: 1.12, 95%CI: 1.01-1.24; P.020) as an independent predictor of MACE. A PPR cut-off value of 175 PRU was associated with an adjusted OR for 1-year MACE occurrence of 3.9 (95%CI: 1.2-15.4; P.024).


CONCLUSIONS
PPR predicts adverse long-term outcomes better than response to clopidogrel in patients with NSTEACS. Patients with PPR values above 175 PRU were identified as being at higher risk for adverse long-term events.
de Miguel Castro
Antonio
A
Servicio de Cardiología, Hospital de León, León, Spain.
Cuellas Ramón
Carlos
C
Diego Nieto
Alejandro
A
Samaniego Lampón
Beatriz
B
Alonso Rodríguez
David
D
Fernández Vázquez
Felipe
F
Alonso Orcajo
Norberto
N
Carbonell de Blas
Raúl
R
Pascual Vicente
Cristina
C
Pérez de Prado
Armando
A
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000601:surgery*; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001792:Blood Platelets / Q000502:physiology*; D000077144:Clopidogrel; D001026:Coronary Artery Bypass; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use*; D010979:Platelet Function Tests; D011183:Postoperative Complications / Q000097:blood / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016896:Treatment Outcome
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine