Clinical Benefit of Direct Oral Anticoagulants Versus Vitamin K Antagonists in Patients with Atrial Fibrillation and Bioprosthetic Heart Valves

Antithrombotic therapy after heart valve intervention: review of mechanisms, evidence and current guidance

As the population ages and treatment options for heart valve disease increase, the number of patients with intracardiac valve prostheses is growing rapidly. Although all devices have the potential to cause thrombus formation, the propensity depends on the type of prosthesis as well as risk of the individual patient. Mechanical valve prostheses carry the highest (and persistent) risk of thromboembolism, and these patients require anticoagulation with vitamin K antagonists (warfarin). Required international normalised ratio levels are dependent on the location of the valve (mitral>aortic), type of valve (ball and cage vs bilealfet vs On-X bilealfet) and rhythm. The risk of tissue (biological) prosthesis is highest soon after surgery and is dependent on individual patient risk including age, valve location (mitral>aortic), history of thromboembolic events and rhythm. In patients with no other indication for anticoagulation, there is uncertainty on the benefits of anticoagulation versus antiplatelet therapy in patients with tissue prostheses or repaired native valves. Patients with an a priori indication for anticoagulation with a direct oral anticoagulant can continue taking this class of drug. Patients with transcatheter aortic valve implantation devices and no additional evidence-based indication for dual antiplatelet therapy or anticoagulation can be maintained on aspirin monotherapy. Patients undergoing transcatheter instrumentation in the mitral valve position should be anticoagulated, although there is currently no published evidence for antithrombotic management in this group of patients. Patients with thrombosed devices (commonly mitral mechanical) should preferably be treated surgically. Patients at high risk of thromboembolism (with mechanical prostheses) should undergo bridging therapy when undergoing surgery.

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.

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.

Anti-Inflammatory and Anticancer Effects of Anticoagulant Therapy in Patients with Malignancy

Optimizing the anticoagulation therapy is of pivotal importance in patients with a malignant tumor, as venous thromboembolism (VTE) has become the second-leading cause of death in this population. Cancer can highly increase the risk of thrombosis and bleeding. Consequently, the management of cancer-associated VTE is complex. In recent years, translational research has intensified, and several studies have highlighted the role of inflammatory cytokines in cancer growth and progression. Simultaneously, the pleiotropic effects of anticoagulants currently recommended for VTE have emerged. In this review, we describe the anti-inflammatory and anticancer effects of both direct oral anticoagulants (DOACs) and low-molecular-weight heparins (LWMHs).

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.

Clinical Relevance of Preclinical and Clinical Studies of Four-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Direct Oral Anticoagulants

Direct oral anticoagulants (DOACs) are widely used for the prevention and treatment of venous thromboembolism and stroke. When emergency reversal of DOAC-related anticoagulation is required, specific DOAC reversal agents are recommended, including idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. However, specific reversal agents are not always available, andexanet alfa has not been approved for urgent surgery, and clinicians need to know the patient's anticoagulant medication before administering these treatments. Four-factor prothrombin complex concentrates (4F-PCCs) are recognized as nonspecific, alternative hemostatic agents for treatment of DOAC-related bleeding. Evidence from preclinical and clinical studies shows that they may reduce the anticoagulant effects of DOACs and may help control DOAC-related bleeding. However, randomized controlled trials are lacking, and most data are from retrospective or single-arm prospective studies in bleeding associated with activated factor X inhibitors. There are no clinical data showing the efficacy of 4F-PCC for the treatment of bleeding in dabigatran-treated patients. This review focuses on the current evidence of 4F-PCC use in controlling bleeding associated with DOACs and provides an expert opinion on the relevance of these data for clinical practice. The current treatment landscape, unmet needs, and future directions are also discussed.

