PURPOSE: To evaluate frequency and clinical variable associated with heparin-induced-thrombocytopenia.To evaluate treatment outcome of heparin-induced-thrombocytopenia patients treated with direct thrombin inhibitors.
METHODS: Retrospective chart analysis on patients suspected of having HIT over 3-years.Included patients’ charts were reviewed for demographics,thrombotic events,calculation of 4T score,GFR,mortality,platelet normalization and hematology/oncology consultations.The data were compared between HIT ELISA positive&negative as well as those who were treated or not treated with Argatroban.
RESULTS: Total of 288 patients were included in our study. 15.6% were HIT ELIZA positive (HIT+). Average 4T score was higher in HIT+ as compared to HIT ELISA negative (HIT-)(4.3 vs. 3.7, p=0.036). HIT+ had higher thrombotic event as compared to HIT- (31.1% vs.13.9%, p=0.004). At the cut off value of 4, 4T score had sensitivity of 68.8, specificity of 44, positive predictive value of 18.56 and negative predictive value of 88.43 to predict HIT ELISA positivity. There was no statistical significance in mortality between HIT+ and HIT- group. Amongst HIT+ patients, ten patients were treated with Argatroban (HIT+ARG+)(N=10, 22.2%). HIT+ARG+ had more females (90%, p=0.004), higher 4T score (5.7 vs. 3.9, p=0.029) and higher documented thrombotic events (70% vs. 20%, p=0.0053). Amongst HIT- group, nine patients were treated with Argatroban (HIT-ARG+, N==9, 3.7%). HIT-ARG+ patients had higher 4T score (5.7 vs.3.6, p=0.0003) and higher documented thrombotic events (77.8% vs.11.2%, p=<0.0001). There was no statistical difference in terms of mortality and platelet normalization in Argatroban treated or not treated patients in both HIT+ and HIT- groups
CONCLUSIONS: Heparin induced thrombocytopenia proven by ELIZA comprises of a relatively small number of patients suspected of having HIT(prevalence 15.6). 4T score with the cutoff point of 4 has high negative predictive value. Those who were HIT ELISA positive had higher 4T score and higher thrombotic events. Those who were treated with Argatroban, had higher 4T score and high number of documented thrombotic events. There was no statistical difference in terms of mortality and platelet normalization in Argatroban treated and not treated patients in both HIT+ and HIT- groups.
CLINICAL IMPLICATIONS: The use of 4T-score can potentially serve to exclude the diagnosis of ELIZA positive HIT. Treatment of HIT positive patients did not result in better normalization of platelet function or mortality.
DISCLOSURE: The following authors have nothing to disclose: Amitkumar Mehta, Sachin Gupta, Francis Bustos, Aria Jamshidi, Muhammad Shibli
No Product/Research Disclosure Information