Impact of heparin-induced thrombocytopenia on postoperative outcomes after cardiac surgery.
BACKGROUND
The objectives of this study are to determine the effect of heparin-induced thrombocytopenia (HIT) on postoperative morbidity and mortality after cardiac surgery and to identify preoperative risk factors for HIT.


METHODS
From 2002 to 2005, 487 cardiac surgery patients with postoperative thrombocytopenia (50% drop in platelet count or absolute count < 100,000/muL) underwent at least one enzyme-linked immunosorbent assay for HIT platelet factor 4 antibodies. Risk factors and outcomes of patients with a positive HIT assay (HIT+) were compared with patients with thrombocytopenia, but without HIT antibodies (HIT-).


RESULTS
23.2% of patients (113 of 487) were HIT+. Multivariable predictors of HIT included previous percutaneous coronary interventions (odds ratio [OR] = 1.76, p = 0.03), class IV New York Heart Association heart failure (OR = 1.80, p = 0.012), and infectious endocarditis (OR = 3.66, p = 0.0123). Postoperative infections occurred more frequently in HIT+ patients, including sepsis (16.8% versus 9.9%, p = 0.0433) and pneumonia (46.9% versus 23.3 %, p < 0.001). The HIT+ patients also had a higher rate of renal failure requiring hemodialysis (23.0% versus 9.1%, p < 0.001) and acute limb ischemia (15.9% versus 4.3%, p < 0.001). Thirty-day mortality was significantly higher in the HIT+ group (24.8% versus 15.2%, p = 0.019). Postoperative HIT emerged as an independent predictor of renal failure (OR = 1.73, p < 0.001) and thromboembolic complications (OR = 2.39, p = 0.02).


CONCLUSIONS
Heparin-induced thrombocytopenia patients are at significantly greater risk of thrombosis, renal failure, and mortality in the postoperative setting. Greater awareness of this devastating problem may allow earlier detection of HIT, with prompt institution of appropriate anticoagulation therapy, which could potentially limit the associated morbidity and mortality.
Kerendi
Faraz
F
Clinical Research Unit, Division of Cardiothoracic Surgery, Joseph B. Whitehead Department of Surgery, Rollins School of Public Health, Emory University School of Medicine, Atlanta, Georgia, USA.
Thourani
Vinod H
VH
Puskas
John D
JD
Kilgo
Patrick D
PD
Osgood
Michael
M
Guyton
Robert A
RA
Lattouf
Omar M
OM
D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood; D000925:Anticoagulants / Q000009:adverse effects*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010978:Platelet Factor 4 / Q000276:immunology; D011183:Postoperative Complications / Q000209:etiology* / Q000401:mortality; D012372:ROC Curve; D012307:Risk Factors; D013921:Thrombocytopenia / Q000139:chemically induced*; D013927:Thrombosis / Q000209:etiology
D000906:Antibodies; D000925:Anticoagulants; D010978:Platelet Factor 4; D006493:Heparin