Bioprosthetic aortic valve thrombosis under effective direct oral anticoagulant therapy

With the increase in transcatheter procedures, the use of bioprosthetic valves has become more frequent in clinical practice. However, the optimal antithrombotic management of patients with bioprosthetic valves remains controversial. In this case report, we describe a patient with a bioprosthetic aortic valve who developed a thrombus while receiving effective dose direct oral anticoagulant (DOAC) therapy. A 73-year-old male patient with a bioprosthetic aortic valve replacement 2 years prior presented with a mobile thrombus and early degeneration of the valve, detected during routine follow-up while being treated with apixaban. Although the valve thrombus regressed after switching to a different anticoagulant drug, we observed that the decreased but still high gradient persisted due to the early degeneration. Anticoagulant management of bioprosthetic valve patients demands careful attention. Although evidence supporting the use of DOACs is growing, close patient follow-up and further evaluation in case of doubt remain critical. The development of a thrombus in a bioprosthetic valve patient who is receiving anticoagulation therapy, as in this case, highlights the need for optimal management to prevent thromboembolic complications and valve degeneration.

Antioxidant Properties of Oral Antithrombotic Therapies in Atherosclerotic Disease and Atrial Fibrillation

The thrombosis-related diseases are one of the leading causes of illness and death in the general population, and despite significant improvements in long-term survival due to remarkable advances in pharmacologic therapy, they continue to pose a tremendous burden on healthcare systems. The oxidative stress plays a role of pivotal importance in thrombosis pathophysiology. The anticoagulant and antiplatelet drugs commonly used in the management of thrombosis-related diseases show several pleiotropic effects, beyond the antithrombotic effects. The present review aims to describe the current evidence about the antioxidant effects of the oral antithrombotic therapies in patients with atherosclerotic disease and atrial fibrillation.

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.

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.

The pharmacology of anticoagulant drug treatment options in COVID-19 patients: reviewing real-world evidence in clinical practice

INTRODUCTION

The optimal anticoagulation strategy for venous thromboembolism (VTE) prevention among COVID-19 patients, hospitalized or in the community setting, is still challenging and largely based on real-world evidence.

AREAS COVERED

We analyzed real-world data regarding the safety and effectiveness of anticoagulant treatment, both parenteral and oral, for VTE prevention or atrial fibrillation (AF)/VTE treatment among COVID-19 patients.

EXPERT OPINION

The efficacy of low-molecular-weight heparin (LMWH) doses for VTE prevention correlates with COVID-19 disease status. LMWH prophylactic dose may be useful in COVID-19 patients at the early stage of the disease. LMWH intermediate or therapeutic dose is recommended in COVID-19 patients with an advanced stage of the disease. COVID-19 patients on VKAs therapy for atrial fibrillation (AF) and VTE should switch to NOACs in the community setting or LMWH in the hospital setting. No definitive data on de-novo starting of NOACs or VKAs therapy for VTE prevention in COVID-19 outpatients are available. In patients at high risk discharged after hospitalization due to COVID-19, thromboprophylaxis with NOACs may be considered.

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.

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.

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.

The Characteristics, Long-Term Outcomes, Risk Factors, and Antithrombotic Therapy in Chinese Patients With Atrial Fibrillation and Bioprosthetic Valves

Introduction: There were few data about the clinical profiles and long-term outcomes in Chinese patients with atrial fibrillation (AF) and bioprosthetic valves.

Methods: The retrospective study enrolled 903 patients with bioprosthetic valve replacement at our hospital and discharged with a diagnosis of AF from January 2010 to December 2018.

