Apixaban in Comparison With Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease

Real-World Use and Outcomes of Apixaban for Early Post-Surgical Fontan Thromboprophylaxis

Patients with Fontan physiology are at heightened risk of thrombosis related to passive venous return leading to increased stasis, as well as acquired thrombophilia from congestive hepatopathy. Variability exists for post-Fontan thromboprophylaxis, with no consensus on best practices. Direct oral anticoagulants offer advantages over conventional anticoagulants including fewer drug-drug interactions, no dietary restrictions, and less frequent monitoring. Herein, we report our single center experience utilizing apixaban thromboprophylaxis in children post-Fontan procedure. Single center, retrospective, cohort study evaluating apixaban thromboprophylaxis dosing strategies, efficacy, and safety in children admitted post-Fontan procedure at Boston Children's Hospital. Between September 2019 and December 2023, 62 children, median age 3.2 years (2.1-10.5 years), weight 13.9 kg (9.5-56.3 kg) received apixaban at a median of 93 days post-Fontan (7-1421 days). Over a total of 93 days of apixaban exposure, there was 1 treatment-related thrombosis event (0.07 per 1000 person-days on apixaban) and 3 combined treatment-related clinically relevant non-major (CRNM) and major bleeding events (0.22 per 1000 person-days on apixaban). Apixaban for post-Fontan thromboprophylaxis was feasible with low rates of bleeding and thrombosis.

Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants Compared with Vitamin K Antagonists in Patients with Atrial Fibrillation and Type 2 Valvular Heart Disease: A Systematic Review and Meta-Analysis

PURPOSE

This meta-analysis aimed to evaluate the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) compared with vitamin K antagonists (VKAs) in patients with atrial fibrillation (AF) and type 2 valvular heart disease (VHD).

METHODS

We searched the PubMed, LILACS, and MEDLINE databases to retrieve, randomized controlled trials (RCTs) comparing NOACs and VKAs in patients with AF and type 2 VHD, excluding mitral stenosis (moderate to severe, of rheumatic origin) or mechanical heart valves. The efficacy outcomes assessed were stroke and systemic embolism (SE), while safety outcomes included major bleeding and intracranial hemorrhage (ICH).

RESULTS

Seven RCTs, including 16,070 patients with AF and type 2 VHD, were included. NOACs reduced the risk of stroke/SE (relative risk [RR], 0.75; 95% confidence interval [CI], 0.64-0.89; P = 0.0005), with no significant difference in major bleeding (RR, 0.88; 95% CI, 0.64-1.21; P = 0.43). The risk of ICH was reduced with NOACs (RR, 0.46; 95% CI, 0.27-0.77; P = 0.003). For patients with AF and bioprosthetic heart valve (five trials, 2805 patients), stroke/SE risks (RR, 0.65, 95% CI, 0.44-0.96) with NOACs were superior to VKAs. Major bleeding risks without ENVISAGE TAVI AF trial (RR, 0.53; 95% CI, 0.30-0.94; P = 0.03) with NOACs were superior to VKAs. The risks of ICH (RR, 0.61; 95% CI 0.34-1.09; P = 0.09) with NOACs were comparable to VKAs.

CONCLUSIONS

NOACs demonstrate efficacy and safety in patients with AF and type 2 VHD and reduce the risk of stroke/SE and ICH when compared with those with VKAs.

Comparison between non-vitamin K oral antagonist versus warfarin in atrial fibrillation with and without valvular heart disease: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) poses a significant stroke risk in heart disease patients. This systematic review aims to evaluate the efficacy and safety of non-vitamin K oral antagonists (NOACs) versus vitamin K antagonists (VKAs) in AF patients with and without any valvular heart disease (VHD/N-VHD).

METHODS

A systematic search was conducted on PubMed, Scopus, and Google Scholar up to March 3, 2022. Efficacy and safety parameters were analyzed.

RESULTS

A total of 85,423 subjects from 10 studies were included in this meta-analysis. NOACs and VKAs showed similar effects on ischemic stroke in AF patients with VHD/N-VHD (RR 0.97; 95% CI 0.72-1.30; p = 0.83) and also on systemic embolic events (RR 1.02; 95% CI 0.83-1.25; p = 0.86). Similar effects were seen in VHD and N-VHD subgroups. Both treatments had similar effects on myocardial infarction in AF patients with VHD/N-VHD (RR 0.79; 95% CI 0.49-1.26; p = 0.32), VHD (RR 0.78; 95% CI 0.59-1.02; p = 0.07), and N-VHD subgroups (RR 0.82; 95% CI 0.30-2.21; p = 0.69). NOACs reduced the risk of intracranial bleeding in AF VHD/N-VHD (RR 0.64; 95% CI 0.54-0.77; p < 0.0001), VHD (RR 0.59; 95% CI 0.42-0.82; p = 0.002), and N-VHD subgroups (RR 0.70; 95% CI 0.57-0.85; p = 0.0003). Additionally, NOACs reduced the risk of gastrointestinal bleeding in AF VHD/N-VHD (RR 0.80; 95% CI 0.66-0.96; p = 0.02), specifically in the VHD subgroup (RR 0.69; 95% CI 0.54-0.89; p = 0.004). Moreover, NOACs were associated with a decreased risk for minor and non-fatal bleeding in AF patients with VHD/N-VHD (RR 0.86; 95% CI 0.75-0.99; p = 0.04).

CONCLUSION

NOACs are effective and safe for ischemic stroke, systemic embolic events, myocardial infarction, intracranial bleeding, and gastrointestinal bleeding in AF patients with VHD/N-VHD.

Efficacy and Safety of Edoxaban in Anticoagulant Therapy Early After Surgical Bioprosthetic Valve Replacement: Rationale and Design of the ENBALV Trial

BACKGROUND AND PURPOSE

Anticoagulant therapy with vitamin K antagonists is recommended within 3 to 6 months after bioprosthetic valve replacement to prevent thromboembolic events. However, data regarding whether direct oral anticoagulants can be an alternative to warfarin in such patients are limited. The purpose of this study is to compare the efficacy and safety of edoxaban versus warfarin within 3 months after bioprosthetic valve replacement.

METHODS

The ENBALV trial is an investigator-initiated, phase 3, randomized, open-label, multicenter study. It involves patients aged 18 to 85 years undergoing bioprosthetic valve replacement at the aortic and/or mitral position. They are randomized 1:1 to receive either edoxaban or warfarin. Administration of edoxaban or warfarin is to be continued for 12 weeks after surgery. The primary outcome is the occurrence rate of stroke or systemic embolism at 12 weeks after surgery. The net clinical outcome is a composite of stroke, systemic embolism, or major bleeding, which is included in the secondary outcomes.

CONCLUSION

The ENBALV trial demonstrates the efficacy and safety of edoxaban compared with warfarin in patients early after bioprosthetic valve replacement, including patients with sinus rhythm, which will bring a significant benefit to patients in clinical practice.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCT) 2051210209. 30 Mar 2022 https://jrct.niph.go.jp/latest-detail/jRCT2051210209 .

