Serum Concentrations and Elimination Rates of Direct-Acting Oral Anticoagulants (DOACs) in Older Hip Fracture Patients Hospitalized for Surgery: A Pilot Study

Early surgical care of the anticoagulated hip fracture patient within 24 hours

INTRODUCTION

Hip fractures are still associated with high morbidity and mortality. Despite international guidelines advocating for urgent surgical treatment, delays often occur, particularly for patients on long-term antithrombotic therapy. We hypothesised that urgent surgical care for the anticoagulated hip fracture patient is not associated with severe bleeding complications.

MATERIAL AND METHODS

For the period from 2015 to 2021, we retrospectively reviewed clinical records of 1142 patients with proximal femur fractures treated within 24 h of admission to our trauma centre (mean age 80.4 ± 12.4 years; 761 females, 381 males). The cohort comprised 409 femoral neck and 733 trochanteric fractures, managed with either arthroplasty (n = 297), hip-preserving techniques (n = 147), or intramedullary nailing (n = 698). Of these, 583 patients (51.1 %) were on long-term antithrombotic therapy. The primary endpoints included transfusion rate and the difference in haemoglobin (Hb) levels from pre- to postoperative. Secondary endpoints were in-patient mortality and occurrence of postoperative haematomas requiring surgical revision. A regression analysis was performed.

RESULTS

The mean time to surgery was 10.3 h, with delays observed in patients on direct oral anticoagulants (DOACs). Overall, 25.9 % (n = 296) of the patients required blood transfusions. The transfusion rate was dependent on duration of the surgery, preoperative Hb level, and anticoagulation with DOACs. Similarly, the Hb difference was found to be dependent on the duration of surgery, preoperative Hb level, and anticoagulation with DOACs. In-patient mortality was 5.3 % (n = 60). Regression analysis indicated that mortality was dependent on a high ASA classification of 4 and the time to surgery, but not on the type of antithrombotic therapy. 3.1 % of the patients needed surgical revision due to postoperative haematoma with prolonged duration of surgery and antithrombotic therapy (PAI [OR = 3.7, 95 % CI: 1.1-12.7], DOACs [OR = 3.4, 95 % CI: 1.3-8.8], and VKA [OR = 5.5, 95 % CI: 1.8-17.1], p < 0.05) as independent risk factors.

CONCLUSION

As postoperative haematoma and the need for transfusion are manageable situations, we conclude that immediate surgical treatment of hip fracture patients on long-term antithrombotic therapy within 24 h is feasible and patients may benefit.

Perioperative Management of Traditional and Direct Oral Anticoagulants in Hip Fracture Patients

Hip fractures are an increasingly common injury in the senior population and almost always require surgical fixation or prosthetic replacement. These surgeries, according to the American Academy of Orthopaedic Surgeons, are considered high-risk for bleeding, especially in a population fraught with comorbidities and often presenting on anticoagulation medications. Direct oral anticoagulants represent a class of drugs that have been becoming more popular in use in this population, with many benefits over the historically used Warfarin. There are recommendations for preoperative discontinuation and postoperative resumption of these medications, which can be more readily managed for elective surgeries. However, there is a paucity of literature detailing best practice guidelines for the perioperative management of direct oral anticoagulants when a patient presents with a hip fracture. This review article summary of the periprocedural management of DOACs for hip surgery was developed by examining the American College of Chest Physicians evidence-based clinical practice guidelines, Perioperative Guidelines on Antiplatelet and Anticoagulant Agents written by anesthesiologists, various retrospective studies, and drug labels for pharmacokinetic data. These recommendations should be used as a guideline, along with the collaboration of multidisciplinary hospital teams during inpatient admission, to manage these complex patients.

Preoperative Drug Monitoring in Management of Patients with Hip Fracture on Treatment with Direct Oral Anticoagulants

Purpose

Aim of the present study was to evaluate whether monitoring direct oral anticoagulant (DOAC) levels may improve management of anticoagulated patients who need surgery for hip fracture.

Patients and Methods

A total of 147 out of 2231 (7.7%) patients with hip fracture admitted to a tertiary teaching hospital were on DOACs (group A), whereas 206 patients matched for age, sex, and type of fracture not on anticoagulant or P2Y12 platelet inhibitors were considered as control group (group B). Patients on DOACs were divided into two subgroups: A1 in which intervention was scheduled in relation to the last drug intake according to current guidelines, and A2 included patients in whom time of surgery (TTS) was defined according to DOAC levels. Neuraxial anesthesia was considered with DOAC levels <30 ng/mL, general anesthesia for levels in the range 30-50 ng/mL.

