title: Association of immature platelets with adverse cardiovascular outcomes.
abstract: BACKGROUND
  Immature platelets are less responsive to the effects of antiplatelet drugs and contain messenger ribonucleic acid that is translationally active. They can be measured easily using an automated hematoanalyzer and reported as part of the complete blood count.
  
  
  OBJECTIVE
  The purpose of this study was to determine the prognostic significance of elevated immature platelet count (IPC) in patients with coronary artery disease (CAD).
  
  
  METHODS
  In this prospective cohort study in patients with CAD, patients underwent IPC measurement and were then followed up for the composite endpoint of major adverse cardiovascular events (MACE), defined as a composite of all-cause mortality, myocardial infarction, unplanned revascularization, or hospitalization for angina. For the purposes of analysis, patients were stratified into tertiles of IPC.
  
  
  RESULTS
  Eighty-nine patients were followed up for a median of 31 months. Stratification to the high IPC tertile was associated with higher rates of MACE compared with the intermediate and low tertiles (60% vs. 24% vs. 16%, respectively; p < 0.001). Time-dependent receiver-operating characteristic analysis revealed that an IPC level ≥7,632 platelets/μl was 70.7% sensitive and 82.1% specific for MACE. After adjustment for age, admission diagnosis, index revascularization, heart failure, smoking, hematocrit, and baseline platelet count, patients with an IPC level ≥7,632 platelets/μl were more likely to experience a MACE (hazard ratio: 4.65; 95% confidence interval: 1.78 to 12.16; p < 0.002).
  
  
  CONCLUSIONS
  IPC is a novel biomarker for MACE risk stratification in patients with CAD. Future studies should focus on the utilization of this marker for individualized antiplatelet therapy.
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas; Weill-Cornell Medical College, New York, New York.
authors.forename: Homam
authors.initials: H
authors.lastname: Ibrahim
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas; Weill-Cornell Medical College, New York, New York.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Schutt
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas; Weill-Cornell Medical College, New York, New York.
authors.forename: Bashar
authors.initials: B
authors.lastname: Hannawi
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas.
authors.forename: Timothy
authors.initials: T
authors.lastname: DeLao
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas; Weill-Cornell Medical College, New York, New York.
authors.forename: Colin M
authors.initials: CM
authors.lastname: Barker
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas; Weill-Cornell Medical College, New York, New York. Electronic address: nkleiman@houstonmethodist.org.
authors.forename: Neal S
authors.initials: NS
authors.lastname: Kleiman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000188:drug therapy; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology*; D010976:Platelet Count / Q000379:methods; D011446:Prospective Studies; D016037:Single-Blind Method; D016896:Treatment Outcome
keywords: Immature platelets; antiplatelet therapy; clinical outcomes; residual platelet reactivity