Comparison of Effectiveness and Safety of Apixaban, Dabigatran, and Rivaroxaban in Patients With Valvular Atrial Fibrillation: A Network Meta-Analysis of Randomized-Control Trials and Observational Studies

The objective of this network meta-analysis was to assess the efficacy and safety of apixaban, dabigatran, rivaroxaban, and edoxaban in patients diagnosed with atrial fibrillation and valvular heart disease. A comprehensive search was conducted across various electronic databases, including PubMed, Embase, and Web of Science, from inception to February 15, 2024. The search strategy utilized a combination of medical subject headings (MeSH) terms and relevant keywords related to valvular heart disease, atrial fibrillation, anticoagulant therapy, and study design, such as randomized controlled trials and observational studies. The outcomes evaluated in this analysis comprised the incidence of stroke or systemic embolism (SE), as well as the occurrences of major bleeding events. A total of 10 studies were incorporated into this meta-analysis, encompassing 40,662 participants. Of these, 12,385 received apixaban, 2,829 received dabigatran, 13,662 received rivaroxaban, 2,582 received edoxaban, and 9,202 received warfarin. The duration of follow-up in the included studies ranged from 3 to 54 months. Among the four direct oral anticoagulants (DOACs) studied, apixaban demonstrated a significant reduction in the risk of stroke or SE when compared to other DOACs and warfarin, highlighting its efficacy in patients with atrial fibrillation and valvular heart disease. Additionally, apixaban exhibited a lower risk of major bleeding events, further emphasizing its favorable safety profile compared to the other agents assessed. In conclusion, our findings suggest that apixaban may be more effective and safer than other DOACs and warfarin in this patient population. However, additional studies are warranted to compare the various DOACs in this cohort to identify the optimal treatment strategy for preventing adverse outcomes.

Apixaban-Associated Intracranial Hemorrhage in a Patient With Elevated International Normalized Ratio

Apixaban has been associated with prolongation of the international normalized ratio (INR), but data surrounding the extent of elevation and its clinical significance are limited. Due to interaction between apixaban and the prothrombin assay, elevations in INR in patients receiving apixaban are common and not always grounds for concern. However, in high risk patients, elevations can represent a need for closer monitoring. This case summarizes an 82-year-old woman with a history of atrial fibrillation and left middle cerebral artery strokes with no residual deficits. She presented with right-sided hemiparesis and aphasia and underwent a mechanical thrombectomy with TICI 2b recanalization of a left M1 occlusion. Post-thrombectomy, she was found to have a left atrial thrombus and 10 days later was started on apixaban 5 mg twice daily. On the fourth day of apixaban therapy, she experienced an INR increase to 2.3, prompting initiation of a vitamin K challenge for nutritional deficiency. Despite initial improvement, her INR increased to 2.7 a week after apixaban was initiated, coinciding with a decline in mental status and an apixaban peak level of 435.6 ng/mL (reference range 91-321 ng/mL). A computed tomography (CT) scan of her head showed new intracranial hemorrhage in the area of her previous infarction, prompting apixaban reversal with andexanet alfa. Unfortunately, the patient expired. This case report highlights the importance and difficulty in performing therapeutic drug monitoring in patients receiving oral anti-factor Xa inhibitors, revealing a downside to administration of high-risk medications that do not have readily available monitoring.

Use of Direct-Acting Oral Anticoagulants in Patients With Atrial Fibrillation and Significant Tricuspid Regurgitation

BACKGROUND

There are limited data on the efficacy and safety of direct oral anticoagulants (DOACs) in patients with atrial fibrillation with significant tricuspid regurgitation (TR), which can lead to hepatic dysfunction and intestinal malabsorption. We aimed to compare the efficacy and safety of DOACs and warfarin for patients with atrial fibrillation with significant (moderate to severe) TR.

METHODS AND RESULTS

A total of 1215 patients with significant TR and atrial fibrillation who were treated with warfarin (N=491) or DOACs (N=724) were retrospectively analyzed. The primary outcomes were ischemic stroke, systemic embolic events, and hospitalization for major bleeding. The secondary outcomes were intracranial hemorrhage, hospitalization for gastrointestinal bleeding, all-cause mortality, and a composite outcome. The median follow-up duration was 2.4 years. In the inverse probability treatment weighting-adjusted cohort, DOACs and warfarin had a similar risk for ischemic stroke and systemic embolic events (adjusted hazard ratio [aHR], 0.95 [95% CI, 0.67-1.36]; P=0.79) and major bleeding (aHR, 0.78 [95% CI, 0.57-1.06]; P=0.11). For the secondary outcomes, relative to warfarin, DOACs had a lower risk of intracranial hemorrhage and the composite outcome, and a comparable risk for gastrointestinal bleeding and all-cause mortality. In the subgroup analysis, the effects of DOACs on ischemic stroke and systemic embolic events were comparable to the effects of warfarin, even in patients with inferior vena cava plethora (increased right atrial pressure) or severe TR.

CONCLUSIONS

In this study, relative to warfarin, DOACs demonstrated comparable efficacy for ischemic stroke and systemic embolic events and major bleeding, with a lower intracranial hemorrhage risk in patients with significant TR and atrial fibrillation, indicating their effectiveness and safety.

Thromboembolic and bleeding events after valvular intervention in patients with atrial fibrillation

AIM

To assess outcomes after cardiac surgery with biological valve replacement, valve repair or transcatheter aortic valve implantation (TAVI) in patients with atrial fibrillation (AF) in accordance with oral anticoagulant (OAC) treatment.

METHODS

All patients in Sweden undergoing valvular intervention with AF were included. Associations between OAC exposure and cardiovascular (CV) events (composite of CV death, ischaemic stroke or systemic embolism) and major bleeding were investigated using Cox regression analysis. The analysis was separated in time periods of 0-3 and 3-12 months after discharge.

RESULTS

4730 patients were included in the first time period, 54.0% had received a surgical biological valve prosthesis, 23.8% valve repair and 22.2% TAVI. Exposure to warfarin (comparator) was 62.3%, to non-vitamin K antagonist oral anticoagulants (NOACs) 10.0% and to no OAC 27.7%. NOAC exposure was associated with similar risk of the composite CV outcome and major bleeding from 0 to 3 months. No OAC was associated with increased risk of the composite CV outcome (HR 1.71; 95% CI 1.26 to 2.32) and similar risk of major bleeding. Further analysis of the bioprosthetic valve replacement subgroup indicated increased risk of CV death when exposed to NOAC (HR 2.58; 95% CI 1.15 to 5.78) and no OAC (HR 2.82; 95% CI 1.65 to 4.82) compared with warfarin from 0 to 3 months. No differences were seen between 3 and 12 months.

CONCLUSION

In this registry-based cohort study of patients with AF with severe valvular heart disease undergoing various valvular interventions, NOAC appears to be comparable with warfarin regarding efficacy and safety. Patients not receiving OAC had higher risk of CV events. NOAC was associated with increased CV death compared with warfarin in the surgical bioprosthetic valve replacement subgroup, illustrating the importance of being cautious when extrapolating data from one patient group to another. Further studies comparing NOAC and warfarin in the early postoperative phase are warranted, especially following surgical bioprosthetic valve replacement.

Ischaemic stroke in a patient with non-valvular atrial fibrillation (NVAF) despite non-vitamin K oral anticoagulant (NOAC) therapy

Primary stroke prevention in non-valvular atrial fibrillation (NVAF) is primarily with non-vitamin K oral anticoagulant (NOAC) therapy. However, 20-36% of ischaemic strokes seem to occur in patients with atrial fibrillation while already on anticoagulation. We present a case of an ischaemic stroke in an elderly female in her 70s with medical history significant for hypertension and NVAF. She had a CHA2DS2-VASc score of 3 and was on apixaban for thromboprophylaxis. She presented with neurological deficits consistent with a left middle cerebral artery stroke, confirmed via head imaging; the most likely stroke aetiology was determined to be cardioembolic in the setting of NVAF. She was treated with continuation of her apixaban at the same dosage She displayed improved function, although with residual expressive aphasia at her 2-month neurology follow-up. Cardioembolic ischaemic stroke in NVAF despite current NOAC therapy does not have current management guidelines.

