2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation

Machine Learning - Based Bleeding Risk Predictions in Atrial Fibrillation Patients on Direct Oral Anticoagulants

Importance

Accurately predicting major bleeding events in non-valvular atrial fibrillation (AF) patients on direct oral anticoagulants (DOACs) is crucial for personalized treatment and improving patient outcomes, especially with emerging alternatives like left atrial appendage closure devices. The left atrial appendage closure devices reduce stroke risk comparably but with significantly fewer non-procedural bleeding events.

Objective

To evaluate the performance of machine learning (ML) risk models in predicting clinically significant bleeding events requiring hospitalization and hemorrhagic stroke in non-valvular AF patients on DOACs compared to conventional bleeding risk scores (HAS-BLED, ORBIT, and ATRIA) at the index visit to a cardiologist for AF management.

Design

Prognostic modeling with retrospective cohort study design using electronic health record (EHR) data, with clinical follow-up at one-, two-, and five-years.

Setting

University of Pittsburgh Medical Center (UPMC) system.

Participants

24,468 non-valvular AF patients aged ≥18 years treated with DOACs, excluding those with prior history of significant bleeding, other indications for DOACs, on warfarin or contraindicated to DOACs.

Exposures

DOAC therapy for non-valvular AF.

Main Outcomes and Measures

The primary endpoint was clinically significant bleeding requiring hospitalization within one year of index visit. The models incorporated demographic, clinical, and laboratory variables available in the EHR at the index visit.

Results

Among 24,468 patients, 553 (2.3%) had bleeding events within one year, 829 (3.5%) within two years, and 1,292 (5.8%) within five years of index visit. We evaluated multivariate logistic regression and ML models including random forest, classification trees, k-nearest neighbor, naive Bayes, and extreme gradient boosting (XGBoost) which modestly outperformed HAS-BLED, ATRIA, and ORBIT scores in predicting clinically significant bleeding at 1-year follow-up. The best performing model (random forest) showed area under the curve (AUC-ROC) 0.76 (0.70-0.81), G-Mean score of 0.67, net reclassification index 0.14 compared to 0.57 (0.50-0.63), G-Mean score of 0.57 for HASBLED score, p-value for difference <0.001. The ML models had improved performance compared to conventional risk across time-points of 2-year and 5-years and within the subgroup of hemorrhagic stroke. SHAP analysis identified novel risk factors including measures from body mass index, cholesterol profile, and insurance type beyond those used in conventional risk scores.

Conclusions and Relevance

Our findings demonstrate the superior performance of ML models compared to conventional bleeding risk scores and identify novel risk factors highlighting the potential for personalized bleeding risk assessment in AF patients on DOACs.

Bilirubin Elevation During Hospitalization Post Radiofrequency Catheter Ablation of Persistent Atrial Fibrillation: Variation Trend, Related Factors, and Relevance to 1-Year Recurrence

Background

The role of total bilirubin (TBIL) in cardiovascular disease has been increasingly recognized in recent decades. Studies have shown a correlation between total bilirubin levels and the prognosis of patients after heart surgery. This study aimed to investigate the clinical significance of bilirubin elevation in persistent atrial fibrillation (PAF) patients who received radiofrequency catheter ablation (RFCA).

Methods and Results

A total of 184 patients with PAF who received RFCA were retrospectively studied. Laboratory examinations and demographic data were analyzed to identify independent predictors of TBIL elevation. The relationship between TBIL and prognosis was further investigated. Our results indicated that TBIL increased significantly after RFCA. Multiple linear regression analysis showed that TBIL elevation owned a negative correlation with the percentile of low voltage areas (LVAs) in left atria (β=-0.490, P<0.001). In contrast, a positive correlation was observed with the white blood cell (WBC) ratio (β=0.153, P=0.042) and left atrial diameter (LAD) (β=0.232, P=0.025). It was found that postoperative TBIL levels increased and then gradually decreased to baseline within 5 days without intervention. The bilirubin ratio <1.211 indicated the possibility of 1-year AF recurrence after ablation with a predictive value of 0.743 (specificity = 75.00%, sensitivity = 66.67%).

Conclusion

Bilirubin elevation post PAF RFCA was a common phenomenon and was associated with 1-year recurrence of AF in PAF patients after RFCA.

Atrial arrhythmias following CAR-chimeric antigen receptor T-cell therapy: Incidence, risk factors and biomarker profile

Recent reports have raised concerns about the association of chimeric antigen receptor T cell (CAR-T) with non-negligible cardiotoxicity, particularly atrial arrhythmias. First, we conducted a pharmacovigilance study to assess the reporting of atrial arrhythmias following CD19-directed CAR-T. Subsequently, to determine the incidence, risk factors and outcomes of atrial arrhythmias post-CAR-T, we compiled a retrospective single-centre cohort of non-Hodgkin lymphoma patients. Only commercial CAR-T products were considered. Atrial arrhythmias were nearly fourfold more likely to be reported after CAR-T therapy compared to all other cancer patients in the FAERS (adjusted ROR = 3.76 [95% CI 2.67-5.29]). Of the 236 patients in our institutional cohort, 23 (10%) developed atrial arrhythmias post-CAR-T, including 12 de novo arrhythmias, with most (83%) requiring medical intervention. Atrial arrhythmias frequently co-occurred with cytokine release syndrome and were associated with higher post-CAR-T infusion peak levels of IL-10, TNF-alpha and LDH, and lower trough levels of fibrinogen. In a multivariable analysis, risk factors for atrial arrhythmia were history of atrial arrhythmia (OR = 6.80 [2.39-19.6]) and using CAR-T product with a CD28-costimulatory domain (OR = 5.17 [1.72-18.6]). Atrial arrhythmias following CD19-CAR-T therapy are prevalent and associated with elevated inflammatory biomarkers, a history of atrial arrhythmia and the use of a CAR-T product with a CD28 costimulatory domain.

Long-Term Results of the Mini Maze Standalone Bi-Atrial Surgical Ablation: A 10-Year Follow-Up

Background: One way to treat atrial fibrillation is through surgical ablation. However, the literature only provides information on patient follow-up results for up to 5 years. Methods: In order to assess long-term monitoring data over ten years, this retrospective study included 58 patients with paroxysmal or persistent atrial fibrillation who underwent Mini Maze surgical ablation at Santaros Clinics between 1 February 2009 and 1 June 2014. The follow-up time after surgery was 144 ± 48 months. We evaluated the absence of atrial fibrillation, echocardiographic and clinical parameters, and EHRA score. Results: Sinus rhythm remained in 69.4%, 75.5%, 55.6%, and 44.1% of patients with paroxysmal AF, and 68,2%, 59.1%, 50%, and 41.9% of patients with persistent AF (p = 0.681). In the post-operative period, one patient (1.7%) had a transient ischemic attack, and another patient (1.7%) had a thoracotomy for post-operative bleeding. A total of 20% of patients were diagnosed with a post-operative respiratory tract infection. EHRA scores showed that patients' quality of life improved after they underwent Mini Maze surgical ablation. Conclusions: Despite AF recurrences after surgery, quality of life remains better than before surgery, showing that Mini Maze surgery is an effective and safe second-line treatment method for atrial fibrillation.

Pulsed field ablation versus thermal energy ablation for atrial fibrillation: a systematic review and meta-analysis of procedural efficiency, safety, and efficacy

BACKGROUND

Pulsed field ablation (PFA) induces cell death through electroporation using ultrarapid electrical pulses. We sought to compare the procedural efficiency characteristics, safety, and efficacy of ablation of atrial fibrillation (AF) using PFA compared with thermal energy ablation.

METHODS

We performed an extensive literature search and systematic review of studies that compared ablation of AF with PFA versus thermal energy sources. Risk ratio (RR) 95% confidence intervals (CI) were measured for dichotomous variables and mean difference (MD) 95% CI were measured for continuous variables, where RR < 1 and MD < 0 favor the PFA group.

RESULTS

We included 6 comparative studies for a total of 1012 patients who underwent ablation of AF: 43.6% with PFA (n = 441) and 56.4% (n = 571) with thermal energy sources. There were significantly shorter procedures times with PFA despite a protocolized 20-min dwell time (MD - 21.95, 95% CI - 33.77, - 10.14, p = 0.0003), but with significantly longer fluroscopy time (MD 5.71, 95% CI 1.13, 10.30, p = 0.01). There were no statistically significant differences in periprocedural complications (RR 1.20, 95% CI 0.59-2.44) or recurrence of atrial tachyarrhythmias (RR 0.64, 95% CI 0.31, 1.34) between the PFA and thermal ablation cohorts.

CONCLUSIONS

Based on the results of this meta-analysis, PFA was associated with shorter procedural times and longer fluoroscopy times, but no difference in periprocedural complications or rates of recurrent AF when compared to ablation with thermal energy sources. However, larger randomized control trials are needed.

