Frequency and analysis of hospital cases of heparin induced thrombocytopenia type 2 (HIT 2) in Germany

S. Wahler1, A. Müller2 (1Hamburg, Germany, 2München, Germany)

Platelets - Physiology and Disorders of platelet number and function
Date: 17.02.2017,
Time: 17:15 - 18:15

Objective: Heparin-induced thrombocytopenia (HIT) is a complication of heparin therapy. There are two types of HIT. Type 2 HIT is an immune-mediated disorder that typically occurs 4-10 days after exposure to heparin and may have life-threatening thrombotic complications. Treatment of HIT 2 consists of discontinuation of heparin and use of alternative anticoagulants. The prevalence of HIT in literature is reported to be 0.2 to 3.0% of heparin exposures. In Germany exist recommendations from the society of medical controllers how to code HIT 2 cases in hospital. Here we researched the frequency of coding of HIT 2 and with which other diagnoses HIT 2 is associated.

Methods: The reports from German DRG Institute (InEK), Statistical Office (DESTATIS) and the hospital quality reports for 2010-2014 were analyzed for cases of HIT 2. Statistical analysis was performed using Microsoft-Excel and Access version 2013.

Results: The annual number of cases with a main diagnosis of HIT 2 (D69.53, ICD10-GM) was in average 59 (±11) from 2005 to 2014 with a low 2014 with 39 cases. The mean age of patients did hardly change over the years (68.2 ±17.0 years in 2014) and the gender distribution (48% male). There were many more cases with a secondary diagnosis of HIT 2: 9.281 cases annually in average between 2005 and 2014, decreasing since 2010 with a low of 8.364 in 2014. Here the share of male patients is higher (58.2%). The female patients are older in average (69.5 y) than male patients (66.9 y). The HIT 2 cases are grouped with 38.4% into a cardiology DRG, followed by DRGs which include a more exensive ICU stay with 27.1%, thereafter follow urology (8.1%) and pulmonology (6.5%). Prevalence in hospital is 0.05% of all cases, which corresponds to 0.2% cases in the operative partition. HIT 2 cases were found to be relatively frequently ending in the error-group in the G-DRG system.

Conclusion: We found a decrease in documented hospital cases with HIT 2 from 2010 to 2014. The overall number is lower than the expected number of patients based on previously reported prevalence. About the reasons can only be hypothesized e.g. in terms of a better pre-surgery diagnostic. By far most cases of HIT 2 are associated with cardiac interventions, followed by urologic and thoracic surgery. Many cases end up in error-DRG which may be interpreted that HIT 2 is not perfectly reflected in the German DRG system.