Dabigatran Versus Warfarin After Bioprosthesis Valve Replacement for the Management of Atrial Fibrillation Postoperatively: DAWA Pilot Study

Direct oral anticoagulants versus vitamin K antagonists: Which one is more effective in atrial fibrillation

BACKGROUND

The optimal approach for anticoagulation in patients with bioprosthetic valves and atrial fibrillation (AF) remains a subject of debate. A meta-analysis using updated evidence to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) compared to vitamin K antagonists (VKAs) in patients with AF and bioprosthetic valves to address this controversy.

METHODS

A comprehensive search was conducted in multiple databases, including PubMed, Scopus, Web of Science, ProQuest, and the Cochrane Central Register of Controlled Trials, up until March 2023. The search aimed to identify relevant randomized controlled trials (RCTs) that examined the efficacy and safety outcomes of both direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in patients with bioprosthetic valves and atrial fibrillation. The primary outcomes of interest were major bleeding and all-cause mortality.

RESULTS

Our study demonstrated that despite the difference was not significant, the hazard of all-cause mortality was 2.5% higher in the DOAC group (HR = 1.03, 95% CI = [0.88, 1.19], p-value = .75). Similarly, the hazard of stroke (HR = 1.03, 95% CI = [0.87, 1.32], p-value = .71) and major bleeding (HR = 1.11, 95% CI = [0.89, 1.38], p-value = .36) were found to be respectively 3.2 and 10.7% higher in the DOAC group, although the difference was not significant. However, the hazard of intracranial hemorrhage was found to be 28.8 lower in the DOAC treatment group (HR = 0.71, 95% CI = [0.39, 1.31], p-value = .27), which again was not statistically significant.

CONCLUSIONS

Our meta-analysis demonstrates that in patients undergoing bioprosthetic valve surgery and presenting with AF afterward, DOAC and VKA are similar regarding life-threatening and all-cause mortality outcomes, including major bleeding, stroke, and intracranial hemorrhage.

Non-vitamin K versus vitamin K antagonist oral anticoagulants in surgical mitral valve repair or bioprosthetic valve replacement in the first three months after surgery

INTRODUCTION AND OBJECTIVES

Oral anticoagulation (OAC) with non-vitamin K antagonist oral anticoagulants (NOACs) after surgical mitral valve repair (MVR) or bioprosthetic valve replacement (BVR) in mitral position remains a controversial topic among the cardiovascular community, in particular in the early postoperative period. This study aimed to evaluate the efficacy and safety of NOACs in the first three months after MVR or mitral BVR compared to vitamin K antagonists (VKAs).

METHODS

This was a single-center retrospective study with prospectively collected peri-intervention outcomes between 2020 and 2021. Records were retrieved and all participants were contacted by telephone. Patients were divided into groups according to OAC strategy. The primary outcome was a composite of death, rehospitalization, myocardial infarction, stroke or transient ischemic attack, systemic embolism, mitral thrombosis, or bleeding during the first three months after surgery.

RESULTS

A total of 148 patients were enrolled, with a mean age of 65.5±12.2 years, 56.8% male. On discharge, 98 (66.2%) patients were on VKAs and 50 (33.8%) were on DOACs for at least three months. The primary outcome occurred in 22 (22.4%) patients in the VKA group and in three (6%) in the NOAC group (p=0.012), mainly driven by more bleeding events in the former. Independent predictors of the primary outcome were smoking (p=0.028) and OAC with VKAs at discharge, the latter predicting three times more events (p=0.046, OR 3.72, 95% CI 1.02-13.5).

CONCLUSIONS

NOACs were associated with fewer events, supporting their efficacy and safety during the first three months after surgical MVR or mitral BVR.

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.

Mechanical Aortic Valve Thrombosis During Anticoagulation Using Oral Rivaroxaban: A Case Report

Direct oral anticoagulants (DOACs) are widely used in cardiovascular medicine. Although rivaroxaban has potential benefits for anticoagulation in certain contexts, DOACs remain contraindicated in patients with mechanical heart valves. This case report highlights the life-threatening risks of rivaroxaban use in patients with mechanical aortic valves, underscoring the lack of proven efficacy and the necessity of adhering to established anticoagulation protocols with warfarin for this patient population. Here, we report a case of a 65-year-old man who had previously undergone aortic valve replacement and developed a thrombus in the mechanical aortic valve six months after switching from warfarin to rivaroxaban. The patient experienced a sudden loss of consciousness and chest discomfort. Echocardiography revealed a thrombus in the valve requiring urgent reoperation and replacement with a bioprosthetic valve. The postoperative recovery was uneventful.

Direct Oral Anticoagulants: Navigating Through Clinical Challenges

PURPOSE

Direct oral anticoagulants (DOACs) have been approved, for over a decade, by both European and American medicine agencies, for treatment and prevention of several cardiovascular conditions. Since then, an increasing amount of data has been added to the medical literature day by day, resulting in a dichotomy in selection of the appropriate agent, dosage, and duration of treatment for special populations with multiple comorbidities. Considering these issues, we have prepared a comprehensive review for the clinical practitioner, to optimize the DOAC utilization in clinical practice.

METHODS

A thorough literature search and review was conducted, concerning mainly the last decade. Our review focused on the current guidelines and the most recently published studies in PubMed, Science Direct Scopus, and Google Scholar to date.

CONCLUSION

The purpose of this study is to provide guidance for healthcare professionals for making proper decisions when confronted with clinical challenges. Nevertheless, further research is required to establish DOAC superiority in complicated cases, where there is clinical uncertainty.