Results and conclusions

TTS was significantly lower in controls than in DOAC patients: surgery within 48 hours was performed in 80.6% of group B versus 51% in group A (p<0.0001). In A2, 41 patients underwent surgery within 48 hours (56%) in comparison to 32 A1 patients (45.1%; p=0.03). TTS and length of hospitalization were on average 1 day lower in patients with assay of DOAC levels. Finally, 35/39 (89%) patients with DOAC levels <50 ng/mL had surgery within 48 hours (26 under neuraxial anesthesia, without any neurological complication, and 13 in general anesthesia).

Conclusion

DOAC assay in patients with hip fracture may be useful for correct definition of time to surgery, particularly in patients who are candidates for neuraxial anesthesia. Two-thirds of patients with DOAC levels <50 ng/mL at 48 hours from last drug intake underwent uneventful neuraxial anesthesia, saving at least 24 hours in comparison to guidelines.

Management of patients with proximal femur fractures under DOACs

PURPOSE

In the past, preinjury direct oral anticoagulant (DOAC) intake has led to delays in time to surgery (TTS) in patients with proximal femur fractures and delays in surgery have been associated with impaired outcomes. Although healthcare institutions/federal committees have set rules for treatment within 24 h of injury, comprehensive guidelines for the perioperative management of these patients, in particular when on preinjury DOACs, are still lacking. This contribution aims to summarize the current evidence on the safe time window for surgery in patients with proximal femur fractures on preinjury DOACs and to outline therapeutic options if emergency DOAC reversal becomes necessary.

METHODS

Narrative review based upon selective review of the pertinent literature.

RESULTS

For the majority of patients with proximal femur fractures and on preinjury DOACs, early surgery appears safe as soon as medical clearance has been obtained. There may be an increase in the need for blood products but with data not yet conclusive. Work-up including assessment of remaining anticoagulant activity and potential reversal should be restricted to patients at risk for bleeding complications, in particular in the presence of renal/hepatic impairment. Methodology for rapid assessment of DOACs including quantitative/qualitative concentration levels is work in progress. In the case of bleeding, rapidly acting reversal agents are available.

CONCLUSION

Preinjury DOAC use should not routinely delay surgery in patients with proximal femur fractures.

Frailty as a Marker for the Plasma Concentrations of Direct Oral Anticoagulants in Older Patients: Results of an Exploratory Study

BACKGROUND

Frailty makes older adults vulnerable to adverse health outcomes and can modify pharmacokinetics and drug exposure.

OBJECTIVE

We aimed to explore the relationship between different frailty assessments and trough plasma concentrations of direct oral anticoagulants in older patients.

METHODS

The frailty status of adults aged ≥ 70 years receiving regular direct oral anticoagulant medication was assessed by four different instruments: Fried physical phenotype, Rockwood frailty index, Short Physical Performance Battery, and FRAIL scale. The two performance measures "slow gait speed" and "weak grip strength" were used to build a separate score depending on the number of positive criteria (none, one, two). For each participant, a single steady-state direct oral anticoagulant trough plasma concentration was collected, dose-normalized, and its relationship to the various frailty assessments analyzed.

RESULTS

Forty-two participants completed the study, with most using apixaban (n = 22). Dose-normalized apixaban trough concentrations were 2.48-fold higher in frail participants (Fried phenotype) than in robust participants (p = 0.009) and correlated positively with Fried physical phenotype (r_s = 0.535, p = 0.010) and negatively with Short Physical Performance Battery (r_s = - 0.434, p = 0.044). Compared with participants who met none of the criteria "slow gait speed" and "weak grip strength", apixaban trough concentrations were approximately 1.9-fold higher in participants who were positive for one (p = 0.018) or two (p = 0.013) of these measures.

CONCLUSIONS

In this exploratory study, higher levels of frailty on performance-based frailty assessments were associated with higher apixaban exposure in older adults.

CLINICAL TRIAL REGISTRATION

German Clinical Trials Register DRKS00016741; registered 20 February, 2019.

Role of DOAC plasma concentration on perioperative blood loss and transfusion requirements in patients with hip fractures

BACKGROUND

There is an ever-increasing number of hip fracture (HF) patients on direct oral anticoagulants (DOAC). The impact of DOAC plasma level prior to HF surgery on perioperative blood loss and transfusion requirements has not been investigated so far.

