Dabigatran versus warfarin in patients with mechanical heart valves

Outcomes of Patients with a Mechanical Heart Valve and Poor Anticoagulation Control on Warfarin

BACKGROUND

 Patients with a mechanical heart valve (MHV) require oral anticoagulation. Poor anticoagulation control is thought to be associated with adverse outcomes, but data are limited.

OBJECTIVE

 To assess the risks of clinical outcomes in patients with a MHV and poor anticoagulation control on warfarin.

METHODS

 We conducted a retrospective study of consecutive patients undergoing MHV implantation at a tertiary care center (2010-2019). Primary outcome was a composite of ischemic stroke, systemic embolism, or prosthetic valve thrombosis. Major bleeding and death were key secondary outcomes. We constructed multivariable regression models to assess the association between time in therapeutic range (TTR) on warfarin beyond 90 days after surgery with outcomes.

RESULTS

 We included 671 patients with a MHV (80.6% in aortic, 14.6% in mitral position; mean age 61 years, 30.3% female). Median follow-up was 4.9 years, mean TTR was 62.5% (14.5% TTR <40%, 24.6% TTR 40-60%, and 61.0% TTR >60%). Overall rates of the primary outcome, major bleeding, and death were 0.73, 1.41, and 1.44 per 100 patient-years. Corresponding rates for patients with TTR <40% were 1.31, 2.77, and 3.22 per 100 patient-years. In adjusted analyses, every 10% decrement in TTR was associated with a 31% increase in hazard for the primary outcome (hazard ratio [HR]: 1.31, 95% confidence interval [CI]: 1.13-1.52), 34% increase in major bleeding (HR: 1.34, 95% CI: 1.17-1.52), and 32% increase in death (HR: 1.32, 95% CI: 1.11-1.57).

CONCLUSION

 In contemporary patients with a MHV, poor anticoagulation control on warfarin was associated with increased risks of thrombotic events, bleeding, and death.

Oral anticoagulant treatment in atrial fibrillation: the AFIRMA real-world study using natural language processing and machine learning

INTRODUCTION

Oral anticoagulation (OAC) is key in atrial fibrillation (AF) thromboprophylaxis, but Spain lacks substantial real-world evidence. We aimed to analyze the prevalence, clinical characteristics, and treatment patterns among patients with AF undertaking OAC, using natural language processing (NLP) and machine learning (ML).

MATERIALS AND METHODS

This retrospective study included AF patients on OAC from 15 Spanish hospitals (2014-2020). Using EHRead® (including NLP and ML), and SNOMED_CT, we extracted and analyzed patient demographics, comorbidities, and OAC treatment from electronic health records. AF prevalence was estimated, and a descriptive analysis was conducted.

RESULTS

Among 4,664,224 patients in our cohort, AF prevalence ranged from 1.9% to 2.9%. A total of 57,190 patients on OAC therapy were included, 80.7% receiving Vitamin K antagonists (VKA) and 19.3% Direct-acting OAC (DOAC). The median age was 78 and 76 years respectively, with males constituting 53% of the cohort. Comorbidities like hypertension (76.3%), diabetes (48.0%), heart failure (42.2%), and renal disease (18.7%) were common, and more frequent in VKA users. Over 50% had a high CHA2DS2-VASc score. The most frequent treatment switch was from DOAC to acenocoumarol (58.6% to 70.2%). In switches from VKA to DOAC, apixaban was the most chosen (35.2%).

CONCLUSIONS

Utilizing NLP and ML to extract RWD, we established the most comprehensive Spanish cohort of AF patients with OAC to date. Analysis revealed a high AF prevalence, patient complexity, and a marked VKA preference over DOAC. Importantly, in VKA to DOAC transitions, apixaban was the favored option.

Chinese guidelines for the diagnosis and management of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, significantly impacting patients' quality of life and increasing the risk of death, stroke, heart failure, and dementia. Over the past two decades, there have been significant breakthroughs in AF risk prediction and screening, stroke prevention, rhythm control, catheter ablation, and integrated management. During this period, the scale, quality, and experience of AF management in China have greatly improved, providing a solid foundation for the development of the guidelines for the diagnosis and management of AF. To further promote standardized AF management, and apply new technologies and concepts to clinical practice timely and fully, the Chinese Society of Cardiology of Chinese Medical Association and the Heart Rhythm Committee of Chinese Society of Biomedical Engineering jointly developed the Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation. The guidelines comprehensively elaborated on various aspects of AF management and proposed the CHA2DS2‑VASc‑60 stroke risk score based on the characteristics of the Asian AF population. The guidelines also reevaluated the clinical application of AF screening, emphasized the significance of early rhythm control, and highlighted the central role of catheter ablation in rhythm control.

Incidence and Prognostic Factors of Radial Artery Occlusion in Transradial Coronary Catheterization

Background/Objectives: Radial artery occlusion (RAO) is the most common complication of transradial coronary catheterization. In this study, we aimed to evaluate the incidence of RAO and identify the risk factors that predispose patients to it. Methods: We conducted an investigator-initiated, prospective, multicenter, open-label study involving 1357 patients who underwent cardiac catheterization via the transradial route for angiography and/or a percutaneous coronary intervention (PCI). Univariate and multivariate logistic regression analyses were performed to identify potential predictors of RAO occurrence. Additionally, a subgroup analysis only for patients undergoing PCIs was performed. Results: The incidence of RAO was 9.5% overall, 10.6% in the angiography-only group and 6.2% in the PCI group. Independent predictors of RAO were as follows: (i) the female gender (aOR = 1.72 (1.05-2.83)), (ii) access site cross-over (aOR = 4.33 (1.02-18.39)), (iii) increased total time of the sheath in the artery (aOR = 1.01 (1.00-1.02)), (iv) radial artery spasms (aOR = 2.47 (1.40-4.36)), (v) the presence of a hematoma (aOR = 2.28 (1.28-4.06)), (vi) post-catheterization dabigatran use (aOR = 5.15 (1.29-20.55)), (vii) manual hemostasis (aOR = 1.94 (1.01-3.72)) and (viii) numbness at radial artery ultrasound (aOR = 8.25 (1.70-40)). Contrariwise, two variables were independently associated with increased odds for radial artery patency (RAP): (i) PCI performance (aOR = 0.19 (0.06-0.63)), and (ii) a higher dosage of intravenous heparin per patient weight (aOR = 0.98 (0.96-0.99)), particularly, a dosage of >50 IU/kg (aOR = 0.56 (0.31-1.00)). In the PCI subgroup, independent predictors of RAO were as follows: (i) radial artery spasms (aOR = 4.48 (1.42-14.16)), (ii) the use of intra-arterial nitroglycerin as a vasodilator (aOR = 7.40 (1.67-32.79)) and (iii) the presence of symptoms at echo (aOR = 3.80 (1.46-9.87)), either pain (aOR = 2.93 (1.05-8.15)) or numbness (aOR = 4.66 (1.17-18.57)). On the other hand, the use of intra-arterial verapamil as a vasodilator (aOR = 0.17 (0.04-0.76)) was independently associated with a greater frequency of RAP. Conclusions: The incidence of RAO in an unselected, all-comers European population after transradial coronary catheterization for angiography and/or PCIs is similar to that reported in the international literature. Several RAO prognostic factors have been confirmed, and new ones are described. The female gender, radial artery trauma and manual hemostasis are the strongest predictors of RAO. Our results could help in the future identification of patients at higher risk of RAO, for whom less invasive diagnostic procedures maybe preferred, if possible.