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.

Selection of Non-vitamin K Antagonist Oral Anticoagulant for Stroke Prevention in Atrial Fibrillation Based on Patient Profile: Perspectives from Vietnamese Experts. Part 2

Part 1 of this review provided an overview of AF in Vietnam, with a particular focus on primary and secondary stroke prevention. Part 2 explores the management of AF in special, high-risk and clinically common patient populations, including those with renal impairment, diabetes, the elderly, and those with coronary artery disease. Furthermore, Part 2 addresses the challenges posed by patients with AF who have a bioprosthetic valve, a group situated in a grey area of consideration. Managing AF in these patient groups presents unique clinical challenges that require careful consideration. Physicians are tasked with addressing specific clinical questions to identify the optimal anticoagulation strategy for each individual. To inform these decisions, subgroup analyses from pivotal studies are presented alongside real-world data derived from clinical practice. By synthesising available information and considering the nuanced clinical context, the aim is to provide informed perspectives that align with current medical knowledge and contribute to the enhancement of patient care in these challenging scenarios.

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.

DOAC versus VKA in patients with atrial fibrillation and bioprosthetic valves: a systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Direct oral anticoagulant (DOAC) therapy has been shown to be safe and effective in patients with atrial fibrillation (AF). However, outcomes in AF patients with bioprosthetic valves are unclear, as this population has been underrepresented in clinical trials. The aim of this study was to assess the safety and efficacy of DOACs in this population based on the existing published literature.

METHODS

A systematic search and review were conducted to identify randomized clinical trials and comparative observational studies published from 2017 to January 2022 that compared DOACs and vitamin K antagonists (VKAs) in AF patients with bioprosthetic valves. Hazard ratios (HR) were collected to compare the 2 treatments in terms of cardiovascular and all-cause mortality, stroke/systemic embolism, and major bleeding. A meta-analysis combining the results was performed.

RESULTS

We included 12 studies (30 283 patients). DOACs and VKAs were compared based on HRs at the 95% confidence interval. DOAC therapy was associated with a significant 9% reduction in all-cause mortality (HR, 0.91; 95%CI, 0.85-0.97; P=.0068; I2=8%), with no significant differences in the risk of stroke/systemic embolism (HR, 0.87; 95%CI, 0.67-1.14; P=.29; I2=45%) or major bleeding (HR, 0.82; 95%CI, 0.67-1.00; P=.054; I2=48.7%).

CONCLUSIONS

DOAC therapy in AF patients with bioprosthetic valves may be associated with a significant reduction in all-cause mortality, with no reduction in the efficacy of stroke/systemic embolism prevention or increase in major bleeding risk.

The efficacy and safety of direct oral anticoagulants versus vitamin K antagonists in patients with left-sided bioprosthetic heart valves and atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) for the treatment of patients with left-sided bioprosthetic heart valves (BHV) and atrial fibrillation (AF) remain controversial. This study aims to perform a meta-analysis to evaluate the efficacy and safety of DOACs versus VKAs in this region.

METHODS

We retrieved all relevant randomized controlled studies and observational cohort studies, which critically assessed the efficacy and safety of DOACs versus VKAs among patients with left-sided BHV and AF in databases of PubMed, Cochrane, ISI Web of Sciences, and Embase. The efficacy outcomes of this meta-analysis were stroke events and all-cause death when the safety outcomes included major and any bleeding.

RESULTS

The analysis integrated 13 studies while enrolling 27,793 patients with AF and left-sided BHV. DOACs reduced the rate of stroke by 33% compared with VKAs (risk ratio [RR] 0.67; 95% CI 0.50-0.91), with no increased incidence of all-cause death (RR 0.96; 95% CI 0.82-1.12). For safety outcomes, major bleeding was reduced by 28% using DOACs rather than VKAs (RR 0.72; 95% CI 0.52-0.99), while there was no difference in the events of any bleeding (RR 0.84; 95% CI 0.68-1.03). In addition, in patients younger than 75 years old, the stroke rate was reduced by 45% in the population using DOACs (RR 0.55; 95% CI 0.37-0.84).

CONCLUSION

Our meta-analysis demonstrated that in patients with AF and BHV, compared with VKAs, using DOACs was associated with reduced stroke and major bleeding events without an increase of all-cause mortality and any bleeding. In the population younger than 75 years old, DOAC might be more effective in preventing cardiogenic stroke.

Direct oral anticoagulants in patients with a left-sided bioprosthetic heart valve: a systematic review and meta-analysis

To compare the efficacy/effectiveness and safety of DOACs versus VKAs in patients with a previously and newly surgically implanted BHV with or without AF. A systematic search on MEDLINE and EMBASE was performed till November 2022. Treatment effects were estimated with relative risk (RR) and 95% confidence intervals (CIs). Statistical heterogeneity was assessed with the I2 statistic. Four randomized controlled trials (RCTs), 2 subgroup analysis from ARISTOTLE and ENGAGE-AF-TIMI 48 and 4 observational studies were included for a total of 5808 patients, 1893 on DOACs and 3915 on VKAs. AF prevalence was 98.28%. In the overall analysis, DOACs vs VKAs were associated with a RR for stroke/transient ischemic attack (TIA)/systemic embolism (SE) of 0.63 (95% CI 0.51-0.79; I2 = 0%) and a RR of major bleeding of 0.50 (95% CI 0.39-0.63; I2 = 0%) in a median follow-up of 19 months (IQR 4.5-33.4). In the 3 RCTs (DAWA, RIVER, ENAVLE), DOACs vs VKAs were associated with a RR of stroke/TIA/SE and major bleeding of 0.38 (95% CI 0.13-1.58, I2 = 0%) and of 0.68 (95% CI 0.32-1.44; I2 = 5%) respectively. In patients randomized during the first three months from valve surgery, DOACs vs VKAs were associated with a RR of stroke/TIA/SE and major bleeding of 0.54 (95% CI 0.14-2.08; I2 = 0%) and of 0.76 (95% CI 0.05-10.72; I2 = 66%). In previously implanted BHV patients with AF, DOACs showed a risk-benefit profile at least comparable to VKAs. DOACs showed a similar, even if underpowered, risk-benefit profile during the first three months after BHV implantation prevalently in patients with AF.

