Utility of Thromboelastography in Detecting NOAC-Related Coagulopathy in Traumatic Brain Injury

INTRODUCTION

Novel oral anticoagulants (NOACs) have gained popularity as a vitamin K antagonist alternative without regular monitoring. There has been an increase in elderly patients on NOACs admitted for traumatic brain injury (TBI). The aim of this study is to determine the efficacy of thromboelastography (TEG) in detecting NOAC-related coagulopathy among TBI patients.

METHODS

A retrospective chart review of 456 TBI patients admitted to Sentara Norfolk General Hospital from 2015 to 2020 was performed. Inclusion criteria comprised patients on NOACs with a TEG performed at presentation (66 patients). Analysis included TEG values, use of prothrombin complex concentrate factor 4 (PCC4), increased intracranial hemorrhage on repeat head computed tomography within 24 h of admission, and mortality.

RESULTS

TEG results showed 0% elevated reaction time, 1.5% elevated kinetics time, 1.5% low alpha angle, 4.5% low max amplitude, and 3.0% elevated clot lysis percent at 30 min in our cohort. Despite overwhelmingly normal TEG results, 42.42% of patients received PCC4. A subset analysis of these patients compared to those who did not receive PCC4, revealed a higher frequency of increased intracranial hemorrhage on repeat head computed tomography within 24 h of admission (42.86% versus 18.42%, P = 0.03), and increased mortality (25.0% versus 5.26%, P = 0.0219). Patients who did not receive PCC4 had no increased frequency of operative intervention or worsening of Glasgow Coma Score.

CONCLUSIONS

Results suggest that TEG does not reliably assess NOAC-related coagulopathy in TBI patients. Caution must be used when interpreting TEG data to determine reversal strategies in TBI patients on NOACs.

Time to surgery and complications in hip fracture patients on novel oral anticoagulants: a systematic review

BACKGROUND

Early surgery has been consistently demonstrated to reduce complications and mortality in hip fracture patients. There remains no general consensus, however, regarding the optimal time to surgery for hip fracture patients who are on novel oral anticoagulants (NOAC) on admission and its effect on clinical outcomes after surgery. The objective of this review was to assess the effect of preoperative NOAC therapy on time to surgery and postoperative complications in hip fracture patients.

METHODS

We performed a systematic review of the literature using the PubMed, Embase, and Cochrane Library electronic databases. Relevant articles were identified and included if they: (i) included patients on NOAC therapy on admission who did not undergo reversal; (ii) included a control group of patients not on any anticoagulation; (iii) included time from admission to surgery; and (iv) included one of the following outcomes: blood transfusion, venous thromboembolism (VTE), stroke, readmission, and mortality.

RESULTS

Nine studies were included with a total of 4,419 patients. There were 414 NOAC patients and 4,005 non-anticoagulated patients. Six of the nine studies found a significant increase in time to surgery for patients on NOAC therapy. Three of the seven studies that reported rates of blood transfusion found a significantly higher incidence of transfusion in patients on NOACs. None of the studies found a significant difference in VTE and stroke. One of the two studies that reported readmissions showed a higher risk of readmission for patients on NOACs. Eight of the nine included studies found no significant difference in postoperative mortality rates between the NOAC and control groups, with the remaining study finding a higher mortality rate only in patients on NOAC therapy who underwent fixation and not those who underwent arthroplasty.

CONCLUSIONS

These mixed findings suggest that delay to surgery may not be warranted in the urgent surgical setting of patients on NOAC therapy who sustain hip fractures.

Low-dose rivaroxaban plus aspirin in older patients with peripheral artery disease undergoing acute limb revascularization: insights from the VOYAGER PAD trial

AIMS

In this secondary analysis of the VOYAGER trial, rivaroxaban 2.5 mg twice/day plus aspirin 100 mg/day was assessed in older adults. Advanced age is associated with elevated bleeding risk and unfavourable net benefit for dual antiplatelet therapy in chronic coronary artery disease. The risk-benefit of low-dose rivaroxaban in patients ≥75 years with peripheral artery disease (PAD) after lower extremity revascularization (LER) has not been described.

METHODS AND RESULTS

The primary endpoint was a composite of acute limb ischaemia, major amputation, myocardial infarction, ischaemic stroke, or cardiovascular death. The principal safety outcome was thrombolysis in myocardial infarction (TIMI) major bleeding analysed by the pre-specified age cut-off of 75 years. Of 6564 patients randomized, 1330 (20%) were >75 years. Absolute 3-year Kaplan-Meier cumulative incidence rates for primary efficacy (23.4% vs. 19.0%) and safety (3.5% vs. 1.5%) endpoints were higher in elderly vs. non-elderly patients. Efficacy of rivaroxaban (P-interaction 0.83) and safety (P-interaction 0.38) was consistent irrespective of age. The combination of intracranial and fatal bleeding was not increased in patients >75 years (2 rivaroxaban vs. 8 placebo). Overall, benefits (absolute risk reduction 3.8%, number needed to treat 26 for the primary endpoint) exceeded risks (absolute risk increase 0.81%, number needed to harm 123 for TIMI major bleeding).