Expanding Indications of Nonvitamin K Oral Anticoagulants Beyond Nonvalvular Atrial Fibrillation and Venous Thromboembolism: A Review of Emerging Clinical Evidence

Direct oral anticoagulants (DOAC) have emerged as a new therapy for patients who need and can tolerate oral anticoagulation. DOACs were initially approved for nonvalvular atrial fibrillation (NVAF) and treatment for deep vein thrombosis (DVT) and pulmonary embolism (PE). Ease of administration, no requirement of bridging with other anticoagulants, and less frequent dosing have made DOACs preferable choice for anticoagulation. Studies are showing promising results regarding use of DOACs beyond the common indications. Studies have been done to show the potential benefit of DOACs in valvular atrial fibrillation, heart failure, acute coronary syndrome, stroke, and peripheral arterial disease. Data have shown safety as well as comparable bleeding incidences with DOACs compared to vitamin K antagonist anticoagulants. Naturally interest is growing to see the use of DOACs apart from the NVAF, DVT, or PE. Authors have highlighted various study results to show the potential beneficial role of DOACs in the above-mentioned situations.

An Evidence-Based Approach to Anticoagulation Therapy Comparing Direct Oral Anticoagulants and Vitamin K Antagonists in Patients With Atrial Fibrillation and Bioprosthetic Valves: A Systematic Review, Meta-Analysis, and Network Meta-Analysis

Direct oral anticoagulants (DOACs) are a newer class of anticoagulants that inhibit factor Xa or factor IIa and include drugs such as rivaroxaban, apixaban, edoxaban, betrixaban, and dabigatran. Although vitamin K antagonists (VKAs) have been traditionally used to prevent thromboembolic events, DOACs have gained popularity because of their faster onset and offset of action and reduced need for monitoring. This study aimed to provide more data for anticoagulants in patients with atrial fibrillation with bioprosthetic heart valves by incorporating all available trials to date. A search was performed across 5 electronic databases to identify relevant studies. We analyzed the data using a pooled risk ratio for categorical outcomes and used the I2 test to determine heterogeneity. The quality of randomized controlled trials was assessed using the Cochrane risk of bias assessment tool, and the National Institutes of Health tool was used for observational studies. Our study included a frequentist network meta-analysis (MA) of the aggregate data to obtain the network estimates for the outcomes of interest. We retrieved 28 studies with a total of 74,660 patients with bioprosthetic heart valves. Our MA significantly showed that DOACs decrease the risk of all-cause bleeding (risk ratio [RR] 0.80, 95% confidence interval [CI] 0.75 to 0.85, p >0.00001), stroke and systemic embolization (RR 0.89, 95% CI 0.80 to 0.99, p = 0.03), and intracranial bleeding outcomes (RR 0.62, 95% CI 0.45 to 0.86, p = 0.004) compared with VKA. In contrast, there was no significant difference between the compared groups in major bleeding (RR = 0.92, 95% CI 0.84 to 1.02, p = 0.10) and all-cause mortality outcomes (RR = 0.96, 95% CI 0.85 to 1.07, p = 0.43), respectively. In addition, the network MA results did not favor any of the studied interventions over each other (p <0.05) regarding all-cause bleeding, mortality, stroke and systemic embolization, and major bleeding outcomes. In conclusion, our study found that DOACs are more effective in reducing the risk of bleeding, stroke, systemic embolism, and intracranial bleeding than VKAs. However, no significant difference was observed in the incidence of gastrointestinal bleeding, major bleeding, thromboembolic events, and all-cause mortality. In addition, our network MA did not identify any specific DOAC treatment as more favorable than others.

Atrial fibrillation and stroke prevention: 25 years of research at EP Europace journal

Stroke prevention in patients with atrial fibrillation (AF) is one pillar of the management of this common arrhythmia. Substantial advances in the epidemiology and associated pathophysiology underlying AF-related stroke and thrombo-embolism are evident. Furthermore, the introduction of the non-vitamin K antagonist oral anticoagulants (also called direct oral anticoagulants) has clearly changed our approach to stroke prevention in AF, such that the default should be to offer oral anticoagulation for stroke prevention, unless the patient is at low risk. A strategy of early rhythm control is also beneficial in reducing strokes in selected patients with recent onset AF, when compared to rate control. Cardiovascular risk factor management, with optimization of comorbidities and attention to lifestyle factors, and the patient's psychological morbidity are also essential. Finally, in selected patients with absolute contraindications to long-term oral anticoagulation, left atrial appendage occlusion or exclusion may be considered. The aim of this state-of-the-art review article is to provide an overview of the current status of AF-related stroke and prevention strategies. A holistic or integrated care approach to AF management is recommended to minimize the risk of stroke in patients with AF, based on the evidence-based Atrial fibrillation Better Care (ABC) pathway, as follows: A: Avoid stroke with Anticoagulation; B: Better patient-centred, symptom-directed decisions on rate or rhythm control; C: Cardiovascular risk factor and comorbidity optimization, including lifestyle changes.

Aortic Stenosis and Outcomes in Patients With Atrial Fibrillation: A Nationwide Cohort Study

Background Patients with aortic stenosis (AS) have been underrepresented in the trials evaluating direct oral anticoagulants (DOACs) in atrial fibrillation (AF). We aimed to assess whether AS impacts outcomes in patients with AF and estimate the effects of DOACs versus warfarin in patients with AF and AS. Methods and Results The registry-based FinACAF (Finnish Anticoagulation in Atrial Fibrillation) study covered all patients with AF diagnosed during 2007 to 2018 in Finland. Hazard ratios (HRs) of first-ever gastrointestinal bleeding, intracranial bleeding, any bleeding, ischemic stroke, and death were estimated with cause-specific hazards regression adjusted for anticoagulant exposure variables. We identified 183 946 patients (50.5% women; mean age, 71.7 [SD, 13.5] years) with incident AF without prior bleeding or ischemic stroke, of whom 5231 (2.8%) had AS. The crude incidence rate of all outcomes was higher in patients with AS than in patients without AS. After propensity score matching, AS was associated with the hazard of any bleeding, gastrointestinal bleeding, and death but not with intracranial bleeding or ischemic stroke (adjusted HRs, 1.36 [95% CI, 1.25-1.48], 1.63 [95% CI, 1.43-1.86], 1.32 [95% CI, 1.26-1.38], 0.96 [95% CI, 0.78-1.17], and 1.11 [95% CI, 0.99-1.25], respectively). Among patients with AS, DOACs were associated with a lower risk of ischemic stroke when compared with warfarin, while bleeding and mortality did not differ between DOACs and warfarin. Conclusions AS is associated with substantially higher risk of gastrointestinal bleeding in patients with AF. DOACs may be more effective in preventing ischemic stroke than warfarin in patients with AF and AS. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04645537.

DOACs and rheumatic valvulopathy: always a red light?

Despite the sharp decline in most high-income industrialized countries, rheumatic heart disease (RHD) continues to be highly prevalent in many rural, low- and middle-income countries. RHD most frequently involves the mitral valve, both in the form of isolated regurgitation and in the form of regurgitation associated with mitral stenosis (mitral stenosis, MS). Atrial fibrillation (AF) is a common complication of RHD that is independently associated with an increased risk of death, heart failure, and systemic thromboembolism. Few studies have focused on the issue of the best oral anticoagulation strategy for patients with RHD and AF. Randomized trials establishing the non-inferiority of new direct oral anticoagulants (DOACs) over vitamin K antagonists (VKAs) in the prevention of stroke and systemic embolism excluded AF patients with mechanical valves or with moderate-to-severe MS. Nevertheless, variable proportions of patients with other VHD types were included. Recently, the INVICTUS trial demonstrated that in patients with RHD-related AF, direct oral anticoagulant rivaroxaban is inferior to VKAs in preventing stroke, systemic embolism, myocardial infarction, or death and is similar in bleeding risk. These results confirm and reinforce the recommendations of current international guidelines supporting the use of VKAs in patients with RHD-related AF.

