To the Editor,
1.
We have read with great interest the paper “Characterization of hospitalized cardiovascular patients with suspected heparin‐induced thrombocytopenia” by Stoll et al1 and we found it very important with a view to clinical prevention.
The authors investigated if the 4T score, a validated score for prediction of heparin‐induced thrombocytopenia (HIT) in surgical patients, is also suitable for assessing HIT probability in cardiovascular patients with unclear thrombocytopenia. They found that the 4T score had a sensitivity of 82.6% and a specificity of 28.6% in their patients, suggesting that it might not sufficiently predict the clinical probability of HIT in cardiovascular patients. They also found that bacteremia was more frequent in patients with non‐confirmed HIT, suggesting infection as a frequent differential diagnosis of thrombocytopenia in these patients (49% vs 17%, P = 0.0185).
With reference to the finding reported in the paper, we would like to make the following contribution to the discussion. We retrospectively analyzed data from 600 post‐cardiac surgery patients in order to evaluate the incremental value of performing 4Ts Test and EuroSCORE test for prediction of heparin‐induced thrombocytopenia.2 Anti‐PF4/heparin antibodies were tested in all patients using a commercial immunoassay (Asserachrom H PF4 ELISA kits).3, 4, 5 Of the 600 patients investigated, 131 (21.8%) were found to have anti‐PF4/heparin antibodies in the post‐operative period (5‐7 days from surgery). The 4Ts score identified high probability patients that developed anti‐PF4/heparin antibodies and had a high number of thrombotic events.2 Among the several parameters analyzed bacteremia was similar in the two groups (P = n.s.) and was not associated with an increased risk of composite cardiovascular events (MACE).
We understand that our post‐cardiac surgery patients carry high risk for bacteremia and this could influence our results.3, 4, 5, 6
We agree with Stoll that further research is needed to specify the risk profile for HIT in different group of cardiovascular patients.
Informed consent was obtained from all individual participants included in the study.
CONFLICTS OF INTEREST
The authors declare no potential conflict of interests.
This letter is related to Stoll F, Gödde M, Leo A, Katus HA, Müller OJ. Characterization of hospitalized cardiovascular patients with suspected heparin‐induced thrombocytopenia. Clin Cardiol. 2018; doi: 10.1002/clc.23061 [Epub ahead of print].
REFERENCES
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