Results: The median age was 65.6 (61.9–69.1) years, and 548 (60.7%) patients were women. During a follow-up period of 3.84 (2.64–5.51) years, 68 (1.8 per 100 person-years) patients died, 81 (2.1 per 100 person-years) patients developed thromboembolism, and 23 (0.6 per 100 person-years) patients experienced major bleeding. The CHA₂DS₂-VASc score, as a categorical variable (low, moderate, or high risk), predicted the risk of thromboembolism with the C-statistic of 0.6 (95% CI: 0.511–0.689, p = 0.046). The incidence of the CHA₂DS₂-VASc score increment was 11.6 per 100 person-years, and the annual reclassification rate of stroke risk (from a low or moderate group to a higher group) was 12.7%. The current proportion of oral anticoagulants was 52.3, 59, and 63.2%, respectively, in the low, moderate, and high stroke risk groups. Age (OR: 1.04, 95% CI: 1.01–1.06, p = 0.01), left atrial size (OR: 1.05, 95% CI: 1.03–1.08, p < 0.001), and rheumatic heart disease (OR: 1.49, 95% CI: 1.05–2.10, p = 0.025) were positively associated with the use of oral anticoagulants. The history of chronic kidney disease (OR: 0.20, 95% CI: 0.05–0.76, p = 0.018), prior surgical ablation (OR: 0.33, 95% CI: 0.24–0.47, p < 0.001), and antiplatelet agent use (OR: 0.08, 95% CI: 0.05–0.13, p < 0.001) were inversely related to the use of oral anticoagulants. Higher admission estimated glomerular filtration rate (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01), left ventricular ejection fraction (HR: 0.961, 95% CI: 0.931–0.992, p = 0.014), concomitant surgical ablation (HR: 0.348, 95% CI: 0.171–0.711, p = 0.004), and rheumatic heart disease history (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01) were associated with a lower risk of death. Surgical ablation (HR: 0.263, 95% CI: 0.133–0.519, p < 0.001) and oral anticoagulants (HR: 0.587, 95% CI: 0.375–0.918, p = 0.019) were related to a lower risk of thromboembolism.

Conclusion: Chinese patients with AF and bioprosthetic valve(s) were relatively young and had a high prevalence of rheumatic heart disease with few comorbidities. The percentage of mitral bioprosthetic valve replacement was high. The proportion of concomitant surgical ablation or surgical left atrial appendage occlusion or exclusion was relatively low. The thromboembolic events were the major long-term adverse events. The anticoagulation therapy was underused in patients at moderate or high stroke risk. The CHA₂DS₂-VASc score was verified to be used for predicting stroke risk in this population. The stroke risk dynamically changed; it needed to be reestimated once the risk factor changed.

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.

Non Vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients Scheduled for Electrical Cardioversion: A Real-Life Propensity Score Matched Study

Aim

The aim of the present study was to assess the safety and effectiveness of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin K antagonists (VKAs) in atrial fibrillation (AF) patients undergoing electrical cardioversion (EC).

Methods

A propensity score-matched analysis was performed in order to identify two homogeneous groups including AF patients on NOACs and VKAs treatment scheduled for EC. The primary safety endpoint was major bleeding. The composite of stroke, transient ischemic attack (TIA) and systemic embolism (SE) was the primary effectiveness endpoint. The discontinuation rate of anticoagulant therapy was assessed.

Results

A total of 495 AF patients on NOACs therapy and scheduled for EC were compared to 495 VKAs recipients. No statistically significant differences in the incidence of both major bleeding (1.01% versus 1.4%; P= 0.5) and thromboembolic events (0.6% versus 0.8%; P= 0.7) were observed during a mean follow-up of 15 ± 3 months. The discontinuation rate of NOACs was significantly lower compared to VKAs (1.6% versus 3.6%, P=0.04).

Conclusion

We showed a safe and effective clinical profile of NOACs among AF patients scheduled for electrical cardioversion in real-life setting. Patients on NOACs therapy showed a lower discontinuation rate compared to those on VKAs.

Evaluation of Prescribing Practices and Outcomes Using Direct-acting Oral Anticoagulants After Cardiac Surgery

PURPOSE

Cardiac surgery patients frequently require anticoagulation. Warfarin remains the preferred agent, and a few trials have reported negative outcomes with the use of direct-acting oral anticoagulants (DOACs) in these patients. Therefore, limited literature exists that supports the dosing, safety, and efficacy of DOACs within the cardiac surgery population.