Safety and efficacy of direct oral anticoagulants in bioprosthetic valves: A systematic review and meta-analysis

Background

Direct oral anticoagulants are efficient alternatives to vitamin K antagonists. There is little evidence regarding their use in patients who underwent bioprosthetic valve replacement whether surgically or through a transcatheter approach and have another indication of anticoagulation. Trials have compared different members of the DOACs family to VKAs and showed that they were at least non-inferior to VKAs with regard to safety and efficacy. However, this is still controversial. Our meta-analysis aims at providing a clearer view of their future use in this subgroup of patients.

Methods

PubMed and Cochrane were searched for randomised clinical trials and observational studies. Bleeding, stroke, and all-cause mortality were the outcomes of interest.

Results

Ten papers with a total of 4,088 patients were included. Our meta-analysis revealed no significant differences between the incidence of bleeding between DOACs and warfarin (16% vs. 17%, OR = 0.94, 95% CI [0.56-1.57], p = 0.81, I 2 = 81%). No statistical difference was found in stroke between both groups (2.5% vs. 3.3%, OR = 0.75, 95% CI [0.41-1.38], p = 0.36, I 2 = 35%). All-cause mortality was not statistically significant between both groups (9.2% vs. 13.7%, OR = 0.85, 95% CI [0.68-1.07], p = 0.16, I 2 = 56%). Interestingly, subgroup analysis of randomised controlled trials and prospective studies favoured DOACs with lower risks of both bleeding and stroke.

Conclusion

Direct oral anticoagulants appear to be at least as safe and effective as VKAs in patients with bioprosthetic valves and another indication of anticoagulation. There could be potential benefit from the use of DOACs; however, further evidence is required.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021222146, identifier CRD42021222146.

Direct Oral Anticoagulants for Stroke Prevention in Special Populations: Beyond the Clinical Trials

Currently, direct oral anticoagulants (DOACs) are the first-line anticoagulant strategy in patients with non-valvular atrial fibrillation (NVAF). They are characterized by a more favorable pharmacological profile than warfarin, having demonstrated equal efficacy in stroke prevention and greater safety in terms of intracranial bleeding. The study population in the randomized trials of DOACs was highly selected, so the results of these trials cannot be extended to specific populations such as obese, elderly, frail, and cancer patients, which, on the other hand, are sub-populations widely represented in clinical practice. Furthermore, due to the negative results of DOAC administration in patients with mechanical heart valves, the available evidence in subjects with biological heart valves is still few and often controversial. We sought to review the available literature on the efficacy and safety of DOACs in elderly, obese, underweight, frail, cancer patients, and in patients with bioprosthetic heart valves with NVAF to clarify the best anticoagulant strategy in these special and poorly studied subpopulations.

Can warfarin be replaced by non-vitamin K anticoagulants in prosthetic valves?

INTRODUCTION

Despite the improved safety and efficacy profile of non-Vitamin K Antagonist Oral Anticoagulants (NOACAs), the current guidelines still limit their use to stroke prevention in non-valvular atrial fibrillation (AF) patients and venous thromboembolism prophylaxis and treatment.

AREAS COVERED

In this report, the authors discussed the published data related to NOACs use in prosthetic valves highlighting the proposed mechanisms of NOACs failure and other controversial data regarding their efficacy and safety in prosthetic valves.

EXPERT OPINION

Although NOACs have proven to be even safer and more effective alternatives to vitamin K antagonists (VKAs) in several indications for anticoagulation, the data regarding their safety and efficacy in prosthetic heart valves is still debatable. The controversial data regarding NOACs use in prosthetic valves renders it difficult to define specific guideline-recommendation for safe and efficient use in this population. The available evidence suggesting that NOACs are as safe and as efficient as VKA regarding thromboembolic prophylaxis and risk of bleeding was primarily based on patients who had undergone bioprosthetic valve and concomitant atrial fibrillation. Further research is warranted to establish if NOACs can be a safer and more efficient alternative to VKAs in patients with prosthetic valves either metallic or bioprosthetic.

Successful use of therapeutic anticoagulation therapy in two patients with moderate stroke from the second day of onset: A case report and literature review

Introduction and importance

Hemorrhagic transformation of ischemic stroke is one of the most traumatic consequences of ischemic stroke. Therefore, deciding the optimal time for anticoagulant application and its effect on clinical outcome, recurrence and risk for hemorrhagic transformation are still in quarry. The European Heart Rhythm Association recommends the usage of anticoagulants after 3–4 days after a mild stroke, 6 days after moderate stroke and 12 days after a severe stroke.

Case presentation

In our case report, we present two patients who started full therapeutic anticoagulation of low molecular weight heparin from the first day after moderate ischemic stroke, warfarin was added later guided by INR and discharged on oral anticoagulants for associated AF. They improved clinically with improved motor function for both upper and lower limbs, sensation and gaze without any complication followed by serial CT.

