title: Clinical implications of thrombocytopenia among patients undergoing intra-aortic balloon pump counterpulsation in the coronary care unit.
abstract: BACKGROUND
  Thrombocytopenia Hypothesis: intra-aortic balloon pump (IABP)-associated thrombocytopenia is not associated with an increased risk of major bleeding or in-hospital death. Thrombocytopenia is a common adverse effect of the IABP. However, the clinical implications of IABP-associated thrombocytopenia are unknown.
  
  
  METHODS
  We assessed the incidence and predictors of thrombocytopenia, and the association between thrombocytopenia and relevant clinical end points, using prospectively collected data on 252 consecutive patients undergoing IABP in a single coronary care unit (CCU).
  
  
  RESULTS
  Anticoagulation with intravenous heparin was administered to 182 patients (72%). Baseline platelet counts were 232 000 +/- 96 000 mL, decreased to 154 000 +/- 74 000 mL at day 3, and recovered to baseline by day 8. Thrombocytopenia (nadir < 150 000 mL or > 50% reduction from baseline) occurred in 109 patients (43%), with a similar incidence among patients who received heparin and those who did not (45% vs 40%, P = 0.5). Independent predictors of thrombocytopenia were lower body weight, cardiogenic shock, and duration of IABP support. The incidence of both major bleeding and in-hospital death were higher among patients who developed thrombocytopenia than among those who did not (13.8% vs 4.2%, P = 0.01 and 28% vs 16%, P = 0.02, respectively). However, after controlling for confounding variables, thrombocytopenia was not an independent predictor of either major bleeding (odds ratio [OR]: 2.2, 95% confidence interval [CI]: 0.8-6.4, P = 0.1) or in-hospital death (OR: 1.5, 95% CI: 0.8-2.9, P = 0.3).
  
  
  CONCLUSIONS
  Among patients undergoing IABP in the CCU, thrombocytopenia is generally mild, appears to be unrelated to concomitant heparin use, and is not associated with an increased risk of major bleeding or in-hospital death.
authors.affiliation: Department of Medicine, Georgetown University Hospital, Washington, DC 20010, USA.
authors.forename: Sion K
authors.initials: SK
authors.lastname: Roy
authors.forename: Edward W
authors.initials: EW
authors.lastname: Howard
authors.forename: Julio A
authors.initials: JA
authors.lastname: Panza
authors.forename: Howard A
authors.initials: HA
authors.lastname: Cooper
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D001835:Body Weight; D016001:Confidence Intervals; D003325:Coronary Care Units; D004219:District of Columbia / Q000453:epidemiology; D005260:Female; D006493:Heparin / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D007423:Intra-Aortic Balloon Pumping / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010976:Platelet Count; D019106:Postoperative Hemorrhage / Q000209:etiology; D011446:Prospective Studies; D012307:Risk Factors; D013921:Thrombocytopenia / Q000453:epidemiology / Q000209:etiology* / Q000401:mortality
chemical_list: D000925:Anticoagulants; D006493:Heparin