Abstract 12955: Heparin Induced Thrombocytopenia (HIT) in Cardiac Surgery May Be Associated to Constant Exposure Rather Than Occasional Previous Administration: A Single Center Study
BACKGROUND: Heparin-induced thrombocytopenia (HIT) is an immune-mediated, life-threatening, complication of heparin therapy, occurring in about 2% of patients undergoing cardiac surgery. These patients receive large doses of unfractionated heparin intraoperatively and may receive heparin for other reasons perioperatively. No definitive study, however, explains how heparin exposure triggers heparin-dependent antibodies to induce platelet aggregation. We investigated various risk factors that predispose these patients to HIT.
METHODS: We retrospectively reviewed all adult cardiac surgery patients at our institution since the induction of HIT data in the STS database, in 2011. Patients with HIT (+ve PF4-antibodies) were compared to NON HIT based on previous exposure (i.e. hemodialysis, redo cardiac surgery, unrelated heparin therapy), type of procedure, length of stay (LOS), and mortality. Age, LOS, and categorical data were compared with the unpaired t-test, Mann-Whitney U, and χ2 test, respectively.
RESULTS: Out of 2507 (1586M/921F) patients, 23 (1%) developed HIT. Redo procedures (p= 0.060) or previous unrelated heparin treatment (p=0.919) did not increase the incidence of HIT. However, the incidence of HIT was clearly higher for dialysis vs non-dialysis patients (5.7% vs 0.8%, p<0.001). Interestingly, the incidence of HIT was lower in isolated CABG, isolated valve, or combined CABG/valve (0%, 0.5%, 0.6%) vs other cardiac procedures (1.6%, p=0.006). HIT patients had longer LOS (22 vs 8 days, p<0.001), younger age (54 vs 64 years, p=0.01), higher perioperative (30.4 vs 7.2%, p<0.001) and overall mortality (39.1 vs 10.8%, p<0.001).
CONCLUSIONS: Chronic heparin exposure (i.e. hemodialysis) is associated with higher risk of HIT than occasional administration (i.e. redo cardiac surgery or unrelated treatment) in cardiac surgery patients. The incidence of HIT is still associated with prolonged LOS and higher mortality.
Author Disclosures: M. Janjua: None. T. Burmeister: None. J.M. Bell: None. A.J. Zhang: None. R.B. Schuessler: None. J.S. Lawton: None. R.J. Damiano: None. S. Schena: None.
- © 2014 by American Heart Association, Inc.