Clinical discussion and conclusion

As a result of this case report, clinical improvement has not been associated with hemorrhagic sequelae of anticoagulant administration on the first day. At this point, we recommend conducting a trial to study the effect of early application of anticoagulants from the first day on clinical outcome, recurrence, and hemorrhagic transfusion of stroke.

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The hemorrhagic transformation of ischemic stroke is one of the most traumatic outcomes.

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Therefore, determining the optimal time to apply anticoagulants.

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And their impact on clinical outcome, recurrence, and hemorrhagic transformation remains challenging.

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According to this case report, there are no hemorrhagic sequelae associated with the first day of anticoagulant therapy.

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Anticoagulation recommendations should therefore be supported or rejected based on more research.

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.

Direct oral anticoagulants in atrial fibrillation following cardiac surgery: a systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been increasingly used as anticoagulation therapy in the postoperative period. However, their effectiveness in post-cardiac surgical atrial fibrillation is yet to be determined.

METHODS

We conducted a meta-analysis, searching three international databases from 1 January 2003 to 26 January 2022 for studies reporting on DOACs in at least 10 adult patients (>18 yr of age) with post-cardiac surgical atrial fibrillation. The primary outcomes were major neurological events (MNEs) and bleeding; secondary outcomes were mortality, hospital and ICU length of stay, cost, and other complications from therapy. We included studies of any design, including RCTs, cohort studies with and without propensity score matching methods, and single-armed case series.

RESULTS

Twelve studies (8587 DOACs; 8315 warfarin) were included in this meta-analysis. The incidences of postoperative bleeding and MNEs with DOACs were 7.3% (95% confidence interval [CI]: 3.4-14.7%) and 2.2% (95% CI: 0.9-4.9%), respectively. The incidence of MNEs was lower in high-risk patients, including those with hypertension and higher CHA₂DS₂-VASc score, whereas patients with prior transient ischaemic attack or stroke had higher incidence of bleeding. Trial sequential analysis revealed that the cumulative Z-curve crossed the conventional boundary of benefit. Compared with warfarin, DOACs reduced the risk of bleeding (relative risk [RR] 0.74; 95% CI: 0.62-0.89; P=0.0011) and MNEs (RR 0.63; 95% CI: 0.48-0.83; P=0.0012) but not mortality (RR 1.02; 95% CI: 0.77-1.35; P=0.090).

CONCLUSIONS

DOACs reduced bleeding and MNEs in patients with post-cardiac surgical atrial fibrillation, appearing safer than warfarin in this context. However, which DOAC provides the most effective anticoagulation in this patient population needs further investigation.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42021282777.

An Updated Meta-Analysis of DOACs vs. VKAs in Atrial Fibrillation Patients With Bioprosthetic Heart Valve

Background

Current guidelines recommend the utilization of direct-acting oral anticoagulants (DOACs) in patients with non-valvular atrial fibrillation (AF). However, the optimal anticoagulation strategy for AF patients with bioprosthetic heart valves (BPHV) remains controversial. Therefore, we conducted this meta-analysis to explore the effect of DOACs versus vitamin K antagonists (VKAs) in this population.

Methods

We systematically searched the PubMed and Embase databases until November 2021 for studies reporting the effect of DOACs versus VKAs in AF patients with BPHV. Adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were pooled using the random-effects model with an inverse variance method.

Results

We selected four randomized clinical trials and seven observational studies (2236 DOAC- and 6403 VKAs-users). Regarding the effectiveness outcomes, there were no significant differences between DOACs and VKAs in stroke or systemic embolism (RR = 0.74, 95%CI: 0.50–1.08), ischemic stroke (RR = 1.08, 95%CI: 0.76–1.55), all-cause death (RR = 0.98, 95%CI: 0.86–1.12), and cardiovascular death (RR = 0.85, 95%CI: 0.40–1.80). In terms of the safety outcomes, DOACs was associated with lower risks of major bleeding (RR = 0.70, 95%CI: 0.59–0.82) and intracranial bleeding (RR = 0.42, 95%CI: 0.26–0.70), but the risks of any bleeding (RR = 0.85, 95%CI: 0.65–1.13) and gastrointestinal bleeding (RR = 0.92, 95%CI: 0.73–1.17) are not significantly different when compared with VKAs. The subgroup analysis with follow-up as a covariate revealed that the DOACs had lower risks of SSE (RR = 0.59, 95%CI: 0.37–0.94) and major bleeding (RR = 0.69, 95%CI: 0.58–0.81) in patients with a mean follow-up of more than 24 months, but no statistical differences were found in patients with the follow-up less than 24 months (SSE: RR = 1.10, 95%CI: 0.92–1.32; major bleeding: RR = 0.91, 95%CI: 0.42–2.01).

Conclusions

In AF with BPHV, patients on DOACs experienced a reduced risk of major bleeding and intracranial bleeding compared with VKAs, while the risks of stroke, cardiovascular death, and all-cause mortality were similar.

DOACs in Mechanical and Bioprosthetic Heart Valves: A Narrative Review of Emerging Data and Future Directions

In the recent years, there has been significant transformation in the management of valvular heart disease (VHD), as a result of new minimally invasive technologies, such as the transcatheter aortic valve implantation (TAVI). Conventionally, mechanical heart valves require anticoagulation with warfarin to prevent thrombogenic events. Lately, there has been an uptrend in the usage of direct-acting oral anticoagulants (DOACs) in both mechanical and bioprosthetic heart valves. In clinical practice, there has shown to be notable heterogeneity in the antithrombotic regimen for patients. Recommendations from clinical guidelines and emerging data on DOAC use in these settings will be critically reviewed here. Future large, randomized-controlled trials are warranted to delineate the role of DOACs in patients receiving a bioprosthetic valve/TAVI or mechanical heart valve, with and without a baseline indication for anticoagulation or antiplatelets. Until clinical trial data from well-designed studies are available, providers must remain vigilant about DOAC use in patients with VHD, especially in patients with a bioprosthetic or mechanical heart valve.