Warfarin-A natural anticoagulant: A review of research trends for precision medication

BACKGROUND

Warfarin is a widely prescribed anticoagulant in the clinic. It has a more considerable individual variability, and many factors affect its variability. Mathematical models can quantify the quantitative impact of these factors on individual variability.

PURPOSE

The aim is to comprehensively analyze the advanced warfarin dosing algorithm based on pharmacometrics and machine learning models of personalized warfarin dosage.

METHODS

A bibliometric analysis of the literature retrieved from PubMed and Scopus was performed using VOSviewer. The relevant literature that reported the precise dosage of warfarin calculation was retrieved from the database. The multiple linear regression (MLR) algorithm was excluded because a recent systematic review that mainly reviewed this algorithm has been reported. The following terms of quantitative systems pharmacology, mechanistic model, physiologically based pharmacokinetic model, artificial intelligence, machine learning, pharmacokinetic, pharmacodynamic, pharmacokinetics, pharmacodynamics, and warfarin were added as MeSH Terms or appearing in Title/Abstract into query box of PubMed, then humans and English as filter were added to retrieve the literature.

RESULTS

Bibliometric analysis revealed important co-occuring MeShH and index keywords. Further, the United States, China, and the United Kingdom were among the top countries contributing in this domain. Some studies have established personalized warfarin dosage models using pharmacometrics and machine learning-based algorithms. There were 54 related studies, including 14 pharmacometric models, 31 artificial intelligence models, and 9 model evaluations. Each model has its advantages and disadvantages. The pharmacometric model contains biological or pharmacological mechanisms in structure. The process of pharmacometric model development is very time- and labor-intensive. Machine learning is a purely data-driven approach; its parameters are more mathematical and have less biological interpretation. However, it is faster, more efficient, and less time-consuming. Most published models of machine learning algorithms were established based on cross-sectional data sourced from the database.

CONCLUSION

Future research on personalized warfarin medication should focus on combining the advantages of machine learning and pharmacometrics algorithms to establish a more robust warfarin dosage algorithm. Randomized controlled trials should be performed to evaluate the established algorithm of warfarin dosage. Moreover, a more user-friendly and accessible warfarin precision medicine platform should be developed.

Comparison of different direct oral anticoagulant regimens in atrial fibrillation patients with high bleeding risk

BACKGROUND

The optimal dose of direct oral anticoagulants (DOACs) to prevent ischemic stroke (IS) and systemic thromboembolism (STE) in atrial fibrillation (AF) patients with a predisposing bleeding risk remains unclear.

OBJECTIVE

The purpose of this study was to compare the effectiveness and safety of different DOAC dosage regimens in AF patients with high bleeding risk but low thrombosis risk.

METHODS

This retrospective observational study was conducted with the National Health Insurance claims database in Taiwan to include AF patients aged 20 up to 75 years, under DOAC therapy, with CHA2DS2-VASc score of 1 for males and 2 for females and HAS-BLED score ≥3. Standard-dose regimen was defined as dabigatran 300 mg, rivaroxaban 20 mg, apixaban 10 mg, or edoxaban 60 mg per day. Any other lower-dose regimen were defined as the low-dose regimen. The primary outcomes were IS and major bleeding (MB). The secondary outcomes were STE, gastrointestinal bleeding, intracranial hemorrhage, and cardiovascular death.

RESULTS

A total of 964 patients were included (52.1% standard-dose regimen). Median HAS-BLED score was 3 [interquartile range 3-3]. Compared with standard-dose group, patients in the low-dose group had a significantly increased risk of IS (adjusted hazard ratio [aHR] 5.13; 95% confidence interval 1.37-19.22) and STE (aHR 3.14 [1.05-9.37]) but similar risk of MB (aHR 0.45 [0.12-1.67]). The risks of other hemorrhage and cardiovascular death were similar between the 2 dose groups.

CONCLUSION

Among patients with a predominant bleeding risk but relatively low thrombosis risk, the low-dose DOAC regimen is not a more appropriate selection than standard-dose regimen.

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.

A Randomized Trial Comparing Standard of Care to Bayesian Warfarin Dose Individualization

The quality of warfarin treatment may be improved if management is guided by the use of models based upon pharmacokinetic-pharmacodynamic theory. A prospective, two-armed, single-blind, randomized controlled trial compared management aided by a web-based dose calculator (NextDose) with standard clinical care. Participants were 240 adults receiving warfarin therapy following cardiac surgery, followed up until the first outpatient appointment at least 3 months after warfarin initiation. We compared the percentage of time spent in the international normalized ratio acceptable range (%TIR) during the first 28 days following warfarin initiation, and %TIR and count of bleeding events over the entire follow-up period. Two hundred thirty-four participants were followed up to day 28 (NextDose: 116 and standard of care: 118), and 228 participants (114 per arm) were followed up to the final study visit. Median %TIR tended to be higher for participants receiving NextDose guided warfarin management during the first 28 days (63 vs. 56%, P = 0.13) and over the entire follow-up period (74 vs. 71%, P = 0.04). The hazard of clinically relevant minor bleeding events was lower for participants in the NextDose arm (hazard ratio: 0.21, P = 0.041). In NextDose, there were 89.3% of proposed doses accepted by prescribers. NextDose guided dose management in cardiac surgery patients requiring warfarin was associated with an increase in %TIR across the full follow-up period and fewer hemorrhagic events. A theory-based, pharmacologically guided approach facilitates higher quality warfarin anticoagulation. An important practical benefit is a reduced requirement for clinical experience of warfarin management.

Design and Rationale for the Direct Oral Anticoagulant Apixaban in Left Ventricular Assist Devices (DOAC LVAD) Study

Implantable left ventricular assist device (LVAD) therapy is used to improve quality of life, alleviate symptoms and extend survival rates in patients with advanced heart failure. Patients with LVADs require chronic anticoagulation to reduce the risk of thromboembolic complications, and they commonly experience bleeding events. Apixaban is a direct oral anticoagulant that has become first-line therapy for patients with nonvalvular atrial fibrillation and venous thromboembolism; however, its safety in patients with LVADs has not been well characterized. The evaluation of the hemocompatibility in the DOAC LVAD (Direct Oral Anti-Coagulant apixaban in Left Ventricular Assist Devices) trial is a phase 2, open-label trial of patients with LVADs who were randomized to either apixaban or warfarin therapy. Patients randomized to apixaban will be started on a dosage of 5 mg twice daily, whereas those randomized to warfarin will be managed at an International Normalized Ratio goal of 2.0-2.5. All patients will be treated with aspirin at 81 mg daily. We plan to randomize and follow as many as 40 patients for 24 weeks to evaluate the primary outcomes of freedom from death or hemocompatibility-related adverse events (stroke, device thrombosis, bleeding, aortic root thrombus, and arterial non-CNS thromboembolism). The DOAC LVAD trial will establish the feasibility of apixaban anticoagulant therapy in patients with LVADs. Clinicaltrials.gov: NCT04865978.