CONCLUSION

Patients ≥75 years with PAD are at both heightened ischaemic and bleeding risk after LER. No excess harm with respect to major, intracranial or fatal bleeding was seen in older patients yet numerically greater absolute benefits were observed. This suggests that low-dose rivaroxaban combined with aspirin should be considered in PAD after LER regardless of age.

Prescription patterns of direct oral anticoagulants and concomitant use of interacting medications in the Netherlands

Objectives

To describe the prevalence, temporal and regional trends in prescribing direct oral anticoagulants (DOACs) in conjunction with interacting medications.

Methods

We performed a cross-sectional study of pharmacy dispensing data in the Foundation for Pharmaceutical Statistics (SFK) registry on patients who have had a prescription for a DOAC filled at one of 831 randomly selected pharmacies in the Netherlands between Jan 2014–Jan 2019.

Results

We identified 99,211 patients who had a first DOAC prescription filled. Mean age was 71.6 ± 10.9 years, 58% were male. In 2014, 8,293 patients were treated with DOACs, in 2018, 35,415 were newly started on a DOAC. In 2018, the use of apixaban was most common (52%) in the Eastern region, whereas rivaroxaban was most frequently prescribed (32–48%) in the other regions. At time of first prescription, the vast majority (99.3%) used ≥ 1 concomitant interacting drug, and 3.2% used ≥ 3 interacting medications. Most common were digoxin (37.8%), atorvastatin (31.5%), verapamil (13.7%) and amiodarone (9.7%). While the number of interacting medications remained unchanged over time (median 1, interquartile range 1–1), there was a notable decrease in antiarrhythmic medications and an increase in non-cardiovascular interacting medications (e.g. dexamethasone from 0.9% to 7.1%, antiepileptic drugs from 2.5% to 3.8%, and haloperidol from 0.5% to 2.2% in 2014 and 2018, respectively).

Conclusion

DOAC use has quadrupled in Dutch clinical practice over the 5‑year period from 2014 to 2018. While the number of patients who take interacting medications remained stable, the profile of interacting medications has changed over time from cardiovascular to medications affecting other organ systems.

Supplementary Information

The online version of this article (10.1007/s12471-021-01612-4) contains supplementary material, which is available to authorized users.

Dabigatran, rivaroxaban, and apixaban are superior to warfarin in Asian patients with non-valvular atrial fibrillation: An updated meta-analysis

BACKGROUND

Most of the randomized clinical trials that led to the wide use of non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with atrial fibrillation (AF) originated from western countries.

AIM

To systematically review and quantitatively synthesize the real-world data regarding the efficacy and safety of dabigatran, rivaroxaban, and apixaban compared to warfarin for stroke prevention in Asian patients with non-valvular AF.

METHODS

Medline, Cochrane, and ClinicalTrial.gov databases were reviewed. A random-effect model meta-analysis was used and I-square was utilized to assess the heterogeneity. The primary outcome was ischemic stroke. The secondary outcomes were all-cause mortality, major bleeding, intracranial hemorrhage, and gastrointestinal bleeding.

RESULTS

Twelve studies from East Asia or Southeast Asia and 441450 patients were included. Dabigatran, rivaroxaban, and apixaban were associated with a significant reduction in the incidence of ischemic stroke [hazard ratio (HR) = 0.78, 95% confidence interval (CI): 0.65-0.94; HR = 0.79, 95%CI: 0.74-0.85, HR = 0.70, 95%CI: 0.62-0.78; respectively], all-cause mortality (HR = 0.68, 95%CI: 0.56-0.83; HR = 0.66, 95%CI: 0.52-0.84; HR = 0.66, 95%CI: 0.49-0.90; respectively), and major bleeding (HR = 0.61, 95%CI: 0.54-0.69; HR = 0.70, 95%CI: 0.54-0.90; HR = 0.58, 95%CI: 0.43-0.78; respectively) compared to warfarin.

CONCLUSION

Dabigatran, rivaroxaban, and apixaban appear to be superior to warfarin in both efficacy and safety in Asians with non-valvular AF.

Comparison of Traumatic Intracranial Hemorrhage Expansion and Outcomes Among Patients on Direct Oral Anticoagulants Versus Vitamin k Antagonists

BACKGROUND

With increasing use of direct oral anticoagulants (DOACs) and availability of new reversal agents, the risk of traumatic intracranial hemorrhage (tICH) requires better understanding. We compared hemorrhage expansion rates, mortality, and morbidity following tICH in patients treated with vitamin k antagonists (VKA: warfarin) and DOACs (apixaban, rivaroxaban, dabigatran).

METHODS

Retrospective chart review of patients from 2010 to 2017 was performed to identify patients with imaging diagnosis of acute traumatic intraparenchymal, subdural, subarachnoid, and epidural hemorrhage with preadmission use of DOACs or VKAs. We identified 39 patients on DOACs and 97 patients on VKAs. Demographic information, comorbidities, hemorrhage size, and expansion over time, as well as discharge disposition and Glasgow Outcome Scale (GOS) were collected. Primary outcome was development of new or enlargement of tICH within the first 48 h of initial CT imaging.

