Periprocedural warfarin reversal with prothrombin complex concentrate

Urgent procedures or surgeries in patients receiving oral anticoagulants: a systematic literature review

There are limited data about the frequency of urgent surgical emergencies among patients receiving oral anticoagulants (OACs). We conducted a systematic literature review of Medline and EMBASE for published English-language articles of adult patients receiving oral anticoagulant treatment (vitamin K antagonists, apixaban, dabigatran, edoxaban, rivaroxaban) that reported on patients experiencing unplanned emergent or urgent surgery/procedure or trauma. Randomized trials, observational studies, and case series (50-100 cases) were included. The primary outcome was the frequency of unplanned urgent surgery or invasive procedures among OAC-treated patients with a focus on those not precipitated by the presence of major bleeding. The protocol was not registered. Funding was provided by Covis Pharmaceuticals. The search yielded 1367 potential studies of which 34 were included in the final review. One study reported the rate of urgent surgery/procedures among a large cohort of patients treated with dabigatran or warfarin for atrial fibrillation (~ 1% per year). Another study reported the rate of bleeding or urgent surgery among OAC-treated patients experiencing a fracture or trauma (0.489% per patient-year). The remaining 32 studies were cohorts of OAC-treated patients who received reversal or hemostatic therapies for major bleeding or urgent surgery. A median of 28.8% of these patients underwent surgery or invasive procedure. Urgent surgery appears to be a common, yet understudied complication during OAC treatment potentially associated with high rates of adverse outcomes. With increased eligibility for OACs, future studies evaluating the management and outcomes in this setting are needed.

Safety and efficacy of a strategy of vitamin K antagonist reversal with prothrombin complex concentrates compared to vitamin K in patients with hip fracture

Background:

Increased preoperative delay in patients with hip fractures may be responsible for increased morbidity and mortality. We hypothesized that a strategy of reversal of vitamin K antagonist (VKA) by prothrombin complexes concentrates (PCCs), as compared to vitamin K, is safe and reduces preoperative delay and hospital length of stay (LOS).

Methods:

In this pilot study, we reviewed the records of patients admitted to a university-affiliated hospital for hip fracture between Jan. 1, 2012, and Dec. 31, 2016, who were taking VKA. Patients were stratified according to reversal strategy (vitamin K v. PCC). Adverse effects, time to surgery, LOS and mortality were collected from the electronic medical record and were compared between the 2 study groups and a control group not treated with VKA.

Results:

A total of 141 patients were included in the study: 65 in the vitamin K group, 26 in the PCC group and 50 in the control group. The median preoperative delay in the PCC group (20 h [interquartile range (IQR)] 13–25 h]) and the control group (20 h [IQR 15–33 h]) was lower than that in the vitamin K group (45 h [IQR 31–52 h]) (p < 0.001). Patients in the PCC group had a shorter median hospital LOS than those in the vitamin K group (6 d [IQR 4–9 d] v. 8 d [IQR 6–11 d], p < 0.05). No difference was observed in the proportion of patients who received a red blood cell transfusion, or had thrombotic or hemorrhagic complications. No difference in mortality at 12 months was observed between the groups.

Conclusion:

In patients with hip fracture, the use of PCCs as compared to vitamin K to reverse the effect of VKA significantly reduced preoperative delay and hospital LOS, and was not associated with an increase in the rates of thrombotic or hemorrhagic complications. Prospective studies involving a greater number of patients are required to confirm these promising results.

Partial warfarin reversal prior to hip fracture surgical intervention in geriatric trauma patients effects on blood loss and transfusions

BACKGROUND

Warfarin reversal is typically sought prior to surgery for geriatric hip fractures; however, patients often proceed to surgery with partial warfarin reversal. The effect of partial reversal (defined as having an international normalized ratio [INR] > 1.5) remains unclear.