Switching from warfarin to direct-acting oral anticoagulants: it is time to move forward!

Oral vitamin K antagonists (VKAs), warfarin, have been in routine clinical use for almost 70 years for various cardiovascular conditions. Direct-Acting Oral Anticoagulants (DOACs) have emerged as competitive alternatives for VKAs to prevent stroke in patients with non-valvular atrial fibrillation (AF) and have become the preferred choice in several clinical indications for anticoagulation. Recent guidelines have limited the use of DOACs to patients with non-valvular AF to reduce the risk of cardioembolic complications and to treat venous thromboembolism (VTE). Although emerging evidence is suggestive of its high efficacy, there was a lack of data to support DOACs safety profile in patients with mechanical valve prosthesis, intracardiac thrombi, or other conditions such as cardiac device implantation or catheter ablation. Therefore, several clinical trials have been conducted to assess the beneficial effects of using DOACs, instead of VKAs, for various non-guideline-approved indications. This review aimed to discuss the current guideline-approved indications for DOACs, advantages, and limitations of DOACs use in various clinical indications highlighting the potential emerging indications and remaining challenges for DOACs use. Several considerations are in favour of switching from warfarin to DOACs including superior efficacy, better adverse effect profile, fewer drug-drug interactions, and they do not require frequent international normalized ratio (INR) monitoring. Large randomized controlled trials are required to determine the safety and efficacy of their use in various clinical indications.

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.

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.

Direct oral anticoagulation in atrial fibrillation and heart valve surgery-a meta-analysis and systematic review

AIMS

Oral anticoagulation with direct oral anticoagulants (DOAC) could provide an alternative to vitamin K antagonists (VKA) for patients with atrial fibrillation (AF) undergoing bioprosthetic heart valve replacement or valve repair.

METHODS AND RESULTS

The aim of this meta-analysis was to review the safety and efficacy of DOAC in patients with surgical implanted bioprosthetic heart valves or valve repairs and AF including data from six clinical trials with a total of 1,857 patients. The efficacy and safety data of DOAC and VKA were pooled to perform random-effects meta-analyses using the Mantel-Haenszel method with pooled risk ratios (RR) and 95% confidence interval (CI). A trial sequential analysis (TSA) was performed to assess statistical robustness. Death caused by cardiovascular cause or thromboembolic events were comparable (RR 0.67, 95% CI: 0.42-1.08; p = 0.10) as DOAC significantly reduced the risk for major bleeding (RR 0.55, 95% CI: 0.35-0.88; p = 0.01) and thromboembolic stroke or systemic embolism rates (RR 0.54, 95% CI: 0.32-0.90; p = 0.02). Rates for intracranial bleeding and hemorrhagic stroke (RR 0.27, 95% CI: 0.07-0.99; p = 0.05) show a trend toward fewer events in the DOAC group. Outcomes for major or minor bleeding events and all-cause mortality were comparable for DOAC and VKA.

CONCLUSION

Cumulative data analysis reveals that DOAC may provide an effective and safe alternative to VKA in patients with AF after surgically implanted bioprosthetic heart valves or repair with AF. Within a relatively heterogeneous study population, this meta-analysis shows a risk reduction of major bleedings and thromboembolic stroke or systemic embolisms for DOAC.

Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Bioprosthetic Valves-A Systematic Review and Meta-analysis

Oral anticoagulation is recommended for patients with atrial fibrillation and an elevated stroke risk. Direct oral anticoagulants (DOACs) are generally preferred over vitamin K antagonists. Nonetheless, there controversy persists regarding whether DOACs should be used in patients with atrial fibrillation and bioprosthetic valves. Therefore, we conducted this systematic review and meta-analysis to assess the safety and efficacy of DOACs compared to warfarin in this patient population. We performed a systematic search of the MEDLINE and PubMed Central databases for relevant articles. The incidence rate and risk ratio (RR) of all-cause mortality, cardiovascular mortality, ischemic stroke/systemic thromboembolism, hemorrhagic stroke/intracranial bleeding, major bleeding, and minor bleeding were calculated. A total of eight studies were included, including 5,300 patients (stratified as 1,638 patients in the DOAC arm and 3,662 patients in the warfarin arm). There was no significant difference in the rate of stroke/systemic thromboembolism [RR: 0.85; 95% confidence interval (CI): 0.43–1.69], all-cause mortality (RR: 0.77; 95% CI: 0.53–1.11), or cardiovascular death (RR: 0.81; 95% CI: 0.40–1.63) between DOACs and warfarin. Major bleeding and hemorrhagic stroke/intracranial bleeding were similar between both treatment arms (RR: 0.61; 95% CI: 0.35–1.06 and RR: 0.27; 95% CI: 0.06–1.13, respectively). In conclusion, DOACs are safe and effective in patients with atrial fibrillation and bioprosthetic valves. Future large-scale randomized studies are warranted to confirm this observation.

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.

Direct oral anticoagulants in patients with atrial fibrillation and bioprosthetic valve replacement: A meta-analysis

OBJECTIVES

This systematic review and meta-analysis compares direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) in patients with atrial fibrillation and bioprosthetic valve replacement or repair (BVR).