RESULTS

Of 136 patients with mean (SD) age 78.7 (13.2) years, most common tICH subtype was subdural hematoma (N = 102/136; 75%), and most common mechanism was a fall (N = 130/136; 95.6%). Majority of patients in the DOAC group did not receive reversal agents (66.7%). Hemorrhage expansion or new hemorrhage occurred in 11.1% in DOAC group vs. 14.6% in VKA group (p = 0.77) at a median of 8 and 11 h from initial ED admission, respectively (p = 0.82). Patients in the DOAC group compared to VKA group had higher median discharge GOS (4 vs. 3 respectively, p = 0.03), higher percentage of patients with good outcome (GOS 4-5, 66.7% vs. 40.2% respectively, p = 0.005), and higher rate of discharge to home or rehabilitation (p = 0.04).

CONCLUSIONS

We report anticoagulation-associated tICH outcomes predominantly due to fall-related subdural hematomas. Patients on DOACs had lower tICH expansion rates although not statistically significantly different from VKA-treated patients. DOAC-treated patients had favorable outcomes versus VKA group following tICH despite low use of reversal strategies. DOAC use may be a safer alternative to VKA in patients at risk of traumatic brain hemorrhage.

Comparison of novel oral anticoagulants versus warfarin for post-operative atrial fibrillation after coronary artery bypass grafting

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘Does the use of Novel Oral Anticoagulants (NOACs) result in more complications than Warfarin for treatment of post-operative atrial fibrillation (AF) following coronary artery bypass grafting (CABG)?’ Altogether more than 93 papers were found using the reported search with 4 studies representing the best evidence to answer the clinical question, including 1 randomised trial and 3 retrospective case-control studies. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. Timing for initiation of anticoagulation was similar across the studies, with both demonstrating longer hospital stays and greater time to reach therapeutic anticoagulation in the warfarin cohort. Three studies reported similar safety between the two groups. One study revealed significantly more invasive interventions for pleural or pericardial effusions in the NOAC group, whilst in contrast another study demonstrated a higher rate of major bleeding in the warfarin cohort. Cost-analysis revealed that NOACs were overall more cost-effective compared to warfarin despite the higher cost for the medication itself. In conclusion, the use of NOACs after CABG for post-operative AF can be used as an alternative to warfarin, however, one should remain vigilant for possible pericardial or pleural effusions which may require reintervention. Further dedicated research and larger appropriately powered randomised control trials are needed to confirm the safety of NOACs in post-cardiac surgery patients.

•

Atrial fibrillation (AF) is the most common arrhythmia post cardiac surgery.

•

While usually self-limiting, AF has increased morbidity and mortality to patients.

•

Anticoagulation is warranted if AF is persistent or recurrent.

•

Warfarin has been the mainstay of therapy, however, NOACs have gained popularity.

•

The safety of NOACs in post-cardiac surgery patients is so far poorly defined.

Meta-analysis of the safety and efficacy of using minimally interrupted novel oral anticoagulants in patients undergoing catheter ablation for atrial fibrillation

PURPOSE

The ideal periprocedural anticoagulation strategy for patients being treated with a novel oral anticoagulant (NOAC) during catheter ablation (CA) for atrial fibrillation (AF) is unclear. We evaluated the safety and efficacy of using a minimally interrupted NOAC strategy versus an uninterrupted NOAC or vitamin K antagonist (VKA) strategy during AF ablation.

METHODS

The Cochrane Library, PubMed, and EMBASE databases were searched for randomized controlled or prospective observational studies that compared a minimally interrupted NOAC strategy with an uninterrupted NOAC or VKA strategy from the time of database establishment up to December 2019. The primary endpoints were major bleeding, minor bleeding, and symptomatic thromboembolism. The secondary endpoint was silent cerebral infarction (SCI) as detected by post-ablation brain magnetic resonance imaging (MRI). A measurement of treatment effect for the endpoint was reported as pooled odds ratio (OR) with 95% confidence interval (CI).

RESULTS

A total of 18 studies (6 randomized, 11 observational, and 1 randomized registry) with 6203 patients were included in the final analysis (47% of the patients received minimally interrupted NOAC). There was no significant difference between treatment groups regarding the risk for major bleeding (OR 1.04, 95% CI 0.69-1.57, P = 0.86, I² = 27%). Different stratification methods did not yield significant difference regarding the risk for major bleeding. There was no difference between groups regarding the risk for minor bleeding (P = 1.00) or symptomatic thromboembolism (P = 0.26). Brain MRI results showed that both uninterrupted NOAC (OR 0.44, 95% CI 0.23-0.83, P = 0.01, I² = 72%) and uninterrupted VKA (OR 0.48, 95% CI 0.24-0.97, P = 0.04, I² = 36%) produced a significant reduction in the rate of SCI when compared with minimally interrupted NOAC.

CONCLUSIONS

A periprocedural anticoagulation strategy of minimally interrupted NOAC is not superior to uninterrupted NOAC or VKA when used during AF ablation. There is evidence favoring the use of uninterrupted NOAC or VKA in terms of the risk for SCI.