Anticoagulant Therapy in Pregnant Women with Mechanical Heart Valves: Italian Federation of Centers for Diagnosis and Surveillance of the Antithrombotic Therapies (FCSA) Position Paper

The management of anticoagulant therapy in pregnant women with mechanical heart valves (MHVs) is difficult and often challenging even for clinicians experienced in the field. These pregnancies, indeed, are burdened with higher rates of complications for both the mother and the fetus, compared to those in women without MHVs. The maternal need for an optimal anticoagulation as provided by vitamin K antagonists is counterbalanced by their teratogen effect on the embryo and fetus. On the other hand, several concerns have been raised about the efficacy of heparins in pregnant women with MHVs, considering the high risk of thrombotic complications in these patients. Therefore, numerous clinical issues about the management of pregnant women with MHVs remain unanswered, such as the selection of the best anticoagulant agent, the optimal anticoagulation levels to be achieved and maintained, and the evaluation of long-term effects for both the mother and the fetus. Based on a comprehensive review of the current literature, the Italian Federation of the Centers for the Diagnosis and the Surveillance of the Antithrombotic Therapies (FCSA) proposes experience-based suggestions and expert opinions. Particularly, this consensus document aims at providing practical guidance for clinicians dealing with pregnant women with MHVs, to optimize maternal and fetal outcomes while guaranteeing adequate anticoagulation. Finally, FCSA highlights the need for the creation of multidisciplinary teams experienced in the management of pregnant women with MHVs during pregnancy, delivery, and postpartum, in order to better deal with such complex clinical issues and provide a comprehensive counseling to these patients.

Perioperative Management of Valvular Heart Disease in Patients Undergoing Non-Cardiac Surgery

Postoperative cardiovascular complications (either in a hospital or within 30 days after the operation) are among the most common problems with non-cardiac surgeries (NCSs). Pre-existing cardiac comorbidities add significant risk to the development of such complications. Valvular heart disease (VHD), a rather frequent cardiac comorbidity (especially in the elderly population), can pose serious life-threatening peri-/postoperative complications. Being familiar with the recommended perioperative management of patients with VHD or an implanted prosthetic heart valve who are scheduled for NCS is of great importance in daily clinical practice. Although recently published guidelines by the European Society of Cardiology (ESC) and the American College of Cardiology and American Heart Association (ACC/AHA) for the management of VHD and perioperative management of patients undergoing NCS addresses the mentioned problem, a comprehensive review of the guidelines that provides an easy-to-use summary of the recommendations and their similarities and differences is missing in the published literature. In this review article, we summarize all of the relevant important information based on the latest data published in both guidelines needed for practical decision-making in the perioperative management of patients with VHD or after valvular repair (with prosthetic heart valve) who are scheduled for NCS.

Changes in Time in Therapeutic Range Within a Warfarin Anticoagulation Clinic Following Introduction of Direct Oral Anticoagulants

Background: As direct oral anticoagulants (DOACs) have become widely recommended as first-line anticoagulation therapy, patients who remain on warfarin are likely those unable to afford, adhere to, or utilize DOAC therapy due to the presence of a contraindication. It is currently unknown how availability of DOACs have affected populations being managed at warfarin (VKA) anticoagulation clinics. Methods: This was a retrospective chart review assessing warfarin-treated patients at an outpatient anticoagulation clinic. The primary endpoint was the 6-month time in therapeutic range (TTR) before and after DOACs were recommended as first-line therapy by clinical guidelines. Study periods were January to June 2015, before DOACs were recommended over VKA, and January to June 2022, when DOACs were often recommended over VKA. TTR, demographic changes, and the presence of contraindications to DOAC therapy in the clinic population between the two time periods were assessed. Results: No difference in 6-month TTR was observed between study periods (59% in 2015 vs 63% in 2022; P = .45). Patient demographics did not significantly vary, which may be due to the clinic retaining 45% of patients between both time periods. Contraindications to DOAC therapy were identified in 39% of the 2015 group and 49% of the 2022 group (P = .18). The most common contraindication was indication for anticoagulation. Conclusion: Availability of DOACs did not seem to significantly affect the population or management of warfarin-treated patients at an outpatient anticoagulation clinic, however, contraindications and potential challenges to use of DOAC therapy are present in many patients.

Evaluation and Management of Mechanical Heart Valve Dysfunction and Thrombosis

PURPOSE OF REVIEW

Dysfunction and thrombosis of mechanical heart valves, although uncommon, represents a challenge that requires multidisciplinary expertise for diagnosis and management. The aim of this review is to summarize strengths and weaknesses of diagnostic methods and therapeutic strategies for this uncommon but potentially life-threatening pathology.

RECENT FINDINGS

Expeditious diagnosis of mechanical valve thrombosis and exclusion of other diagnostic considerations, often with incorporation of multimodality imaging, can inform the best treatment strategy. Presentation of mechanical valve thrombosis can be asymptomatic or can include heart failure, life-threatening embolic events, or cardiogenic shock. Echocardiography, fluoroscopy and computed tomography are important in the evaluation of mechanical valve dysfunction. Therapeutic strategies for thrombosis include anticoagulation, systemic thrombolysis, and surgery. Choice of treatment depends on multiple factors including thrombus size, degree of valve dysfunction, clinical presentation, and available surgical expertise.

Evaluation of the safety and efficacy of direct oral anticoagulants compared with vitamin-k antagonists in the treatment of left ventricular thrombosis. A systematic review and meta-analysis

BACKGROUND

Since the introduction of direct oral anticoagulants (DOACs) and their comparison with vitamin K antagonists (VKAs), conflicting results have been reported regarding the optimal treatment for left ventricular thrombosis (LVT).

OBJECTIVES

In this meta-analysis, we intend to comprehensively evaluate the safety and efficacy of these treatments.

METHODS

All clinical trials and cohorts that compared the efficacy or safety of VKAs with DOACs in the treatment of LVTs were systematically searched until April 15, 2023.

RESULTS

The results of 32 studies with a pooled sample size of 4213 patients were extracted for meta-analysis. DOACs, especially rivaroxaban and apixaban, cause faster resolution, lower mortality, and fewer complications (SSE and bleeding events) than VKAs in the management of LVTs.

CONCLUSION

Compared with VKAs, DOACs result in significantly faster (only rivaroxaban) and safer resolution of left ventricular thrombosis.

On-X aortic valve replacement patients treated with low-dose warfarin and low-dose aspirin

OBJECTIVES

To assess if warfarin targeted to international normalized ratio (INR) 1.8 (range 1.5-2.0) is safe for all patients with an On-X aortic mechanical valve.

METHODS

This prospective, observational registry follows patients receiving warfarin targeted at an INR of 1.8 (range 1.5-2.0) plus daily aspirin (75-100 mg) after On-X aortic valve replacement. The primary end point is a composite of thromboembolism, valve thrombosis and major bleeding. Secondary end points include the individual rates of thromboembolism, valve thrombosis and major bleeding, as well as the composite in subgroups of home or clinic-monitored INR and risk categorization for thromboembolism. The control was the patient group randomized to standard-dose warfarin (INR 2.0-3.0) plus daily aspirin 81 mg from the PROACT trial.

RESULTS

A total of 510 patients were enroled at 23 centres in the UK, USA and Canada. Currently, the median follow-up duration is 3.4 years, and median achieved INR is 1.9. The primary composite end point rate in the low INR patients is 2.31% vs 5.39% (95% confidence interval 4.12-6.93%) per patient-year in the PROACT control group, constituting a 57% reduction. Results are consistent in subgroups of home or clinic-monitored, and high-risk patients, with reductions of 56%, 57% and 57%, respectively. Major and total bleeding are decreased by 85% and 73%, respectively, with similar rates of thromboembolic events. No valve thrombosis occurred.

CONCLUSIONS

Interim results suggest that warfarin targeted at an INR of 1.8 (range 1.5-2.0) plus aspirin is safe and effective in patients with an On-X aortic mechanical valve with or without home INR monitoring.