MATERIALS AND METHODS

In this retrospective study of HF patients on DOACs admitted to the AUVA Trauma Center Salzburg between February 2015 and December 2021. DOAC plasma levels were analysed prior to surgery. Patients were categorized into four DOAC groups: Group A < 30 ng/mL, Group B 30-49 ng/mL, Group C 50-79 ng/mL, and Group D ≥ 80 ng/mL. Haemoglobin concentration was measured upon admission, prior to surgery, after ICU/IMC admission, and on day 1 and 2 post-surgery. Difference in the blood loss via drains, transfusion requirements and time to surgery were compared.

RESULTS

A total of 155 subjects fulfilled the predefined inclusion criteria. The median age of the predominantly female patients was 86 (80-90) years. Haemoglobin concentration in Group D was lower upon admissions but did not reach statistical significance. The decrease in haemoglobin concentration over the entire observation time was comparable between groups. Blood transfusion requirements were significantly higher in Group D compared to Group A and B (p = 0.0043). Time to surgery, intra- and postoperative blood loss via drains were not different among groups.

CONCLUSION

No strong association between the DOAC plasma levels and perioperative blood loss was detected. Higher transfusion rates in patients with DOAC levels ≥ 80 ng/mL were primarily related to lower admission haemoglobin levels. DOAC concentration measurement is feasible and expedites time to surgery.

Early Surgical Care of Anticoagulated Hip Fracture Patients Is Feasible-A Retrospective Chart Review of Hip Fracture Patients Treated with Hip Arthroplasty within 24 Hours

Anticoagulative medication such as antiplatelet drugs (PAI, acetylsalicylic acid and direct platelet aggregation inhibitors), vitamin-K-antagonist Warfarin (VKA) or direct oral anticoagulants (DOAC) are common among hip fracture patients, and the perioperative management of these patients is a rising challenge in orthopaedic trauma. Our objective was to determine the effect of oral anticoagulation in patients receiving early endoprosthetic treatment within 24 h after their admission. For the period from 2016 to 2020, a retrospective chart review of 221 patients (mean age 83 ± 7 years; 161 women and 60 men) who were treated either with hemi- (n = 209) or total hip arthroplasty (n = 12) within 24 h after their admission was performed. We identified 68 patients who took PAI, 34 who took DOAC and 9 who took VKA medications. The primary outcome measures were the transfusion rate and the pre- and postoperative haemoglobin (Hb) difference. The secondary outcome measures were the in-patient mortality and the rate of postoperative haematomas that needed operative treatment. A logistic/ordinal regression was performed considering the related variables to prevent cofounding occurring. The mean time to surgery was significantly longer for the DOAC and VKA groups when they were compared to the controls (none 14.7 ± 7.0 h; PAI 12.9 ± 6.7 h; DOAC 18.6 ± 6.3 h; VKA 19.4 ± 5.5 h; p < 0.05). There was no difference in the preoperative Hb level between the groups. Overall, 62 patients (28%) needed blood transfusions during the in-patient stay with an ASA classification (p = 0.022), but the type of anticoagulative medication was not a significant predictor in the logistic regression. Anticoagulation with DOAC and grouped surgery times were positive predictors for a higher Hb difference in the patients who did not undergo an intraoperative blood transfusion (n = 159). Postoperative haematomas only occurred in patients taking anticoagulative medication (four cases in PAI group, and three cases in DOAC group), but the logistic regression showed that the anticoagulative medication had no effect. The in-patient mortality was significantly influenced by a high ASA grade (p = 0.008), but not by the type of anticoagulative medication in patients who were treated within 24 h. We conclude that the early endoprosthetic treatment of the anticoagulated hip fracture patient is safe, and a delayed surgical treatment is no longer justifiable.

Synthesis of the evidence on the impact of pre-operative direct oral anticoagulants on patient health outcomes after hip fracture surgery: rapid systematic review

PURPOSE

To synthesise the evidence on the impact of pre-operative direct oral anticoagulants (DOACs) on health outcomes for patients who sustain a hip fracture.