Aggressive Rhythm Control Strategy in Atrial Fibrillation Patients Presenting at the Emergency Department: The HEROMEDICUS Study Design and Initial Results

Atrial fibrillation has progressively become a more common reason for emergency department visits, representing 0.5% of presenting reasons. Registry data have indicated that about 60% of atrial fibrillation patients who present to the emergency department are admitted, emphasizing the need for more efficient management of atrial fibrillation in the acute phase. Management of atrial fibrillation in the setting of the emergency department varies between countries and healthcare systems. The most plausible reason to justify a conservative rather than an aggressive strategy in the management of atrial fibrillation is the absence of specific guidelines from diverse societies. Several trials of atrial fibrillation treatment strategies, including cardioversion, have demonstrated that atrial fibrillation in the emergency department can be treated safely and effectively, avoiding admission. In the present study, we present the epidemiology and characteristics of atrial fibrillation patients presenting to the emergency department, as well as the impact of diverse management strategies on atrial-fibrillation-related hospital admissions. Lastly, the design and initial data of the HEROMEDICUS protocol will be presented, which constitutes an electrophysiology-based aggressive rhythm control strategy in patients with atrial fibrillation in the emergency department setting.

Impact of Oral Anticoagulation on Clinical Outcomes in Postoperative Atrial Fibrillation

INTRODUCTION

The impact of postoperative oral anticoagulation (OAC) with warfarin on postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) was the focus of this examination of patients from the randomized endo-vein graft prospective (REGROUP) Trial.

MATERIAL AND METHODS

REGROUP was a prospective randomized Veterans Affairs cooperative study comparing endoscopic versus open vein harvest in elective CABG patients (March 2014-April 2017) at 16 Veterans Affairs facilities. This study compared new-onset POAF patients who were treated with warfarin versus no-warfarin. Outcomes included stroke during active follow-up and a major adverse cardiac event composite of mortality, acute myocardial infarction, and repeat revascularization during active and passive follow-up.

RESULTS

Of the 316/1103 (28.6%) of REGROUP patients who developed new-onset POAF, 45 patients were excluded - mainly for preoperative warfarin use. Of the remaining 269 patients, 85 received OAC with warfarin (OAC group); 184 did not (no-OAC group). Stroke rates during active follow-up (32 [IQR 24-38] mo) were 3.5% OAC group versus 5.4% no-OAC group (P = 0.76); major adverse cardiac eventrates were 20% OAC versus 11.4% no-OAC (P = 0.06). On longer follow-up of (median 4.61 [IQR 3.9-5.1] y), discharge OAC use was associated with all-cause mortality after adjusting for Society of Thoracic Surgeons mortality risk (20.0% versus 11.4% no-OAC use; HR = 2.00, 95% CI: 1.05-3.81, P = 0.035).

CONCLUSIONS

REGROUP patients with POAF treated with OAC had similar stroke and higher mortality rates versus no-OAC patients. Further investigation of the risk-benefit ratio of OAC in post-CABG patients and which POAF patient subgroups might derive the most benefit with anticoagulation appears warranted.

Heart failure and atrial fibrillation: Is atrial fibrillation ablation in heart failure pointless or mandatory?

A vast amount of now well-established clinical and epidemiological data indicates a close, interdependent, and symbiotic association between atrial fibrillation (AF) and heart failure (HF). Both AF and HF, when co-exist in a patient, have serious treatment and prognostic implications. Based on the prevailing knowledge of the topic, various societies have issued a number of guidelines regarding the management of patients with AF and HF. Overall, it is the rhythm control strategy that has shown beneficial effect over the rate control strategy with improvement in symptoms of AF and HF. While antiarrhythmic drugs (AADs) and catheter ablation (CA) may be utilized as rhythm control strategy for AF, both AADs and CA have limitations of their own. Furthermore, with the progress made in various pharmacotherapeutic agents in HF, one could question the utility of CA in HF (i.e., whether ablation is mandatory or pointless in patients who have HF). The purpose of this review is to discuss this very point, focusing on the beneficial, neutral, or detrimental outcome of CA based on the category and class of HF.

The Impact of Polypharmacy on the Effectiveness and Safety of Non-vitamin K Antagonist Oral Anticoagulants in Patients with Atrial Fibrillation

BACKGROUND

 Polypharmacy may affect outcomes in patients with atrial fibrillation (AF) using non-vitamin K antagonist oral anticoagulants (NOACs) or vitamin K antagonists (VKAs) due to interactions or reduced adherence, but comparative data are lacking. Therefore, the impact of polypharmacy on AF-related outcomes and benefit-risk profiles of NOACs in patients with polypharmacy were investigated.

METHODS

 AF patients initiating anticoagulation between 2013 and 2019 were included using Belgian nationwide data. Inverse probability of treatment weighted Cox regression was used to investigate outcomes.

RESULTS

 Among 254,478 AF patients, 167,847 (66.0%) used ≥5 drugs. Polypharmacy was associated with higher stroke or systemic embolism (stroke/SE) (adjusted hazard ratio [aHR]: 1.08, 95% confidence interval [CI]: 1.02-1.15), all-cause mortality (aHR: 1.45, 95% CI: 1.40-1.50), and major bleeding risks (aHR: 1.29, 95% CI: 1.23-1.35). Among patients with polypharmacy, NOACs were associated with lower stroke/SE (aHR: 0.68, 95% CI: 0.63-0.73), all-cause mortality (aHR: 0.80, 95% CI: 0.77-0.84), major bleeding (aHR: 0.92, 95% CI: 0.87-0.97), and intracranial bleeding risks (aHR: 0.77, 95% CI: 0.69-0.85), but higher gastrointestinal bleeding risks (aHR: 1.10, 95% CI: 1.01-1.19) compared to VKAs. Major bleeding risks were lower with apixaban (aHR: 0.79, 95% CI: 0.74-0.85), but nonsignificantly different with other NOACs compared to VKAs. Lower major bleeding risks were observed with dabigatran (aHR: 0.91, 95% CI: 0.85-0.97) and apixaban (aHR: 0.77, 95% CI: 0.73-0.81) compared to rivaroxaban, and with apixaban compared to dabigatran (HR: 0.83, 95% CI: 0.77-0.90) and edoxaban (HR: 0.77, 95% CI: 0.70-0.85).

CONCLUSION

 Polypharmacy was associated with increased thromboembolic, bleeding, and mortality risks in AF patients. NOACs had better benefit-risk profiles than VKAs in patients with polypharmacy.

Comparing the Efficacy of Targeted and Blast Portal Messaging in Message Opening Rate and Anticoagulation Initiation in Patients With Atrial Fibrillation in the Preventing Preventable Strokes Study II: Prospective Cohort Study

BACKGROUND

The gap in anticoagulation use among patients with atrial fibrillation (AF) is a major public health threat. Inadequate patient education contributes to this gap. Patient portal-based messaging linked to educational materials may help bridge this gap, but the most effective messaging approach is unknown.

OBJECTIVE

This study aims to compare the responsiveness of patients with AF to an AF or anticoagulation educational message between 2 portal messaging approaches: sending messages targeted at patients with upcoming outpatient appointments 1 week before their scheduled appointment (targeted) versus sending messages to all eligible patients in 1 blast, regardless of appointment scheduling status (blast), at 2 different health systems: the University of Massachusetts Chan Medical School (UMass) and the University of Florida College of Medicine-Jacksonville (UFL).

METHODS

Using the 2 approaches, we sent patient portal messages to patients with AF and grouped patients by high-risk patients on anticoagulation (group 1), high-risk patients off anticoagulation (group 2), and low-risk patients who may become eligible for anticoagulation in the future (group 3). Risk was classified based on the congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke, vascular disease, age between 65 and 74 years, and sex category (CHA2DS2-VASc) score. The messages contained a link to the Upbeat website of the Heart Rhythm Society, which displays print and video materials about AF and anticoagulation. We then tracked message opening, review of the website, anticoagulation use, and administered patient surveys across messaging approaches and sites using Epic Systems (Epic Systems Corporation) electronic health record data and Google website traffic analytics. We then conducted chi-square tests to compare potential differences in the proportion of patients opening messages and other evaluation metrics, adjusting for potential confounders. All statistical analyses were performed in SAS (version 9.4; SAS Institute).

RESULTS

We sent 1686 targeted messages and 1450 blast messages. Message opening was significantly higher with the targeted approach for patients on anticoagulation (723/1156, 62.5% vs 382/668, 57.2%; P=.005) and trended the same in patients off anticoagulation; subsequent website reviews did not differ by messaging approach. More patients off anticoagulation at baseline started anticoagulation with the targeted approach than the blast approach (adjusted percentage 9.3% vs 2.1%; P<.001).