Anticoagulation for rheumatic mitral stenosis, INVICTUS in perspective

PURPOSE OF REVIEW

Rheumatic mitral stenosis (MS) while declining in high- and middle-income countries, continues to be a major cause of death and disability in low-income countries. Although the nonvitamin-K antagonist oral anticoagulants (NOACs) have essentially supplanted vitamin K antagonists (VKA) in patients with nonvalvular atrial fibrillation (AF), their efficacy for stroke prevention in patients with rheumatic MS and AF has not been widely studied until recently. The purpose of this review is to provide a succinct synopsis of the current anticoagulation recommendations for patients with native and prosthetic heart valve disease, with a specific focus on patients with rheumatic MS.

RECENT FINDINGS

The INVICTUS trial was the first large randomized evaluation of a NOAC vs. VKA in approximately 4600 patients with moderate to severe rheumatic MS and AF. The primary outcome of stroke, systemic embolization, myocardial infarction, vascular and all-cause death, VKA treated patients exhibited lower event rates (including mortality) compared to rivaroxaban. We discuss and contextualize these findings as they relate to the broader use of anticoagulants in patients with valvular heart disease, with and without concomitant AF.

SUMMARY

VKA remains the standard of care for patients with moderate to severe rheumatic MS who have concomitant AF. Rates of stroke in anticoagulated patients with rheumatic MS and AF are lower than what is traditionally held, while nonstroke related deaths remain the most common mechanism of mortality.

Trend of anticoagulant therapy in elderly patients with atrial fibrillation considering risks of cerebral infarction and bleeding

The introduction of direct oral anticoagulants (DOACs) has greatly changed the use of anticoagulant therapy in patients with non-valvular atrial fibrillation (Af). Therefore, this study aimed to examine changes in the proportions of oral anticoagulant prescriptions in patients with non-valvular Af aged ≥ 65 years, taking into consideration the risk of cerebral infarction and bleeding. Anticoagulant prescriptions in outpatients aged ≥ 65 years with Af were temporally analyzed using the nationwide claims database in Japan. Trends in anticoagulant prescriptions were examined according to cerebral infarction and bleeding risk. The proportion of anticoagulant prescriptions for 12,076 Af patients increased from 41% in 2011 to 56% in 2015. An increase in DOAC prescriptions was accompanied by an increase in the proportion of anticoagulant prescriptions in each group according to the CHA2DS2-VASc and HAS-BLED scores. The proportion of anticoagulant prescriptions for patients with a high risk of developing cerebral infarction and bleeding showed a marked increase. Trends in anticoagulant prescriptions in Af patient with a CHA₂DS₂-VASc score ≥ 2 and HAS-BLED scores ≥ 3 showed a marked increase in DOAC prescriptions. The widespread use of DOACs greatly changes the profile the prescription of anticoagulant therapy in patients with Af.

To Measure or Not to Measure: Direct Oral Anticoagulant Laboratory Assay Monitoring in Clinical Practice

The need for therapeutic drug monitoring of direct oral anticoagulants (DOACs) remains an area of clinical equipoise. Although routine monitoring may be unnecessary given predictable pharmacokinetics in most patients, there may be altered pharmacokinetics in those with end organ dysfunction, such as those with renal impairment, or with concomitant interacting medications, at extremes of body weight or age, or in those with thromboembolic events in atypical locations. We aimed to assess real-world practices in situations in which DOAC drug-level monitoring was used at a large academic medical center. A retrospective review of the records of patients who had a DOAC drug-specific activity level checked from 2016 to 2019 was included. A total of 119 patients had 144 DOAC measurements (apixaban (n = 62) and rivaroxaban (n = 57)). Drug-specific calibrated DOAC levels were within an expected therapeutic range for 110 levels(76%), with 21 levels (15%) above the expected range and 13 levels (9%) below the expected range. The DOAC levels were checked in the setting of an urgent or emergent procedure in 28 patients (24%), followed by renal failure in 17 patients (14%), a bleeding event in 11 patients (9%), concern for recurrent thromboembolism in 10 patients (8%), thrombophilia in 9 patients (8%), a history of recurrent thromboembolism in 6 patients (5%), extremes of body weight in 7 patients (5%), and unknown reasons in 7 patients (5%). Clinical decision making was infrequently affected by the DOAC monitoring. Therapeutic drug monitoring with DOACs may help predict bleeding events in elderly patients, those with impaired renal function, and in the event of an emergent or urgent procedure. Future studies are needed to target the select patient-specific scenarios where monitoring DOAC levels may impact clinical outcomes.

Novel Oral Anticoagulants in Patients With Atrial Fibrillation and Moderate to Severe Mitral Stenosis: A Systematic Review

The use of novel oral anticoagulants (NOAC) in patients with moderate to severe mitral stenosis (MS) and atrial fibrillation (AF) is not recommended. We aimed to evaluate the efficacy and safety of NOAC usage compared to vitamin K antagonist (VKA) in patients with moderate to severe MS and AF. We conducted a systematic review to identify articles that compared warfarin to NOAC in patients with moderate to severe MS and AF. Only four studies (two observational studies and two trials) met our search criteria and reported a total of 7529 patients with MS and AF with MS and AF, 4138 of them treated with NOAC. In both observational studies, the severity of MS was not determined, and there was heterogeneity in MS etiology. Nevertheless, both studies showed a positive signal toward the efficacy and safety of NOAC compared to VKA in this population. A randomized pilot trial (n=40) was done on patients with moderate to severe MS, and it showed further acceptable efficacy and safety for rivaroxaban use. However, a larger randomized controlled trial (n=4531) disclosed that VKA (warfarin) led to a significantly lower rate of a composite of cardiovascular events or mortality than rivaroxaban, without a higher rate of major bleeding but not fatal bleeding. Our systematic review provides exploratory information on NOAC safety and effectiveness in patients with MS; it also discourages using NOACs for patients with moderate to severe MS and supports the current treatment guidelines. However, more dedicated clinical trials evaluating the use of NOACs in moderate to severe MS are underway. They will categorically establish the safety profile and clinical effectiveness of NOAC in this high-risk population.

Gastrointestinal Bleeding Due to NOACs Use: Exploring the Molecular Mechanisms

Novel oral anticoagulants (NOACs) are drugs approved for the prevention and treatment of many thromboembolic cardiovascular conditions as a safer alternative to warfarin. We reviewed studies published in PubMed^®, UpToDate^®, Web of Science^®, and Cochrane^® about NOACs' risks and benefits in patients requiring anticoagulation, with a focus on gastrointestinal bleeding and on molecular and pathophysiological mechanisms underlying the risk of bleeding in patients treated with them. Apixaban resulted in a lower rate of gastrointestinal bleeding compared to dabigatran and rivaroxaban. However, data reported that gastrointestinal bleeding in patients treated with NOACs was less severe compared to warfarin. Studies show promising results on the increased and widespread use of NOACs in patients who require anticoagulation (for example-in case of atrial fibrillation or high risk of venous thromboembolism), reporting an overall lower risk of major bleeding events. The profile of NOACs was more effective and secure compared to warfarin, but a more careful medical prescription is required in patients who are at high risk of gastrointestinal bleeding.

Apixaban Versus Rivaroxaban in Patients With Atrial Fibrillation and Valvular Heart Disease : A Population-Based Study

BACKGROUND

Although apixaban and rivaroxaban are commonly used in patients with atrial fibrillation (AF) and valvular heart disease (VHD), there is limited evidence comparing the 2 drugs in these patients.

OBJECTIVE

To emulate a target trial of effectiveness and safety of apixaban and rivaroxaban in patients with AF and VHD.

DESIGN

New-user, active comparator, cohort study design.

SETTING

Commercial health insurance database from 1 January 2013 to 31 December 2020.

PATIENTS

New users of apixaban or rivaroxaban who had a diagnosis of AF and VHD before initiation of anticoagulant therapy.