Safety of 4-factor prothrombin complex concentrate (4F-PCC) for emergent reversal of factor Xa inhibitors

Background

Although factor Xa inhibitors have become a popular choice for chronic oral anticoagulation, effective drug reversal remains difficult due to a lack of specific antidote. Currently, 4-factor prothrombin complex concentrate (4F-PCC) is considered the treatment of choice for factor Xa inhibitor-related major bleeding. However, safety of 4F-PCC and its risk of thrombosis when used for this off-label purpose remain unclear. The purpose of this retrospective study is to determine the rate of thromboembolism when 4F-PCC is used for the emergent reversal of factor Xa inhibitors.

Methods

We conducted a single-center retrospective review of medical records between 2013 and 2017. Patients were included if they received 4F-PCC to reverse rivaroxaban, apixaban, or edoxaban for emergent invasive procedures or during episodes of major bleeding defined as bleeding with hemodynamic instability, fall in hemoglobin of 2 g/dL, or bleeding requiring blood transfusion. Thrombotic events including myocardial infarction, pulmonary embolism, deep vein thrombosis, cerebral vascular accident, and arterial thrombosis of the limb or mesentery were recorded if they occurred within 14 days of 4F-PCC administration. Data was analyzed using point and interval estimation to approximate the rate and confidence interval of thromboembolic events.

Results

Forty-three patients were identified in our review. Doses of 4F-PCC were determined by the treating physician and mainly ranged from 25 to 50 IU/kg. Twenty-two patients (51.2%) received both sequential compression devices (SCDs) and subcutaneous heparin for DVT prophylaxis. Twenty-one patients (48.8%) were placed on SCDs only. Three patients received concomitant FFP. Thrombotic events within 14 days of 4F-PCC administration occurred in 1 out of 43 patients (2.1%, 95% CI [0.1–12.3]). This thrombotic event was an upper extremity DVT which occurred 1 day after the patient received 1325 IU (25 IU/kg) of 4F-PCC to reverse rivaroxaban for traumatic intracranial hemorrhage. The patient was taken for emergent decompressive craniotomy after rivaroxaban reversal. In patients who did not undergo surgery or who underwent minor invasive procedures, no thrombotic events were noted.

Conclusion

Based on our preliminary data, the thromboembolic rate of 4F-PCC when given at a dose of 25–50 IU/kg to emergently reverse rivaroxaban and apixaban appears acceptable. Since many patients who require 4F-PCC to emergently reverse factor Xa inhibitors will be at high risk of developing thrombotic events, practitioners should be highly vigilant of these complications. Large, multicenter prospective trials are needed to further determine this risk.

Perioperative Management of New Oral Anticoagulants in Urological Surgery

New oral anticoagulants (NOACs) are increasingly replacing the use of warfarin in clinical practice. Their use has now also been extended to thromboprophylaxis in many orthopedic surgeries. This, in addition to an increasingly aging population with many complex comorbidities means that these medications will be ever more frequently encountered by urologists. Thus, a clear understanding of the mechanism of action of NOACs, their time to peak action and half-life is essential for the purpose of managing these patients perioperatively. This article demonstrates the patient and procedural variability that must be taken into account in the perioperative management of the anticoagulated patient. While the time to peak onset and half-life of NOACs can aid in determining the interval of interruption of anticoagulation, the risks of thrombosis and bleeding must be assessed before the decision to stop anticoagulation. This article takes into account the evidence available on NOACs in urological surgery in order to inform the perioperative management of these medications and to propose guidelines to aid in clinical decision making. In attempting this, we address the issue of the lack of high-level evidence surrounding NOACs in urological surgery given their relative novelty and the need for further research to better guide practice.

Phacoemulsification cataract surgery in patients receiving novel oral anticoagulant medications

INTRODUCTION

An increasing number of patients are taking novel oral anticoagulant (NOAC) medication, making perioperative management in phacoemulsification surgery an important issue. This study reports the haemorrhagic complications of NOAC in phacoemulsification surgery.

DESIGN

Retrospective case study over a 4-year period.

METHODS

Consecutive cases receiving NOAC during the time of phacoemulsification were reviewed. Patients were either advised to continue medications (continued group) or withhold medications before surgery (withheld group).

MAIN OUTCOME MEASURES

Details including patient demographics, preoperative assessment, postoperative outcome and intraoperative, postoperative and systemic complications were recorded.

RESULTS

A total of 20,100 cases of phacoemulsification were performed. Of which, 66 cases were found to be on NOAC (0.33%). This included 66 eyes of 53 patients, with 42 continued and 24 withheld medications before surgery. There was no statistically significant difference between the two groups in demographics, cataract risk factors, baseline renal function, clotting profile, type of NOAC, incision size, phacoemulsification energy, preoperative and postoperative visual acuity. There was also no significant difference in intraoperative, postoperative and systemic complications (p = 1.00 and 0.53, Fischer's exact test). None of the patients in the continued group had postoperative complications; two cases in the withheld group receiving retrobulbar anaesthesia had bruising and subconjunctival haemorrhage after resumption of NOAC (p = 0.13, Fischer's exact test).