CONCLUSIONS

Patients were more responsive in terms of message opening and subsequent anticoagulation initiation with the targeted approach.

Prediabetes: An overlooked risk factor for major adverse cardiac and cerebrovascular events in atrial fibrillation patients

BACKGROUND

Prediabetes is a well-established risk factor for major adverse cardiac and cerebrovascular events (MACCE). However, the relationship between prediabetes and MACCE in atrial fibrillation (AF) patients has not been extensively studied. Therefore, this study aimed to establish a link between prediabetes and MACCE in AF patients.

AIM

To investigate a link between prediabetes and MACCE in AF patients.

METHODS

We used the National Inpatient Sample (2019) and relevant ICD-10 CM codes to identify hospitalizations with AF and categorized them into groups with and without prediabetes, excluding diabetics. The primary outcome was MACCE (all-cause inpatient mortality, cardiac arrest including ventricular fibrillation, and stroke) in AF-related hospitalizations.

RESULTS

Of the 2965875 AF-related hospitalizations for MACCE, 47505 (1.6%) were among patients with prediabetes. The prediabetes cohort was relatively younger (median 75 vs 78 years), and often consisted of males (56.3% vs 51.4%), blacks (9.8% vs 7.9%), Hispanics (7.3% vs 4.3%), and Asians (4.7% vs 1.6%) than the non-prediabetic cohort (P < 0.001). The prediabetes group had significantly higher rates of hypertension, hyperlipidemia, smoking, obesity, drug abuse, prior myocardial infarction, peripheral vascular disease, and hyperthyroidism (all P < 0.05). The prediabetes cohort was often discharged routinely (51.1% vs 41.1%), but more frequently required home health care (23.6% vs 21.0%) and had higher costs. After adjusting for baseline characteristics or comorbidities, the prediabetes cohort with AF admissions showed a higher rate and significantly higher odds of MACCE compared to the non-prediabetic cohort [18.6% vs 14.7%, odds ratio (OR) 1.34, 95% confidence interval 1.26-1.42, P < 0.001]. On subgroup analyses, males had a stronger association (aOR 1.43) compared to females (aOR 1.22), whereas on the race-wise comparison, Hispanics (aOR 1.43) and Asians (aOR 1.36) had a stronger association with MACCE with prediabetes vs whites (aOR 1.33) and blacks (aOR 1.21).

CONCLUSION

This population-based study found a significant association between prediabetes and MACCE in AF patients. Therefore, there is a need for further research to actively screen and manage prediabetes in AF to prevent MACCE.

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

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

Characteristics of two different cryoballoon systems for treatment of paroxysmal atrial fibrillation: study protocol for a multicenter randomized controlled trial (CONTRAST-CRYO Trial)

BACKGROUND

Single-shot pulmonary vein isolation (PVI) utilizing cryothermal energy is an effective and safe treatment for atrial fibrillation (AF) patients. A novel cryoballoon system, POLARx™, has been recently introduced. The aim of this study was to compare the efficacy, safety, and biophysical parameters of PVI between the novel cryoballoon system, POLARx™, and the standard cryoballoon system, Arctic Front Advance Pro™ (AFA-Pro), in patients with paroxysmal AF.

METHODS

The CONTRAST-CRYO trial is a prospective, multicenter, open-label, randomized controlled study performed at seven large cardiac centers. This study was approved by the central ethics committee or the local ethics committee of each participating hospital and has been registered at UMIN Clinical Trials Registry (UMIN000049948). The trial will assign 200 patients with paroxysmal AF undergoing PVI to POLARx™ and AFA-Pro in a 1:1 randomization. The primary endpoint is the one-shot acute success rate of the right inferior pulmonary vein. Second endpoints include freedom from documented atrial fibrillation, atrial flutter, or atrial tachycardia without antiarrhythmic drugs at 12 months after the procedure, freedom from re-do procedures, the incidence of procedure-related adverse events, freezing duration, and the biophysical parameters during applications for each PV, total procedure and fluoroscopy time, and PVI durability during re-do procedures.

CONCLUSION

The CONTRAST-CRYO trial is a prospective, multicenter, randomized study designed to elucidate the difference in the efficacy, safety, and biophysical parameters between POLARx™ and AFA-Pro in paroxysmal AF patients undergoing PVI. The findings from this trial may provide a valuable indication for selecting the optimal cryoballoon system.

CLINICAL TRIAL REGISTRATION

 UMIN000049948.

Use of Computed Tomography for Left Atrial Appendage Occlusion Procedure Planning and Post-Procedure Assessment

Transcatheter left atrial appendage occlusion (LAAO) is an alternative to systemic anticoagulation in patients with non-valvular atrial fibrillation with increased risk for thromboembolic events. Pre- and post-procedural imaging is essential for technical success, allowing practitioners to identify contraindications, select appropriate devices, and recognize procedural complications. Although transesophageal echocardiography has traditionally served as the preeminent imaging modality in LAAO, cardiac computed tomography imaging has emerged as a noninvasive surrogate given its excellent isotropic spatial resolution, multiplanar reconstruction capability, rapid temporal resolution, and large field of view.

Management of Arrhythmias in the Cardiovascular Intensive Care Unit

Arrhythmias in the cardiovascular intensive care unit (CVICU) can be difficult to manage because of the complex hemodynamic and respiratory states of critically ill patients. Treating physicians must be educated to prevent, diagnose, and treat a multitude of tachyarrhythmias and bradyarrhythmias. In this review article, the authors outline a pragmatic approach to patient assessment, arrhythmia diagnosis, and management of the most common arrhythmias seen in the CVICU.

Patients Who Have Pre-Existing Atrial Fibrillation Require Increased Postoperative Care Following Total Joint Arthroplasty

BACKGROUND

Approximately 9% of total joint arthroplasty (TJA) patients have pre-existing atrial fibrillation (AF). This study examined the effect of pre-existing AF on TJA outcomes.

METHODS

We conducted a 1:3 propensity match of 545 TJA patients who have pre-existing AF to TJA patients who do not have AF at a tertiary care center between January 1st, 2012, and January 1st, 2021. Bivariate and multivariate regressions were performed. Changes over time were evaluated.

RESULTS

Patients undergoing total knee arthroplasty (TKA) who have pre-existing AF, experienced more post-operative AFs (P < .001), acute kidney injuries (P = .026), post-operative complications (POC) (P < .001), and 30-day readmissions (P = .036). Patients undergoing total hip arthroplasty (THA) who have pre-existing AF experienced more post-operative AFs (P < .001), pulmonary embolisms (P < .001), increased estimated blood losses (P = .007), more blood transfusions (P = .002), more POCs (P < .001), and longer lengths of stay (LOS) (P < .002). Over time, POC and LOS decreased in both groups, but remained increased in TJA patients who have pre-existing AF. Multivariate analyses of TKA patients showed an increased odds ratio (OR) of any POCs (P < .001), while THA patients had an increased OR of any POCs (P = .01), and LOS (P = .002).

CONCLUSION

Patients who have pre-existing AF undergoing TJA have more POCs. TKA patients have more readmissions. THA patients have longer LOS. These findings demonstrate the importance of enhanced peri-operative medical management in patients who have pre-existing AF undergoing TJA.

Epicardial Pulsed Field Ablation of Ganglionated Plexi: Computational and Pre-Clinical Evaluation of a Bipolar Sub-Xiphoid Catheter for the Treatment of Atrial Fibrillation

Epicardial pulsed field ablation (PFA) of ganglionated plexi (GPs) is being explored as a potential treatment for atrial fibrillation. Initial work using open-chest access with a monopolar ablation device has been completed. This study describes the early development work for a device that can be used with subxiphoid access and deliver bipolar ablation pulses. Electric field computational models have been used for the initial guidance on pulse parameters. An in vivo assessment of these ablation parameters has been performed in an open-chest canine study, while subxiphoid access and navigation of the device has been demonstrated in a porcine model. Results from this acute study have demonstrated the promising potential of this approach.

Country and health expenditure are major predictors of withholding anticoagulation in atrial fibrillation patients at high risk of stroke

BACKGROUND

Guidelines for patients with atrial fibrillation (AF) at high thromboembolic risk recommend oral anticoagulants (OACs) for preventing stroke and systemic embolism (SE). The reasons for guideline non-adherence are still unclear.

AIM

The aim is to identify clinical, demographic and non-patient characteristics associated with withholding OAC in patients with AF at high stroke risk.

METHODS

Patients in the Global Anticoagulant Registry in the FIELD-AF, newly diagnosed with AF between March 2010 and August 2016, and with CHA2DS2-VASc Score≥2 (excluding sex), were grouped by OAC treatment at enrolment. Factors associated with OAC non-use were analysed by multivariable logistic regression.