METHODS

This was a retrospective cohort study. Geriatric patients (≥65 y/o) admitted to six level I trauma centers from 01/2014-01/2018 with isolated hip fractures requiring surgery who were taking warfarin pre-injury were included. Warfarin reversal methods included: vitamin K, factor VIIa, (a)PCC, fresh frozen plasma (FFP), and the "wait and watch" method. An INR of ≤ 1.5 defined complete reversal. The primary outcome was the volume of blood loss during surgery; other outcomes included packed red blood cell (pRBC) and FFP transfusions, and time to surgery.

RESULTS

There were 135 patients, 44% partially reversed and 56% completely reversed. The median volume of blood loss was 100 mL for both those completely and partially reversed, p = 0.72. There was no difference in the proportion of patients with blood loss by study arm, 95% vs. 95%, p > 0.99. Twenty-five percent of those completely reversed and 39% of those partially reversed had pRBCs transfused, p = 0.08. Of those completely reversed 5% received an FFP transfusion compared to 14% of those partially reversed, p = 0.09. There were no statistically significant differences observed for the volume of pRBC or FFP transfused, or for time to surgery.

CONCLUSIONS

Partial reversal may be safe for blood loss and blood product transfusions for geriatric patients with isolated hip fractures. Complete warfarin reversal may not be necessary prior to hip fracture surgery, especially for mildly elevated INRs.

Is anticoagulation reversal necessary prior to surgical treatment of geriatric hip fractures?

OBJECTIVE

Hip fracture surgery in geriatric patients on anticoagulants may increase the risk for blood loss. Anticoagulation reversal may lower these risks; however, data on blood loss and transfusions are limited. The study purpose was to compare outcomes between hip fracture patients 1) not on anticoagulants 2) whose anticoagulants were reversed, and 3) whose anticoagulants were not reversed.

METHODS

This four-year retrospective cohort study at six Level 1 Trauma Centers enrolled geriatric patients (≥65) with isolated hip fractures. The primary outcome was total hospital blood loss (ml). Secondary outcomes: hospital length of stay (HLOS) and volume of packed red blood cells (pRBC) transfusions (ml). Statistical analyses included: Fisher's, chi-squared, Kruskal-Wallis, linear mixed-effect and logistic regression. Bonferroni adjusted alpha = 0.025.

RESULTS

Of the 459 patients, 189 (41%) were not on anticoagulants, 186 (41%) were reversed, and 84 (18%) were not reversed. The LS mean (SE) blood loss was 134 ml (12) for not reversed patients and 159 (17) for reversed patients; no significant difference compared to those not on anticoagulants [138 (12)], p-diff = 0.14 and 0.83, respectively. The LS mean (SE) HLOS was significantly longer for the reversed patients, 7.7 (0.4) days, when compared to those not on anticoagulants, 6.8 (0.4), p = 0.02, and when compared to those not reversed, 6.3 (0.6), p = 0.01. There was no significant difference in pRBC transfusions.

CONCLUSION

Not reversing anticoagulants for geriatric hip fractures was not associated with increased volume of blood loss or transfusions when compared to those reversed. Delayed surgery for anticoagulant reversal may be unnecessary and contributing to an increased HLOS.

A Retrospective Propensity Score-Matched Early Thromboembolic Event Analysis of Prothrombin Complex Concentrate vs Fresh Frozen Plasma for Warfarin Reversal Prior to Emergency Neurosurgical Procedures

BACKGROUND

Reversal of therapeutic anticoagulation prior to emergency neurosurgical procedures is required in the setting of intracranial hemorrhage. Multifactor prothrombin complex concentrate (PCC) promises rapid efficacy but may increase the probability of thrombotic complications compared to fresh frozen plasma (FFP).

OBJECTIVE

To compare the rate of thrombotic complications in patients treated with PCC or FFP to reverse therapeutic anticoagulation prior to emergency neurosurgical procedures in the setting of intracranial hemorrhage at a level I trauma center.

