Joseph Lee, Gomes Marcelo P V, Al Solaiman Firas, St John Julie, Ozaki Asuka, Raju Manjunath, Dhariwal Manoj, Kim Esther S H
Esther S. H. Kim, MD, MPH, Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, 9500 Euclid Avenue/J3-5, Cleveland, OH 44195, USA, Tel.: +1 216 444 1680, Fax: +1 216 636 6958, E-mail:
Thromb Haemost. 2015 Mar;113(3):633-40. doi: 10.1160/TH14-05-0472. Epub 2015 Jan 15.
The diagnosis of heparin-induced thrombocytopenia (HIT) can be challenging. The HIT Expert Probability (HEP) Score has recently been proposed to aid in the diagnosis of HIT. We sought to externally and prospectively validate the HEP score. We prospectively assessed pre-test probability of HIT for 51 consecutive patients referred to our Consultative Service for evaluation of possible HIT between August 1, 2012 and February 1, 2013. Two Vascular Medicine fellows independently applied the 4T and HEP scores for each patient. Two independent HIT expert adjudicators rendered a diagnosis of HIT likely or unlikely. The median (interquartile range) of 4T and HEP scores were 4.5 (3.0, 6.0) and 5 (3.0, 8.5), respectively. There were no significant differences between area under receiver-operating characteristic curves of 4T and HEP scores against the gold standard, confirmed HIT [defined as positive serotonin release assay and positive anti-PF4/heparin ELISA] (0.74 vs 0.73, p = 0.97). HEP score ≥ 2 was 100 % sensitive and 16 % specific for determining the presence of confirmed HIT while a 4T score > 3 was 93 % sensitive and 35 % specific. In conclusion, the HEP and 4T scores are excellent screening pre-test probability models for HIT, however, in this prospective validation study, test characteristics for the diagnosis of HIT based on confirmatory laboratory testing and expert opinion are similar. Given the complexity of the HEP scoring model compared to that of the 4T score, further validation of the HEP score is warranted prior to widespread clinical acceptance.
肝素诱导的血小板减少症（HIT）的诊断可能具有挑战性。最近有人提出了HIT专家概率（HEP）评分来辅助HIT的诊断。我们试图对HEP评分进行外部前瞻性验证。我们前瞻性地评估了2012年8月1日至2013年2月1日期间连续转诊至我们咨询服务部门以评估可能的HIT的51例患者的HIT预测试概率。两名血管医学研究员分别对每位患者应用4T和HEP评分。两名独立的HIT专家裁决者做出了HIT可能性大或不大的诊断。4T和HEP评分的中位数（四分位间距）分别为4.5（3.0，6.0）和5（3.0，8.5）。4T和HEP评分相对于金标准（定义为血清素释放试验阳性和抗PF4/肝素ELISA阳性）的受试者工作特征曲线下面积之间无显著差异（0.74对0.73，p = 0.97）。HEP评分≥2对确定确诊HIT的存在具有100%的敏感性和16%的特异性，而4T评分>3具有93%的敏感性和35%的特异性。总之，HEP和4T评分是用于HIT的优秀筛查预测试概率模型，然而，在这项前瞻性验证研究中，基于确证实验室检测和专家意见的HIT诊断测试特征相似。鉴于HEP评分模型与4T评分相比更为复杂，在广泛临床应用之前，有必要对HEP评分进行进一步验证。