METHOD

A rapid systematic review of three databases (MEDLINE, Embase and Scopus) for English-language articles from January 2000 to August 2021 was conducted. Abstracts and full text were screened by two reviewers and articles were critically appraised. Data synthesis was undertaken to summarise health outcomes examined for DOAC users versus a no anticoagulant group. Key information was extracted for study type, country and time frame, population and sample size, type of DOACs, comparator population(s), key definitions, health outcome(s), and summary study findings.

RESULTS

There were 21 articles identified. Of the 18 studies that examined time to surgery, 12 (57.1%) found DOAC users had a longer time to surgery than individuals not using anticoagulants. Five (83.3%) of six studies identified that DOAC users had a lower proportion of surgery conducted within 48 h Four (40.0%) of ten studies reporting hospital length of stay (LOS) identified a higher LOS for DOAC users. Where reported, DOAC users did not have increased mortality, blood loss, transfusion rates, complication rates of stroke, re-operation or readmissions compared to individuals not using anticoagulants.

CONCLUSIONS

The effect of DOAC use on hip fracture patient health was mixed, although patients on DOACs had a longer time to surgery. The review highlights the need for consistent measurement of health outcomes in patients with a hip fracture to determine the most appropriate management of patients with a hip fracture taking DOACs.

Reversal of direct oral anticoagulants in adult hip fracture patients. A systematic review and meta-analysis

BACKGROUND

Increasing numbers of patients are taking Direct Oral Anticoagulants at the time of hip fracture. Evidence is limited on how and if the effects of DOAC's should be reversed before surgical fixation. Wide variations in practice exist. We conducted a systematic review to investigate outcomes for three reversal strategies. These were: "watch and wait" (also referred to as "time-reversal"), plasma product reversal and reversal with specific antidotes.

METHODS

A systematic search was conducted using multiple databases. Results were obtained for studies directly comparing different DOAC reversal strategies in hip fracture patients and for studies comparing DOAC-taking hip fracture patients (including patients "reversed" using any method and "non-reversed" patients) against matched controls taking either a vitamin-K antagonist or not receiving anticoagulation therapy. This allowed construction of a network meta-analysis to indirectly compare outcomes between "reversed" and "non-reversed" DOAC patients. With respect to "watch and wait"/"time-reversal", a cut-off time to surgery of 36 hours was used to distinguish between "time-reversed" and "non time-reversed" DOAC patients. The primary outcome was early/inpatient mortality, reported as Odds Ratios (OR).

RESULTS

No studies investigating plasma products or reversal agents specifically in hip fracture patients were obtained. Fourteen studies were suitable for analysis of "watch and wait"/"time- reversal". Two studies directly compared "time-reversed" and "non time-reversed" DOAC-taking hip fracture patients (58 "time-reversed", 62 "non time-reversed"). From 12 other studies we used indirect comparisons between "time-reversed" and "non time-reversed" DOAC patients (total, 357 "time-reversed", 282 "non time-reversed"). We found no statistically significant differences in mortality outcomes between "time-reversal" and "non time-reversal" (OR 1.48 [95%CI: 0.29-7.53]). We also did not find a statistically significant difference between "time reversal" and "non time-reversal" in terms of blood transfusion requirements (OR 1.16 [95% CI 0.42-3.23]). However, several authors described that surgical delay is associated with worse outcomes related to prolonged hospitalisation, and that operating within 36 hours is safe.

CONCLUSIONS

We suggested against "watch and wait" to reverse the DOAC effect in hip fractures. Further work is required to assess the optimal timing for surgery as well as the use of plasma products or specific antidotes in DOAC-taking hip fracture patients.

Pharmacokinetics of Direct Oral Anticoagulants in Emergency Situations: Results of the Prospective Observational RADOA-Registry

BACKGROUND

Direct oral anticoagulants (DOACs) are increasingly used worldwide. Little is known so far about their pharmacokinetics in emergency situations.

METHODS

A prospective, observational registry was performed to determine the clinical course in consecutive patients with major bleeding or urgent surgery treated with DOACs. In samples collected as part of routine care DOAC drug concentrations were measured using ultraperformance liquid chromatography-tandem mass spectrometry. Anticoagulant intensity at first presentation and drug half-life (t _1/2), tested in repeat samples, were evaluated.

