Incidence and outcomes of heparin-induced thrombocytopenia in patients undergoing cardiac surgery in North America: an analysis of the nationwide inpatient sample.

OBJECTIVES

The objective of this study was to quantify the impact of heparin-induced thrombocytopenia (HIT) on outcomes after cardiac surgery.

DESIGN

Retrospective analysis of national database.

SETTING

United States hospitals.

PARTICIPANTS

Patients identified from 186,771 discharge records undergoing cardiac surgery from the Nationwide Inpatient Sample between 2009 and 2010.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN

RESULTS

Heparin-induced thrombocytopenia was diagnosed in 506 (0.3%), and secondary thrombocytopenia was diagnosed in 16,809 (8.7%). Operative mortality was 11.1% in patients with HIT compared to 4.5% for patients without thrombocytopenia (p<0.001) and 4.0% for patients with a diagnosis of secondary thrombocytopenia (p<0.001). After adjusting for baseline patient comorbidity, the strongest independent predictors of HIT in patients undergoing cardiac surgery were female gender (OR 1.4, 95% confidence interval [CI] 1.28-1.48), congestive heart failure (OR 1.8, 95% CI 1.71-1.98), cardiac insufficiency (OR 2.2, 95% CI 1.97-2.39), atrial fibrillation (OR 1.4, 95% CI 1.30-1.51), liver disease (OR 2.2, 95% CI 1.96-2.50), and chronic renal failure (OR 1.4, 95% CI 1.30-1.51). HIT was associated with significantly increased risk of major adverse postoperative outcomes including death (OR 1.5, 95% CI 1.3-1.7), stroke (OR 2.4, 95% CI 1.9-3.1), amputation (OR 7.46, 95% CI 4.0-14.0), and acute renal failure (OR 2.3, 95% CI 2.1-2.5), respiratory failure (OR 1.9, 95% CI 1.8-2.1), and need for tracheostomy (OR 2.7, 95% CI 2.3-3.1).

CONCLUSIONS

Heparin-induced thrombocytopenia is associated with a 50% increase in early mortality, and most patients with this diagnosis experience major postoperative morbidity or functional deficits.