RESULTS

Of 40 416 eligible patients, 12 126 (30.0%) did not receive OACs at baseline. Globally, OAC prescription increased over time, from 60.4% in 2010-2011 to 74.7% in 2015-2016. Country of enrolment was the major predictor for OAC withholding (χ2-df=2576). Clinical predictors of OAC non-use included type of AF (χ2-df=404), history of bleeding (χ2-df=263) and vascular disease (χ2-df=99). OACs were used most frequently around the age of 75 years and decreasingly with younger as well as older age beyond 75 years (χ2-df=148). Non-cardiologists (χ2-df=201) and emergency room physicians (χ2-df=14) were less likely to prescribe OACs. OAC prescription correlated positively with country health expenditure.

CONCLUSIONS

Approximately one out of three AF patients did not receive OAC, while eligible according to the guidelines. Country of enrolment was the major determinant of anticoagulation strategy, while higher country health expenditure was associated with lower likelihood of withholding anticoagulation.

Evaluation of Machine Learning Approaches for Predicting Warfarin Discharge Dose in Cardiac Surgery Patients: Retrospective Algorithm Development and Validation Study

BACKGROUND

Warfarin dosing in cardiac surgery patients is complicated by a heightened sensitivity to the drug, predisposing patients to adverse events. Predictive algorithms are therefore needed to guide warfarin dosing in cardiac surgery patients.

OBJECTIVE

This study aimed to develop and validate an algorithm for predicting the warfarin dose needed to attain a therapeutic international normalized ratio (INR) at the time of discharge in cardiac surgery patients.

METHODS

We abstracted variables influencing warfarin dosage from the records of 1031 encounters initiating warfarin between April 1, 2011, and November 29, 2019, at St Michael's Hospital in Toronto, Ontario, Canada. We compared the performance of penalized linear regression, k-nearest neighbors, random forest regression, gradient boosting, multivariate adaptive regression splines, and an ensemble model combining the predictions of the 5 regression models. We developed and validated separate models for predicting the warfarin dose required for achieving a discharge INR of 2.0-3.0 in patients undergoing all forms of cardiac surgery except mechanical mitral valve replacement and a discharge INR of 2.5-3.5 in patients receiving a mechanical mitral valve replacement. For the former, we selected 80% of encounters (n=780) who had initiated warfarin during their hospital admission and had achieved a target INR of 2.0-3.0 at the time of discharge as the training cohort. Following 10-fold cross-validation, model accuracy was evaluated in a test cohort comprised solely of cardiac surgery patients. For patients requiring a target INR of 2.5-3.5 (n=165), we used leave-p-out cross-validation (p=3 observations) to estimate model performance. For each approach, we determined the mean absolute error (MAE) and the proportion of predictions within 20% of the true warfarin dose. We retrospectively evaluated the best-performing algorithm in clinical practice by comparing the proportion of cardiovascular surgery patients discharged with a therapeutic INR before (April 2011 and July 2019) and following (September 2021 and May 2, 2022) its implementation in routine care.

RESULTS

Random forest regression was the best-performing model for patients with a target INR of 2.0-3.0, an MAE of 1.13 mg, and 39.5% of predictions of falling within 20% of the actual therapeutic discharge dose. For patients with a target INR of 2.5-3.5, the ensemble model performed best, with an MAE of 1.11 mg and 43.6% of predictions being within 20% of the actual therapeutic discharge dose. The proportion of cardiovascular surgery patients discharged with a therapeutic INR before and following implementation of these algorithms in clinical practice was 47.5% (305/641) and 61.1% (11/18), respectively.

CONCLUSIONS

Machine learning algorithms based on routinely available clinical data can help guide initial warfarin dosing in cardiac surgery patients and optimize the postsurgical anticoagulation of these patients.

Diagnosis and Treatment of New-Onset Perioperative Atrial Fibrillation

This article reviews medical and surgical risk factors for developing atrial fibrillation (AF), the most common sustained dysrhythmia in the United States. Evidence for assessment and management of patients with AF, including AF newly identified in the preoperative clinic, immediately preoperatively, intraoperatively, and unstable AF, is presented. A stepwise approach to guide anesthetic decision-making in the assessment of newly identified preoperative AF is proposed. Anesthetic considerations, including the potential impacts of anesthetic and vasopressor selection, and current evidence related to rate control and rhythm control via pharmacologic or electrical cardioversion as well as anticoagulation strategies are discussed.

Development and Validation of a Novel Prognostic Model Predicting the Atrial Fibrillation Recurrence Risk for Persistent Atrial Fibrillation Patients Treated with Nifekalant During the First Radiofrequency Catheter Ablation

BACKGROUND

This study aimed to establish and assess a prediction model for patients with persistent atrial fibrillation (AF) treated with nifekalant during the first radiofrequency catheter ablation (RFCA).

METHODS

In this study, 244 patients with persistent AF from January 17, 2017 to December 14, 2017, formed the derivation cohort, and 205 patients with persistent AF from December 15, 2017 to October 28, 2018, constituted the validation cohort. The least absolute shrinkage and selection operator regression was used for variable screening and the multivariable Cox survival model for nomogram development. The accuracy and discriminative capability of this predictive model were assessed according to discrimination (area under the curve [AUC]) and calibration. Clinical practical value was evaluated using decision curve analysis.

RESULTS

Body mass index, AF duration, sex, left atrial diameter, and the different responses after nifekalant administration were identified as AF recurrence-associated factors, all of which were selected for the nomogram. In the development and validation cohorts, the AUC for predicting 1-year AF-free survival was 0.863 (95% confidence interval (CI) 0.801-0.926) and 0.855 (95% CI 0.782-0.929), respectively. The calibration curves showed satisfactory agreement between the actual AF-free survival and the nomogram prediction in the derivation and validation cohorts. In both groups, the prognostic score enabled stratifying the patients into different AF recurrence risk groups.

CONCLUSIONS

This predictive nomogram can serve as a quantitative tool for estimating the 1-year AF recurrence risk for patients with persistent AF treated with nifekalant during the first RFCA.

Periodontal disease and risk of atrial fibrillation or atrial flutter: A systematic review and meta-analysis

Background

We conducted a study to evaluate the risk of atrial fibrillation (AF) and atrial flutter (AFL) in periodontal disease (PD) patients.

Methods

Cohort studies that evaluate the risk of AF or AFL in PD patients were included. The risk was expressed in the pooled odd ratio (OR) with 95% confidence interval (CI).

Results

A total of four cohort studies were included. We found that patients with PD have a significantly higher risk of AF/AFL compared to those without PD with the pooled OR of 1.33 (95% CI 1.29-1.38; p = 0.357, I 2 = 3.0%).

Conclusions

PD increases the risk of AF and AFL.

Left atrial appendage occlusion using the LAmbre device in atrial fibrillation patients with a history of ischemic stroke: 1-Year outcomes from a multicenter study in China

BACKGROUND

Patients with non-valvular atrial fibrillation (NVAF) and previous stroke have a significantly higher risk of stroke recurrence. This study aimed to examine the safety and efficacy of the LAmbre left atrial appendage occlusion device in NVAF patients with a history of stroke.

METHODS

We examined 103 consecutive NVAF patients in 11 Chinese medical centers who had a history of stroke or transient ischemic attacks (TIA) and underwent placement of the LAmbre device. Follow-up was conducted 1, 3, 6, and 12 months after the procedure. The primary endpoints were the incidence of new ischemic or hemorrhagic stroke, TIA, systemic embolism, or cardiac death. Secondary endpoints were serious perioperative or device-related complications and cerebral, gastrointestinal, or other bleeding events requiring transfusion of at least 2 units of packed red blood cells.

RESULTS

Mean patient age was 67.63 ± 7.14 years; mean CHA2DS2-VASc score was 4.72 ± 1.18 and mean HAS-BLED score was 1.90 ± 1.00. LAmbre device placement was successful in 101 patients (98.05%). Mean follow-up was 12.2 months. Five patients (4.95%) developed a new pericardial effusion after the procedure; none required treatment. Eighty-six patients (85.15%) exhibited no peri-device leak (PDL). However, 13 (12.8%) had a small (0-3 mm) PDL and two (2.3%) had a moderate PDL (3-5 mm). One recurrent stroke occurred during follow-up (1.1%). No other complications occurred.

CONCLUSIONS

This multicenter study shows the safety and efficacy of LAmbre left atrial appendage occlusion for NVAF patients with a history of stroke or TIA.

Prediction of Sudden Death Risk in Patients with Congenital Heart Diseases

Risk stratification for sudden death should be discussed with patients with congenital heart disease at each stage of personal and cardiac development. For most patients, risk is low through teenage years and the critical factors to consider are anatomy, ventricular function, and symptoms. By adulthood, these are supplemented by screening for atrial arrhythmias, ventricular arrhythmias, and pulmonary hypertension. Therapies include medication, ablation, and defibrillator placement.

