Long-term oral anticoagulant after catheter ablation for atrial fibrillation

Harnessing Risk Assessment for Thrombosis and Bleeding to Optimize Anticoagulation Strategy in Nonvalvular Atrial Fibrillation

Oral anticoagulation (OAC) following catheter ablation (CA) of nonvalvular atrial fibrillation (NVAF) is essential for the prevention of thrombosis events. Inappropriate application of OACs does not benefit stroke prevention but may be associated with a higher risk of bleeding. Therefore, this study aims to develop clinical data-driven machine learning (ML) methods to predict the risk of thrombosis and bleeding to establish more precise anticoagulation strategies for patients with NVAF.Patients with NVAF who underwent CA therapy were enrolled from Southwest Hospital from 2015 to 2023. This study compared eight ML algorithms to evaluate the predictive power for both thrombosis and bleeding. Model interpretations were recognized by feature importance and SHapley Additive exPlanations methods. With potential essential risk factors, simplified ML models were proposed to improve the feasibility of the tool.A total of 1,055 participants were recruited, including 105 patients with thrombosis and 252 patients with bleeding. The models based on XGBoost achieved the best performance with accuracies of 0.740 and 0.781 for thrombosis and bleeding, respectively. Age, BNP, and the duration of heparin are closely related to the high risk of thrombosis, whereas the anticoagulation strategy, BNP, and lipids play a crucial role in the occurrence of bleeding. The optimized models enrolling crucial risk factors, RF-T for thrombosis and Xw-B for bleeding, achieved the best recalls of 0.774 and 0.780, respectively.The optimized models will have a great application potential in predicting thrombosis and bleeding among patients with NVAF and will form the basis for future score scales.

Left Atrial Appendage Closure after Ablation for Atrial Fibrillation

BACKGROUND

Oral anticoagulation is recommended after ablation for atrial fibrillation among patients at high risk for stroke. Left atrial appendage closure is a mechanical alternative to anticoagulation, but data regarding its use after atrial fibrillation ablation are lacking.

METHODS

We conducted an international randomized trial involving 1600 patients with atrial fibrillation who had an elevated score (≥2 in men and ≥3 in women) on the CHA2DS2-VASc scale (range, 0 to 9, with higher scores indicating a greater risk of stroke) and who underwent catheter ablation. Patients were randomly assigned in a 1:1 ratio to undergo left atrial appendage closure or receive oral anticoagulation. The primary safety end point, tested for superiority, was non-procedure-related major bleeding or clinically relevant nonmajor bleeding. The primary efficacy end point, tested for noninferiority, was a composite of death from any cause, stroke, or systemic embolism at 36 months. The secondary end point, tested for noninferiority, was major bleeding, including procedure-related bleeding, through 36 months.

RESULTS

A total of 803 patients were assigned to undergo left atrial appendage closure, and 797 to receive anticoagulant therapy. The mean (±SD) age of the patients was 69.6±7.7 years, 34.1% of the patients were women, and the mean CHA2DS2-VASc score was 3.5±1.3. At 36 months, a primary safety end-point event had occurred in 65 patients (8.5%) in the left atrial appendage closure group (device group) and in 137 patients (18.1%) in the anticoagulation group (P<0.001 for superiority); a primary efficacy end-point event had occurred in 41 patients (5.3%) and 44 patients (5.8%), respectively (P<0.001 for noninferiority); and a secondary end-point event had occurred in 3.9% and 5.0% (P<0.001 for noninferiority). Complications related to the appendage closure device or procedure occurred in 23 patients.

CONCLUSIONS

Among patients who underwent catheter-based atrial fibrillation ablation, left atrial appendage closure was associated with a lower risk of non-procedure-related major or clinically relevant nonmajor bleeding than oral anticoagulation and was noninferior to oral anticoagulation with respect to a composite of death from any cause, stroke, or systemic embolism at 36 months. (Funded by Boston Scientific; OPTION ClinicalTrials.gov number, NCT03795298.).