Validation of large animal models in mechanical valve research: a histologic comparison

OBJECTIVES

Mechanical valves still require life-long anticoagulation. Preclinical animal testing is a crucial step in the assessment of valves; however, the chosen animal model should be carefully considered, and a well-controlled animal model of mechanical valve thrombosis has not been established yet. In this study, a histopathologic comparison was performed to evaluate the representativity of pigs and sheep as large animal models in bileaflet mechanical valve thrombosis research.

METHODS

10 pigs and 8 sheep were implanted with a bileaflet mechanical valve in pulmonary position. During follow-up, no anticoagulative therapy was administered. Pigs were sacrificed between 14 and 38 days for explantation and assessment of the valve. Sheep were sacrificed between 71 and 155 days. Thrombus samples were processed and (immuno)histochemical stainings were applied. A pathologist evaluated the samples morphologically and semiquantitatively and compared these samples to available slides from 3 human patients who underwent redo surgery for acute bileaflet mechanical valve thrombosis, caused by insufficient anticoagulation.

RESULTS

All pigs showed macroscopically evident thrombi on the mechanical valve surface at sacrifice. In contrast, none of the sheep showed any sign of thrombus formation. Histology showed a high fibrin content in thrombi of both human and porcine cases (3/3 vs 8/10). Porcine thrombi showed more cellular organization (0/3 vs 6/10), more calcification (0/3 vs 9/10) and more endothelialization (0/3 vs 6/10). Inflammatory cells were present in all samples and were considered physiological.

CONCLUSIONS

Contrary to sheep, pigs develop thrombi on their mechanical valves in the short-term if no anticoagulation is administered. Histologic comparison of human and porcine thrombi shows comparable findings. The pig model might serve interestingly for further research on valve thrombosis, if it shows not to be an overly aggressive model.

Antithrombotic therapy after heart valve surgery: contemporary practice in the UK

OBJECTIVES

There is a lack of high-quality data informing the optimal antithrombotic drug strategy following bioprosthetic heart valve replacement or valve repair. Disparity in recommendations from international guidelines reflects this. This study aimed to document current patterns of antithrombotic prescribing after heart valve surgery in the UK.

METHODS

All UK consultant cardiac surgeons were e-mailed a custom-designed survey. The use of oral anticoagulant (OAC) and/or antiplatelet drugs following bioprosthetic aortic valve replacement or mitral valve replacement, or mitral valve repair (MVrep), for patients in sinus rhythm, without additional indications for antithrombotic medication, was assessed. Additionally, we evaluated anticoagulant choice following MVrep in patients with atrial fibrillation.

RESULTS

We identified 260 UK consultant cardiac surgeons from 36 units, of whom 103 (40%) responded, with 33 units (92%) having at least 1 respondent. The greatest consensus was for patients undergoing bioprosthetic aortic valve replacement, in which 76% of surgeons favour initial antiplatelet therapy and 53% prescribe lifelong treatment. Only 8% recommend initial OAC. After bioprosthetic mitral valve replacement, 48% of surgeons use an initial OAC strategy (versus 42% antiplatelet), with 66% subsequently prescribing lifelong antiplatelet therapy. After MVrep, recommendations were lifelong antiplatelet agent alone (34%) or following 3 months OAC (20%), no antithrombotic agent (20%), or 3 months OAC (16%). After MVrep for patients with established atrial fibrillation, surgeons recommend warfarin (38%), a direct oral anticoagulant (37%) or have no preference between the 2 (25%).

CONCLUSIONS

There is considerable variation in the use of antithrombotic drugs after heart valve surgery in the UK and a lack of high-quality evidence to guide practice, underscoring the need for randomized studies.

Low-dose warfarin with a novel mechanical aortic valve: Interim registry results at 5-year follow-up

OBJECTIVES

To evaluate whether warfarin targeted at an international normalized ratio of 1.8 (range, 1.5-2.0) after On-X mechanical aortic valve implant is safe for all patients.

METHODS

This prospective, observational clinical registry assessed adverse event rates in adult patients receiving low-dose warfarin (target international normalized ratio, 1.8; range, 1.5-2.0) plus daily aspirin (75-100 mg) during a 5-year period after On-X aortic valve implant. The primary end point is the combined rate of major bleeding, valve thrombosis, and thromboembolism overall and in 4 subgroups. The comparator is the Prospective Randomized On-X Anticoagulation Trial control group patients on standard-dose warfarin (international normalized ratio, 2.0-3.0) plus aspirin 81 milligrams daily.

RESULTS

A total of 510 patients were recruited at 23 centers in the United States, United Kingdom, and Canada between November 2015 and January 2022. This interim analysis includes 229 patients scheduled to complete 5-year follow-up by August 16, 2023. The linearized occurrence rate (in percent per patient-year) of the primary composite end point of major bleeding, valve thrombosis, and thromboembolism is 1.83% compared with 5.39% (95% confidence interval, 4.12%-6.93%) in the comparator group. Results are consistent in clinic-monitored and home-monitored patients and in those at high risk for thromboembolism. Major bleeding and total bleeding were reduced by 87% and 71%, respectively, versus the comparator group, without an increase in thromboembolic events.

CONCLUSIONS

Interim results support the continued safety of the On-X aortic mechanical valve with a target international normalized ratio of 1.8 plus low-dose aspirin through 5 years after implant, with or without home monitoring.

Apixaban in bridge to transplant and destination LVAD - rationale and study design: the ApixiVAD trial

AIMS

Use of novel anticoagulation in mechanical circulatory support is controversial. We report the rationale and design of the ApixiVad pilot trial, a pilot study testing the safety of apixaban as an anticoagulant in patients bridged to transplant (BTT) or for destination (DT) with Heartmate 3 (HM3) left ventricular assist device (LVAD).

METHODS AND RESULTS

Apixaban has been used in small non-randomized cohorts in LVAD patients and shown to be effective in ex vivo studies. The ApixiVAD study examines apixaban use in a multicentre, international, open-label, randomized, controlled trial aiming to include 50 BTT or DT HM3 patients with a 1:1 randomization ratio. This event-driven study has a maximum follow-up period of 24 months with interim analysis at 6 months. The primary outcome is death, thromboembolic events and major bleeding, including operative bleeding and immediate transplant outcomes. The secondary outcome focuses on patients' quality of life related to anticoagulation. This investigator-driven pilot study is not powered to determine the non-inferiority of apixaban. An increase in primary outcome in the apixaban group of 20% will be considered a signal of harm.

CONCLUSIONS

A positive outcome in the ApixiVAD study would provide the basis for future, larger, pivotal anticoagulation trials in LVAD patients.

Treatment options for isolated aortic valve insufficiency: a review

Aortic insufficiency (AI) is a valvular disease with increasing prevalence in older patients. The modern era provides numerous options for the management of AI which is explored here. Traditional interventions included aortic valve replacement with either mechanical or bioprosthetic aortic valves. While the former is known for its durability, it has grown out of favor due to the potential complications of anticoagulation. The preference for bioprosthetic valves is thus on the rise, especially with the advancements of transcatheter technology and the use of valve-in-valve therapy. Surgical options are also no longer limited to replacement but include complex techniques such as those required for aortic valve repair, Ozaki neocuspidization, Ross procedure and valve-sparring aortic root repair. Transcatheter options for the management of AI are not commercially available currently; however, preliminary data from ad-hoc trials, showed promising results and potential use of transcatheter technology in a variety of patients with pure AI.