RESULTS

A total of 140 patients were prospectively included. Pharmacokinetic data were available in 94% (132/140) of patients. Note that 67% (89/132) experienced life-threatening bleeding and 33% (43/132) needed an urgent surgery. For pharmacokinetic analysis a total of 605 blood samples was available. Median concentration on admission was 205 ng/mL for rivaroxaban and 108 ng/mL for apixaban. All treatment groups showed a high variation of drug concentrations at baseline. In rivaroxaban-treated patients t _½ was 17.3 hours (95% confidence interval [CI]: 15.4-19.7) without significant difference in both groups (major bleeding: t _½ 16.7 hours, 95% CI: 14.7-19.3; urgent surgery: t _½ 19.7 hours, 95% CI: 15.2-27.9; p = 0.292). In apixaban-treated patients t _½ was 25.0 hours (95% CI: 22.9-27.6) with a longer t _½ after urgent surgery (t _1/2: 30.8 hours; 95% CI: 26.9-36.4) compared with severe bleeding (t _1/2: 20.8 hours; 95% CI: 18.8-23.2; p < 0.001).

CONCLUSION

Emergency patients under DOAC treatment show a high variation of anticoagulant concentrations at baseline. Compared with rivaroxaban, apixaban showed a lower median concentration on admission and a longer t _½.

Management of ongoing direct anticoagulant treatment in patients with hip fracture

Aim of the present study was to investigate the effects of ongoing treatment with DOACs on time from trauma to surgery and on in-hospital clinical outcomes (blood losses, need for transfusion, mortality) in patients with hip fracture. Moreover we evaluated the adherence to current guidelines regarding the time from last drug intake and surgery. In this observational retrospective study clinical records of patients admitted for hip fracture from January 2016 to January 2019 were reviewed. 74 patients were in treatment with DOACs at hospital admission. Demographic data, comorbidities and functional status before trauma were retrieved. As control group we evaluated 206 patients not on anticoagulants matched for age, gender, type of fracture and ASA score. Time to surgery was significantly longer in patients treated with DOACs (3.6 + 2.7 vs. 2.15 ± 1.07 days, p < 0.0001) and treatment within 48 h was 47% vs. 80% in control group (p < 0.0001). The adherence to guidelines’ suggested time from last drug intake to surgery was 46%. Neither anticipation nor delay in surgery did result in increased mortality, length of stay or complication rates with the exception of larger perioperative blood loss (Hb levels < 8 g/dl) in DOACs patients (34% vs 9% p < 0.0001). Present results suggest that time to surgery is significantly longer in DOAC patients in comparison to controls and adherence to guidelines still limited.

Dual Antiplatelet Therapy and Surgical Timing in Geriatric Hip Fracture

OBJECTIVE

To determine how timing of surgery affects transfusion, major complications, and mortality in patients who sustain a geriatric hip fracture while taking dual antiplatelet therapy (DAPT; typically aspirin and clopidogrel).

DESIGN

Retrospective cohort study.

SETTING

University-affiliated Level 1 Trauma Center.

PATIENTS

Patients 65 years of age or older on DAPT with a geriatric hip fracture were investigated at a single institution between 2002 and 2017. Demographic and perioperative data were collected from patient records, institutional databases, and national hip fracture registry.

INTERVENTION

Fixation or arthroplasty.

MAIN OUTCOME MEASUREMENT

Transfusion, major complications, and 30-day mortality.

RESULTS

Of the 6724 patients sustaining a geriatric hip fracture, 122 patients were taking DAPT on admission. Timing of surgery did not influence transfused units (incidence rate ratio 1.00, 95% confidence interval: 0.87-1.15, P = 0.968) but did affect major complications (time modeled as quadratic term; odds ratios ranging from 0.20 to 7.91, ptime = 0.001, ptime*time<0.001) and 30-day mortality (odds ratio 1.32, 95% confidence interval: 1.03-1.68, P = 0.030).

CONCLUSION

Surgical delay does not change the need for transfusion of hip fracture patients on DAPT, but it is associated with increased probabilities of major complications and 30-day mortality.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Early Surgical Fixation for Hip Fractures in Patients Taking Direct Oral Anticoagulation: A Retrospective Cohort Study

Introduction:

Currently, evidence-based guidelines regarding delay to theatre for urgent surgical intervention in patients taking direct oral anticoagulants (DOACs) are lacking. Therefore, this study aims to investigate the effect of DOACs on patient outcomes receiving early (<48 hours) versus delayed (>48 hours) surgery for neck of femur fractures.