BACKGROUND

The optimal anticoagulation therapy for patients with atrial fibrillation and a history of bioprosthetic valve replacement or repair (BVR) is not well understood.

METHODS

We performed a systematic literature review to identify clinical studies that compared anticoagulation therapies for patients with atrial fibrillation and BVR. The primary outcomes of stroke, major bleeding, and mortality were reported as random effects risk ratio (RR) with 95% confidence interval. No prior ethical approval was required since all data is public.

RESULTS

Our search yielded 101 potential studies. We included six studies reporting on 1911 patients. There was a lower risk of stroke and major bleeding in patients with atrial fibrillation after BVR treated with DOACs when compared to VKAs with risk ratios of 0.44 (95% CI 0.24-0.82, p < 0.01) and 0.53 (95% CI 0.34-0.83, p < 0.01), respectively. There was no statistically significant difference in mortality between patients with atrial fibrillation after BVR treated with DOACs compared to patients treated with VKAs with a risk ratio of 1.12 (95% CI 0.73-1.74, p = 0.60).

CONCLUSION

This systematic review and meta-analysis suggests that DOACs are superior to VKAs with respect to stroke and major bleeding in patients with atrial fibrillation and BVR.

Direct oral anticoagulants versus vitamin K antagonists in patients with atrial fibrillation and bioprosthetic valves: A meta-analysis

BACKGROUND

The optimal anticoagulation strategy for patients with bioprosthetic valves and atrial fibrillation remains uncertain. We conducted a meta-analysis using updated evidence comparing direct anticoagulants (DOACs) and vitamin K antagonists (VKAs) in patients with bioprosthetic valves and atrial fibrillation.

METHODS

Medline and Embase were searched through March 2021 to identify randomized controlled trials (RCTs) and observational studies investigating the outcomes of DOAC therapy and VKA therapy in patients with bioprosthetic valves and atrial fibrillation. The outcomes of interest were all-cause death, major bleeding, and stroke or systemic embolism.

RESULTS

Our analysis included 4 RCTs and 6 observational studies enrolling a total of 6405 patients with bioprosthetic valves and atrial fibrillation assigned to a DOAC group (n = 2142) or a VKA group (n = 4263). Pooled analysis demonstrated the similar rates of all-cause death (hazard ratio [HR], 0.90; 95% confidence interval [CI], 0.77-1.05; P = .18; I² = 0%) in the DOAC and VKA groups. However, the rate of major bleeding was significantly lower in the DOAC group (HR, 0.66; 95% CI, 0.48-0.89; P = .006; I² = 0%), whereas the rate of stroke or systemic embolism was similar in the 2 groups (HR, 0.72; 95% CI, 0.44-1.17; P = .18; I² = 39%).

CONCLUSIONS

DOAC might decrease the risk of major bleeding without increasing the risk of stroke or systemic embolism or all-cause death compared with VKA in patients with bioprosthetic valves and atrial fibrillation.

Intracardiac thrombus in a patient with mitral bioprosthesis and atrial fibrillation treated with direct oral anticoaugulant: A case report

RATIONALE

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with increased morbidity, especially stroke and heart failure. There is also increasing awareness that atrial fibrillation is a major cause of embolic events which in 75% of cases are complicated by cerebrovascular accidents.

PATIENT CONCERNS

A 50-year-old woman with mitral bioprosthesis under warfarin for nonvalvular atrial fibrillation was referred to our Coronary Intensive Care Unit due to acute myocardial infarction without evidence of significant coronary artery stenosis.

DIAGNOSES

Cardiovascular examination showed an irregular pulse and a grade II diastolic murmur was audible at the apical area. The patient underwent coronary angiography showing absence of obstructive coronary artery disease. We decided to replace Warfarin with direct oral anticoagulants as anticoagulant therapy.

INTERVENTIONS

Transoesophageal echocardiography revealed a thrombus in left atrial appendage that was treated by replacing warfarin with an oral direct thrombin inhibitor.

OUTCOMES

At 2-month follow-up, the therapy showed to be effective for thrombus resolution.

LESSONS

Our case demonstrated how AF has high risk of thromboembolic complications, not only in terms of stroke but also of myocardial infarction and death.The use of direct oral anticoagulants in AF patients with bioprosthetic heart valves is still debated due to an unclear definition of "nonvalvular" AF.

Safety of Direct Oral Anticoagulants Compared to Warfarin for Atrial Fibrillation after Cardiac Surgery: A Systematic Review and Meta-Analysis

The evidence for use of direct oral anticoagulants (DOACs) in the management of post-operative cardiac surgery atrial fibrillation is limited and mostly founded on clinical trials that excluded this patient population. We performed a systematic review and meta-analysis of clinical trials and observational studies to evaluate the hypothesis that DOACs are safe compared to warfarin for the anticoagulation of patients with post-operative cardiac surgery atrial fibrillation. We searched PubMed, EMBASE, Web of Science, clinicaltrials.gov, and the Cochrane Library for clinical trials and observational studies comparing DOAC with warfarin in patients ≥18 years old who had post-cardiac surgery atrial fibrillation. Primary outcomes included stroke, systemic embolization, bleeding, and mortality. We performed a random-effects meta-analysis of all outcomes. The meta-analysis for the primary outcomes showed significantly lower risk of stroke with DOAC use (6 studies, 7143 patients, RR 0.64; 95% CI 0.50-0.81, I²: 0.0%) compared to warfarin, a trend towards lower risk of systemic embolization (4 studies, 7289 patients, RR 0.64, 95% CI 0.41-1.01, I²: 31.99%) and similar risks of bleeding (14 studies, 10182 patients, RR 0.91; 95% CI 0.74-1.10, I²: 26.6%) and mortality (12 studies, 9843 patients, relative risk [RR] 1.01; 95% CI 0.74-1.37, I²: 26.5%). Current evidence suggests that DOACs, compared to warfarin, in the management of atrial fibrillation after cardiac surgery is associated with lower risk of stroke and a strong trend for lower risk of systemic embolization, and no evidence of increased risk for hospital readmission, bleeding and mortality.