Secondary stroke prevention in people with atrial fibrillation: treatments and trials

Atrial fibrillation is one of the most common cardiac arrhythmias and is a major cause of ischaemic stroke. Recent findings indicate the importance of atrial fibrillation burden (device-detected, subclinical, or paroxysmal and persistent or permanent) and whether atrial fibrillation was known before stroke onset or diagnosed after stroke for the risk of recurrence. Secondary prevention in patients with atrial fibrillation and stroke aims to reduce the risk of recurrent ischaemic stroke. Findings from randomised controlled trials assessing the optimal timing to introduce direct oral anticoagulant therapy after a stroke show that early start (ie, within 48 h for minor to moderate strokes and within 4-5 days for large strokes) seems safe and could reduce the risk of early recurrence. Other promising developments regarding early rhythm control, left atrial appendage occlusion, and novel factor XI inhibitor oral anticoagulants suggest that these therapies have the potential to further reduce the risk of stroke. Secondary prevention strategies in patients with atrial fibrillation who have a stroke despite oral anticoagulation therapy is an unmet medical need. Research advances suggest a heterogeneous spectrum of causes, and ongoing trials are investigating new approaches for secondary prevention in this vulnerable patient group. In patients with atrial fibrillation and a history of intracerebral haemorrhage, the latest data from randomised controlled trials on stroke prevention shows that oral anticoagulation reduces the risk of ischaemic stroke but more data are needed to define the safety profile.

Stroke prevention strategies for cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Stroke is a much-feared complication of cardiac surgery, but existing literature on preventive strategies is fragmented. Hence, a systematic review and meta-analysis of stroke prevention strategies for cardiac surgery was conducted.

METHODS

An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) investigating perioperative interventions for cardiac surgery, with stroke as an outcome. Random-effects meta-analyses were conducted to generate risk ratios (RRs), 95% confidence intervals (95% CI), and forest plots. Descriptive analysis and synthesis of literature was conducted for interventions not amenable to meta-analysis, focusing on risks of stroke, myocardial infarction and study-defined major adverse cardiovascular events (MACE).

RESULTS

Fifty-six RCTs (61 894 patients) were retrieved. Many included trials were underpowered to detect differences in stroke risk. Among pharmacological therapies, only preoperative amiodarone was shown to reduce stroke risk in one trial. Concomitant left atrial appendage closure (LAAC) significantly reduced stroke risk (RR = 0.55, 95% CI = 0.36-0.84, P = 0.006) in patients with preoperative atrial fibrillation, and there was no difference in on-pump versus off-pump coronary artery bypass grafting (CABG) (RR = 0.94, 95% CI = 0.64-1.37, P = 0.735). Much controversy exists in literature on the timing of carotid endarterectomy relative to CABG in patients with severe carotid stenosis. The use of preoperative remote ischemic preconditioning was not found to reduce rates of stroke or MACE.

CONCLUSION

This review presents a comprehensive synthesis of existing interventions for stroke prevention in cardiac surgery, and identifies gaps in research which may benefit from future, large-scale RCTs. LAAC should be considered to reduce stroke incidence in patients with preoperative atrial fibrillation.

Trends in oral anticoagulant use - A 10-year retrospective analysis from a general medicine department of a tertiary care hospital in south India

BACKGROUND

The prescribing practice of newer oral anticoagulants (NOACs) has not been adequately studied in the Indian scenario.

AIMS

We aimed to describe the prescribing practices of oral anticoagulants, the patient profile and medical comorbidities among patients admitted in a general medicine unit.

METHODS

In this retrospective study of the 2742 patients prescribed vitamin- K antagonists (VKAs), during the study period, 150 cases were randomly taken for analysis to match the 105 NOACs cases. Their demographic details, clinical characteristics and treatment details were analyzed.

RESULTS

More than 95% of anticoagulants prescribed were VKAs. The prescription of anticoagulants was more common in men (median age 63 years) for prescription of NOACs and 52 years for VKAs. Dabigatran (60.9%) and warfarin (81.3%) were the most prescribed drugs in their respective classes. The most common indication was for cardiovascular diseases with atrial fibrillation (32%). Diabetes and hypertension were the most common comorbidities in patients prescribed oral anticoagulants with a larger proportion of patients with heart failure being prescribed VKAs ( P < 0.01). Patients in the NOACs group had a higher HAS-BLED high-risk score (33.3% vs. 17.3%; P = 0.002). Logistic regression analysis revealed that patients with co-morbidities of congestive heart failure were more likely to be prescribed VKAs while diabetics were more likely to receive NOACs.

CONCLUSIONS

VKAs were the most prescribed anticoagulants; congestive heart failure, diabetes, and hypertension were the commonest comorbidities; and atrial fibrillation was the commonest indication. Patients with a high HAS-BLED score were prescribed NOACs more often.

Management of ischaemic stroke survivors in primary care setting: the road to holistic care

The management of ischaemic stroke survivors is multidisciplinary, necessitating the collaboration of numerous medical professionals and rehabilitation specialists. However, due to the lack of comprehensive and holistic follow-up, their post-discharge management may be suboptimal. Achieving this holistic, patient-centred follow-up requires coordination and interaction of subspecialties, which general practitioners can provide as the first point of contact in healthcare systems. This approach can improve the management of stroke survivors by preventing recurrent stroke through an integrated post-stroke care, including appropriate Antithrombotic therapy, assisting them to have a Better functional and physiological status, early recognition and intervention of Comorbidities, and lifestyles. For such work to succeed, close interdisciplinary collaboration between primary care physicians and other medical specialists is required in a holistic or integrated way.

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.

Anticoagulant Prescribing Patterns in New-Onset Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery and is associated with an increased risk of thromboembolic stroke. Recommendations regarding the optimal anticoagulant, timing of initiation, and duration of therapy remain uncertain.

METHODS

Administrative databases were used to include adult patients who presented with POAF after cardiac surgery between January 1, 2015, and December 31, 2020. Key exclusion criteria included preexisting atrial fibrillation, mechanical valve replacement, or anticoagulant prescription fill within 6 months before the index admission.

RESULTS

A total of 3214 of patients were included, and 878 (27.3%) were prescribed an oral anticoagulant (OAC) on discharge, with 536 (61%) prescribed warfarin and 342 (39%) prescribed a direct OAC. More than half of the patients (56.1%) stopped their OAC by 6 months. There was no difference in stroke or systemic embolism at 30 days, 3 months, or 6 months between those with and without anticoagulation prescribed. However, those on any OAC had higher rates of any bleeding at all time points.

CONCLUSIONS

A minority of patients who presented with POAF after cardiac surgery were prescribed OAC, with warfarin being the most common agent. OAC initiation was associated with increased bleeding risk, warranting special consideration when assessing a patient's risk of stroke with the increased risk of bleeding, particularly in the postoperative period.

Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, significantly impacting patients' quality of life and increasing the risk of death, stroke, heart failure, and dementia. Over the past two decades, there have been significant breakthroughs in AF risk prediction and screening, stroke prevention, rhythm control, catheter ablation, and integrated management. During this period, the scale, quality, and experience of AF management in China have greatly improved, providing a solid foundation for the development of guidelines for the diagnosis and management of AF. To further promote standardized AF management, and apply new technologies and concepts to clinical practice in a timely and comprehensive manner, the Chinese Society of Cardiology of the Chinese Medical Association and the Heart Rhythm Committee of the Chinese Society of Biomedical Engineering have jointly developed the Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation. The guidelines have comprehensively elaborated on various aspects of AF management and proposed the CHA2DS2-VASc-60 stroke risk score based on the characteristics of AF in the Asian population. The guidelines have also reevaluated the clinical application of AF screening, emphasized the significance of early rhythm control, and highlighted the central role of catheter ablation in rhythm control.

