Taking the ‘HIT’ (Heparin-induced thrombocytopenia): Balancing Local Testing with Delayed Central Results

Abstract

Aims
To evaluate the frequency, turnaround time (TAT), and outcomes of Heparin-induced thrombocytopenia testing referrals from Cork University Hospital (CUH) and assess whether local specialised testing is justified.

Methods
Retrospective review of HIT referral forms and laboratory records (2021–2022). Data collected included demographics, referring specialty, platelet nadir, 4Ts score, HIT assay results, and TAT.

Results
Ninety-three patients were referred; 73 had complete data. Median TAT was 6 days (mean 31.9 days; adjusted mean 8.8 days after excluding six extreme outliers). Mean age was 66 years, 53% post-cardiothoracic surgery, mean 4Ts score 4.9. Three patients (4.1%) tested positive. Twenty-three (31.5%) had severe thrombocytopenia (<50 ×10⁹/L).

Conclusion
HIT testing referrals are frequent but delayed. Local in-house testing could improve patient safety, reduce unnecessary use of costly anticoagulants, and support timely clinical decision-making.