Comparative effectiveness and safety of direct acting oral anticoagulants in nonvalvular atrial fibrillation for stroke prevention: a systematic review and meta-analysis

PURPOSE

To systematically review available evidence of indirect comparisons from RCTs and direct comparisons from observational studies regarding the comparative effectiveness and safety of DOACs in patients with AF.

METHODS

Electronic databases including EMBASE, MEDLINE, and PUBMED were searched up to June 5th, 2020. Primary endpoints included effectiveness (stroke or systemic embolism [SE]) and safety (major bleeding) outcomes. Bucher methods and random-effects models were conducted for indirect and direct comparisons among DOACs, respectively. Ranking probability analyses and the number needed to treat for net effect (NNTnet) were applied.

RESULTS

A total of 36 studies, involving 7 RCTs (n = 60,292 patients) and 29 observational studies (n = 1,164,821 patients), were included for analyses. Regarding the risk of stroke/SE, no significant differences were found from indirect comparisons of RCTs among the DOACs. For major bleeding, apixaban tended to be safer than rivaroxaban and dabigatran based on both direct and indirect comparisons (all p < 0.05; evidence quality: very low to moderate). Ranking probability analysis showed that apixaban had a high probability of being the best treatment in decreased risk of stroke/SE and major bleeding (80.30% and 91.30%, respectively). Likewise, apixaban was found to have the highest net clinical benefit (0.02, 95% CI: 0.014-0.029) and smallest NNTnet (48, 95% CI: 35-74).

CONCLUSIONS

Apixaban appeared to have a favorable effectiveness-safety profile compared with the other DOACs in AF for stroke prevention, based on evidence from both direct and indirect comparisons. However, additional high-quality evidence is needed to support firm recommendations on clinical decision-making.

Systematic Review and Meta-Analysis: Can We Compare Direct Oral Anticoagulants to Warfarin in Patients With Atrial Fibrillation and Bio-Prosthetic Valves?

Background There are no clear consensus guidelines on the indications and types of anticoagulation therapies in patients with bio-prosthetic valves either with concomitant atrial fibrillation (AF) or sinus rhythm. In our meta-analysis, we assessed the safety and efficacy of DOACs as compared to the standard treatment with warfarin in patients with AF and bioprosthetic valves. Methods We included randomized controlled trials (RCTs), cohort studies in the English language, and studies reporting patients with valvular heart disease that included bioprosthetic valvular disease. A systematic literature review using Embase, PubMed, and Web of Science was performed using the terms "Direct Acting Oral Anticoagulant," "Oral Anticoagulants," "Non-Vitamin K Antagonist Oral Anticoagulant," "Atrial Fibrillation," "Bioprosthetic Valve" for literature published prior to January 2021. Extraction of data from included studies was carried out independently by three reviewers from Covidence. We assessed the methodical rigor of the included studies using the modified Downs and Black checklist. Results Four RCTs and one observational study (n=1776) were included in our study. A random-effect model using RevMan (version 5.4; The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen) was used for data analysis. The pooled data showed that there was a non-significant reduction in the incidence of stroke and systemic embolism in the patients taking DOACs as compared to warfarin (HR 0.69; 95% CI, 0.29, 1.67; I2 = 50%). The incidence of major bleeding was lower in the DOACs group; the difference was statistically significant (HR 0.42; 95% CI, 0.26, 0.67; I2 = 7%). The difference was not statistically significant for all-cause mortality in both groups (HR 1.24; 95% CI, 0.91, 1.67; I2 = 0%). Conclusion Our results showed that there was no difference in the outcomes of stroke and systemic embolism between DOACs and warfarin but there were statistically significantly lower major bleeding events. We conclude that larger clinical trials are needed to assess the true safety and efficacy of DOACs in patients with AF and bioprosthetic valves.

NEW ORAL ANTICOAGULANTS VERSUS WARFARIN IN ATRIAL FIBRILLATION AFTER EARLY POST-OPERATIVE PERIOD IN PATIENTS WITH BIOPROSTHETIC AORTIC VALVE

BACKGROUND

The efficacy of novel non-vitamin K antagonist oral anticoagulants (NOACs) in nonvalvular atrial fibrillation (AF) to prevent stroke is well assessed but the use in AF occurred after bioprosthetic aortic valve replacement (AVR) is not endorsed. This retrospective real-world study evaluated the efficacy and safety of NOACs prescribed no earlier than 4 months after AVR as alternative to warfarin in patient with AF.

METHODS

We pooled 1032 patients from databases of five centres. Ischemic/embolic events and major bleeding rates were compared between 340 patients assuming NOACs and 692 warfarin. Propensity score matching was performed to avoid the bias between groups.