Being precise with anticoagulation to reduce adverse drug reactions: are we there yet?

Anticoagulants are potent therapeutics widely used in medical and surgical settings, and the amount spent on anticoagulation is rising. Although warfarin remains a widely prescribed oral anticoagulant, prescriptions of direct oral anticoagulants (DOACs) have increased rapidly. Heparin-based parenteral anticoagulants include both unfractionated and low molecular weight heparins (LMWHs). In clinical practice, anticoagulants are generally well tolerated, although interindividual variability in response is apparent. This variability in anticoagulant response can lead to serious incident thrombosis, haemorrhage and off-target adverse reactions such as heparin-induced thrombocytopaenia (HIT). This review seeks to highlight the genetic, environmental and clinical factors associated with variability in anticoagulant response, and review the current evidence base for tailoring the drug, dose, and/or monitoring decisions to identified patient subgroups to improve anticoagulant safety. Areas that would benefit from further research are also identified. Validated variants in VKORC1, CYP2C9 and CYP4F2 constitute biomarkers for differential warfarin response and genotype-informed warfarin dosing has been shown to reduce adverse clinical events. Polymorphisms in CES1 appear relevant to dabigatran exposure but the genetic studies focusing on clinical outcomes such as bleeding are sparse. The influence of body weight on LMWH response merits further attention, as does the relationship between anti-Xa levels and clinical outcomes. Ultimately, safe and effective anticoagulation requires both a deeper parsing of factors contributing to variable response, and further prospective studies to determine optimal therapeutic strategies in identified higher risk subgroups.

New Triazole-Based Potent Inhibitors of Human Factor XIIa as Anticoagulants

Factor XIIa (FXIIa) functions as a plasma serine protease within the contact activation pathway. Various animal models have indicated a substantial role for FXIIa in thromboembolic diseases. Interestingly, individuals and animals with FXII deficiency seem to maintain normal hemostasis. Consequently, inhibiting FXIIa could potentially offer a viable therapeutic approach for achieving effective and safer anticoagulation without the bleeding risks associated with the existing anticoagulants. Despite the potential, only a limited number of small molecule inhibitors targeting human FXIIa have been documented. Thus, we combined a small library of 32 triazole and triazole-like molecules to be evaluated for FXIIa inhibition by using a chromogenic substrate hydrolysis assay under physiological conditions. Initial screening at 200 μM involved 18 small molecules, revealing that 4 molecules inhibited FXIIa more than 20%. In addition to being the most potent inhibitor identified in the first round, inhibitor 8 also exhibited a substantial margin of selectivity against related serine proteases, including factors XIa, Xa, and IXa. However, the molecule also inhibited thrombin with a similar potency. It also prolonged the clotting time of human plasma, as was determined in the activated partial thromboplastin time and prothrombin time assays. Subsequent structure-activity relationship studies led to the identification of several inhibitors with submicromolar activity, among which inhibitor 22 appears to demonstrate significant selectivity not only over factors IXa, Xa, and XIa, but also over thrombin. In summary, this study introduces novel triazole-based small molecules, specifically compounds 8 and 22, identified as potent and selective inhibitors of human FXIIa. The aim is to advance these inhibitors for further development as anticoagulants to provide a more effective and safer approach to preventing and/or treating thromboembolic diseases.

Factor XI Inhibitors: A New Horizon in Anticoagulation Therapy

Anticoagulation therapy has undergone significant evolution, marked by the emergence of direct oral anticoagulants with distinct advantages. Despite these advancements, challenges persist in managing residual thrombotic and bleeding risks, particularly among vulnerable populations. The pursuit of alternative drugs has honed in on factor XI/XIa inhibitors. This comprehensive review delves into several key aspects regarding this new target: (i) the role of factor XI in the coagulation cascade; (ii) the genetic evidence and pathophysiologic rationale supporting factor XI inhibition as a therapeutic target; (iii) an exploration of the various types of factor XI/XIa inhibitors currently under investigation; (iv) potential applications of these medications, spanning thromboprophylaxis after orthopedic surgery, stroke prevention in atrial fibrillation, secondary prevention after acute coronary syndrome, non-cardioembolic stroke, thromboprophylaxis after foreign material implantation, end-stage renal disease, and patients with cancer; and (v) an overview of ongoing studies, recent findings, and the future trajectory of research into these drugs.

Anticoagulation for Atrial Fibrillation: A Review of Current Literature and Views

Atrial fibrillation is a common supraventricular tachyarrhythmia with uncoordinated atrial activation and ineffective atrial contraction. This leads to an increased risk of atrial thrombi, most commonly in the left atrial appendage, and increased risks of embolic strokes and/or peripheral thromboembolism. It is associated with significant morbidity and mortality. To meet the concerns of thrombi and stroke, anticoagulation has been the mainstay for prevention and treatment thereof. Historically, anticoagulation involved the use of aspirin or vitamin K antagonists, mainly warfarin. Since early 2010s, direct oral anticoagulants (DOACs) including dabigatran, rivaroxaban, apixaban, and edoxaban have been introduced and approved for anticoagulation of atrial fibrillation. DOACs demonstrated a dramatic reduction in the rate of intracranial hemorrhage as compared to warfarin, and offer the advantages of absolution of monitoring therefore avoid the risk of hemorrhages in the context of narrow therapeutic window and under-treatment characteristic of warfarin, particularly in high-risk patients. One major concern and disadvantage for DOACs was lack of reversal agents, which have largely been ameliorated by the approval of Idarucizumab for dabigatran and Andexanet alfa for both apixaban and rivaroxaban, with Ciraparantag as a universal reversal agent for all DOACs undergoing Fast-Track Review from FDA. In this article, we will be providing a broad review of anticoagulation for atrial fibrillation with a focus on risk stratification schemes and anticoagulation agents (warfarin, aspirin, DOACs) including special clinical considerations.

Utility of a pharmacist-managed Anticoagulation Program in patients with congenital heart disease

BACKGROUND

Warfarin remains the preferred anticoagulant for many patients with CHD. The complexity of management led our centre to shift from a nurse-physician-managed model with many providers to a pharmacist-managed model with a centralized anticoagulation team. We aim to describe the patient cohort managed by our Anticoagulation Program and evaluate the impact of implementation of this consistent, pharmacist-managed model on time in therapeutic range, an evidence-based marker for clinical outcomes.

METHODS

A single-centre retrospective cohort study was conducted to evaluate the impact of the transition to a pharmacist-managed model to improve anticoagulation management at a tertiary pediatric heart centre. The percent time in therapeutic range for a cohort managed by both models was compared using a paired t-test. Patient characteristics and time in therapeutic range of the program were also described.

RESULTS

After implementing the pharmacist-managed model, the time in therapeutic range for a cohort of 58 patients increased from 65.7 to 80.2% (p < .001), and our Anticoagulation Program consistently maintained this improvement from 2013 to 2022. The cohort of patients managed by the Anticoagulation Program in 2022 included 119 patients with a median age of 24 years (range 19 months-69 years) with the most common indication for warfarin being mechanical valve replacement (n = 81, 68%).