CONCLUSION

The present study found no difference in haemorrhagic complications between cases continuing and withholding NOAC during phacoemulsification. Nevertheless, the potential risks and benefits to continue or withhold NOAC perioperatively should be carefully considered via a multidisciplinary approach.

Hemorrhagic pericarditis associated with rivaroxaban in an atrial fibrillation patient with pacemaker

Rivaroxaban is a new oral anticoagulant used for the prevention of stroke in patients with atrial fibrillation. Hemorrhagic pericarditis is known to occur with rivaroxaban; however, only a few case reports in the literature describe such events. Recently, we experienced hemorrhagic pericarditis that treated with rivaroxaban for anticoagulation of newly diagnosed, non valvular AF patients with pacemaker. An 83 year old male with permanent pacemaker receiving rivaroxaban 20 mg daily once for 3 months presented at our emergency department complaining of exertional dyspnea. ECG showed intermittent atrial pacing failure and echocardiography showed large amount of pericardial effusion. After urgent pericardiocentesis, which resulted in removal of 500cc bloody fluid, there was an immediate and dramatic improvement in the patient's clinical state. He was discharged without anticoagulation therapy due to concern for further bleeding. This case highlight the potential for bleeding complications associated with novel anticoagulants. Rivaroxaban is being used with increasing frequently in outpatient care. However, no available laboratory test specifically measures the anticoagulant effect of rivaroxaban. Also, in the events of serious bleeding, no specific antidotes, reversal agents were available. Clinicians should be aware of the possibility of hemopericardium in patients treated with anticoagulants, including rivaroxaban who presented with cardiomegaly.

Deep Venous Thrombosis

Deep venous thrombosis (DVT) is a frequently encountered condition that is often diagnosed and treated in the outpatient setting. Risk stratification is helpful and recommended in the evaluation of DVT. An evidence-based diagnostic approach is discussed here. Once diagnosed, the mainstay of DVT treatment is anticoagulation. The specific type and duration of anticoagulation depend upon the suspected etiology of the venous thromboembolism, as well as risks of bleeding and other patient comorbidities. Both specific details and a standardized approach to this vast treatment landscape are presented.

Novel Oral Anticoagulants in Patients Undergoing Cranial Surgery

BACKGROUND

The number of patients treated with novel oral anticoagulants (NOACs) is increasing. Despite growing clinical relevance, guidelines on the perioperative management of neurosurgical patients treated with NOACs are still lacking. The aim of this study was to analyze the occurrence of postoperative bleeding events and factors that might influence bleeding rates in these patients.

METHODS

Out of 1353 consecutive patients undergoing cranial neurosurgical procedures, 30 (2.2%) received NOACs preoperatively. The rates of perioperative and postoperative intracranial bleeding events, rate of postoperative thromboembolic events, hematologic findings, morbidity, and mortality were reviewed. A subanalysis of factors influencing the bleeding risk of these patients and the bleeding rate depending on the preoperative discontinuation time of NOACS, with cutoff of 24 and 48 hours, was performed as well.

RESULTS

The rate of perioperative bleeding was 13.3% (n = 4 of 30). Postoperative bleeding led to death in 2 patients. The median discontinuation time was significantly shorter in the patients experiencing a bleeding event compared to those without a bleeding event (1.5 days [range 0-3 days] vs. 11 days [range, 0-120 days]). The rate of perioperative thromboembolic events was 3.3% (n = 1), and overall mortality was 13.3% (n = 4).

CONCLUSIONS

The postoperative bleeding rate in patients undergoing cranial surgery treated with NOACs was 13.3%. A shorter preoperative discontinuation time seems to have a significant effect on bleeding rate. Further studies evaluating the management and postsurgical outcomes of these patients are warranted.

Italian intersociety consensus on DOAC use in internal medicine

The direct oral anticoagulants (DOACs) are drugs used in clinical practice since 2009 for the prevention of stroke or systemic embolism in non-valvular atrial fibrillation, and for the treatment and secondary prevention of venous thromboembolism. The four DOACs, including the three factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) and one direct thrombin inhibitor (dabigatran) provide oral anticoagulation therapy alternatives to Vitamin K antagonists (VKAs). Despite their clear advantages, the DOACs require on the part of the internist a thorough knowledge of their pharmacokinetic and pharmacodynamic characteristics to ensure their correct use, laboratory monitoring and the appropriate management of adverse events. This document represents a consensus paper on the use of DOACs by representatives of three Italian scientific societies: the Italian Society of Internal Medicine (SIMI), the Federation of the Associations of Hospital Managers (FADOI), and the Society for the Study of Haemostasis and Thrombosis (SISET). This document formulates expert opinion guidance for pragmatic managing, monitoring and reversing the anticoagulant effect of DOACs in both chronic and emergency settings. This practical guidance may help the internist to create adequate protocols for patients hospitalized ion internal medicine wards, where patients are often elderly subjects affected by poly-morbidities and renal insufficiency, and, thus, require particular attention to drug-drug interactions and peri-procedural protocols.

Apixaban, concomitant medicines and spontaneous reports of haemorrhagic events

INTRODUCTION

Little is known about the potential safety issues associated with apixaban in clinical practice and their reporting in spontaneous adverse event (SAE) databases.

OBJECTIVE

To describe SAE reports associated with the oral anticoagulant apixaban from Australia, Canada and USA and to examine associated concomitant medicine use.

METHODS

SAE report databases from Australia, Canada and the USA were examined for all reports of adverse events associated with apixaban and concomitant medicines from 1 January 2012 to 30 September 2014. Disproportionality analysis (proportional reporting ratio (PRR) and reporting odds ratio (ROR)) was conducted for the quantitative detection of signals using the USA database.

RESULTS

There were 97 SAE reports associated with apixaban from Australia, 77 from Canada and 2877 from the USA. Reporting of haemorrhage (any type) was common, ranging from 18% for USA to 31% for Australia. Gastrointestinal (GI) haemorrhage was the most commonly reported haemorrhage, accounting for approximately 10% of adverse event reports across all countries. Positive signals were confirmed in the USA data (haemorrhage (any type) PRR, 12.1; χ², 5582.2 and ROR, 13.4; 95% CI: 12.13-14.6; GI haemorrhage PRR, 11.8; χ², 2325.4 and ROR, 12.3; 95% CI, 10.8-14.0). Reporting of concomitant use of medicines with the potential to increase bleeding risk ranged from 47.6% in Canada to 65.5% in Australia.

CONCLUSION

A large proportion of adverse event reports for apixaban were associated with use of concomitant medicines which may have increased the risk of haemorrhage.

Trends in physiological coagulation factors in Japanese patients receiving novel oral anticoagulants

Background

Little is known about physiological anticoagulation effects via antithrombin III (AT III) and protein C/S (PC/PS) in patients using new oral anticoagulants (NOACs).

Methods

We evaluated 120 consecutive patients with non-valvular atrial fibrillation (AF) receiving NOACs. Patients were randomly divided into three groups: a dabigatran group (DG, N=40), a rivaroxaban group (RG, N=40) or an apixaban group (AG, N=40). A warfarin group (WG, N=40) was matched with NOAC groups for age, sex and type of AF during the same time period. Blood samples were obtained in pretreatment, trough and peak phases to measure the activity of physiological coagulation inhibitors, including AT III and PC/PS or thrombus formation markers such as D-dimer and thrombin–antithrombin complex (TAT).

Results

D-dimer, TAT and AT III values for the NOAC groups were equivalent in the peak and trough phases. PC/PS activity in both phases was equally maintained in the pretreatment phase in the NOAC groups, while the activity in the WG was significantly suppressed in steady state. Moreover, no differences in trends for PC/PS activity were observed among NOAC groups.

Conclusions

PC/PS activity was constant in both peak and trough phases in the patients on NOACs compared with activity of those on warfarin. In addition, there was no difference in the findings among NOACs.

Decision-making around antithrombotics for stroke prevention in atrial fibrillation: the health professionals' views

Background For stroke prevention in patients with atrial fibrillation (AF), the decision-making around antithrombotic therapy has been complicated by older age, multiple comorbidities, polypharmacy and the different pharmacological properties of warfarin and the nonvitamin K antagonist oral anticoagulants (NOACs). The complexity of decision-making has been associated with a reluctance by health professionals to use antithrombotic therapy, leading to poor clinical outcomes. In order to improve stroke prevention in patients with AF, the contemporary perspectives of health professionals on the decision-making around antithrombotic therapy needs exploration. Objective To elicit emerging themes describing health professionals' perspectives on the decision-making around antithrombotic therapy for stroke prevention in patients with AF. Setting Sydney metropolitan area of New South Wales, Australia. Method A qualitative study based on face-to-face interviews was conducted from August to October 2014. Seven pharmacists, seven specialists, six general practitioners and six nurses practising in the Sydney metropolitan area and managing antithrombotic therapy for AF were interviewed until theme saturation was achieved in each subgroup. Interview transcripts were analysed using manual inductive coding. Main outcome measure Emerging themes describing health professionals' perspectives on the decision-making around antithrombotic therapy for stroke prevention in patients with AF. Results Three overarching themes emerged. (1) Comprehensive assessment is necessary for decision-making but is not always implemented. Health professionals mostly focused on stroke risk assessment, not on the bleeding risk and medication safety issues. (2) Health professionals from different disciplines have different preferences for antithrombotic therapies. Although the majority of health professionals considered warfarin as the first-line therapy, NOACs were preferred by neurologists and haematologists. (3) Health professionals focused on different aspects of the decision making process: GPs and specialists were concerned about the appropriate prescription of antithrombotics, while pharmacists and nurses focused on daily medication management by patients. Conclusion The decision-making process appears to be partially preference based rather than systematic, and health professionals from various disciplines focus on different parts of the decision-making process.

Complete response to rivaroxaban in a case of invaginated thrombus thought to have extended through a patent foramen ovale with an accompanying pulmonary embolism

Occurrence of paradoxical embolisms caused by deep venous thrombosis (DVT) is often encountered in the clinical setting. However, a thrombus that is invaginated from the right atrium into the left atrium (an impending paradoxical embolism) is rare. We report a case of an 80-year-old woman who had the complication of an impending paradoxical embolism and a pulmonary embolism. Because an indication of new anticoagulants was expanded to treatment of venous thromboembolism and oral administration became available, we initially administered edoxaban, which did not cause the thrombus to disappear. Therefore, we switched to rivaroxaban, which resulted in successful elimination of the thrombus. Our findings indicate the differences in effects between each novel oral anticoagulant. <Learning objective: Paradoxical thrombosis is a common clinical occurrence. However, we believe that our case is rare because we were able to collect images confirming that the thrombus had passed through the interatrial septum and was nearly invaginated into the left atrium. Beyond warfarin, current anticoagulant therapy options may involve the factor Xa blockers edoxaban or rivaroxaban for patients with venous thromboembolism. Findings in our case suggested that there are different effects for novel oral anticoagulants in treatment of venous thromboembolism.>.

Does novel oral anticoagulant improve anticoagulation for non-valvular atrial fibrillation associated stroke: An inpatient registration study in Shanghai

OBJECTIVE

To summarize the use rate, safety, efficacy of antithrombotics in stroke/transient ischemic attack (TIA) prevention, and reasons for not using dabigatran etexilate (DE) in Shanghai, China.

METHODS

Non-valvular atrial fibrillation (NVAF)-associated stroke patients were prospectively registered as an electronic database. Use rate of antithrombotics and reasons for not using DE were extracted during follow-up. Patients' baseline characteristics, recurrent ischemic stroke/TIA events and bleeding complications were analyzed.

PATIENTS

From April 2012 to August 2014, 110 inpatients with NVAF-associated stroke were studied in our hospital. NVAF was diagnosed by 12-lead electrocardiogram, 24 h Holter and echocardiography.

RESULTS

Before introduction of DE (April 2013), use rates of warfarin and antiplatelets were 28.9% (11/38) and 60.5% (23/38) respectively; after that, use rates of warfarin, DE, and antiplatelets were 20.8% (15/72), 12.5% (9/72), and 43.1% (31/72). The DE did not improve use of anticoagulants (P = 0.639). There were 19 (17.3%) recurrent ischemic stroke events up to October 2015; two (9.5%) in the non-user group, 10 (18.5%) in the antiplatelet group, and seven (20.0%) in the anticoagulants group (P = 0.570). Furthermore, recurrence rates were similar between the DE group (20.0%) and the Warfarin group (20.0%, P = 1.000). The most common reason for not using DE was financial concerns (61.0%), followed by inconvenience to purchase (14.0%) and hemorrhage concerns (11.0%). Two patients using warfarin found fecal occult blood so they stopped warfarin and began to use antiplatelet drugs. No bleeding event occurred in the other groups. Only one patient had side effects (dyspepsia and gastroesophageal reflux) from DE.

CONCLUSION

The use rate of either DE or warfarin in Shanghai was low; DE had not improved anticoagulation therapy for NVAF patients in Shanghai mainly because DE had not been covered by health insurance.

Anticoagulation Therapy and NOACs in Heart Failure

Current evidence indicates that heart failure (HF) confers a hyper-coagulable state that is associated with adverse events including stroke, systemic embolism, and mortality. This may be due to the elevated levels of pro-thrombotic and pro-inflammatory cytokines that are seen in patients with acute and chronic HF. Left ventricular wall motion abnormalities in patients with systolic dysfunction predispose to local thrombosis due to blood stasis as does atrial fibrillation (AF) which leads to blood stasis in regions of the atria. The high risk of thromboemboli in HF patients with AF has resulted in the use anticoagulation therapy to prevent the occurrence of catastrophic events. There is evidence, however, that the pro-inflammatory, pro-thrombotic state that exists in HF puts patients who are in sinus rhythm at risk. The novel oral anticoagulants (NOACs) have been shown in RCT to have at least equivalent efficacy in reducing stroke as warfarin while exposing patients to a lower risk of bleeding. The fact that the NOACs don't require routine monitoring to assure that patients remain within the therapeutic range and have relatively simple dosing requirements and a safer risk profile makes them attractive substitutes to warfarin in HF patients with atrial fibrillation and other conditions (e.g. deep venous thrombosis). Post hoc analyses from a subset of HF patients from the RCTs in AF patients have demonstrated similar findings as were reported in the entire populations that were included in the trials. As a result, NOACS are commonly used now in HF patients with AF. For HF patients with reduced ejection fraction in sinus rhythm, the use of warfarin in randomized clinical trials (RCT) to reduce stroke has been disappointing and associated with increase bleeding risk when compared to aspirin. The advantages of the NOACs over warfarin, however, raise the question of whether they might improve outcomes in HF patients who are in sinus rhythm. The currently ongoing COMMANDER-HF trial has been designed to address this issue. In this chapter we review evidence of existence of a prothombotic state in HF, the pharmacodynamics and clinical trials of the NOACs and the outcomes from NOAC substudies in the HF subgroup. We also discuss the rationale for using anticoagulation in HF independent of arrhythmia burden.

Misconceptions and Facts About Atrial Fibrillation

Atrial fibrillation is an increasingly common arrhythmia associated with substantial but largely preventable risk of ischemic stroke. There has been an exponential increase in research related to atrial fibrillation in recent years, resulting in some major advances in the therapeutic management. Novel oral anticoagulant agents have become available and require thorough assessment of risk-to-benefit ratio. While the knowledge is rapidly accumulating, the basic principles of atrial fibrillation management remain proper recognition, risk stratification, and appropriate prevention of thromboembolic complications. This review highlights some common misconceptions about atrial fibrillation.

Management of Antiplatelet Agents and Anticoagulants in Patients with Gastrointestinal Bleeding

Antithrombotic drugs (anticoagulants, aspirin, and other antiplatelet agents) are used to treat cardiovascular disease and to prevent secondary thromboembolic events. These drugs are independently associated with an increased risk of gastrointestinal bleeding (GIB), and, when prescribed in combination, further increase the risk of adverse bleeding events. Clinical evidence to inform the choice of endoscopic hemostatic procedure, safe temporary drug cessation, and use of reversal agents is reviewed to optimize management following clinically significant GIB.

Left atrial thrombus formation and resolution during dabigatran therapy: A Japanese Heart Rhythm Society report

BACKGROUND

Protocols on the use of novel oral anticoagulants for stroke prevention in patients with atrial fibrillation (AF) undergoing electrical cardioversion (ECV) are lacking.

AIM

The study was aimed at evaluating the efficacy of dabigatran (Dabi) treatment in preventing peri-ECV stroke.

METHODS

A retrospective survey of the incidence and fate of left atrial (LA) thrombus during Dabi therapy in patients with AF was conducted between December 2012 and January 2013 by the Japanese Heart Rhythm Society.

RESULTS

A total of 198 patients from 299 institutions underwent transesophageal echocardiography (TEE) to rule out LA thrombus before ECV. Of these, LA thrombus was found in eight patients (4%), who tended to be older (67.3 vs. 61.3 years, p=0.175), had higher CHADS2 scores (1.88 vs. 0.95, p=0.058), and a higher prevalence of prior stroke or transient ischemic attack (22.2% vs. 2.6%, p=0.034) than those without LA thrombus. Of the eight patients with LA thrombus, one had LA thrombus during a Dabi 150 mg b.i.d treatment, whereas the remaining seven were receiving 110 mg b.i.d for 3 weeks or longer. In 6 of the 8 patients with LA thrombus, a second TEE was performed, revealing complete resolution of LA thrombus in five; among these five patients, one received Dabi dosage of 150 mg b.i.d unchanged, two received an increased dosage from 110 mg to 150 mg b.i.d, and two were switched to warfarin. Two patients had a stroke 3 and 15 days after ECV, and one had a major large intestine bleeding episode during Dabi therapy.

CONCLUSIONS

LA thrombus developed in 4% of patients with AF receiving Dabi. Older patients with a higher CHADS2 score receiving a lower Dabi dosage were more likely to develop LA thrombus, which was resolved with a prolonged or increased dosage. A higher Dabi dosage may be more beneficial before ECV but prospective randomized studies would be needed to confirm these results.

Clinical and procedural predictors of early complications of ablation for atrial fibrillation: analysis of the national registry data

BACKGROUND

The risk assessment of the complication from atrial fibrillation (AF) ablation is important and needs to be updated.

OBJECTIVE

The purpose of this study was to investigate the clinical and procedural factors associated with AF ablation-related early complications.

METHODS

The Japanese Heart Rhythm Society invited electrophysiology centers in Japan to register data regarding all AF ablation procedures performed in September 2011, March 2012, and September 2012. Of the 46 putative predictors assessed in the univariate analysis, significant variables (P < .1) were entered into a stepwise logistic regression model for multivariate analysis.

RESULTS

Data for 3373 cases were submitted by 165 centers, with 158 early complications reported in 151 patients (4.5%). We identified 13 significant variables in the univariate analysis. Multivariate analysis revealed that 8 (62%) of them were independent predictors of early complications. Female sex (odds ratio and 95% confidence interval 1.6; 1.13-2.27), hypertrophic cardiomyopathy (2.2; 1.08-4.5), valvular heart disease (2.53; 1.28-5.05), deep sedation during the procedure (1.53; 1.09-2.12), and complex fractionated atrial electrocardiogram ablation (1.88; 1.23-2.87) increased early complications. Preprocedural transesophageal echocardiography (0.63; 0.43-0.92), irrigated-tip catheter use (0.46; 0.3-0.69), and periprocedural novel oral anticoagulant use (0.55; 0.32-0.97) decreased them.

CONCLUSION

The risk of early complications is increased by female sex, hypertrophic cardiomyopathy, valvular heart disease, deep sedation, and complex fractionated atrial electrocardiogram ablation. It is decreased by preprocedural transesophageal echocardiography, periprocedural novel oral anticoagulant, and irrigated-tip catheter use.