D. Sharma1, L. Sadri1, A. Rogers1, G. Filosa1, Q. Yan1, R. Shadis1, R. Josloff1, T. Vu1 1Abington Memorial Hospital,Abington, PA, USA
Introduction: Elderly patients (>65 years) often present to the trauma bay on anticoagulants with an elevated INR. Among these patients, traumatic brain injury (TBI) is a common mechanism of injury. We aim to investigate if elderly patients presenting with supratherapeutic INRs have increased mortality compared to those with therapeutic and subtherapeutic INRs after blunt trauma. For patients with TBI, we will also determine if a supratherapeutic INR has higher risk of mortality.
Methods: A retrospective chart review was performed for patients on the trauma service from 2010 to 2015 at Abington Jefferson Hospital, a level 2 trauma center. Elderly patients on anticoagulation with blunt traumatic injury were divided into three cohorts based on INR: subtherapeutic (< 2.0), therapeutic (2.0-3.5), and supratherapeutic INR (>3.5). The primary outcome of mortality and relative risk (RR) was determined for each group, with the therapeutic group serving as the control. The data was then stratified by mechanism of injury (TBI versus other polytrauma) and mortality and relative risk was reported by INR cohorts.
Results:
Seven hundred and forty-seven patients were included. In this group, 189 patients were subtherapeutic (25%), 440 were therapeutic (59%), and 118 were supratherapeutic (16%). There was no statistically significant difference in mortality rates between the subtherapeutic group and therapeutic group (RR: 0.58; 95% CI: 0.24-1.40; P = 0.23). However, compared to the therapeutic group, the supratherapeutic group had a statistically significant increase in mortality (RR: 2.18; 95% CI: 1.16-4.07; P= 0.015).
Of the 220 patients with TBI, the mortality of the subtherapeutic (N = 53), therapeutic (N = 123) and supratherapeutic group (N = 26) was 1.9%, 12.2% and 46.2%, respectively. The RR of death of the subtherapeutic group compared to therapeutic group was 0.15 and not statistically significant (95% CI: 0.02-1.14; P = 0.067). However, compared to the therapeutic group, the supratherapeutic group had a significantly higher risk of mortality (RR: 3.78; 95% CI: 2.02-7.11; P < 0.0001).
Of 545 patients without TBI, the mortality of the subtherapeutic (N = 136), therapeutic (N = 317) and supratherapeutic groups (N = 92) were 3.7%, 2.8% and 2.2%, respectively. Compared to the therapeutic group, the RR of death was not statistically significant for the subtherapeutic (p=0.64) or supratherapeutic group (P = 0.73).
Conclusion: Elderly trauma patients with supratherapeutic INRs have a significantly higher risk of death during hospitalization than those with therapeutic or subtherapeutic INRs. Furthermore, those with traumatic brain injury and supratherapeutic INRs also have a significantly higher risk of death. Therefore, elderly patients on anticoagulants with supratherapeutic INRs warrant purposeful and aggressive monitoring given the increased risk of mortality following blunt traumatic injury.