CONCLUSIONS

Through a practice change incorporating a collaborative, centralized, pharmacist-managed model, this cohort of CHD patients on warfarin had a fifteen percent increase in time in therapeutic range, which was sustained for nine years.

Non-Vitamin K Antagonist Versus Vitamin K Antagonist Oral Anticoagulant Agents After Transcatheter Aortic Valve Replacement

BACKGROUND

Studies comparing long-term outcomes between non-vitamin K antagonist (VKA) oral anticoagulant agents (direct oral anticoagulant agents [DOACs]) and VKA anticoagulant agents after transcatheter aortic valve replacement (TAVR) are scarce, with conflicting results.

OBJECTIVES

The aim of this study was to examine the periprocedural, short-term, and long-term safety and effectiveness of DOACs vs VKAs in patients undergoing TAVR via femoral access with concomitant indications for oral anticoagulation.

METHODS

Consecutive patients undergoing transfemoral TAVR in the prospective national SwissTAVI Registry between February 2011 and June 2021 were analyzed. Net clinical benefit (a composite of all-cause mortality, myocardial infarction, stroke, and life-threatening or major bleeding) and the primary safety endpoint (a composite of life-threatening and major bleeding) were compared between the VKA and DOAC groups at 30 days, 1 year, and 5 years after TAVR.

RESULTS

After 1:1 propensity score matching, 1,454 patients were available for analysis in each group. There was no significant difference in the rate of the net clinical benefit and the safety endpoints between the groups as assessed at 30 days and 1 and 5 years post-TAVR between VKAs and DOACs. VKAs were associated with significantly higher rates of 1- year (HR: 1.28; 95% CI: 1.01-1.62) and 5-year (HR: 1.25; 95% CI: 1.11-1.40) all-cause mortality. Long-term risk for disabling stroke was significantly lower in the VKA group after excluding periprocedural events (HR: 0.64; 95% CI: 0.46-0.90).

CONCLUSIONS

At 5 years after TAVR, VKAs are associated with a higher risk for all-cause mortality, a lower risk for disabling stroke, and a similar rate of life-threatening or major bleeding compared with DOACs. (SwissTAVI Registry; NCT01368250).

Atrial fibrillation: stroke prevention

Stroke prevention is central to the management of patients with atrial fibrillation (AF) which has moved towards a more holistic or integrative care approach. The published evidence suggests that management of AF patients following such a holistic approach based on the Atrial fibrillation Better Care (ABC) pathway is associated with a lower risk of stroke and adverse events. Risk assessment, re-assessment and use of direct oral anticoagulants (DOACs) are important for stroke prevention in AF. The stroke and bleeding risks of AF patients are not static and should be re-assessed regularly. Bleeding risk assessment is to address and mitigate modifiable bleeding risk factors, and to identify high bleeding risk patients for early review and follow-up. Well-controlled comorbidities and healthy lifestyles also play an important role to achieve a better clinical outcome. Digital health solutions are increasingly relevant in the diagnosis and management of patients with AF, with the potential to improve stroke prevention. In this review, we provide an update on stroke prevention in AF, including importance of holistic management, risk assessment/re-assessment, and stroke prevention for special AF populations. Evidence-based and structured management of AF patients would reduce the risk of stroke and other adverse events.

Direct Oral Anticoagulation Versus Warfarin in Patients with Atrial Fibrillation and Bioprosthetic Heart Valves: a Retrospective, Real-World Cohort Study

OBJECTIVE

In this retrospective cohort study of consecutive patients with atrial fibrillation and surgical or transcatheter bioprosthetic valve, we compared the efficacy and safety of direct oral anticoagulants with warfarin.

METHODS

Using linked health administrative databases housed at the Institute for Clinical Evaluative Sciences, we identified consecutive patients in Ontario (Canada) 65 years of age or older with AF who underwent bioprosthetic valve replacement between 1 April 2012 and 31 March 2017. We created a time-varying Cox model to examine the relationship between the type of anticoagulant and time to thrombotic or bleeding events after adjustment for baseline risk of thrombosis using the CHA2DS2-VASc score and risk of bleeding using the HAS-BLED scores. We conducted prespecified subgroup analyses according to whether valve implantation was surgical or transcatheter.

RESULTS

We identified 2245 eligible patients. The mean age was 79 years, 41% were female, and 39% had transcatheter aortic valve replacement. Risk of death or thrombosis was not different between direct oral anticoagulants and warfarin after adjustment for CHA2DS2-VASc score (hazard ratio [HR] 1.02, 95% confidence interval [CI], 0.83-1.25). Risk of death or bleeding was not different between direct oral anticoagulants and warfarin after adjustment for HAS-BLED score (HR 0.89, 95% CI 0.75-1.07). Subgroup analyses of surgical or transcatheter valves were consistent with overall results.

CONCLUSIONS

In a real-world population of patients with atrial fibrillation and bioprosthetic valve replacement, we found no difference between direct oral anticoagulants and warfarin with regard to the risk of thrombosis or bleeding.

Direct Oral Anticoagulant Use Early After Cardiac Surgery: A Retrospective Cohort Study

Background

There is limited literature guiding the prescribing of direct oral anticoagulants (DOACs) early after cardiac surgery as this population has been excluded from landmark randomized controlled trials. This study aims to determine the rate of in-hospital DOAC use compared with warfarin early after cardiac surgery, evaluate factors associated with DOAC use, determine difference in postoperative length of stay, and characterize bleeding events.

Methods

A retrospective cohort study was conducted in adult patients with indications for anticoagulation and receiving either a DOAC or warfarin after cardiac surgery during their index hospitalization. Patients were excluded if they had any contraindications to DOAC use. The primary outcome was the proportion of patients discharged on a DOAC compared with warfarin.

Results

Of included 210 patients, 30% received DOACs and 70% received warfarin on discharge. The most common DOAC used was apixaban (74.6%), and median postoperative day of initiation was 5 days. Patients receiving DOACs were older (70.8 vs 68.0 years), had less valvular heart disease (38.1% vs 63.9%), were more likely to be on DOACs preoperatively (50.8% vs 31.3%), and were more likely to have undergone coronary artery bypass graft alone (54.0% vs 24.5%) compared with those on warfarin. Postoperative length of stay (7 vs 9 days; P = 0.59) and in-hospital bleeding (1.6% vs 2.0%; P = 1.00) did not differ between DOAC and warfarin groups.

Conclusions

At a quaternary referral centre for cardiac surgery, DOACs were used in approximately one-third of patients with an indication for anticoagulation early after cardiac surgery.

Left Atrial Appendage Occlusion and Post-procedural Antithrombotic Management

Left atrial appendage occlusion (LAAO) is an established alternative to oral anticoagulation for stroke prevention in atrial fibrillation. Antithrombotic therapy is used in the post-procedural period to prevent device-related thrombosis (DRT). The risk of DRT is considered highest in the first 45-90 days after device implantation, based on animal studies of the device healing process. Clinically applied antithrombotic regimens vary greatly across studies, continents, and centers. This article gives an overview of the evidence behind current antithrombotic regimens, ongoing randomized trials, and future post-procedural management.

