title: Nuisance and alarming bleeding do not correlate with on-treatment platelet reactivity.
abstract: OBJECTIVE
  We hypothesized that patients with a history of either alarming or nuisance bleeding events, compared to those with no history of bleeding, would have lower levels of on-treatment platelet reactivity (aspirin and a thienopyridine).
  
  
  RESULTS
  In total, 42 patients with no bleeding, 34 with nuisance bleeding, and 14 with alarming bleeding underwent platelet reactivity testing 1 month to 1 year after PCI with light transmission aggregometry (LTA 5 and 20 μM adenosine disphosphate [ADP]), vasodilator stimulated phosphoprotein phosphorylation (VASP) and VerifyNow P2Y12. Clinical and demographic characteristics of the 3 groups were generally similar, except that patients with alarming bleeding were less likely to be Caucasian; only 6 patients (6.7%) were taking prasugrel. There was considerable overlap between no bleeding, nuisance bleeding and alarming bleeding groups with respect to on-treatment platelet reactivity. Furthermore, there was no difference in the median platelet reactivity values for all assays. Prevalence of high on-treatment platelet reactivity did not differ among the 3 groups; 32.6% of patients had high on-treatment platelet reactivity as measured by LTA with 5 μM ADP (P=.91); 40.0% as measured by VASP (P=.35); and 35.6% as measured by VerifyNow P2Y12 (P=.61).
  
  
  CONCLUSIONS
  The use of platelet reactivity assays to identify patients on thienopyridine therapy at higher risk of bleeding is an unfounded strategy.
authors: Division of Cardiology, MedStar Washington Hospital Center, Washington, DC 20010, USA.
authors: Michael A
authors: MA
authors: Gaglia
authors: Rebecca
authors: R
authors: Torguson
authors: Shreejana
authors: S
authors: Pokharel
authors: Rajbabu
authors: R
authors: Pakala
authors: Zhenyi
authors: Z
authors: Xue
authors: William O
authors: WO
authors: Suddath
authors: Kenneth M
authors: KM
authors: Kent
authors: Lowell F
authors: LF
authors: Satler
authors: Augusto D
authors: AD
authors: Pichard
authors: Ron
authors: R
authors: Waksman
mesh_terms: D000368:Aged; D001241:Aspirin / Q000009:adverse effects*; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000097:blood; D016009:Chi-Square Distribution; D000077144:Clopidogrel; D003430:Cross-Sectional Studies; D004359:Drug Therapy, Combination; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D008297:Male; D008840:Microfilament Proteins / Q000097:blood; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects; D010750:Phosphoproteins / Q000097:blood; D010879:Piperazines / Q000009:adverse effects*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D010979:Platelet Function Tests; D000068799:Prasugrel Hydrochloride; D011237:Predictive Value of Tests; D058921:Purinergic P2Y Receptor Antagonists / Q000009:adverse effects*; D058925:Receptors, Purinergic P2Y12 / Q000097:blood / Q000187:drug effects; D012307:Risk Factors; D012720:Severity of Illness Index; D013876:Thiophenes / Q000009:adverse effects*; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives*; D013997:Time Factors; D016896:Treatment Outcome; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; C548576:P2RY12 protein, human; D010750:Phosphoproteins; D010879:Piperazines; D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D058925:Receptors, Purinergic P2Y12; D013876:Thiophenes; D000098662:Vasodilator-Stimulated Phosphoprotein; D000077144:Clopidogrel; D000068799:Prasugrel Hydrochloride; D013988:Ticlopidine; D001241:Aspirin