title: Long-term outcomes associated with hospital acquired thrombocytopenia among patients with non-ST-segment elevation acute coronary syndrome.
abstract: BACKGROUND
  Acquired thrombocytopenia after a non-ST-segment-elevation-acute coronary syndrome (NSTE-ACS) has been associated with increased in-hospital mortality and hemorrhagic complications, but longer term outcomes are unclear. We examined the association between thrombocytopenia and long-term outcomes after accounting for thrombocytopenia severity and discharge medication use.
  
  
  METHODS
  Data from 7,435 NSTE-ACS patients enrolled in the SYNERGY trial were analyzed. Severe thrombocytopenia was defined as a nadir platelet count <100 × 10(9)/L or a ≥ 50% drop from baseline. Mild thrombocytopenia was defined as a nadir platelet count between 100 and 149 × 10(9)/L with a <50% drop from baseline. The primary outcomes of interest were in-hospital GUSTO moderate-severe bleeding and 1-year mortality.
  
  
  RESULTS
  Overall, 675 patients (9.1%) developed mild thrombocytopenia and 139 patients (1.9%) developed severe thrombocytopenia. In-hospital bleeding risks were higher in patients with mild (7.7%, adjusted HR 1.63, 95% CI 1.16-2.29) or severe (28.2%, adjusted HR 6.93, 95% CI 4.55-10.56) thrombocytopenia than in patients without thrombocytopenia (5.2%). One-year mortality rates were 6.5%, 8.1%, and 28.1% among patients with no, mild, and severe thrombocytopenia, respectively (log rank P < 0.001) but only severe thrombocytopenia remained significantly associated with increased mortality after adjustment: HR 4.07, 95% CI 2.86-5.78. Patients who developed severe thrombocytopenia were less likely to be discharged on guideline-recommended antiplatelet therapy. The relationship between severe thrombocytopenia and mortality was attenuated by but persisted after adjusting for discharge medication use (HR 2.83, 95% CI 1.49-5.38).
  
  
  CONCLUSIONS
  Thrombocytopenia occurs commonly during the course of NSTE-ACS care; even mild decreases are associated with clinically meaningful bleeding. Patients who developed severe thrombocytopenia were less likely to be discharged on guideline-recommended antiplatelet therapy; this may contribute to their higher associated long-term mortality.
authors: Duke Clinical Research Institute, Durham, NC. Electronic address: a.vora@duke.edu.
authors: Amit N
authors: AN
authors: Vora
authors: Cleveland Clinic, Cleveland OH.
authors: Michael
authors: M
authors: Chenier
authors: Duke Clinical Research Institute, Durham, NC.
authors: Phillip J
authors: PJ
authors: Schulte
authors: Division of Cardiology, St Michael's Hospital, University of Toronto, and the Canadian Heart Research Centre, Toronto, Canada.
authors: Shaun
authors: S
authors: Goodman
authors: Duke Clinical Research Institute, Durham, NC.
authors: Eric D
authors: ED
authors: Peterson
authors: Duke Clinical Research Institute, Durham, NC.
authors: Karen
authors: K
authors: Pieper
authors: Montréal Heart Institute, Montréal, Québec, Canada.
authors: Marc E
authors: ME
authors: Jolicoeur
authors: Duke Clinical Research Institute, Durham, NC.
authors: Kenneth W
authors: KW
authors: Mahaffey
authors: Green Lane Cardiovascular Service, Auckland, New Zealand.
authors: Harvey
authors: H
authors: White
authors: Duke Clinical Research Institute, Durham, NC.
authors: Tracy Y
authors: TY
authors: Wang
mesh_terms: D054058:Acute Coronary Syndrome / Q000401:mortality*; D000368:Aged; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D010976:Platelet Count; D012720:Severity of Illness Index; D013921:Thrombocytopenia / Q000401:mortality*; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors