Patients With Atrial Fibrillation Who Are Not on Anticoagulant Treatment Due to Increased Bleeding Risk Are Common and Have a High Risk of Stroke

Percutaneous left atrial appendage occlusion discrepancy between randomised trials and clinical practice

In patients with atrial fibrillation and previous episodes of bleeding on oral anticoagulant treatment, left atrial appendage occlusion (LAAO) has emerged as an alternative way to decrease the risk of stroke.

The use of the procedure has been on the rise, and the news coverage has been dominated by an uncritical acceptance of the benefit of this procedure, which probably have contributed to the increasing number of procedures.

This commentary is a presentation and critical appraisal of the available evidence on the efficacy and safety of left atrial appendage closure as stroke prophylaxis.

We illustrate that LAAO is supported by limited randomised data risk of serious complications, which we do not believe supports the current widespread use.

The burden of undertreatment and non-treatment among patients with non-valvular atrial fibrillation and elevated stroke risk: a systematic review

OBJECTIVE

Global treatment guidelines recommend treatment with oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and an elevated stroke risk. However, not all patients with NVAF and an elevated stroke risk receive guideline-recommended therapy. A literature review and synthesis of observational studies were undertaken to identify the body of evidence on untreated and undertreated NVAF and the association with clinical and economic outcomes.

METHODS

An extensive search (1/2010-4/2020) of MEDLINE, the Cochrane Library, conference proceedings, and health technology assessments (HTAs) was conducted. Studies must have evaluated rates of nontreatment or undertreatment in NVAF. Nontreatment was defined as absence of OACs (but with possible antiplatelet treatment), while undertreatment was defined as treatment with only antiplatelet agents.

RESULTS

Sixteen studies met our inclusion criteria. Rates of nontreatment for patients with elevated stroke risk ranged from 2.0-51.1%, while rates of undertreatment ranged from 10.0-45.1%. The clinical benefits of anticoagulation were reported in the evaluated studies with reductions in stroke and mortality outcomes observed among patients treated with anticoagulants compared to untreated or undertreated patients. Adverse events associated with all bleeding types (i.e. hemorrhagic stroke, major bleeding or gastrointestinal hemorrhaging) were found to be higher for warfarin patients compared to untreated patients in real-world practice. Healthcare resource utilization was found to be lower among patients highly-adherent to warfarin compared to untreated patients.

CONCLUSIONS

Rates of nontreatment and undertreatment among NVAF patients remain high and are associated with preventable cardiovascular events and death. Strategies to increase rates of treatment may improve clinical outcomes.

Safety and effectiveness of left atrial appendage closure in patients with non-valvular atrial fibrillation and prior major bleeding

OBJECTIVES

To investigate safety and effectiveness of left atrial appendage closure (LAAC) in atrial fibrillation patients with prior major bleeding.

METHODS

A total of 377 consecutive patients scheduled for LAAC with Watchman device were divided into bleeding group (n = 137) and non-bleeding group (n = 240). Data were compared between groups.

RESULTS

The bleeding group had more patients ≥75 years old (P = 0.044), higher CHA₂DS₂-VASc (P = 0.029) and HAS-BLED scores (P = 0.001) than the non-bleeding group. During the long-term follow-up, except for thromboembolism event (P = 0.031), the incidences of major bleeding  , all-cause death  , co-primary efficacy events  , and the cumulative survival ratio after adjustment of confounding factors    were comparable. The observed thromboembolism rate was reduced by 86.3% (P = 0.0002) and 55.1% (P = 0.0293) and the observed major bleeding rate was decreased by 61.9% (P = 0.0393) and 35.7% (P = 0.2426) compared with expected risks in bleeding and non-bleeding groups, respectively. The risk reduction in thromboembolism and major bleeding were significantly greater in bleeding group versus non-bleeding group (all P < 0.0001).

CONCLUSIONS

Among patients with prior bleeding, LAAC is a safe and effective alternative to anticoagulation therapy and seems to emerge as a higher efficacy in risk reduction of thromboembolism and major bleeding compared to those without prior bleeding.

Patients with perceived high-bleeding risk and computerized decision support for stroke prevention in atrial fibrillation: an AF-ALERT substudy : Piazza: outcomes of high-bleeding risk AF patients

A perceived increased risk of bleeding is one of the most frequent reasons for withholding anticoagulation for stroke prevention in atrial fibrillation (AF). We previously conducted a randomized controlled trial of alert-based computerized decision support to increase prescription of anticoagulation in hospitalized patients with AF. To determine the clinical characteristics and outcomes of those patients whose inpatient health care providers received a computer alert, we analyzed all 248 patients in the alert group. Patients for whom providers elected to omit anticoagulation and provided a rationale of a perceived high risk of bleeding were compared with those who were not designated as high-risk. Perceived high risk of bleeding was the most common reason (77%) for omitting anticoagulation. Median HAS-BLED scores were similar in these patients compared with those who were not deemed to have an increased bleeding risk (3 vs. 3, p = 0.44). Despite being categorized as too high-risk for bleeding to receive antithrombotic therapy at the time of the alert, nearly 12% of these patients were ultimately prescribed anticoagulation by 90 days. The frequency of major and clinically-relevant non-major bleeding was similar between the groups. The frequency of death, myocardial infarction, stroke, or systemic embolic event was similar in both groups (10.2% vs. 12.4%, p = 0.59). In conclusion, a perceived high risk of bleeding was the most common reason for omission of anticoagulation in patients with AF after a computerized alert. Perceived high risk of bleeding was not reflected in a higher HAS-BLED score.Clinical trial registration: ClinicalTrials.gov Identifier: NCT02339493 https://clinicaltrials.gov/ct2/show/NCT02339493 In a randomized controlled trial of computerized decision support to increase prescription of antithrombotic therapy in hospitalized patients with atrial fibrillation (AF), a perceived high risk of bleeding was the most common reason (77%) for omitting antithrombotic therapy after an on-screen alert. Median HAS-BLED scores were similar in these patients compared with those who were not deemed to have an increased bleeding risk (3 vs. 3, p = 0.44). Despite being categorized as too high-risk for bleeding to receive antithrombotic therapy for stroke prevention at the time of the alert, nearly 12% of these patients were ultimately prescribed anticoagulation over the ensuing 90 days.

Percutaneous Left Atrial Appendage Occlusion: A View From the UK

AF is associated with an increased risk of thromboembolic events, which is usually managed with oral anticoagulation therapy. However, despite a broad range of anticoagulant options and improved uptake in anticoagulation over the past decade, there are some limitations to this approach. Percutaneous left atrial appendage occlusion has been shown to be an effective alternative in this setting, and population data suggest a clear demand for this procedure. Over the past decade, several important changes to the commissioning and delivery of this service have occurred in the UK. In this article, the authors describe the use of percutaneous left atrial appendage occlusion in the UK and discuss the challenges that lie ahead.

Treatment strategies for patients with atrial fibrillation and anticoagulant-associated intracranial hemorrhage: an overview of the pharmacotherapy

INTRODUCTION

Oral anticoagulants (OAC) reduce stroke/systemic embolism and mortality risks in atrial fibrillation (AF). However, there is an inherent bleeding risk with OAC, where intracranial hemorrhage (ICH) is the most feared, disabling, and lethal complication of this therapy. Therefore, the optimal management of OAC-associated ICH is not well defined despite multiple suggested strategies.

AREAS COVERED

In this review, the authors describe the severity and risk factors for OAC-associated ICH and the associated implications for using DOACs in AF patients. We also provide an overview of the management of OAC-associated ICH and treatment reversal strategies, including specific and nonspecific reversal agents as well as a comprehensive summary of the evidence about the resumption of DOAC and the optimal timing.

EXPERT OPINION

In the setting of an ICH, supportive care/measures are needed, and reversal of anticoagulation with specific agents (including administration of vitamin K, prothrombin complex concentrates, idarucizumab and andexanet alfa) should be considered. Most patients will likely benefit from restarting anticoagulation after an ICH and permanently withdrawn of OAC is associated with worse clinical outcomes. Although the timing of OAC resumption is still under debate, reintroduction after 4-8 weeks of the bleeding event may be possible, after a multidisciplinary approach to decision-making.

Incidence and causes of in-hospital outcomes and 30-day readmissions after percutaneous left atrial appendage closure: A US nationwide retrospective cohort study using claims data

BACKGROUND

Percutaneous left atrial appendage closure (pLAAC) emerged as an option for stroke prevention in patients with atrial fibrillation ineligible for long-term anticoagulation. Real-world data on pLAAC's in-hospital and 30-day readmission measures are limited.

OBJECTIVE

We sought to report the nationwide incidence of the above outcomes using 2016 claims data.

METHODS

We used the National Inpatient Sample for in-hospital outcomes and Nationwide Readmissions Database for readmissions. We identified hospitalizations with a primary diagnosis of atrial fibrillation and pLAAC procedure by using International Classification of Diseases, Tenth Revision codes and compared the outcomes mentioned above between the endocardial and epicardial cohorts. Statistical analyses were performed using R 3.3.2.

RESULTS

Among 5480 pLAAC procedures (endocardial: 5145; epicardial: 335), the in-hospital mortality was 0.3%. Endocardial left atrial appendage closure (LAAC) had lower complications (8.5% vs 25.4%; P < .001) and shorter length of stay median [interquartile range] 1 [1-1] day vs 2 [1-3] days; P < .001) but higher hospitalization cost (24.13 [18.45-30.17] × 1000 dollars vs 21.21 [14.03-27.86] × 1000 dollars; P = .016). The most common complications include pericardial (endocardial vs epicardial: 3% vs 10.4%; P < .001) and renal failure (1.4% vs 6.0%; P = .004). Epicardial LAAC had higher 30-day unplanned readmissions (19.5% vs 8.3%; P = .001), with the most common reason being pericarditis and/or effusion (33.9%).

CONCLUSION

Endocardial LAAC had lower complications and 30-day readmissions but higher hospitalization cost. Although epicardial LAAC showed higher complications, given recent improvements in its technique, and postprocedural care demonstrated a significant reduction in pericardial complications, more contemporary data comparing these outcomes are needed.

Left Atrial Appendage Epicardial Clip (AtriClip): Essentials and Post-Procedure Management

Left atrial appendage exclusion is a viable alternative to anticoagulation for stroke risk reduction in atrial fibrillation patients. In this article we address the essentials and post-procedural management of left atrial appendage exclusion using the AtriClip.

Plasma contact factors as therapeutic targets

Direct oral anticoagulants (DOACs) are small molecule inhibitors of the coagulation proteases thrombin and factor Xa that demonstrate comparable efficacy to warfarin for several common indications, while causing less serious bleeding. However, because their targets are required for the normal host-response to bleeding (hemostasis), DOACs are associated with therapy-induced bleeding that limits their use in certain patient populations and clinical situations. The plasma contact factors (factor XII, factor XI, and prekallikrein) initiate blood coagulation in the activated partial thromboplastin time assay. While serving limited roles in hemostasis, pre-clinical and epidemiologic data indicate that these proteins contribute to pathologic coagulation. It is anticipated that drugs targeting the contact factors will reduce risk of thrombosis with minimal impact on hemostasis. Here, we discuss the biochemistry of contact activation, the contributions of contact factors in thrombosis, and novel antithrombotic agents targeting contact factors that are undergoing pre-clinical and early clinical testing.

A Propensity Score Matched Comparison of Clinical Outcomes in Atrial Fibrillation Patients Taking Vitamin K Antagonists: Comparing the "Real-World" vs Clinical Trials

OBJECTIVE

To investigate the incidence and risk of adverse clinical outcomes in a "real-world" cohort of patients with atrial fibrillation (AF) anticoagulated with vitamin K antagonists (VKAs) from the Murcia AF Project in comparison with the warfarin arm of the randomized clinical trial (RCT) AMADEUS (Evaluating the Use of SR34006 Compared to Warfarin or Acenocoumarol in Patients With Atrial Fibrillation).

PATIENTS AND METHODS

We included 1361 patients with AF from the Murcia AF Project (recruitment from May 1, 2007, to December 1, 2007) and 2293 from the AMADEUS trial (started in September 2003 and primary completed in March 2006), all taking VKA treatment. After propensity score matching (PSM), we investigated differences in rates and risks of several events, including major bleeding, ischemic stroke, and all-cause mortality at 365 (interquartile range, 275-428) days of follow-up.

RESULTS

After PSM there were 1324 patients for the comparative analysis, whereby annual event rates for most adverse events were significantly higher in the "real-world" population. Cox regression analyses demonstrated that the risk of primary outcomes was also increased in the "real-world" (vs RCT: hazard ratio [HR], 6.32; 95% CI, 2.84-14.03 for major bleeding; HR, 3.56, 95% CI, 1.22-10.42 for ischemic stroke; HR, 5.13, 95% CI, 3.02-8.69 for all-cause mortality). The risk of all other adverse events was higher in the real-world cohort, except for cardiovascular mortality.

CONCLUSION

This study comparing the Murcia AF Project and the AMADEUS trial demonstrates that there is a great heterogeneity in both populations, which is translated into a higher risk of several adverse outcomes in the real-world cohort, including major bleeding, ischemic stroke, and mortality.

Contemporary approach to stroke prevention in atrial fibrillation: Risks, benefits, and new options

Atrial fibrillation is a common diagnosis affecting nearly 3 million adults in the United States. Morbidity and mortality in these patients is driven largely by the associated increased risk of thromboembolic complications, especially stroke. Atrial fibrillation is a stronger risk factor than hypertension, coronary disease, or heart failure and is associated with an approximately five-fold increased risk. Mitigating stroke risk can be challenging and requires accurate assessment of stroke risk factors and careful selection of appropriate therapy. Anticoagulation, including the more recently introduced direct oral anticoagulants, is the standard of care for most patients. In addition, emerging non-pharmacologic mechanical interventions are playing an expanding role in reducing stroke risk in select patients. In this review we highlight the current approach to stroke risk stratification in atrial fibrillation and discuss in detail the mechanism, risks, and benefits of current and evolving therapies.