When Direct Oral Anticoagulants Should Not Be Standard Treatment: JACC State-of-the-Art Review

For most patients, direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists for stroke prevention in atrial fibrillation and for venous thromboembolism treatment. However, randomized controlled trials suggest that DOACs may not be as efficacious or as safe as the current standard of care in conditions such as mechanical heart valves, thrombotic antiphospholipid syndrome, and atrial fibrillation associated with rheumatic heart disease. DOACs do not provide a net benefit in conditions such as embolic stroke of undetermined source. Their efficacy is uncertain for conditions such as left ventricular thrombus, catheter-associated deep vein thrombosis, cerebral venous sinus thrombosis, and for patients with atrial fibrillation or venous thrombosis who have end-stage renal disease. This paper provides an evidence-based review of randomized controlled trials on DOACs, detailing when they have demonstrated efficacy and safety, when DOACs should not be the standard of care, where their safety and efficacy are uncertain, and areas requiring further research.

Oral Anticoagulants Beyond Warfarin

Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists, mostly warfarin, for the main indications for oral anticoagulation, prevention and treatment of venous thromboembolism, and prevention of embolic stroke in atrial fibrillation. While DOACs offer practical, fixed-dose anticoagulation in many patients, specific restrictions or contraindications may apply. DOACs are not sufficiently effective in high-thrombotic risk conditions such as antiphospholipid syndrome and mechanical heart valves. Patients with cancer-associated thrombosis may benefit from DOACs, but the bleeding risk, particularly in those with gastrointestinal or urogenital tumors, must be carefully weighed. In patients with frailty, excess body weight, and/or moderate-to-severe chronic kidney disease, DOACs must be cautiously administered and may require laboratory monitoring. Reversal agents have been developed and approved for life-threatening bleeding. In addition, the clinical testing of potentially safer anticoagulants such as factor XI(a) inhibitors is important to further optimize anticoagulant therapy in an increasingly elderly and frail population worldwide.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Association of sex with major bleeding risks in sub-Saharian anticoagulated patients with mechanical heart valves: A cohort study from the Khartoum Emergency Salam Centre

BACKGROUND

Rheumatic heart disease (RHD) with mechanical heart valve (MHV) replacement is common in Africa. However, MHV requires lifelong anticoagulation that could have a particular impact in women in reproductive age.

METHODS

We report data of a prospective observational cohort study conducted between August 2018 and September 2019 in MHV patients in the Salam Centre for Cardiac Surgery built in Khartoum by Emergency, an Italian Non-Governmental Organization, to evaluate bleeding risk, its associated determinants, and the impact of lifelong anticoagulation in fertile women.

RESULTS

We studied 3647 patients (median age 25.1 years; 53.9% female). During follow-up [median time 1.1 (0.1-1.2) years], we recorded 85 major bleedings (rate 2.16 × 100 pt-years), Major bleedings occurred more frequently among women (64/85 cases, 75.3%; rate 3.0 × 100 pt-years), compared to men (21/85 cases, 24.7%; rate 1.16 × 100 pt-years) (RR 2.6; 95% CI 1.6-4.5; p = 0.0001). Multivariate analysis was performed to identify variables associated with major bleeding, and female sex was the only risk factor significantly associated, whereas aspirin treatment and higher INR target showed a non-significant trend for higher bleeding risk. Thirty-two/85 (37.6%) of major bleedings were metrorrhagias. When we calculate the incidence of major bleedings after the exclusion of gynecological events, no sex differences in the bleeding risk were found (HR 1.3, 95% CI 0.8-2.3; p = 0.3).

CONCLUSIONS

Bleeding risk of young MHV patients on oral anticoagulant therapy is higher among women, mainly due to metrorrhagia. Women in the reproductive life are at high risk for gynecological bleeding when treated with anticoagulants.

Update of Anticoagulation Use in Cardioembolic Stroke With a Special Reference to Endovascular Treatment

Cardioembolic stroke is a major cause of morbidity, with a high risk of recurrence, and anticoagulation represents the mainstay of secondary stroke prevention in most patients. The implementation of endovascular treatment in routine clinical practice complicates the decision to initiate anticoagulation, especially in patients with early hemorrhagic transformation who are considered at higher risk of hematoma expansion. Late hemorrhagic transformation in the days and weeks following stroke remains a potentially serious complication for which we still do not have any established clinical or radiological prediction tools. The optimal time to initiate therapy is challenging to define since delaying effective secondary prevention treatment exposes patients to the risk of recurrent embolism. Consequently, there is clinical equipoise to define and individualize the optimal timepoint to initiate anticoagulation combining the lowest risk of hemorrhagic transformation and ischemic recurrence in cardioembolic stroke patients. In this narrative review, we will highlight and critically outline recent observational and randomized relevant evidence in different subtypes of cardioembolic stroke with a special focus on anticoagulation initiation following endovascular treatment. We will refer mainly to the commonest cause of cardioembolism, non-valvular atrial fibrillation, and examine the possible risk and benefit of anticoagulation before, during, and shortly after the acute phase of stroke. Other indications of anticoagulation after ischemic stroke will be briefly discussed. We provide a synthesis of available data to help clinicians individualize the timing of initiation of oral anticoagulation based on the presence and extent of hemorrhagic transformation as well as stroke severity.

Effectiveness and safety of short-term anticoagulant regimens after left atrial appendage occlusion: A systematic review and meta-analysis

INTRODUCTION

Left atrial appendage occlusion (LAAO) provides an alternative for poor candidates of long-term oral anticoagulant (OAC) therapy; however, anticoagulant therapy after surgical procedures has limited use due to associated uncertainties. We aimed to evaluate the effectiveness and safety of the short-term use of direct oral anticoagulant (DOAC) and warfarin after LAAO.

METHOD

Electronic databases such as PubMed, Embase, Medline, and Cochrane Library databases were searched up to November 11, 2022. Our study compared DOAC therapy and warfarin in patients after LAAO. A meta-analysis was conducted with the Review Manager software (version 5.4).

RESULTS

The meta-analysis included 13 cohort studies with a total of 32,607 patients. Our findings indicated that the incidence of stroke/TIA/SE, peri-device leaks>5 mm, device-related thrombosis, and all-cause mortality were not significantly different between the two groups after LAAO (P > 0.05). The DOAC group had a significantly lower incidence of major bleeding (OR = 0.83, 95 % CI: 0.74-0.94, P = 0.003), any bleeding (OR = 0.34, 95 % CI: 0.23-0.51, P < 0.001), stroke/TIA/SE and major bleeding (OR = 0.57, 95 % CI: 0.34-0.95, P = 0.03), and any major adverse event (OR = 0.89, 95 % CI:0.82-0.97, P = 0.010) than the warfarin group. The subgroup analysis revealed that the rate of stroke/TIA/SE was similar in the two groups in terms of the different regions, follow-up time, study type, anticoagulant strategy, and bleeding risk. The incidence of major bleeding in the DOAC group was significantly lower than that in the warfarin group in North America, as well as at follow-up period ≤6 months, retrospective cohort, HAS-BLED average score ≥ 3. In addition, the risk of major bleeding was higher with the combination of OAC and single antiplatelet therapy (SAPT) than with OAC alone. Finally, in the North American region, retrospective cohort, and HAS-BLED average score ≥ 3, the incidence of any serious adverse event in the DOAC group was still significantly lower than that in the warfarin group.

CONCLUSION

Compared to warfarin, DOAC reduced the risk of major bleeding and any serious adverse event in patients after LAAO. This advantage was particularly notable in North America and high-risk populations for bleeding. In addition, the incidence of device-related thrombosis, peri-device leaks, stroke/TIA/SE and all-cause mortality were similar in both groups. The risk of major bleeding was lower in patients taking OAC alone compared with those taking OAC plus SAPT, without increasing the risk of thrombosis.

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.