MEASUREMENTS

The primary effectiveness outcome was a composite of ischemic stroke or systemic embolism. The primary safety outcome was a composite of gastrointestinal or intracranial bleeding. Cox proportional hazards regression with a robust variance estimator was used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

When compared with rivaroxaban in a propensity score-matched cohort of 19 894 patients (9947 receiving each drug), apixaban was associated with a lower rate of ischemic stroke or systemic embolism (HR, 0.57 [95% CI, 0.40 to 0.80]) and bleeding (HR, 0.51 [CI, 0.41 to 0.62]). The absolute reduction in the probability of stroke or systemic embolism with apixaban compared with rivaroxaban was 0.0026 within 6 months and 0.011 within 1 year of treatment initiation. The absolute reduction in the probability of bleeding events with apixaban compared with rivaroxaban was 0.012 within 6 months and 0.019 within 1 year of treatment initiation.

LIMITATION

Short follow-up time and inability to ascertain some types of VHD.

CONCLUSION

In this study of patients with AF and VHD, patients receiving apixaban had a lower risk for ischemic stroke or systemic embolism and for bleeding when compared with those receiving rivaroxaban.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Comparison of Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation and an Aortic Bioprosthetic Valve

BACKGROUND

Current guidelines equally recommend direct oral anticoagulants (DOACs) and warfarin for atrial fibrillation (AF) patients with a bioprosthetic valve (BPV); however, there are limited data comparing DOACs and warfarin in AF patients with an aortic BPV.

METHODS AND RESULTS

This post-hoc subgroup analysis of a multicenter, prospective, observational registry (BPV-AF Registry) aimed to compare DOACs and warfarin in AF patients with an aortic BPV. The primary outcome was a composite of stroke, systemic embolism, major bleeding, heart failure requiring hospitalization, all-cause death, or BPV reoperation. The analysis included 479 patients (warfarin group, n=258; DOAC group, n=221). Surgical aortic valve replacement was performed in 74.4% and 36.7% of patients in the warfarin and DOAC groups, respectively. During a mean follow up of 15.5 months, the primary outcome occurred in 45 (17.4%) and 32 (14.5%) patients in the warfarin and DOAC groups, respectively. No significant difference was found in the primary outcome between the 2 groups (adjusted hazard ratio: 0.88, 95% confidence interval: 0.51-1.50). No significant multiplicative interaction was observed between the anticoagulant effects and type of aortic valve procedure (P=0.577).

CONCLUSIONS

Among AF patients with an aortic BPV, no significant difference was observed in the composite outcome of adverse clinical events between patients treated with warfarin and those treated with DOACs, suggesting that DOACs can be used as alternatives to warfarin in these patients.

Direct Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation and Valve Replacement or Repair

Background We sought to examine outcomes of direct oral anticoagulants (DOACs) versus warfarin in atrial fibrillation with valve repair/replacement. Methods and Results Two atrial fibrillation cohorts from Medicare were identified from 2015 to 2019. They comprised patients who underwent surgical or transcatheter mitral valve repair (MV repair cohort) and surgical aortic or mitral bioprosthetic or transcatheter aortic valve replacement (bioprosthetic cohort). Each cohort was divided into warfarin and DOACs (apixaban, rivaroxaban, and dabigatran) groups. Study outcomes included mortality, stroke, and major bleeding. Inverse probability weighting was used for adjustment between the 2 groups in each cohort. The MV repair cohort included 1178 patients. After a median of 468 days, DOACs were associated with lower risk of mortality (hazard ratio [HR], 0.67 [95% CI, 0.55-0.82], P<0.001), ischemic stroke (HR, 0.72 [95% CI, 0.52-1.00], P=0.05) and bleeding (HR, 0.79 [95% CI, 0.63-0.99], P=0.04) compared with warfarin. The bioprosthetic cohort included 8089 patients. After a median follow-up of 413 days, DOACs were associated with similar risk of mortality (adjusted HR, 0.93 [95% CI, 0.86-1.01], P=0.08), higher risk of ischemic stroke (adjusted HR, 1.27 [95% CI, 1.13-1.43], P<0.001), and lower risk of bleeding (adjusted HR, 0.86 [95% CI, 0.80-0.93], P<0.001) compared with warfarin. Conclusions In patients with atrial fibrillation, DOACs are associated with similar mortality, lower bleeding, but higher stroke with bioprosthetic valve replacement and lower risk of all 3 outcomes with MV repair compared with warfarin.

Comparison of Direct Oral Anticoagulants and Warfarin in the Prevention of Stroke in Patients With Valvular Heart Disease: A Meta-Analysis

Warfarin is the standard of care, and direct oral anticoagulants (DOACs) are a group of newer drugs to prevent stroke in patients with valvular heart disease. The aim of this meta-analysis is to compare the efficacy and safety of DOACs and warfarin in the prevention of stroke in patients with valvular heart disease (VHD). The current meta-analysis was conducted using the standards developed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendation. The databases from the Cochrane library, PubMed, and Excerpta Medica database (EMBASE) were used to search for relevant articles without placing restrictions on the year of publication. Outcomes assessed in the current meta-analysis included a number of patients with stroke or systemic embolism, patients having myocardial infarction during the study period, patients with major bleeding events, and patients who died due to any reason. Overall, five studies were included in the current meta-analysis. Direct oral anticoagulants were associated with a lower risk of stroke or systemic embolism in patients with VHD (relative risk (RR): 0.75, 95% confidence interval (C)I: 0.60 to 0.94). The risk of major bleeding events is 31% lower in patients receiving DOAC compared to patients receiving warfarin (RR: 0.69, 95% CI: 0.58 to 0.83). No significant difference was found between the two groups in terms of all-cause mortality and myocardial infarction. The current meta-analysis shows that DOACs were associated with a lower risk of stroke or systemic embolism as compared to warfarin in patients with VHD. Besides this, the risk of major bleeding events was also lower in patients receiving DOACs compared to patients receiving warfarin. No significant differences were reported in terms of myocardial infarction and all-cause mortality between the two groups.

Comparison of Dabigatran Versus Warfarin Treatment for Prevention of New Cerebral Lesions in Valvular Atrial Fibrillation

Warfarin is the standard anticoagulation therapy for valvular atrial fibrillation (AF); however, new oral anticoagulants have emerged as an alternative. We compared the efficacy and safety of dabigatran with conventional treatment in AF associated with left-sided valvular heart disease (VHD), including mitral stenosis (MS). Patients with AF and left-sided VHD were randomly assigned to receive dabigatran or conventional treatment. The primary end point was the occurrence of clinical stroke or a new brain lesion (silent brain infarct and microbleed) on 1-year follow-up brain magnetic resonance imaging. Patients in the dabigatran group were switched from warfarin (n = 52), antiplatelets alone (n = 5), or no therapy (n = 2) to dabigatran. In the conventional group, 53 used warfarin (including 42 MS patients), and 7 used antiplatelets. No death or clinical stroke event occurred in either group during follow-up. Silent brain infarct and microbleed occurred in 20 and 2 patients in the dabigatran group and 20 and 4 patients in the conventional treatment group. The incidence rate of the primary end point did not significantly differ between groups (34% vs 40%, relative risk 0.87, 95% confidence interval 0.59 to 1.29, p = 0.491). The primary end point rate was similar between groups in 82 patients (40 in the dabigatran group and 42 in the conventional group) with MS (32% vs 34%, relative risk 0.93, 95% confidence interval: 0.57 to 1.50, p = 0.759). In conclusion, primary end point rates after treatment with dabigatran were similar to conventional treatment in patients with significant VHD and AF. New oral anticoagulants could be a reasonable alternative to warfarin in patients with AF and VHD, which should be confirmed in future large-scale studies.