Effectiveness and safety of oral anticoagulant therapy in a real-world cohort with atrial fibrillation: The SIESTA-A study protocol

INTRODUCTION

Oral anticoagulants (OACs) are first-line drugs for stroke prevention in patients with atrial fibrillation (AF). The introduction of new lines of therapy with direct oral anticoagulants (DOACs) has led to a decreased use of vitamin K antagonists (VKAs). Comparative analyses of DOACs in clinical trials are scarce and the comparator has mostly been warfarin. Their impact on health outcomes in observational studies has not always been consistent. The aim of this study is to evaluate the effectiveness and safety of DOACs and VKAs in patients with AF using Real-World Data (RWD).

METHODS AND ANALYSIS

Population-based retrospective cohort study using RWD from actual practice. Period: January 2012-December 2020. Inclusion criteria: patients with AF who had not taken OACs in the previous 12 months. Exclusion criteria: <40 years, with severe mitral stenosis, or valvular heart disease or aortic and/or mitral valve procedures. Data source: The Andalusian Population Health Database, Spain. Outcome measures: a) Effectiveness: ischaemic stroke, transient ischaemic attack, systemic and pulmonary embolism, and death; b) Safety: gastrointestinal and intracranial haemorrhaging; Independent variables: age, sex, comorbidities, medication and health resource use, CHA2DS2-VASC, HAS-BLED, and analytical tests. Statistical analysis: crude incidence analysis, survival models, Kaplan-Meier, Cox regression analysis adjusted for possible confounding and paired analysis by propensity score matching.

Atrial fibrillation, electroconvulsive therapy, stroke risk, and anticoagulation

BACKGROUND

Electroconvulsive therapy (ECT) is a therapy used to treat refractory mental health conditions, ranging from depression to catatonia, and it has gained renewed prominence in practice and the literature of late. Given that ECT involves the application of direct current to the body, there exists a risk of a change in cardiac rhythm during therapy. When atrial fibrillation is induced, ECT carries a potential risk of stroke. These risks have not been previously analyzed or summarized in the literature to allow physicians to make educated decisions about periprocedural risk and anticoagulation needs.

METHODS

To better describe this risk, the authors reviewed PubMed for articles that described the post-ECT cardioversion of AF to sinus rhythm, new development of AF post-ECT, and new stroke after either rhythm change.

RESULTS

Included were 14 studies describing 19 unique patients. Most patients had no rhythm change during at least one of many ECT sessions. Five patients converted from AF to sinus rhythm during at least one session, while AF followed ECT in seventeen patients during at least one ECT session. Four patients experienced both ECT-related cardioversion from AF to sinus rhythm as well as conversion from sinus rhythm to AF. Although no patients with a rhythm change experienced a stroke, one unanticoagulated patient who remained in AF developed a stroke post-ECT.

CONCLUSIONS

Electroconvulsive therapy is demonstrated to be associated with rhythm changes-from atrial fibrillation to sinus rhythm as well as from sinus rhythm to atrial fibrillation. Thus, stroke risk during and after ECT remains a possibility. The anticoagulation of patients with AF who undergo ECT should be based on individual stroke risk factors, using validated stroke risk models, rather than prescribed routinely.

Results of a 4-Year Follow Up of Patients with Paroxysmal and Persistent Atrial Fibrillation after Cryoablation

Background and Objectives: Cryoablation is an established treatment method for atrial fibrillation (AF). We present the long-term results of cryoablation in 94 patients with paroxysmal and persistent AF treated in our center. Materials and Methods: This was an observational, retrospective study of 94 patients who underwent a cryoablation procedure for paroxysmal or persistent AF from 2015 to 2017. The follow up was 51 ± 3 months. The absence of arrhythmia was checked at 6, 12, 24, and 48 months after the procedure with 24 h Holter monitoring. We evaluated echocardiography parameters before and 48 months after cryoablation. The quality of life was assessed by calculating EHRA scores at each visit. Results: The mean history of pre-procedural AF duration was 55.3 ± 8.6 months. Paroxysmal AF was present in 42% of patients and persistent AF in 58%. Comparing the EHRA classes, a statistically significant difference was observed between the score assessed before the procedure and the score after one year, as well as when comparing the rates before the procedure and four years after the procedure (p < 0.000). The recurrence of AF was observed in 22.3% of patients 1 year after the procedure, in 26.6% of patients 2 years after the procedure, and in 34% of patients 4 years after the procedure; 9.3% of them were left in permanent AF. During the observation period, 28% of patients underwent a repeated pulmonary vein isolation procedure, and 6% of patients had a permanent pacemaker implanted. Five hematomas (5%) and one instance of phrenic nerve palsy (1%) were observed during the procedure. Conclusions: The rate of arrhythmia recurrence increased every year after cryoablation. Quality of life improved after the procedure, despite the recurrence of AF. A quarter of patients had to undergo a repeat pulmonary vein isolation procedure.

Effectiveness and safety of reduced-dose rivaroxaban for elderly patients with non-valvular atrial fibrillation: A subanalysis of the EXPAND study

BACKGROUND

Establishing the appropriate rivaroxaban dose in older patients with non-valvular atrial fibrillation (NVAF) is important because of the high risk of adverse events. In this EXPAND study subanalysis, we examined the safety and efficacy of standard-dose (15 mg/day) and non-recommended reduced-dose (10 mg/day) rivaroxaban in patients aged ≥65 years with NVAF and preserved renal function.

METHODS

The entire analysis population (ALL cohort [n = 3982]; ≥65 years) was divided into early elderly (ELD) (65-74 years [n = 1444]) and late ELD (≥75 years [n = 2386]) sub-cohorts. Each sub-cohort was divided into reduced-dose and standard-dose groups. Kaplan-Meier survival curves with adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were used to assess efficacy (thromboembolic events) and safety (hemorrhagic events) outcomes.

RESULTS

The aHR for major bleeding did not differ between the dosages in any of the cohorts (aHRs: 0.86-0.93). There were no significant differences in the occurrence of stroke + systemic embolism (SE) or stroke + SE + myocardial infarction (MI) + cardiovascular (CV) death among the cohorts. The aHR for MI/unstable angina + interventional/CV surgery + CV death was higher with 10-mg/day rivaroxaban than 15-mg/day rivaroxaban in the ALL cohort (aHR: 1.56 [95% CI 1.02-2.37], p = 0.039) and the late ELD sub-cohort (aHR: 1.86 [95% CI 1.01-3.42], p = 0.045).

CONCLUSIONS

Reduced-dose rivaroxaban may increase the risk of coronary artery events. The use of rivaroxaban 15 mg/day in patients with NVAF aged ≥75 years with preserved renal function was supported.

Atrial Fibrillation Recurrence in Patients With Transient New-Onset Atrial Fibrillation Detected During Hospitalization for Noncardiac Surgery or Medical Illness : A Matched Cohort Study

BACKGROUND

Atrial fibrillation (AF) is often detected for the first time in patients who are hospitalized for another reason. Long-term risks for AF recurrence in these patients are unclear.

OBJECTIVE

To estimate risk for AF recurrence in patients with new-onset AF during a hospitalization for noncardiac surgery or medical illness compared with a matched population without AF.

DESIGN

Matched cohort study. (ClinicalTrials.gov: NCT03221777).

SETTING

Three academic hospitals in Hamilton, Ontario, Canada.

PARTICIPANTS

The study enrolled patients hospitalized for noncardiac surgery or medical illness who had transient new-onset AF. For each participant, an age- and sex-matched control participant with no history of AF from the same hospital ward was recruited. All participants left the hospital in sinus rhythm.

MEASUREMENTS

14-day electrocardiographic (ECG) monitor at 1 and 6 months and telephone assessment at 1, 6, and 12 months. The primary outcome was AF lasting at least 30 seconds on the monitor or captured by ECG 12-lead during routine care at 12 months.

RESULTS

Among 139 participants with transient new-onset AF (70 patients with medical illness and 69 surgical patients) and 139 matched control participants, the mean age was 71 years (SD, 10), the mean CHA2DS2-VASc score was 3.0 (SD, 1.5), and 59% were male. The median duration of AF during the index hospitalization was 15.8 hours (IQR, 6.4 to 49.6 hours). After 1 year, recurrent AF was detected in 33.1% (95% CI, 25.3% to 40.9%) of participants in the transient new-onset AF group and 5.0% (CI, 1.4% to 8.7%) of matched control participants; after adjustment for the number of ECG monitors worn and for baseline clinical differences, the adjusted relative risk was 6.6 (CI, 3.2 to 13.7). After exclusion of participants who had electrical or pharmacologic cardioversion during the index hospitalization (n = 40) and their matched control participants and limiting to AF events detected by the patch ECG monitor, recurrent AF was detected in 32.3% (CI, 23.1% to 41.5%) of participants with transient new-onset AF and 3.0% (CI, 0% to 6.4%) of matched control participants.

