title: Does Preoperative Platelet Function Predict Bleeding in Patients Undergoing Off Pump Coronary Artery Bypass Surgery?
abstract: OBJECTIVE
  We sought to examine the relationship between preoperative platelet function and perioperative bleeding in patients undergoing CABG.
  
  
  BACKGROUND
  There are many ways to measure platelet aggregability. Little is known about their correlations with one another, or with bleeding.
  
  
  METHODS
  We prospectively studied 50 patients undergoing a first isolated off-pump CABG. Thirty-four were exposed to a thienopyridine prior to surgery; 16 were not. Preoperative platelet function was measured by VerifyNow®, TEG®, AggreGuide™, Plateletworks®, vasodilator-stimulated phosphoprotein (VASP) phosphorylation, and light transmission aggregometry. Bleeding was assessed 2 ways: drop from pre- to nadir postoperative hematocrit, and chest tube drainage. Correlation coefficients were calculated using Spearman's rank-order correlation.
  
  
  RESULTS
  Mean age was 62 years. Patient characteristics and surgical details were similar between the thienopyridine-exposed and non-exposed patients. The correlation coefficients between the 4 point-of-care platelet function measurements and hematocrit change ranged from -0.2274 to 0.2882. Only Plateletworks® correlated with drop in hematocrit (r = 0.2882, P = 0.0470). The correlation coefficients between each of the 4 point-of-care platelet function tests and the chest tube drainage were also poor, ranging from -0.3073 to 0.2272. Both AggreGuide™ (r = -0.3073, P = 0.0317) and VASP (r = -0.3187, P = 0.0272) were weakly but significantly correlated with chest tube drainage. The correlation among the 4 point-of-care platelet function measurements was poor, with coefficients ranging from -0.2504 to 0.1968.
  
  
  CONCLUSIONS
  We observed little correlation among 4 platelet function tests, and between those assays and perioperative bleeding defined 2 different ways. Whether any of these assays should be used to guide decision making in individual patients is unclear.
authors.affiliation: Department of Cardiology, Geisinger Medical Center, Danville, Pennsylvania.|Cardiovascular Center for Clinical Research, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Berger
authors.affiliation: Center for Health Research, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: H Lester
authors.initials: HL
authors.lastname: Kirchner
authors.affiliation: Cardiovascular Center for Clinical Research, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Wagner
authors.affiliation: General Internal Medicine, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Ismail-Sayed
authors.affiliation: Siskiyou Pediatrics Clinic, Grants Pass, Oregon.
authors.forename: Salma
authors.initials: S
authors.lastname: Yahya
authors.affiliation: Department of Cardiothoracic Surgery, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Charles
authors.initials: C
authors.lastname: Benoit
authors.affiliation: Department of Cardiology, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: James C
authors.initials: JC
authors.lastname: Blankenship
authors.affiliation: Department of Cardiothoracic Surgery, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Russell
authors.initials: R
authors.lastname: Carter
authors.affiliation: Department of Cardiothoracic Surgery, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Alfred S
authors.initials: AS
authors.lastname: Casale
authors.affiliation: Department of Cardiology, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Sandy M
authors.initials: SM
authors.lastname: Green
authors.affiliation: Department of Cardiology, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Scott
authors.affiliation: Department of Cardiology, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Skelding
authors.affiliation: Department of Cardiothoracic Surgery, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Edward
authors.initials: E
authors.lastname: Woods
authors.affiliation: Cardiovascular Center for Clinical Research, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: Yvette M
authors.initials: YM
authors.lastname: Henry
mesh_terms: D000368:Aged; D001780:Blood Coagulation Tests; D016063:Blood Loss, Surgical; D015505:Chest Tubes; D047549:Coronary Artery Bypass, Off-Pump; D004322:Drainage; D005260:Female; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation; D019095:Point-of-Care Systems; D057234:Preoperative Period; D011446:Prospective Studies