METHODS

This single-center, retrospective analysis was conducted at a tertiary academic medical center. All data were extrapolated from electronic medical records of qualifying patients from August 2017 to August 2019. Adult patients were included if they received at least 1 of 4 DOACs (apixaban, rivaroxaban, edoxaban, or dabigatran) after undergoing one of the following cardiac surgeries: coronary artery bypass graft, bioprosthetic valve replacement, aortic surgery, or valve repair. The composite safety end point included major bleeding and clinically relevant nonmajor bleeding, as defined by the International Society on Thrombosis and Hemostasis. The composite efficacy outcome of thromboembolic events included deep vein thrombosis, pulmonary embolism, ischemic stroke, and intracardiac thrombus.

FINDINGS

A total of 305 patient charts were identified for analysis; 229 patients met the inclusion criteria. The composite safety outcome occurred in 12 patients (5.2%) within 90 days after cardiac surgery. One patient (0.4%) experienced a thromboembolic event within 90 days after cardiac surgery. The most commonly prescribed DOAC was apixaban (79.0%). US Food and Drug Administration-approved dosing was used in 91.3% of patients, and DOACs were primarily used for the indication of stroke prevention in atrial fibrillation or atrial flutter (88.2%).

IMPLICATIONS

These data provide insight into the prescribing practices, efficacy, and safety of DOACs in cardiac surgery patients.

Nursing Teleconsultation for the Outpatient Management of Patients with Cardiovascular Disease during COVID-19 Pandemic

Introduction: During the COVID-19 outbreak, non-urgent clinic visits or cardiac interventional procedures were postponed to a later date, and the implementation of telemedicine has guaranteed continuity of care for patients with chronic diseases. The aim of our study was to describe the medical interventions following nursing teleconsultation for the outpatient management of patients with cardiovascular diseases during the COVID-19 pandemic. Materials and Methods: All patients who did not attend the follow-up visit from 4 to 15 April 2020 at our institution and who were re-scheduled due to the COVID-19 lockdown were selected to be enrolled in the study. Each patient was followed by a semi-structured telephonic interview performed by a nurse. The outcomes of our study were to assess the patients' adherence to nursing teleconsultation and the usefulness of nursing teleconsultation to detect clinical conditions in need of medical intervention. Results: In total, 203 patients (81%) underwent nursing teleconsultation in a mean time of 7 ± 3 days from the outpatient visit lost due to the COVID-19 lockdown. Furthermore, 53 patients (26%) showed poor adherence to nursing teleconsultation. Among the 150 patients (mean age 67 ± 10 years; 68% male) who completed the telephonic interview, the nursing teleconsultation revealed the need of medical intervention in 69 patients (46%), who were more likely at very high cardiovascular risk (77% vs. 48%; p < 0.0003) and who showed a higher prevalence of dyslipidemia (97% vs. 64%; p < 0.0001) and coronary artery disease (75% vs. 48%, p < 0.0008) compared to those not in need of any intervention. The up-titration of the lipid-lowering drugs (n: 32, 74%) was the most frequent medical intervention following the nursing teleconsultation. The mean time between the nursing teleconsultation and the date of the rescheduled in-person follow-up visit was 164 ± 36 days. Conclusions: Nursing teleconsultation is a simple and well-tolerated strategy that ensures the continuity of care and outpatient management for patients with cardiovascular diseases during the COVID-19 pandemic.

Edoxaban (LIXIANA®) in the treatment of venous thromboembolism

Standard therapy for venous thromboembolism (VTE) includes the use of heparins and vitamin K antagonists. Randomized clinical trials have shown that non-vitamin K oral anticoagulants are as effective and safe as standard therapy in VTE treatment, with an improved pharmacological profile. Edoxaban, a direct inhibitor of factor Xa, has demonstrated noninferiority to standard therapy for the treatment of VTE, preserving a high safety profile even in long-term therapy, in frail patients and in severe clinical presentations. The present paper focuses on the role of edoxaban in VTE treatment, from general population to cancer patients, presenting the available data from randomized clinical trials and real world, to discuss edoxaban use in clinical practice.