LIMITATIONS

Generalizability is limited, and the study was underpowered to evaluate subgroups and clinical predictors.

CONCLUSION

Among patients who have transient new-onset AF during a hospitalization for noncardiac surgery or medical illness, approximately 1 in 3 will have recurrent AF within 1 year.

PRIMARY FUNDING SOURCE

Peer-reviewed grants.

2023 HRS expert consensus statement on the management of arrhythmias during pregnancy

This international multidisciplinary expert consensus statement is intended to provide comprehensive guidance that can be referenced at the point of care to cardiac electrophysiologists, cardiologists, and other health care professionals, on the management of cardiac arrhythmias in pregnant patients and in fetuses. This document covers general concepts related to arrhythmias, including both brady- and tachyarrhythmias, in both the patient and the fetus during pregnancy. Recommendations are provided for optimal approaches to diagnosis and evaluation of arrhythmias; selection of invasive and noninvasive options for treatment of arrhythmias; and disease- and patient-specific considerations when risk stratifying, diagnosing, and treating arrhythmias in pregnant patients and fetuses. Gaps in knowledge and new directions for future research are also identified.

Iodine-Induced Hyperthyroidism and Long-term Risks of Incident Atrial Fibrillation and Flutter

CONTEXT

Although iodine-induced hyperthyroidism is a potential consequence of iodinated radiologic contrast administration, its association with long-term cardiovascular outcomes has not been previously studied.

OBJECTIVE

To investigate the relationships between hyperthyroidism observed after iodine contrast administration and incident atrial fibrillation/flutter.

METHODS

Retrospective cohort study of the U.S. Veterans Health Administration (1998-2021) of patients age ≥18 years with a normal baseline serum thyrotropin (TSH) concentration, subsequent TSH <1 year, and receipt of iodine contrast <60 days before the subsequent TSH. Cox proportional hazards regression was employed to ascertain the adjusted hazard ratio (HR) with 95% CI of incident atrial fibrillation/flutter following iodine-induced hyperthyroidism, compared with iodine-induced euthyroidism.

RESULTS

Iodine-induced hyperthyroidism was observed in 2500 (5.6%) of 44 607 Veterans (mean ± SD age, 60.9 ± 14.1 years; 88% men) and atrial fibrillation/flutter in 10.4% over a median follow-up of 3.7 years (interquartile range 1.9-7.4). Adjusted for sociodemographic and cardiovascular risk factors, iodine-induced hyperthyroidism was associated with an increased risk of atrial fibrillation/flutter compared with those who remained euthyroid after iodine exposure (adjusted HR 1.19, 95% CI 1.06-1.33). Females were at greater risk for incident atrial fibrillation/flutter than males (females, HR 1.81, 95% CI 1.12-2.92; males, HR 1.15, 95% CI 1.03-1.30; P for interaction = .04).

CONCLUSION

Hyperthyroidism following a high iodine load was associated with an increased risk of incident atrial fibrillation/flutter, particularly among females. The observed sex-based differences should be confirmed in a more sex-diverse study sample, and the cost-benefit analysis of long-term monitoring for cardiac arrhythmias following iodine-induced hyperthyroidism should be evaluated.

Influence of monitoring and atrial arrhythmia burden on quality of life and health care utilization in patients undergoing pulsed field ablation: A secondary analysis of the PULSED AF trial

BACKGROUND

Freedom from atrial arrhythmia (AA) recurrence ≥30 seconds after pulsed field ablation (PFA) in patients with atrial fibrillation (AF) was reported in PULSED AF (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF; ClinialTrials.gov Identifier: NCT04198701). AA burden may be a more clinically meaningful endpoint.

OBJECTIVE

The purpose of this study was to determine the influence of monitoring strategies on AA detection and AA burden association with quality of life (QoL) and health care utilization (HCU) after PFA.

METHODS

Patients underwent 24-hour Holter monitoring at 6 and 12 months and weekly, and symptomatic transtelephonic monitoring (TTM). AA burden post-blanking was calculated as the greater of (1) percentage of AA on total Holter time; or (2) percentage of weeks with ≥1 TTM with AA out of all weeks with ≥1 TTM.

RESULTS

Freedom from all AAs varied by >20% when differing monitoring strategies were used. PFA resulted in zero burden in 69.4% of paroxysmal atrial fibrillation (PAF) and 62.2% of persistent atrial fibrillation (PsAF) patients. Median burden was low (<9%). Most PAF and PsAF patients had ≤1 week of AA detection on TTM (82.6% and 75.4%) and <30 minutes of AA per day of Holter monitoring (96.5% and 89.6%), respectively. Only PAF patients with <10% AA burden averaged a clinically meaningful (>19 point) QoL improvement. PsAF patients experienced clinically meaningful QoL improvements irrespective of burden. Repeat ablations and cardioversions significantly increased with higher AA burden (P <.01).

CONCLUSION

The ≥30-second AA endpoint is dependent on the monitoring protocol used. PFA resulted in low AA burden for most patients, which was associated with clinically relevant improvement in QoL and reduced AA-related HCU.

Factors affecting electrogram sensing in an insertable cardiac monitor: Insights from surface electrocardiogram mapping analysis

BACKGROUND

Fidelity of electrogram sensing may reduce false alerts from an insertable cardiac monitor (ICM).

OBJECTIVE

The purpose of this study was to assess the effect of vector length, implant angle, and patient factors on electrogram sensing using surface electrocardiogram (ECG) mapping.

METHODS

Twelve separate precordial single-lead surface ECGs were acquired from 150 participants at 2 interelectrode distances (75 and 45 mm), at 3 vector angles (vertical, oblique, and horizontal), and in 2 postures (upright and supine). A subset of 50 patients also received a clinically indicated ICM implant in 1:1 ratio (Reveal LINQ [Medtronic, Minneapolis, MN]/BIOMONITOR III [Biotronik, Berlin, Germany]). All ECGs and ICM electrograms were analyzed by blinded investigators using DigitizeIt software (V2.3.3, Braunschweig, Germany). The P-wave visibility threshold was set at > 0.015 mV. Logistic regression was used to identify factors affecting P-wave amplitude.

RESULTS

A total of 1800 tracings from 150 participants (44.5% [n = 68] female; median age 59 [35-73] years) were assessed. The median P- and R-wave amplitudes were 45% and 53% larger with vector lengths of 75 and 45 mm, respectively (P < .001 for both). The oblique orientation yielded the best P- and R-wave amplitudes, while posture change did not affect P-wave amplitude. Mixed effects modeling found that visible P-waves occur more frequently with a vector length of 75 mm than with 45 mm (86% vs 75%, respectively; P < .0001). A longer vector length improved both P-wave amplitude and visibility in all body mass index categories. There was a moderate correlation of P- and R-wave amplitudes from the ICM electrograms to those from surface ECG recordings (intraclass correlation coefficient 0.74 and 0.80, respectively).

CONCLUSION

Longer vector length and oblique implant angle yielded the best electrogram sensing and are relevant considerations for ICM implantation procedures.

Insertable cardiac monitoring results in higher rates of atrial fibrillation diagnosis and oral anticoagulation prescription after ischaemic stroke

AIMS

After an ischaemic stroke, atrial fibrillation (AF) detection allows for improved secondary prevention strategies. This study aimed to compare AF detection and oral anticoagulant (OAC) initiation in patients with an insertable cardiac monitor (ICM) vs. external cardiac monitor (ECM) after ischaemic stroke.

METHODS AND RESULTS

Medicare Fee-for-Service (FFS) insurance claims and Abbott Labs device registration data were used to identify patients hospitalized with an ischaemic stroke in 2017-2019 who received an ICM or ECM within 3 months. Patients with continuous Medicare FFS insurance and prescription drug enrolment in the prior year were included. Patients with prior AF, atrial flutter, cardiac devices, or OAC were excluded. Insertable cardiac monitor and ECM patients were propensity score matched 1:4 on demographics, comorbidities, and stroke hospitalization characteristics. The outcomes of interest were AF detection and OAC initiation evaluated with Kaplan-Meier and Cox proportional hazard regression analyses. A total of 5702 Medicare beneficiaries (ICM, n = 444; ECM, n = 5258) met inclusion criteria. The matched cohort consisted of 2210 Medicare beneficiaries (ICM, n = 442; ECM, n = 1768) with 53% female, mean age 75 years, and mean CHA₂DS₂-VASc score 4.6 (1.6). Insertable cardiac monitor use was associated with a higher probability of AF detection [(hazard ratio (HR) 2.88, 95% confidence interval (CI) (2.31, 3.59)] and OAC initiation [HR 2.91, CI (2.28, 3.72)] compared to patients monitored only with ECM.