Methods:

A retrospective cohort study was conducted at a tertiary teaching hospital. Treatment groups were hip fracture patients taking DOACs on admission and receiving surgery in <48 hours (n = 17) and >48 hours (n = 11). A control cohort of hip fracture patients not taking DOACs (n = 56) was matched to the <48 hours treatment group for comparison. Patient demographics were recorded and key outcome measures included perioperative hemoglobin levels, transfusion rates, time to surgery, 90-day mortality, hematoma rates, and length of stay in hospital.

Results:

There was no significant difference in perioperative hemoglobin levels, transfusion rates, or hematoma between groups. Patients taking DOACs and receiving early surgery had significantly longer time to surgery compared to the non-DOAC control (32.21 ± 7.83 vs 25.98 ± 11.4, P = .01). No deaths were recorded in the early DOAC group at 90 days, compared to 4 (36%) in the late DOAC group (P = .04).

Discussion and Conclusions:

Our study suggests hip fracture patients taking DOACs on admission is not a reason to delay surgery. However, given the lack of literature in this area, further prospective research with larger patient numbers is required to definitively guide clinical practice.

Direct Oral Anticoagulants and Timing of Hip Fracture Surgery

Timely surgical intervention in hip fracture has been linked to improved outcomes. Direct Oral Anticoagulants (DOACs) are an emerging class of anticoagulants without evidence-based guidelines on surgical timing. This study aims to investigate how DOACs affect surgical timing and hence perioperative outcomes. A retrospective database/registry review was conducted for geriatric hip fracture patients aged 65 and over between 2011 and 2018. Primary outcome was 30-day mortality. Secondary outcomes included serious adverse events (SAE), transfusion and postoperative day (POD) 1 haemoglobin (Hb) levels. From a cohort of 3264 patients, 112 admitted subjects were taking DOACs; the annual proportion on DOACs increased over time. Mean time to surgery from last dose (T_s) was 2.2 (±1.0 SD) days. The primary outcome, 30-day mortality, occurred in 16 (14%) patients with secondary outcomes of SAEs in 25 (22%) patients and transfusion in 30 (27%) patients. T_s (days) did not significantly affect 30-day mortality (odds ratio (OR): 1.37, 95% confidence interval (CI): 0.80–2.33; p = 0.248), SAE (hazard ratio (HR): 1.03, 95% CI: 0.70–1.52; p = 0.885), transfusion (OR: 0.72 95% CI: 0.45 to 1.16; p = 0.177) or POD 1 Hb (OR: 1.99, 95% CI: −0.59 to 4.57; p = 0.129). Timing of surgery does not influence common surgical outcomes such as 30-day mortality, SAE, transfusion, and POD1 Hb in patients taking DOACs on admission.

A New Test for the Detection of Direct Oral Anticoagulants (Rivaroxaban and Apixaban) in the Emergency Room Setting

Determining whether a patient has taken a direct oral anticoagulant (DOAC) is critical during the periprocedural and preoperative period in the emergency department. However, the inaccessibility of complete medical records, along with the generally inconsistent sensitivity of conventional coagulation tests to these drugs, complicates clinical decision making and puts patients at risk of uncontrollable bleeding. In this study, we evaluate the utility of inhibitor-II-X (i-II-X), a novel, microfluidics-based diagnostic assay for the detection and identification of Factor Xa inhibitors (FXa-Is) in an acute care setting.

DESIGN

First-in-human, 91-patient, single-center retrospective pilot study.

SETTING

Emergency room.

PATIENTS

Adult patients admitted into the emergency department, which received any clinician-ordered coagulation test requiring a 3.2% buffered sodium citrate blood collection tube.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma samples from patients admitted to the emergency department were screened for the use of FXa-Is, including apixaban and rivaroxaban, within the past 24 hours using our new i-II-X microfluidic test. i-II-X results were then compared with results from conventional coagulation tests, including prothrombin time (PT) and international normalized ratio (INR), which were ordered by treating clinicians, and an anti-Xa assay for rivaroxaban. The i-II-X test detected DOACs in samples collected from the emergency department with 95.20% sensitivity and 100.00% specificity. Unlike PT and INR, i-II-X reliably identified patients who had prolonged clotting times secondary to the presence of a FXa-I.

CONCLUSIONS

The i-II-X test overcomes the limitations of currently available coagulation tests and could be a useful tool by which to routinely screen patients for DOACs in emergency and critical care settings. Our new diagnostic approach is particularly relevant in clinical situations where medical records may be unavailable, or where precautions need to be taken prior to invasive interventions, such as specific reversal agent administration.