title: Platelet reactivity during ticagrelor maintenance therapy: a patient-level data meta-analysis.
abstract: BACKGROUND
  Factors associated with platelet reactivity (PR) during ticagrelor maintenance dose (MD) are not well defined. We aimed to examine factors that influence levels of PR during chronic ticagrelor therapy.
  
  
  METHODS
  We performed individual participant data meta-analysis of 445 patients from 8 studies who had PR assessment with the VerifyNow P2Y12 assay (Accumetrics, Inc, San Diego, CA) while on ticagrelor 90 mg twice a day MD for at least 14 days.
  
  
  RESULTS
  Distribution of PR during ticagrelor MD was highly skewed toward lower values. No case of high PR (≥230 P2Y12 reaction units [PRU]) was observed. Age and body mass index (BMI) positively affected PR, with every increase in decade and 5 units of BMI resulting in 7.9% and 4.1% increase in PR, respectively. Current smoking status negatively affected PR with 13.7% decrease in PR in current smokers, compared with nonsmokers. Low PR (LPR) was defined as the lowest quartile of PR values (<10 PRU). In multivariate analysis, diabetes mellitus and age >70 years were independently associated with lower probability for LPR with a relative risk (95% CIs) of 0.570 (0.361-0.899) and 0.554 (0.325-0.944), P = .016 and P = .030, respectively.
  
  
  CONCLUSIONS
  Age, BMI, and current smoking status affect PR during ticagrelor MD. Diabetes mellitus and age >70 years were found to be associated with lower probability for LPR. Further research is required to assess the clinical implications of these findings in ticagrelor-treated patients.
authors.affiliation: Patras University Hospital, Patras, Greece. Electronic address: dalex@med.upatras.gr.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Alexopoulos
authors.affiliation: Patras University Hospital, Patras, Greece.
authors.forename: Ioanna
authors.initials: I
authors.lastname: Xanthopoulou
authors.affiliation: University of Sheffield, Sheffield, United Kingdom.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Storey
authors.affiliation: Sinai Center for Thrombosis Research, Baltimore, MD.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Bliden
authors.affiliation: Sinai Center for Thrombosis Research, Baltimore, MD.
authors.forename: Udaya S
authors.initials: US
authors.lastname: Tantry
authors.affiliation: University of Florida College of Medicine, Jacksonville, Jacksonville, FL.
authors.forename: Dominick J
authors.initials: DJ
authors.lastname: Angiolillo
authors.affiliation: Sinai Center for Thrombosis Research, Baltimore, MD.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gurbel
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000188:drug therapy*; D000241:Adenosine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects*; D006801:Humans; D015539:Platelet Activation / Q000187:drug effects*; D010979:Platelet Function Tests; D058921:Purinergic P2Y Receptor Antagonists / Q000627:therapeutic use; D000077486:Ticagrelor; D016896:Treatment Outcome
chemical_list: D058921:Purinergic P2Y Receptor Antagonists; D000077486:Ticagrelor; D000241:Adenosine