The ABC-Stroke Score Refines Stroke Risk Stratification in Patients With Atrial Fibrillation at the Emergency Department

Aims

To evaluate the performance of the ABC (Age, Biomarkers, Clinical history) and CHA2DS2-VASc stroke scores under real-world conditions in an emergency setting.

Methods and Results

The performance of the biomarker-based ABC-stroke score and the clinical variable-based CHA2DS2-VASc score for stroke risk assessment were prospectively evaluated in a consecutive series of 2,108 patients with acute symptomatic atrial fibrillation at a tertiary care emergency department. Performance was assessed according to methods for the development and validation of clinical prediction models by Steyerberg et al. and the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis. During a cumulative observation period of 3,686 person-years, the stroke incidence rate was 1.66 per 100 person-years. Overall, the ABC-stroke and CHA2DS2-VASc scores revealed respective c-indices of 0.64 and 0.55 for stroke prediction. Risk-class hazard ratios comparing moderate to low and high to low were 3.51 and 2.56 for the ABC-stroke score and 1.10 and 1.62 for the CHA2DS2-VASc score. The ABC-stroke score also provided improved risk stratification in patients with moderate stroke risk according to the CHA2DS2-VASc score, who lack clear recommendations regarding anticoagulation therapy (HR: 4.35, P = 0.001). Decision curve analysis indicated a superior net clinical benefit of using the ABC-stroke score.

Conclusion

In a large, real-world cohort of patients with acute atrial fibrillation in the emergency department, the ABC-stroke score was superior to the guideline-recommended CHA2DS2-VASc score at predicting stroke risk and refined risk stratification of patients labeled moderate risk by the CHA2DS2-VASc score, potentially easing treatment decision-making.

Outcomes of Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Valvular Heart Disease

PURPOSE OF REVIEW

Direct oral anticoagulants (DOACs) are increasingly used for the treatment and prevention of thromboembolic events in patients with non-valvular atrial fibrillation (AF). Evidence regarding their role in patients with AF and concurrent valvular heart disease (VHD) continues to evolve.

RECENT FINDINGS

Post hoc analyses of randomized clinical trials suggest that DOACs are non-inferior to warfarin for the prevention of stroke or systemic embolism in patients with AF and VHD. Emerging evidence from observational data showed a favorable benefit-risk profile for DOACs compared to warfarin in patients with AF and VHD. DOACs are an attractive option for the treatment of patients with AF and VHD who cannot tolerate or have contraindications to warfarin therapy. Future studies are needed to evaluate their effectiveness, safety, and examine variability in the direction and magnitude of treatment effects in selected VHD subgroups.

Anticoagulation and Stroke

In 2019, the American Heart Association did not recommend the emergent use of anticoagulation to prevent recurrence or progression of acute ischemic stroke. However, its indication in patients with extracranial artery intraluminal thrombus with artery-to-artery cerebral embolization must be analyzed. In this article, we will also discuss other indications of anticoagulation. This treatment could be indicated in patients with ischemic stroke caused by embolization from cervical artery dissection, catastrophic antiphospholipid antibodies syndrome (APS) and some cases of Covid 19. For secondary prevention, anticoagulation is recommended for Cardioembolic stroke such as nonvalvular atrial fibrillation and other cardiopathies, some patients with cervical artery dissection, stroke associated with cancer, and thrombophilia such as APS. The timing to restart anticoagulation after a large ischemic stroke or after a cerebral hemorrhagic transformation always represent a challenge. Even in patients with high risk of thromboembolism it should be delayed at least two weeks, ideal after four weeks.

Off-Label Use and Inappropriate Dosing of Direct Oral Anticoagulants in Cardiopulmonary Disease

Direct oral anticoagulants (DOACs) are increasingly used in clinical practice and have become essential in the management of atrial fibrillation and VTE. The enthusiasm for DOACs has fueled the off-label application of these agents in cardiopulmonary disease, and their use has often outpaced the evidence supporting their application. This article reviews the evidence and current off-label use of DOACs in various cardiopulmonary disease states.

Non-vitamin K antagonist oral anticoagulants in patients with valvular heart disease

The non-vitamin K antagonist oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, and edoxaban have transformed the management of atrial fibrillation (AF), but are only approved by regulatory authorities for stroke prophylaxis in patients with so-called "non-valvular AF." This terminology has spawned confusion about which patients with valvular heart disease benefit from NOACs and which should be treated with vitamin K antagonists (VKAs) instead. Patients with valvular heart disease other than mechanical prosthetic valves or severe mitral stenosis (including those with bioprosthetic valves) were included in pivotal trials demonstrating the benefit of NOACs over VKAs, and consensus guidelines recommend NOACs over VKAs in these patients. Subsequent devoted randomized controlled trials in patients with AF and bioprosthetic valves, including transcatheter valves, have confirmed the safety of NOACs in this population. In patients with rheumatic mitral stenosis, observational studies indicate that NOACs may be safe and effective, but randomized controlled trials are ongoing. By contrast, a randomized controlled trial showed that dabigatran is harmful in patients with mechanical prosthetic mitral valves; however, these data may not extrapolate to patients with mechanical valve prostheses in other locations or to other NOACs, and randomized controlled trials are ongoing. In this review, we discuss these data in greater depth, and make recommendations for the use of NOACs in patients with valvular heart disease.

Direct Acting Oral Anticoagulant vs. Warfarin in the Prevention of Thromboembolism in Patients With Non-valvular Atrial Fibrillation With Valvular Heart Disease-A Systematic Review and Meta-Analysis

Purpose: There is uncertainty as to which anticoagulant should be used in non-valvular atrial fibrillation (AF) with valvular heart disease. This systematic review and meta-analysis aimed to assess the efficacy and safety of direct-acting oral anticoagulants (DOACs) compared with warfarin in patients with non-valvular AF with valvular heart disease.

Methods: We performed a comprehensive literature search using PubMed, Scopus, Embase, and Clinicaltrials.gov from the inception of databases up until August 2, 2021, and the search was updated and finalized on October 17, 2021. The intervention group was DOACs and the control group was warfarin. The primary outcome was systemic embolism and stroke (SSE), and the secondary outcome was major bleeding and intracranial hemorrhage. The pooled effect estimate was reported as the hazard ratio (HR) and odds ratio (OR).

Results: There were 21,185 patients from seven studies included in this systematic review and meta-analysis. Stroke and systemic embolism were lower in patients receiving DOACs [HR 0.76 (95% CI 0.67, 0.87), p < 0.001; I²: 5%] compared with warfarin. The subgroup analysis on RCTs showed the significant reduction of SSE in the DOACs group [HR 0.73 (95% CI 0.60, 0.89), p = 0.002; I²: 16%]. There was no significant difference in terms of major bleeding [HR 0.89 (95% CI 0.75, 1.05), p = 0.18; I²: 69%]. Intracranial hemorrhage [HR 0.42 (95% CI 0.22, 0.80), p = 0.008; I²: 73%] were lower in the DOAC group.

Conclusion: This meta-analysis indicates that DOACs were associated with a lower risk of SSE and intracranial hemorrhage compared with patients receiving warfarin. There was no significant difference between the two groups in terms of major bleeding.

Non-Vitamin K Antagonists Versus Warfarin in Patients with Atrial Fibrillation and Bioprosthetic Valves: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with atrial fibrillation and bioprosthetic valves are at high risk for thromboembolic events. The pooled efficacy and safety of non-vitamin K oral anticoagulants (NOACs), as a class, relative to warfarin in this population is not well-known. We aimed to compare the efficacy and safety of NOACs relative to warfarin in patients with bioprosthetic valves or valve repair.

METHODS

We systematically searched EMBASE, PubMed, and Cochrane databases for randomized controlled trials comparing NOACs to warfarin in patients with atrial fibrillation and bioprosthetic valves or valve repair. We pooled outcomes for stroke or systemic embolism, ischemic stroke, hemorrhagic stroke, and major bleeding.