CONCLUSION

Patients with an ischaemic stroke monitored with an ICM were almost three times more likely to be diagnosed with AF and to be prescribed OAC compared to patients who received ECM only.

Characterising symptom clusters in patients with atrial fibrillation undergoing catheter ablation

OBJECTIVE

This study aims to leverage natural language processing (NLP) and machine learning clustering analyses to (1) identify co-occurring symptoms of patients undergoing catheter ablation for atrial fibrillation (AF) and (2) describe clinical and sociodemographic correlates of symptom clusters.

METHODS

We conducted a cross-sectional retrospective analysis using electronic health records data. Adults who underwent AF ablation between 2010 and 2020 were included. Demographic, comorbidity and medication information was extracted using structured queries. Ten AF symptoms were extracted from unstructured clinical notes (n=13 416) using a validated NLP pipeline (F-score=0.81). We used the unsupervised machine learning approach known as Ward's hierarchical agglomerative clustering to characterise and identify subgroups of patients representing different clusters. Fisher's exact tests were used to investigate subgroup differences based on age, gender, race and heart failure (HF) status.

RESULTS

A total of 1293 patients were included in our analysis (mean age 65.5 years, 35.2% female, 58% white). The most frequently documented symptoms were dyspnoea (64%), oedema (62%) and palpitations (57%). We identified six symptom clusters: generally symptomatic, dyspnoea and oedema, chest pain, anxiety, fatigue and palpitations, and asymptomatic (reference). The asymptomatic cluster had a significantly higher prevalence of male, white and comorbid HF patients.

CONCLUSIONS

We applied NLP and machine learning to a large dataset to identify symptom clusters, which may signify latent biological underpinnings of symptom experiences and generate implications for clinical care. AF patients' symptom experiences vary widely. Given prior work showing that AF symptoms predict adverse outcomes, future work should investigate associations between symptom clusters and postablation outcomes.

Association of isoproterenol infusion during catheter ablation of atrial fibrillation with outcomes: insights from the UC San Diego AF Ablation Registry

BACKGROUND

High-dose isoproterenol infusion is a useful provocative maneuver to elicit triggers of atrial fibrillation (AF) during ablation. We evaluated whether the use of isoproterenol infusion to elicit triggers of AF after ablation is associated with differential outcomes.

METHODS

We performed a retrospective study of all patients who underwent de novo radiofrequency catheter ablation of AF enrolled in the University of California, San Diego AF Ablation Registry. The primary outcome was freedom from atrial arrhythmias on or off antiarrhythmic drugs (AAD).

RESULTS

Of 314 patients undergoing AF ablation, 235 (74.8%) received isoproterenol while 79 (25.2%) did not. Among those who received isoproterenol, 11 (4.7%) had additional triggers identified. There were no statistically significant differences in procedure time (p = 0.432), antiarrhythmic drug use (p = 0.289), procedural complications (p = 0.279), recurrences of atrial arrhythmias on or off AAD [adjusted hazard ratio (AHR) 0.92 (95% CI 0.58-1.46); p = 0.714], all-cause hospitalizations [AHR 1.00 (95% CI 0.60-1.67); p = 0.986], or all-cause mortality [AHR 0.14 (95% CI 0.01-3.52); p = 0.229] between groups.

CONCLUSIONS

In this registry analysis, use of isoproterenol is safe but was not associated with a reduction in recurrence of atrial arrhythmias.

Impact of Percutaneous Mitral Valve Repair on Left Atrial Strain and Atrial Fibrillation Progression

Transcatheter edge-to-edge repair (TEER) currently represents a valuable therapeutic option for patients with severe mitral regurgitation (MR) considered at high surgical risk. Besides symptoms and left ventricular (LV) echocardiographic improvements upon TEER, it has been postulated that left atrial (LA) function plays a prognostic role. The aims of our study were to evaluate LA changes after TEER, measured by two-dimensional speckle-tracking echocardiography analysis (2D-STE), their association with atrial fibrillation (AF) occurrence, and relative arrhythmic burden. We considered in a single-center study 109 patients affected by symptomatic severe MR undergoing TEER from February 2015 to April 2022. By 2D-STE, LA reservoir (R_s), conduct (D_s), and contractile (C_s) strains were assessed along with four-chamber emptying fraction (LAEF-4CH) before, 1, 6, and 12 months following TEER. Statistical analysis for comparison among baseline, and follow-ups after TEER was carried out by ANOVA, MANOVA, and linear regression. Successful TEER significantly improved LV dimensions and LA performances, as indicated by all strain components, and LAEF-4CH after 1 year. Strikingly, a significant reduction in arrhythmic burden was observed, since only one case of subclinical AF detected by a previously implanted cardiac electronic device was found in the cohort of sinus rhythm patients (n = 48) undergone TEER; in addition, ventricular rate was reduced in the AF cohort (n = 61) compared to baseline, together with few episodes of nonsustained ventricular tachycardias (5/61, 8.2%) after MR improvement. Overall, TEER was associated with improved cardiac performance, LA function amelioration, and reduced arrhythmic burden.

Association between interatrial septum adiposity and atrial fibrillation: transesophageal echocardiography imaging and autopsy study

Recent clinical evidence has suggested that interatrial septal (IAS) adiposity contributes to atrial fibrillation (AF). The present study aimed to confirm the usefulness of transesophageal echocardiography (TEE) to estimate IAS adiposity in patients with AF. The histological IAS analysis based on autopsy samples sought to clarify characteristics that underlie the contribution of IAS adiposity to AF. The imaging study analyzed the TEE results in patients with AF (n = 184) in comparison with transthoracic echocardiography (TTE) and computed tomography (CT) results. The autopsy study histologically analyzed IAS in subjects with (n = 5) and without (n = 5) history of AF. In the imaging study, the ratio of interatrial septum adipose tissue (IAS-AT) volume per epicardial adipose tissue (EpAT) volume was greater in patients with persistent AF compared (PerAF) to those with paroxysmal AF (PAF). Multivariable analysis revealed that both TEE-assessed IAS thickness and TTE-assessed left atrial dimension were predicted by CT-assessed IAS-AT volume. In the autopsy study, the histologically-assessed IAS section thickness was greater in the AF group than that in the non-AF group and was positively correlated with the IAS-AT area percentage. In addition, the size of adipocytes in IAS-AT was smaller, compared to EpAT and subcutaneous adipose tissue (SAT). IAS-AT infiltrated into the IAS myocardium, as if adipose tissue split the myocardium (designated as myocardial splitting by IAS-AT). The number of island-like myocardium pieces as a result of myocardial splitting by IAS-AT was greater in the AF group than in the non-AF group and was positively correlated with the IAS-AT area percentage. The present imaging study confirmed the usefulness of TEE to estimate IAS adiposity in patients with AF without radiation exposure. The autopsy study suggested that the myocardial splitting by IAS-AT may contribute to atrial cardiomyopathy leading to AF.

Contemporary trends and barriers to oral anticoagulation therapy in Non-valvular atrial fibrillation during DOAC predominant era

There is a need to reassess contemporary oral anticoagulation (OAC) trends and barriers against guideline directed therapy in the United States. Most previous studies were performed before major guideline changes recommended direct oral anticoagulant (DOAC) use over warfarin or have otherwise lacked patient level data. Data on overuse of OAC in low-risk group is also limited. To address these knowledge gaps, we performed a nationwide analysis to analyze current trends. This is a retrospective cohort study assessing non-valvular AF identified using a large United States de-identified administrative claims database, including commercial and Medicare Advantage enrollees. Prescription fills were assessed within a 90-day follow-up from the patient's index AF encounter between January 1, 2016, and December 31, 2020. Among the 339,197 AF patients, 4.4%, 8.0%, and 87.6% were in the low-, moderate-, and high-risk groups (according to CHA₂DS₂-VASc score). An over (29.6%) and under (52.2%) utilization of OAC was reported in low- and high-risk AF patients. A considerably high frequency for warfarin use was also noted among high-risk group patients taking OAC (33.1%). The results suggest that anticoagulation use for stroke prevention in the United States is still comparable to the pre-DOAC era studies. About half of newly diagnosed high-risk non-valvular AF patients remain unprotected against stroke risk. Several predictors of OAC and DOAC use were also identified. Our findings may identify a population at risk of complications due to under- or over-treatment and highlight the need for future quality improvement efforts.