[Oral anticoagulation in supraventricular arrhythmia]

Atrial fibrillation represents the most frequent persistent cardiac arrhythmia and is associated with an increased morbidity and mortality. An important component of the holistic treatment of atrial fibrillation is oral anticoagulation (OAC) for the prevention of stroke. The CHA2DS2-VASc score as a risk score is recommended for estimation of the individual stroke risk and the concomitant need of OAC in these patients. In the majority of patients the OAC is nowadays carried out with direct oral anticoagulants (DOAC), which have proved to be effective with a moderate side effect profile and have replaced vitamin K antagonists as the standard substance. In the meantime, these principles have become established as the usual practice but some issues regarding OAC in patients with atrial fibrillation are still insufficiently answered. Furthermore, it is unclear whether OACs need to be continued after successful treatment of atrial fibrillation with pulmonary vein ablation or in some cases can even be discontinued. Unanswered questions also remain regarding the treatment of subclinical atrial fibrillation and atrial high-frequency episodes detected by implanted heart rhythm devices. Especially the duration of atrial high-frequency episodes that should trigger the initiation of OAC treatment is still under debate. Therefore, currently the benefits of stroke prevention must be carefully weighed up against the risk of bleeding complications.

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.

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.

Discontinuation of Oral Anticoagulants in Atrial Fibrillation Patients: Impact of Treatment Strategy and on Patients' Health Status

AIMS

The discontinuation of oral anticoagulants (OACs) remains as a significant concern in the management of atrial fibrillation (AF). The discontinuation rate may vary depending on management strategy, and physicians may also discontinue OACs due to concerns about patient satisfaction with their care. We aimed to assess the incidence of OAC discontinuation and its relationship to patients' health in an outpatient AF registry.

METHODS AND RESULTS

From a multicenter registry for newly recognized AF patients (n = 3313), we extracted 1647 (49.7%) patients with OACs and a CHA2DS2-Vasc score of ≥2. Discontinuation was defined as sustained cessation of OACs within a 1-year follow-up. We examined predictors associated with discontinuation and its relations to health status defined by the AFEQT questionnaire. Of the 1647 patients, 385 (23.6%) discontinued OACs after 1 year, with discontinuation rates varying across treatment strategies (15.3% for catheter ablation, 4.9% for rhythm control with antiarrhythmic drugs, and 3.0% for rate control). Successful rhythm control was associated with discontinuation in the catheter ablation (OR 6.61, 95% CI 3.00-14.6, p < 0.001) and antiarrhythmic drugs (OR 6.47, 95% CI 2.62-15.9, p < 0.001) groups, whereas the incidence of bleeding events within 1 year was associated with discontinuation in the rate control group. One-year AFEQT scores did not significantly differ between patients who discontinued OACs and those who did not in each treatment strategy group.

CONCLUSIONS

OAC discontinuation was common among AF patients with significant stroke risk but varied depending on the chosen treatment strategy. This study also found no significant association between OAC discontinuation and patients' health status.

A cross-sectional study of appropriateness evaluation of anticoagulation therapy for inpatients with nonvalvular atrial fibrillation

Background: Oral anticoagulants (OACs) are essential for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). However, the appropriateness of anticoagulation treatment in locally practice remains unclear. This study evaluated compliance with anticoagulation therapy concerning the guidelines and drug labels in patients with NVAF. Methods: Hospitalized patients diagnosed with NVAF between 1 November 2020, and 31 December 2021, were retrospectively enrolled. The appropriateness of anticoagulation regimens at discharge was evaluated based on a flowchart designed according to atrial fibrillation (AF) guidelines and medication labels. Furthermore, we explored factors potentially influencing the "no-use of OACs" using binary logistic regression and verified anticoagulation-related issues through a physician questionnaire. Results: A total of 536 patients were enrolled in this study, including 254 patients (47.4%) with inappropriate anticoagulation regimens. 112 patients (20.9%) were categorized as "underdosing-use of OACs," 134 (25%) who needed anticoagulation therapy were "no-use of OACs" and eight (1.5%) were "over-use of OACs." The results of a binary logistic regression analysis showed that paroxysmal AF (odds ratio [OR], 7.74; 95% confidence interval [CI], 4.57-13.10), increased blood creatinine levels (OR, 1.88; 95% CI, 1.11-3.16), hospitalized pacemaker implantation (OR, 6.76; 95% CI, 2.67-17.11), percutaneous coronary intervention (OR, 3.35; 95% CI, 1.44-7.80), and an increased HAS-BLED score (OR, 1.62; 95% CI, 1.11-2.35) were associated with "no-use of OACs" in patients with NVAF who had indications for anticoagulation therapy. Conclusion: For patients with NVAF with severe renal dysfunction and paroxysmal AF, anticoagulation therapy was inadequate. The underdosing-use of OACs in patients with NVAF was frequently observed. We recommend an anticoagulation management team to tailor anticoagulation regimens to suit each patient's needs.

A prediction model based on functional mitral regurgitation for the recurrence of paroxysmal atrial fibrillation (PAF) after post-circular pulmonary vein radiofrequency ablation (CPVA)

AIM

To construct a prediction model based on functional mitral regurgitation (FMR) in patients with paroxysmal atrial fibrillation (PAF) to predict atrial fibrillation recurrence after the post-circular pulmonary vein radiofrequency ablation (CPVA).