RESULTS

We included 4 trials with 1379 patients, of whom 723 (52.4%) received a NOAC. Mean follow-up ranged from 90 days to 2.8 years. In the pooled analysis, stroke or systemic embolism was significantly lower in patients treated with NOACs (1.9%) compared with warfarin (3.7%) (odds ratio [OR] 0.43; 95% confidence interval [CI] 0.22-0.85; P = .02). Ischemic stroke (OR 0.72; 95% CI 0.18-2.93), hemorrhagic stroke (OR 0.18; 95% CI 0.03-1.05), cardiovascular death (OR 0.78; 95% CI 0.38-1.62), and all-cause mortality (OR 0.94; 95% CI 0.55-1.62) were not significantly different among groups. Major bleeding was significantly lower in patients treated with NOAC (2.8%) compared with warfarin (4.7%) (OR 0.49; 95% CI 0.28-0.88; P = .02).

CONCLUSIONS

In patients with atrial fibrillation and bioprosthetic valves or valve repair, NOACs are associated with a reduced incidence of thromboembolic events and major bleeding as compared with warfarin. Thus, NOACs may be considered a preferred option for this patient population.

Oral anticoagulant treatment after bioprosthetic valvular intervention or valvuloplasty in patients with atrial fibrillation-A SWEDEHEART study

AIMS

To describe the prevalence of atrial fibrillation (AF), use of oral anticoagulants (OAC) and change in antithrombotic treatment patterns during follow-up after valve intervention with a biological prosthesis or valvuloplasty.

METHODS AND RESULTS

All patients with history of AF or new-onset AF discharged alive after valvular intervention (biological prosthesis or valvuloplasty) between 2010-2016 in Sweden were included (n = 7,362). Information about comorbidities was collected from national patient registers. Exposure to OAC was based on pharmacy dispensation data. In total 4,800 (65.2%) patients had a history of AF, and 2,562 (34.8%) patients developed new-onset AF, with 999 (39.0%) developing new-onset AF within 3 months after intervention. The proportion of patients with biological valve prosthesis was higher in patients with new-onset AF compared to history of AF (p<0.001). CHA2DS2-VASc score ≥2 was observed in 83.1% and 75.5% patients with history of AF and new-onset AF, respectively. Warfarin was more frequently dispensed than NOAC at discharge in patients with history of AF (43.9% vs 7.3%), and in patients with new-onset AF (36.6% vs 17.1%). Almost half of the AF population was not dispensed on any OAC at discharge (48.8% in patients with history of AF and 46.3% in patients with new-onset AF).

CONCLUSION

In this real world study of patients with AF and recent valvular intervention, risk of new-onset AF after valvular intervention is high emphasizing need for frequent rhythm monitoring after intervention. A considerable undertreatment with OAC was observed despite being indicated for the majority of the patients. Warfarin was the OAC most frequently dispensed.

Effectiveness and Safety of NOAC Versus Warfarin in Patients With Atrial Fibrillation and Aortic Stenosis

Background

Guideline recommendations on the use of non–vitamin K antagonist oral anticoagulants (NOACs) in atrial fibrillation (AF) patients with aortic stenosis are based on studies including a low number of patients with aortic stenosis. The aim of this study was to estimate the effects of NOAC versus warfarin on thromboembolism and major bleeding among AF patients with aortic stenosis.

Methods and Results

We emulated a target trial using observational data from Danish nationwide registries between 2013 and 2018. Thromboembolism was defined as a hospital diagnosis of ischemic stroke and/or systemic embolism, and major bleeding was defined as a hospital diagnosis of intracranial bleeding, gastrointestinal bleeding, or major or clinically relevant bleeding in other anatomic sites. Treatment effect estimates were based on an intention‐to‐treat and per‐protocol approach. A total of 3726 patients with AF and aortic stenosis claimed a prescription for either a NOAC (2357 patients) or warfarin (1369 patients) and met the eligibility criteria for the trial. During 3 years of follow‐up, the adjusted hazard ratios for thromboembolism and major bleeding were 1.62 (95% CI, 1.08–2.45) and 0.73 (0.59–0.91) for NOAC compared with warfarin in the intention‐to‐treat analyses. Similar results were observed in the per‐protocol analyses.

Conclusions

In this observational study, we observed a higher risk of thromboembolism but a lower risk of major bleeding for treatment with NOACs compared with warfarin in patients with AF and aortic stenosis. This observation needs confirmation in large randomized trials in these commonly encountered patients.

Direct Acting Oral Anticoagulants Following Gastrointestinal Tract Surgery

ABSTRACT

Direct-acting oral anticoagulants (DOACs) vary in bioavailability and sites of absorption in the gastrointestinal tract (GIT). Data on DOAC use after major GIT surgery are limited. The aim of this case series was to report the impact of surgical resection or bypass of the GIT on rivaroxaban and apixaban peak plasma concentrations. This was a case series of patients who received rivaroxaban or apixaban after GIT surgery, during the period of July 1, 2019, to December 31, 2020. Peak plasma concentrations of rivaroxaban and apixaban were assessed for the expected concentrations. Of the 27 assessed patients, 18 (66.7%) received rivaroxaban, and 9 (33.3%) received apixaban. After rivaroxaban therapy, 4 of 5 patients (80%) who underwent gastrectomy, and 3 of 3 patients (100%) who underwent duodenum and proximal jejunum exclusion had peak plasma concentrations of rivaroxaban lower than the effective range, whereas 11 of 11 patients (100%) who underwent distal bowel or ileostomy had peak rivaroxaban plasma within the effective range. After apixaban therapy, 5 of 6 patients (83.3%) who underwent total or partial gastrectomy achieved effective peak concentrations. All the patients who underwent proximal and distal bowel resection or bypass had peak concentrations of apixaban within the effective range. In conclusion, surgical resection or bypass of the upper GIT could affect DOAC absorption and subsequently peak plasma concentrations. This effect was more observed among rivaroxaban recipients. An injectable anticoagulant or vitamin K antagonist may be preferred if DOAC concentrations cannot be measured after GIT surgery.

2021 Focused update of the 2017 consensus guidelines of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation

The consensus of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation (AF) has been published in 2017 which provided useful clinical guidance for cardiologists, neurologists, geriatricians, and general practitioners in Asia-Pacific region. In these years, many important new data regarding stroke prevention in AF were reported. The Practice Guidelines subcommittee members comprehensively reviewed updated information on stroke prevention in AF, and summarized them in this 2021 focused update of the 2017 consensus guidelines of the APHRS on stroke prevention in AF. We highlighted and focused on several issues, including the importance of AF Better Care (ABC) pathway, the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) for Asians, the considerations of use of NOACs for Asian patients with AF with single 1 stroke risk factor beyond gender, the role of lifestyle factors on stroke risk, the use of oral anticoagulants during the "coronavirus disease 2019" (COVID-19) pandemic, etc. We fully realize that there are gaps, unaddressed questions, and many areas of uncertainty and debate in the current knowledge of AF, and the physician's decision remains the most important factor in the management of AF.

Effect of Cancer on Clinical Outcomes in Elderly Patients With Non-Valvular Atrial Fibrillation - Substudy of the ANAFIE Registry

BACKGROUND

Data on outcomes for patients with atrial fibrillation (AF) and active cancer are scarce. The effect of active cancer on thrombosis and bleeding risks in elderly (≥75 years) patients with non-valvular AF (NVAF) enrolled in the All Nippon AF In the Elderly (ANAFIE) Registry were prospectively analyzed.Methods and Results:In this subanalysis of the ANAFIE Registry, a prospective, multicenter, observational study conducted in Japan, we compared the incidence rates of clinical outcomes between active cancer and non-cancer groups. Relationships between primary outcomes and anticoagulation status were evaluated. Of the 32,725 patients enrolled in the Registry, 3,569 had active cancer at baseline; 92.0% of active cancer patients received anticoagulants (23.7%, warfarin; 68.2%, direct oral anticoagulants [DOACs]). Two-year probabilities of stroke/systemic embolic events (SEE) were similar in the cancer (3.33%) and non-cancer (3.16%) groups. Patients with cancer had greater incidences of major bleeding (2.86% vs. 2.04%), all-cause death (10.95% vs. 6.77%), and net clinical outcomes (14.63% vs. 10.00%) than those without cancer. In patients without cancer, DOACs were associated with a decreased risk of stroke/SEE, major bleeding, all-cause death, and net clinical outcome compared with warfarin. No between-treatment differences were observed in patients with active cancer.