Left Atrial Appendage Closure: What the Evidence Does and Does Not Reveal-A View from the Outside

This review summarizes the evidence for left atrial appendage closure (LAAC) as an alternative to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation. LAAC reduces hemorrhagic stroke and mortality versus warfarin, but is inferior for ischemic stroke reduction based on randomized data. Whilst a feasible treatment in OAC-ineligible patients, questions remain over procedural safety, and the improvement in complications observed in nonrandomized registries is uncorroborated by contemporary randomized trials. Management of device-related thrombus and peridevice leak remain unclear, and robust randomized data versus direct OACs are required before recommendations can be made for widespread adoption in OAC-eligible populations.

Mobile health-technology integrated care in secondary prevention atrial fibrillation patients: a post-hoc analysis from the mAFA-II randomized clinical trial

AF patients with history of thromboembolic events are at higher risk of thromboembolic recurrences, despite appropriate antithrombotic treatment. We aimed to evaluate the effect of mobile health (mHealth) technology-implemented 'Atrial fibrillation Better Care' (ABC) pathway approach (mAFA intervention) in secondary prevention AF patients. The Mobile Health Technology for Improved Screening and Optimized Integrated Care in AF (mAFA-II) cluster randomized trial enrolled adult AF patients across 40 centers in China. The main outcome was the composite outcome of stroke or thromboembolism, all-cause death, and rehospitalization. Using Inverse Probability of Treatment Weighting (IPTW), we evaluated the effect of the mAFA intervention in patients with and without prior history of thromboembolic events (i.e., ischemic stroke or thromboembolism). Among the 3324 patients enrolled in the trial, 496 (14.9%, mean age: 75.1 ± 11.4 years, 35.9% females) had a previous episode of thromboembolic event. No significant interaction was observed for the effect of mAFA intervention in patients with vs. without history of thromboembolic events [Hazard ratio, (HR): 0.38, 95% confidence interval (CI):0.18-0.80 vs. HR 0.55, 95% CI 0.17-1.76, p for interaction = 0.587); however, a trend towards lower efficacy of mAFA intervention among AF patients in secondary prevention was observed for secondary outcomes, with significant interaction for bleeding events (p = 0.034) and the composite of cardiovascular events (p = 0.015). A mHealth-technology-implemented ABC pathway provided generally consistent reduction of the risk of primary outcome in both primary and secondary prevention AF patients. Secondary prevention patients may require further specific approaches to improve clinical outcomes such as bleeding and cardiovascular events.Trial registration: WHO International Clinical Trials Registry Platform (ICTRP) Registration number ChiCTR-OOC-17014138.

Natriuretic peptides as predictors for atrial fibrillation recurrence after catheter ablation: A meta-analysis

BACKGROUND

Catheter ablation (CA) has become the first-line treatment strategy for atrial fibrillation (AF) but remains with a substantial recurrence rate. The aim of this meta-analysis was to determine the association between baseline natriuretic peptide levels and AF recurrence after CA.

METHODS

We systematically searched PubMed, EMBASE, Web of Science, and Wiley-Cochrane Library for relevant studies published up until May 2022. Overall effect analysis and subgroup analysis were performed with Review Manager software.

RESULTS

Finally, 61 studies that met the inclusion criteria were included in our meta-analysis. Compared with the nonrecurrence group, the recurrence group had increased baseline level of atrial natriuretic peptide (ANP) (standardized mean difference [SMD] = 0.39, 95% confidence interval [CI]: 0.21-0.56), brain natriuretic peptide (BNP) (SMD = 0.51, 95% CI: 0.31-0.71), N-terminal pro-BNP (SMD = 0.71, 95% CI: 0.49-0.92), and midregional N-terminal pro-ANP (SMD = 0.91, 95% CI: 0.27-1.56).

CONCLUSIONS

Increased baseline natriuretic peptide levels, including ANP, BNP, N-terminal pro-BNP, and midregional N-terminal pro-ANP, are associated with a higher risk of AF recurrence after CA. Nonetheless, further studies are needed to elucidate the predictive value of baseline natriuretic peptides in AF patients undergoing CA.

Predictors of stroke or systemic embolism in patients with non-valvular atrial fibrillation with CHA2 DS2 -VASc score of 0

BACKGROUND

Anticoagulant therapy has been important for stroke prevention in patients with atrial fibrillation (AF). However, it was not recommended due to its relatively higher risk of bleeding than its lower risk of stroke in patients with a CHA₂ DS₂ -VASc score of 0.

HYPOTHESIS

This study aimed to evaluate the predictors of stroke in AF patients with very low risk of stroke.

METHODS

Between 1990 and 2020, 542 patients with non-valvular AF (NVAF) with a CHA₂ DS₂ -VASc score of 0 followed up for at least 6 months were enrolled. Patients with only being woman as a risk factor were included as a CHA₂ DS₂ -VASc score of 0 in this study. The primary outcome was stroke or systemic embolism.

RESULTS

The primary outcome rate was 0.78%/year. In Cox hazard model, age of ≥50 years at diagnosis (hazard ratio [HR] 6.710, 95% confidence interval [CI] 1.811-24.860, p = .004), LVEDD of ≥46 mm (HR 4.513, 95% CI 1.038-19.626, p = .045), and non-paroxysmal AF (HR 5.575, 95% CI 1.621-19.175, p = .006) were identified as independent predictors of stroke or systemic embolism. Patients with all three independent predictors had a higher risk of stroke or systemic embolism (4.21%/year), whereas those without did not have a stroke or systemic embolism.

CONCLUSION

The annual stroke or systemic embolism rate in NVAF patients with CHA₂ DS₂ -VASc score of 0 was 0.78%/year, and age at AF diagnosis, LVEDD, and non-paroxysmal AF were independent predictors of stroke or systemic embolism in patients considered to have a very low risk of stroke.

CHA2DS2VASc score predicts risk of end stage renal disease in patients with atrial fibrillation: Long-term follow-up study

Background

End stage renal disease (ESRD) is an increasing worldwide epidemic disease. CHA2DS2-VASc score is a well-established predictor of cardiovascular outcome among atrial fibrillation (AF) patients.

Objective

The aim of this study was to test whether CHA2DS2-VASc score is a good predictor for incident ESRD events.

Methods

This is a retrospective cohort study (from January 2010 to December 2020) with median follow-up of 61.7 months. Clinical parameters and baseline characteristics were recorded. The endpoint was defined as ESRD with dialysis dependent.

Results

The study cohort comprised 29,341 participants. Their median age was 71.0 years, 43.2% were male, 21.5% had diabetes mellitus, 46.1% had hypertension, and mean CHA2DS2-VASc score was 2.89. CHA2DS2-VASc score was incrementally associated with the risk of ESRD status during follow-up. Using the univariate Cox model, we found a 26% increase in ESRD risk with an increase of one point in the CHA2DS2-VASc score (HR 1.26 [1.23-1.29], P < 0.001). And using the multi-variate Cox model adjusted by initial CKD stage, we still observed a 5.9% increase in risk of ESRD with a one-point increase in the CHA2DS2-VASc score (HR 1.059 [1.037-1.082], P < 0.001). The CHA2DS2-VASC score and the initial stage of CKD were associated with the risk of ESRD development in patients with AF.

Conclusions

Our results first confirmed the utility of CHA2DS2-VASC score in predicting progression to ESRD in AF patients. The efficiency is best in CKD stage 1.

Insertable cardiac monitor-guided early intervention to reduce atrial fibrillation burden following catheter ablation: Study design and clinical protocol (ICM-REDUCE-AF trial)

BACKGROUND

Percutaneous catheter ablation (CA) to achieve pulmonary vein isolation is an effective treatment for drug-refractory paroxysmal and persistent atrial fibrillation (AF). However, recurrence rates after a single AF ablation procedure remain elevated. Conventional management after CA ablation has mostly been based on clinical AF recurrence. However, continuous recordings with insertable cardiac monitors (ICMs) and patient-triggered mobile app transmissions post-CA can now be used to detect early recurrences of subclinical AF (SCAF). We hypothesize that early intervention following CA based on personalized ICM data can prevent the substrate progression that promotes the onset and maintenance of atrial arrhythmias.

METHODS

This is a randomized, double-blind (to SCAF data), single-tertiary center clinical trial in which 120 patients with drug-refractory paroxysmal or persistent AF are planned to undergo CA with an ICM. Randomization will be to an intervention arm (n = 60) consisting of ICM-guided early intervention based on SCAF and patient-triggered mobile app transmissions versus a control arm (n = 60) consisting of a standard intervention protocol based on clinical AF recurrence validated by the ICM. Primary endpoint is AF burden, which will be assessed from ICMs at 15 months post-AF ablation. Secondary endpoints include healthcare utilization, functional capacity, and quality of life.

CONCLUSION

We believe that ICM-guided early intervention will provide a novel, personalized approach to post-AF ablation management that will result in a significant reduction in AF burden, healthcare utilization, and improvements in functional capacity and quality of life.