METHODS

We retrospectively analyzed 289 patients with PAF who underwent CPVA for the first time. The patients were randomly divided into modeling group and verification group at the ratio of 75:25. In the modeling group, the multivariate logistic regression was used to analyze and construct a prediction model for post-CPVA recurrence in PAF patients, which was then validated in the verification group.

RESULTS

(1) After 3-6 months of follow-up, the patients were divided into sinus rhythm group (252 cases) and recurrence group (24 cases); (2) In the modeling group, the age, left atrial diameter (LAD), and the degree of MR (mild, moderate, severe) were higher in recurrence group than that of the sinus rhythm group, and the left atrial appendage emptying velocity (LAAV) was lower in recurrence group (all p < .05). (3) A model for predicting the recurrence of PAF after radiofrequency ablation was constructed in the modeling group. The equation was: Logit(P) = -3.253 + .092 × age + 1.263 × mild MR + 2.325 × moderate MR + 5.111 × severe MR -.113 × LAAV. The area under the curve (AUC) of the model was .889 in modeling group and .866 in verification group, and the difference was not statistically significant (p > .05).

CONCLUSION

The prediction model of atrial fibrillation (AF) recurrence after CPVA in PAF patients has good predictive efficacy, specificity, and accuracy.

A prediction model of atrial fibrillation recurrence after first catheter ablation by a nomogram: HASBLP score

Background

At present, catheter ablation is an effective method for rhythm control in patients with atrial fibrillation (AF). However, AF recurrence is an inevitable problem after catheter ablation. To identify patients who are prone to relapse, we developed a predictive model that allows clinicians to closely monitor these patients and treat them with different personalized treatment plans.

Materials and methods

A total of 1,065 patients who underwent AF catheter ablation between January 2015 and December 2018 were consecutively included in this study, which examines the results of a 2-year follow-up. Patients with AF were divided into development cohort and validation cohort. Univariate and multivariate analyses were carried out on the potential risk factors. Specific risk factors were used to draw the nomogram according to the above results. Finally, we verified the performance of our model compared with CHADS2 and CHA₂DS₂-Vasc scores by receiver operating characteristic (ROC) curve and calibration curve and plotted the decision analysis curve (DAC).

Results

A total of 316 patients experienced AF recurrence. After univariate and multivariate analyses, AF history (H), age (A), snoring (S), body mass index (BMI) (B), anteroposterior diameter of left atrial (LA) (L), and persistent AF (P) were included in our prediction model. Our model showed a better performance compared with CHADS2 and CHA2DS2-Vasc scores, and the area under ROC curve (95%CI) was 0.7668 (0.7298–0.8037) vs. 0.6225 (0.5783–0.6666) and 0.6267 (0.5836–0.6717).

Conclusion

We established a nomogram (HASBLP score) for predicting AF recurrence after the first catheter ablation at a 2-year follow-up, which can be used as a tool to guide future follow-up of patients. However, its usefulness needs further validation.

Comparison of anticoagulation with left atrial appendage closure after atrial fibrillation ablation: Rationale and design of the OPTION randomized trial

BACKGROUND

For patients with symptomatic atrial fibrillation (AF), physicians typically offer AF ablation for symptom relief; however, patients often anticipate/expect a life free from anticoagulation. This belief puts patients at increased risk of stroke due to the potential for asymptomatic AF postablation if anticoagulation is ceased contrary to clinical guidelines. Although the WATCHMAN device has been FDA-approved to decrease the risk of thromboembolism from the left atrial appendage (LAA) in patients with an appropriate rationale to avoid oral anticoagulation, it has not been well-studied following AF ablation. Additionally, there are limited data comparing the WATCHMAN device to direct oral anticoagulants. The OPTION study will investigate whether LAA closure with the WATCHMAN FLX device is a reasonable alternative to oral anticoagulation following percutaneous catheter ablation for nonvalvular AF.

