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

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.

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.

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).

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.