A simple, hospital-wide “avoid heparin” intervention dramatically cut the rate of suspected heparin-induced thrombocytopenia by 42%, that of positive ELISA screens for HIT by 63%, that of adjudicated HIT by 79%, and that of HIT with thrombosis by 91%, while also reducing the costs of HIT-related care by 83% at one large university hospital.
The medical literature has focused on early recognition and treatment of heparin-induced thrombocytopenia, “but its prevention has been largely overlooked,” noted Dr. Kelly E. McGowan of Sunnybrook Health Sciences Centre and the University of Toronto and her associates.
Sunnybrook introduced an “avoid heparin” program in 2006 in which most intravenous and subcutaneous unfractionated heparin was replaced with low-molecular-weight heparin (LMWH) in prophylactic or therapeutic doses; heparinized saline in arterial and central venous lines was replaced with saline flushes; order sets were modified to exclude unfractionated heparin options; and unfractionated heparin stores were removed from most nursing units.
Unfractionated heparin remained available for use in hemodialysis, cardiovascular surgery, and certain cases of acute coronary syndrome. Most hospital clinicians were unaware that LMWH was being substituted for unfractionated heparin, and none were aware that the effects of this change were being studied.
The investigators assessed all 1,118 cases of suspected heparin-induced thrombocytopenia that occurred during a 10-year period before and after this intervention was implemented. The use of LMWH rose fourfold after the program was initiated, but the annual rate of HIT associated with LMWH remained constant at 0.9 cases per 10,000 admissions over the course of the study.
The annual incidence of suspected HIT decreased from 85.5 per 10,000 admissions per year before the intervention to 49.0 afterward (relative risk reduction, 41.7%). The rate of positive ELISA screens for the disorder dropped from 16.5 to 6.1 per 10,000 (RRR, 62.9%), the rate of adjudicated HIT decreased from 10.7 to 2.2 per 10,000, and the rate of HIT with thrombosis declined from 4.6 to 0.4 per 10,000.
The program’s greatest impact was on cardiac surgery, but the burden of HIT also markedly decreased in other surgical and medical patients. HIT decreased by 77% in cardiovascular surgeries, 77% in other surgeries, 75% in cardiology patients, and 62% in medical patients, Dr. McGowan and her associates said (Blood 2016 Apr 21;127[16]:1954-9).
Patients with HIT during the preintervention years more often developed thrombosis (43%), usually venous thromboembolism, compared with those who had HIT in the postintervention years (19%), and median length of stay declined accordingly. The average estimated costs of HIT care per year dropped by about $267,000 dollars per year, from $322,000 before the program was implemented to $55,000 afterward.
The investigators added that this is the first study ever to show the success of an HIT prevention strategy. Their findings indicate that a hospital-wide “avoid heparin” program can substantially reduce morbidity, mortality, and costs associated with HIT. “The heparin avoidance strategy that we used was not complex or costly and would be feasible in other centers,” they noted.