RESULTS

NOACs vs warfarin embolic/ischemic rate was 13.5% (46/340) vs 22.7% (157/692) (HR 0.5; 95% CI, 0.37-0.75; p<0.001); incidence rates 3.7% vs 6.9% patients/year; log rank test p=0.009. Major bleeding rates was 7.3% (25/340) vs 13% (90/692) (HR 0.5; 95% CI, 0.33-0.84; p=0.007); incidence rates 2% vs 4% patients/year; log rank test p=0.002. After Propensity score matching, NOACs vs warfarin embolic/ischemic rate was 13.1% (42/321) vs 21.8% (70/321) (HR 0.6; 95% CI, 0.4-0.9; p=0.02); incidence rates 4.1% vs 6.7% patients/year; log rank test p=0.01. Major bleeding rates was 7.8% (25/321) vs 13.7% (44/321) (HR 0.5; 95% CI, 0.31-0.86; p=0.01), incidence rates 2.4% vs 4.2% patients/year; log-rank p=0.01.

CONCLUSIONS

In real-word, NOACs use overcomes the indications provided by guidelines. This study evidenced that NOACs use in patients who developed AF after bioprosthetic AVR was more effective in prevention of thromboembolism and safe in reduction of major bleeding events compared to warfarin.

Atrial fibrillation and stroke prevention: state of the art-epidemiology and pathophysiology: new risk factors, concepts and controversies

Atrial fibrillation (AF) increases the risk of thromboembolism, and risk assessment for thromboembolism is necessary for the management of AF patients. CHADS2 and CHA2DS2-VASc scores have been adopted in international guidelines for AF management, but the significance of each risk factor included in these risk scores are sometimes controversial, and the performance of these scores is only modest. There are several other risk factors not included in the scores such as renal dysfunction, low body weight, type of AF (paroxysmal or non-paroxysmal) as well as echocardiographic parameters and blood biomarkers, and physicians should assess patients risk in an integrated manner.

Rivaroxaban in Patients with Atrial Fibrillation and a Bioprosthetic Mitral Valve

BACKGROUND

The effects of rivaroxaban in patients with atrial fibrillation and a bioprosthetic mitral valve remain uncertain.

METHODS

In this randomized trial, we compared rivaroxaban (20 mg once daily) with dose-adjusted warfarin (target international normalized ratio, 2.0 to 3.0) in patients with atrial fibrillation and a bioprosthetic mitral valve. The primary outcome was a composite of death, major cardiovascular events (stroke, transient ischemic attack, systemic embolism, valve thrombosis, or hospitalization for heart failure), or major bleeding at 12 months.

RESULTS

A total of 1005 patients were enrolled at 49 sites in Brazil. A primary-outcome event occurred at a mean of 347.5 days in the rivaroxaban group and 340.1 days in the warfarin group (difference calculated as restricted mean survival time, 7.4 days; 95% confidence interval [CI], -1.4 to 16.3; P<0.001 for noninferiority). Death from cardiovascular causes or thromboembolic events occurred in 17 patients (3.4%) in the rivaroxaban group and in 26 (5.1%) in the warfarin group (hazard ratio, 0.65; 95% CI, 0.35 to 1.20). The incidence of stroke was 0.6% in the rivaroxaban group and 2.4% in the warfarin group (hazard ratio, 0.25; 95% CI, 0.07 to 0.88). Major bleeding occurred in 7 patients (1.4%) in the rivaroxaban group and in 13 (2.6%) in the warfarin group (hazard ratio, 0.54; 95% CI, 0.21 to 1.35). The frequency of other serious adverse events was similar in the two groups.

CONCLUSIONS

In patients with atrial fibrillation and a bioprosthetic mitral valve, rivaroxaban was noninferior to warfarin with respect to the mean time until the primary outcome of death, major cardiovascular events, or major bleeding at 12 months. (Funded by PROADI-SUS and Bayer; RIVER ClinicalTrials.gov number, NCT02303795.).

Off-label Use for Direct Oral Anticoagulants: Valvular Atrial Fibrillation, Heart Failure, Left Ventricular Thrombus, Superficial Vein Thrombosis, Pulmonary Hypertension-a Systematic Review

OBJECTIVE

To evaluate clinical literature for direct oral anticoagulants (DOACs) therapy for non-Food and Drug Administration approved indications.

DATA SOURCES

Articles from MEDLINE, Cochrane Library, Google Scholar, and OVID databases were reviewed from 1946 through September 4, 2020.

STUDY SELECTION AND DATA EXTRACTION

Fully published studies assessing DOACs for atrial fibrillation (AF) with valvular heart disease (VHD), heart failure (HF), left ventricular thrombus (LVT), superficial vein thrombosis (SVT), or pulmonary hypertension (PH) were evaluated.

DATA SYNTHESIS

Our review showed that DOACs are safe to use in patients with AF and VHD except for mitral stenosis or mechanical heart valve. Rivaroxaban 2.5 mg twice daily should be used with caution in patients with HF with reduced ejection fraction until further evaluation is performed. Four retrospective studies for DOAC use in patients with LVT showed conflicting results. One phase 3 randomized controlled trial showed noninferiority of rivaroxaban to fondaparinux for SVT treatment. The use of DOACs for pulmonary arterial hypertension was not evaluated in any clinical study, but 2 retrospective studies for the use of DOACs in patients with chronic thromboembolic PH (CTEPH) showed similar efficacy between DOACs and warfarin.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review provides clinicians with a comprehensive literature review surrounding DOAC use in common off-label indications.

CONCLUSION

DOACs can be considered for AF complicated by VHD except for mitral stenosis or mechanical valve replacement. DOACs (especially rivaroxaban) are considered as an alternative therapy for SVT and CTEPH. Further prospective studies for DOAC uses are needed for HF or LVT.