CONCLUSIONS

Active cancer had no effect on stroke/SEE incidence in elderly NVAF patients, but those with cancer had higher incidences of major bleeding events and all-cause death than those without cancer.

Use of oral anticoagulants in patients with valvular atrial fibrillation: findings from the NCDR PINNACLE Registry

Recent data suggest direct oral anticoagulants are as safe and efficacious as warfarin among select patients with valvular heart disease and atrial fibrillation (AF). However, real-world treatment patterns of AF stroke prophylaxis in the setting of valvular AF are currently unknown. Accordingly, using the prospective, ambulatory National Cardiovascular Data Registry Practice Innovation and Clinical Excellence (PINNACLE) Registry, we sought to characterize overall use, temporal trends in use, and the extent of practice-level variation in the use of any direct oral anticoagulant and warfarin among patients with valvular AF from January 1, 2013, to March 31, 2019.

Comparison of the Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease: Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Direct oral anticoagulants (DOACS) are approved for use in non-valvular atrial fibrillation (AF). This systematic review and meta-analysis aimed to evaluate the efficacy and safety of DOACs vs. warfarin and update the evidence for treatment of AF and valvular heart disease (VHD). Methods: We identified randomized clinical trials (RCTs) and post-hoc analyses comparing the use of DOACS and Warfarin in AF and VHD, including biological and mechanical heart valves (MHV), updating from 2010 to 2020. Through systematic review and meta-analysis, by using the "Rev Man" program 5.3, the primary effectiveness endpoints were stroke and systemic embolism (SE). The primary safety outcome was major bleeding, while the secondary outcome included intracranial hemorrhage. We performed prespecified subgroup analyses. Data were analyzed by risk ratio (RR) and 95% confidence interval (CI) and the I-square (I 2) statistic as a quantitative measure of inconsistency. Risk of bias and methodological quality assessment of included trials was evaluated with the modified Cochrane risk-of-bias tool. Results: We screened 326 articles and included 8 RCTs (n = 14.902). DOACs significantly reduced the risk of stroke/SE (RR 0.80, 95% CI: 0.68-0.94; P = 0.008; moderate quality evidence; I 2 = 2%) and intracranial hemorrhage (RR 0.40, 95% CI: 0.24-0.66; P = 0.0004; I 2 = 49%) with a similar risk of major bleeding (RR 0.83, 95% CI: 0.56-1.24; P = 0.36; I 2 = 88%) compared to Warfarin. Conclusions: In this update, DOACs remained with similar efficacy and safety compared to warfarin in thromboprophylaxis for AF and VHD.

Prognostic implications of valvular heart disease in patients with non-valvular atrial fibrillation

BACKGROUND

Valvular heart disease (VHD) in non-valvular atrial fibrillation (AF) is a puzzling clinical entity. The aim of this study was to evaluate the prognostic effect of significant VHD (sVHD) among patients with non-valvular AF.

METHODS

This is a post-hoc analysis of the MISOAC-AF trial (NCT02941978). Consecutive inpatients with non-valvular AF who underwent echocardiography were included. sVHD was defined as the presence of at least moderate aortic stenosis (AS) or aortic/mitral/tricuspid regurgitation (AR/MR/TR). Cox regression analyses with covariate adjustments were used for outcome prediction.

RESULTS

In total, 983 patients with non-valvular AF (median age 76 [14] years) were analyzed over a median follow-up period of 32 [20] months. sVHD was diagnosed in 575 (58.5%) AF patients. sVHD was associated with all-cause mortality (21.6%/yr vs. 6.5%/yr; adjusted HR [aHR] 1.55, 95% confidence interval [CI] 1.17-2.06; p = 0.02), cardiovascular mortality (16%/yr vs. 4%/yr; aHR 1.70, 95% CI 1.09-2.66; p = 0.02) and heart failure-hospitalization (5.8%/yr vs. 1.8%/yr; aHR 2.53, 95% CI 1.35-4.63; p = 0.02). The prognostic effect of sVHD was particularly evident in patients aged < 80 years and in those without history of heart failure (p for interaction < 0.05, in both subgroups). After multivariable adjustment, moderate/severe AS and TR were associated with mortality, while AS and MR with heart failure-hospitalization.

CONCLUSION

Among patients with non-valvular AF, sVHD was highly prevalent and beared high prognostic value across a wide spectrum of clinical outcomes, especially in patients aged < 80 years or in the absence of heart failure. Predominantly AS, as well as MR and TR, were associated with worse prognosis.

Is this the beginning of end for warfarin in bioprosthetic mitral valve recipients with atrial fibrillation? - New insights from RIVER trial

Novel oral anticoagulants, with dabigatran in particular have failed in their quest to replace the traditional anticoagulation in the form of vitamin K antagonist in patients with mechanical valvular implants. However, the same had not been tried in bioprosthetic valve recipients until recently in a large trial where rivaroxaban was found to be non-inferior to warfarin on head-to-head basis. This commentary discusses the various aspects related to oral anticoagulation in bioprosthetic valve recipients in the light of recent clinical evidence.

Pharmacokinetics and Biologic Activity of Apixaban in Healthy Dogs

Thrombosis is common in critically ill dogs and causes considerable morbidity and mortality. The direct factor Xa inhibitor apixaban is safe, efficacious, and convenient in humans. This study aimed to determine the pharmacokinetics (PK), bioactivity, protein binding, and bioavailability of apixaban following intravenous (IV) and oral (PO) administration to healthy dogs. Six healthy, adult, mixed-breed dogs were administered apixaban 0.18 mg/kg IV and then following a minimum 2-week washout period administered apixaban 0.2 mg/kg PO. Dogs were monitored using an apixaban-calibrated anti-Xa bioassay, prothrombin time (PT) and activated partial thromboplastin time (aPTT) and tissue-factor thromboelastography (TF-TEG). Plasma apixaban concentrations were measured using liquid chromatography-tandem mass spectrometry. Concentration-time plots were constructed, and PK modeling performed using compartmental methods. Administration of IV and PO apixaban was well-tolerated. Following IV administration, mean half-life was 4.1 h, and volume of distribution was 177 ml/kg. Apixaban was highly protein bound (98.6%). Apixaban concentrations and anti-Xa activity were highly correlated (R2 0.994, P < 0.0001). Intravenous apixaban significantly prolonged PT at time points up to 1 h, and aPTT at time points up to 0.25 h post-administration. Coagulation times were positively correlated with apixaban concentrations (PT R2 0.599, P < 0.0001; aPTT R2 0.430, P < 0.0001) and TF-TEG R-time was significantly prolonged 0.25 h post-administration. Following oral administration, mean bioavailability was 28.4%, lag time was 2 h, time to Cmax was 5 h and the apparent elimination half-life was 3.1 h. Oral apixaban significantly prolonged PT at 4, 6, and 8 h but aPTT and TF-TEG were not consistently affected by oral apixaban. Apixaban concentrations are best monitored using anti-Xa activity. Future studies should determine PK and bioactivity of other doses using commercial tablets and following multidose administration and establish safe, effective dosing ranges in sick dogs.