Direct Current Cardioversion in Atrial Fibrillation Patients on Edoxaban Therapy Versus Vitamin K Antagonists: a Real-world Propensity Score-Matched Study

Purpose

The purpose of the present study was to compare the long-term effectiveness and safety of newly initiated anticoagulation with edoxaban (EDO) versus uninterrupted vitamin K antagonist (VKA) therapy in patients with atrial fibrillation (AF) scheduled for transesophageal echocardiogram (TEE)-guided direct electrical current cardioversion (DCC).

Methods

A propensity score-matched cohort observational study was performed comparing the safety and effectiveness of edoxaban versus well-controlled VKA therapy among a cohort of consecutive non-valvular AF patients scheduled for DCC. The primary safety outcome was major bleeding. The primary efficacy outcome was the composite of stroke, transient ischemic attack (TIA), and systemic embolism (SE).

Findings

A total of 130 AF patients receiving edoxaban 60-mg (EDO) treatment were compared with the same number of VKA recipients. The cumulative incidence of major bleedings was 1.54% in the EDO group and 3.08% in the VKA group (P = 0.4). The cumulative incidence of thromboembolic events was 1.54% in the EDO group and 2.31% in the VKA group (P = 0.9). A non-significant trend in improved adherence was observed between the EDO and VKA groups with a total anticoagulant therapy discontinuation rate of 4.62% (6/130) vs 6.15% (8/130), respectively (P = 0.06).

Implications

Our study provides the evidence of a safe and effective use of edoxaban in this clinical setting, justified by no significant difference in major bleedings and thromboembolic events between edoxaban and well-controlled VKA treatments.

Anticoagulation and antiplatelet therapy in patients with prosthetic heart valves

BACKGROUND

The choice of antithrombotic therapy, anticoagulants or antiplatelets, after prosthetic heart valve replacement or repair, remains a disputed topic in the literature. Antithrombotic therapies are used after heart valve intervention to reduce the rates of thromboembolic events, therefore improving patient outcomes. Different interventions may require different therapeutic regimens to achieve the most efficacious clinical outcome for patients.

METHODS AND DISCUSSION

This review aims to summarize and critique the available literature concerning therapeutic agents used for bioprosthetic and mechanical valves as well as for valve repair, so as to assist clinicians and researchers in making decisions with regard to their patients and research endeavors.

Atrial Fibrillation and Mitral Regurgitation: Clinical Performance of Direct Oral Anticoagulants in a Real-World Setting

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is frequently present in patients with mitral regurgitation (MR). Currently, there is a lack of real-world evidence specifically addressing the clinical performance of direct oral anticoagulants (DOACs) in patients with AF and concomitant MR. Therefore, the aim of the present study was to assess the efficacy and safety profile of DOACs therapy in patients with AF and MR.

METHODS

Data for this study were sourced from the Atrial Fibrillation Research Database in the Department of Cardiology at Monaldi Hospital. The database was queried for AF patients with MR who were prescribed DOACs therapy. The primary safety outcome was defined as the annual incidence rate of major bleeding events and the primary effectiveness outcome as the annual incidence rate of all events classified as ischemic stroke, transient ischemic attacks, and systemic embolisms.

RESULTS

Consecutive AF patients with concomitant mild to severe MR who received DOACs therapy (n = 259) were included. Patients were dichotomized in 2 groups according to MR severity: a mild-to-moderate group (MR 1-2+; n = 151) and a moderate-to-severe group (MR 3-4+; n = 108). The incidence rate of major bleedings was significantly higher in MR 3-4+ group (3.92%) compared with the MR 1-2+ group (1.18%; hazard ratio [HR]: 3.2; 95% CI: 1.4-7.3; P = .0059). The incidence rate of thromboembolic events between MR 3-4+ group (0.66%) and MR 1-2+ group (0.62%) was not significantly different (HR: 0.75; P = .823).

CONCLUSIONS

In the present study, there was no difference in the efficacy profile of DOACs between AF patients with mild-to-moderate and moderate-to-severe MR. Considering the increased bleeding risk, a close and careful follow-up should be warranted for patients with moderate-to-severe MR.