TRIAL DESIGN

OPTION is a multinational, multicenter, prospective randomized clinical trial. Patients with a CHA₂DS₂-VASc of ≥2 in men or ≥3 in women and who underwent a AF catheter ablation procedure between 90 and 180 days prior to randomization (sequential) or are planning to have catheter ablation within 10 days of randomization (concomitant) will be randomized in a 1:1 allocation of WATCHMAN FLX vs control. Control patients will start or continue market-approved oral anticoagulation for the duration of the trial. A total of 1600 patients were randomized from 130 global investigational sites. Follow-up for both device and control patients will occur at 3, 12, 24, and 36 months. The primary effectiveness noninferiority endpoint is stroke (ischemic or hemorrhagic), all-cause death, or systemic embolism at 36 months. The primary safety superiority endpoint is nonprocedural bleeding through 36 months (International Society on Thrombosis and Haemostasis [ISTH] major bleeding or clinically relevant nonmajor bleeding). The secondary noninferiority endpoint is ISTH major bleeding through 36 months (including procedural bleeding).

CONCLUSIONS

This trial will assess the safety and efficacy of WATCHMAN FLX in a postablation contemporary clinical AF patient population at risk of stroke.

Mitral Regurgitation and Body Mass Index Increase the Predictability of Perioperative Bleeding in Anticoagulated Patients With Nonvalvular Atrial Fibrillation

Background

Catheter ablation (CA) effectively restores sinus rhythm in atrial fibrillation (AF) but causes a short-term fluctuation in the coagulation state. Potential risk factors and better management during this perioperative period remain understudied.

Methods

We consecutively included 940 patients with nonvalvular AF who received CA at Fuwai Hospital, Beijing, China. Patients were divided into two groups according to their bleeding status during 3 months' anticoagulation. Any adverse events related to bleeding in the 3 months were evaluated. The HAS-BLED score and ABC-bleeding score, as well as other potential factors, were explored to predict bleeding risk.

Results

In this observational study, 8.0% and 0.9% of the whole population suffered from bleeding and thromboembolic events, respectively. After adjusting for known factors related to bleeding, mitral regurgitation (MR, p for trend &lt;0.001) and body mass index (BMI, odds ratio (OR) = 0.920, 95% CI 0.852–0.993, p = 0.033) were the most significant ones. C-indexes of the HAS-BLED score and ABC-bleeding score for bleeding were 0.558 (0.492–0.624) and 0.585 (0.515–0.655), respectively. The incorporation of MR and BMI significantly improved the predictive value based on HAS-BLED score (C-index = 0.650, 95% CI 0.585–0.715, p = 0.004) and ABC-bleeding score (C-index = 0.671, 95% CI 0.611–0.731, p &lt; 0.001). The relative risk of mild-moderate MR was 4.500 (95% CI 1.625–12.460) in patients with AF having HAS-BLED = 1 and 4.654 (95% CI 1.496–14.475) in HAS-BLED ≥ 2, while it was not observed in patients with HAS-BLED = 0 (p = 0.722).

Conclusion

More severe MR and lower BMI are associated with a higher incidence of perioperative bleeding, which helps improve the predictability of increased individual bleeding risk of a patient with nonvalvular AF who has received CA therapy and oral anticoagulants.

Discontinuation of oral anticoagulation and risk of stroke and death after ablation for typical atrial flutter: A nation-wide Danish cohort study

INTRODUCTION

Oral anticoagulation (OAC) is indicated for patients with atrial fibrillation (AF) and atrial flutter (AFL) with a CHA₂DS₂-VASc score ≥ 2 for men and ≥3 for women. This is regardless of successful catheter ablation for their arrhythmia. Studies have mainly focused on AF, and little is known regarding use of OAC in AFL patients following catheter ablation.

PURPOSE

To describe discontinuation of OAC in a national cohort of patients who have undergone first-time cavo-tricuspid isthmus ablation (CTIA) for AFL.

METHODS

We identified patients undergoing first-time CTIA during the period 2010-2016 using the Danish National Ablation Registry. Information on comorbidities and OAC use were gathered using the Danish National Patient Registry and the Danish National Prescription Registry. Patients were followed until March 1st, 2018.

RESULTS

We identified 2409 consecutive patients. Median age was 66 (IQR 58-72) years, and 1952 (81%) were men. During mean follow-up of 4 ± 1.7 years, 723 (30%) patients discontinued OAC. Patients discontinuing OAC were younger, had less comorbidity, and a lower CHA₂DS₂-VASc score. During follow-up, 252 (10%) patients died, and 112 (5%) patients had a stroke. Incidence of both these events increased with increasing age and CHA₂DS₂-VASc score. In adjusted analysis, we observed higher mortality (p < 0.0001) in patients discontinuing OAC, while stroke rate was not significantly higher (p = 0.21).

CONCLUSION

In this national cohort of patients who have undergone first-time CTIA, patients discontinuing OAC treatment were younger and had less comorbidities. Patients remain at elevated risk of death and stroke/TIA, increasing with their age and CHA₂DS₂-VASc score.