METHODS

Sixty-three consecutive patients on warfarin therapy presenting with intracranial hemorrhage who received anticoagulation reversal prior to emergency neurosurgical procedures were retrospectively identified between 2007 and 2016. They were divided into 2 cohorts based on reversal agent, either PCC (n = 28) or FFP (n = 35). The thrombotic complications rates within 72 h of reversal were compared using the χ2 test. A multivariate propensity score matching analysis was used to limit the threat to interval validity from selection bias arising from differences in demographics, laboratory values, history, and clinical status.

RESULTS

Thrombotic complications were uncommon in this neurosurgical population, occurring in 1.59% (1/63) of treated patients. There was no significant difference in the thrombotic complication rate between groups, 3.57% (1/28; PCC group) vs 0% (0/35; FFP group). Propensity score matching analysis validated this finding after controlling for any selection bias.

CONCLUSION

In this limited sample, thrombotic complication rates were similar between use of PCC and FFP for anticoagulation reversal in the management of intracranial hemorrhage prior to emergency neurosurgical procedures.

Prothrombin Complex Concentrates for Perioperative Vitamin K Antagonist and Non-vitamin K Anticoagulant Reversal

Vitamin K antagonist therapy is associated with an increased bleeding risk, and clinicians often reverse anticoagulation in patients who require emergency surgical procedures. Current guidelines for rapid anticoagulation reversal for emergency surgery recommend four-factor prothrombin complex concentrate and vitamin K coadministration. The authors reviewed the current evidence on prothrombin complex concentrate treatment for vitamin K antagonist reversal in the perioperative setting, focusing on comparative studies and in the context of intracranial hemorrhage and cardiac surgery. The authors searched Cochrane Library and PubMed between January 2008 and December 2017 and retrieved 423 English-language papers, which they then screened for relevance to the perioperative setting; they identified 36 papers to include in this review. Prothrombin complex concentrate therapy was consistently shown to reduce international normalized ratio rapidly and control bleeding effectively. In comparative studies with plasma, prothrombin complex concentrate use was associated with a greater proportion of patients achieving target international normalized ratios rapidly, with improved hemostasis. No differences in thromboembolic event rates were seen between prothrombin complex concentrate and plasma, with prothrombin complex concentrate also demonstrating a lower risk of fluid overload events. Overall, the studies the authors reviewed support current recommendations favoring prothrombin complex concentrate therapy in patients requiring vitamin K antagonist reversal before emergency surgery.

Reversal of direct oral anticoagulants

An understanding of how to counteract the anticoagulant effect of direct oral anticoagulants is essential in the event of haemorrhage, emergency surgery and overdose. This review summarizes strategies for the reversal of direct oral anticoagulants, including the use of novel agents.

Management of bleeding in patients treated with direct oral anticoagulants

BACKGROUND

Recently, a new generation of direct-acting oral anticoagulants (DOACs) with a greater specificity towards activated coagulation factors was introduced based on encouraging results for efficacy and safety in clinical studies. An initial limitation of these new drugs was the absence of an adequate strategy to reverse the effect if a bleeding event occurs or an urgent invasive procedure has to be carried out.

MAIN TEXT

Specific reversing agents for DOACs have become available, however, and are now evaluated in clinical studies. For the anti-factor Xa agents (rivaroxaban, apixaban, and edoxaban) a number of studies have shown that the administration of prothrombin complex concentrate resulted in a correction of the prolonged prothrombin time and restored depressed thrombin generation after rivaroxaban treatment in a controlled trial in healthy human subjects. In view of the relatively wide availability of prothrombin complex concentrates, this would be an interesting option if the results can be confirmed in patients on oral factor Xa inhibitors who present with bleeding complications. More specific reversal can be achieved with andexanet, a new agent currently in development that competitively binds to the anti-factor Xa agents. For the direct thrombin inhibitor dabigatran, the administration of prothrombin complex concentrates showed variable results in various volunteer trials and efficacy at relatively high doses in animal studies. Recently, a Fab fragment of a monoclonal antibody (idarucizumab) was shown to be an effective reversal agent for dabigatran in human studies.

CONCLUSION

For the new generation of DOACs, several reversal strategies and specific antidotes are under evaluation, although most interventions need further evaluation in clinical trials.