Association between high-density mapping of atypical atrial flutter, clinical outcomes and healthcare utilization.

BACKGROUND: Success of atypical atrial flutter (AAFL) ablation has historically been limited by difficulty mapping the complex re-entrant circuits involved. While high-density (HD) mapping has become commonplace in clinical practice, there are limited data on outcomes of HD versus non-HD mapping for AAFL ablation. OBJECTIVE: To compare clinical outcomes and healthcare utilization using HD mapping versus non-HD mapping for AAFL ablation. METHODS: Retrospective analysis of all AAFL procedures between 2005 and 2022 at an academic medical center was conducted. Procedures utilizing a 16-electrode HD Grid catheter and Precision mapping system were compared to procedures using prior generation 10-20 electrode spiral catheters and the Velocity system (Abbott, IL). Cox regression models and Poisson regression models were utilized to examine procedural and healthcare utilization outcomes. Models were adjusted for left ventricular ejection fraction, CHA2DS2-VASc, and history of prior ablation. RESULTS: There were 108 patients (62% HD mapping) included in the analysis. Baseline clinical characteristics were similar between groups. Use of HD mapping was associated with a higher rate of AAFL circuit delineation (92.5% vs. 76%; p = .014) and a greater adjusted procedure success rate, defined as non-inducibility at procedure end, (aRR (95% CI) 1.26 (1.02-1.55) p = .035) than non-HD mapping. HD mapping was also associated with a lower rate of ED visits (aIRR (95% CI) 0.32 (0.14-0.71); p = .007) and hospitalizations (aIRR (95% CI) 0.32 (0.14-0.68); p = .004) for AF/AFL/HF through 1 year. While there was a lower rate of recurrent AFL through 1 year among HD mapping cases (aHR (95% CI) 0.60 (0.31-1.16) p = .13), statistical significance was not met likely due to the low sample size and higher rate of ambulatory rhythm monitoring in the HD group (61% vs. 39%, p = .025). CONCLUSION: Compared to non-HD mapping, AAFL ablation with HD mapping is associated with improvements in the ability to define the AAFL circuit, greater procedural success, and a reduction in the number of ED visits and hospitalization for AF/AFL/HF.

Association of Atrial Fibrillation Burden and Mortality Among Patients With Cardiac Implantable Electronic Devices.

BACKGROUND: Current estimates of atrial fibrillation (AF)-associated mortality rely on claims- or clinical-derived diagnoses of AF, limit AF to a binary entity, or are confounded by comorbidities. The objective of the present study is to assess the association between device-recognized AF and mortality among patients with cardiac implantable electronic devices capable of sensitive and continuous atrial arrhythmia detection. Secondary outcomes include relative mortality among cohorts with no AF, paroxysmal AF, persistent AF, and permanent AF. METHODS: Using the deidentified Optum Clinformatics US claims database (2015 to 2020) linked to the Medtronic CareLink database, we identified individuals with a cardiac implantable electronic device who transmitted data ≥6 months after implantation. AF burden was assessed during the first 6 months after implantation (baseline period). Subsequent mortality, assessed from claims data, was compared between patients with and those without AF, with adjustment for age, geographic region, insurance type, Charlson Comorbidity Index, and implantation year. RESULTS: Of 21 391 patients (age, 72.9±10.9 years; 56.3% male) analyzed, 7798 (36.5%) had device-recognized AF. During a mean of 22.4±12.9 months (median, 20.1 [12.8-29.7] months) of follow-up, the overall incidence of mortality was 13.5%. Patients with AF had higher adjusted all-cause mortality than patients without AF (hazard ratio, 1.29 [95% CI, 1.20-1.39]; P<0.001). Among those with AF, patients with nonparoxysmal AF had the greatest risk of mortality (persistent AF versus paroxysmal AF: hazard ratio, 1.36 [95% CI, 1.18-1.58]; P<.001; permanent AF versus paroxysmal AF: hazard ratio, 1.23 [95% CI, 1.14-1.34]; P<.001). CONCLUSIONS: After adjustment for potential confounding factors, presence of AF was associated with higher mortality than no AF in our cohort of patients with cardiac implantable electronic devices. Among those with AF, nonparoxysmal AF was associated with the greatest risk of mortality.

Severe Periprocedural Complications After Ablation for Atrial Fibrillation: An International Collaborative Individual Patient Data Registry.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) including pulmonary vein isolation and possibly further substrate ablation is the most common electrophysiological procedure. Severe complications are uncommon, but their detailed assessment in a large worldwide cohort is lacking. OBJECTIVES: The aim of this study was to determine the incidence of periprocedural severe complications and to provide a detailed characterization of the diagnostic evaluation and management of these complications in patients undergoing AF ablation. METHODS: Individual patient data were collected from 23 centers worldwide. Limited data were collected for all patients who underwent catheter ablation, and an expanded series of data points were collected for patients who experienced severe complications during periprocedural follow-up. Incidence, predictors, patient characteristics, management details, and overall outcomes of patients who experienced ablation-related complications were investigated. RESULTS: Data were collected from 23 participating centers at which 33,879 procedures were performed (median age 63 years, 30% women, 71% radiofrequency ablations). The incidence of severe complications (n = 271) was low (tamponade 6.8‰, stroke 0.97‰, cardiac arrest 0.41‰, esophageal fistula 0.21‰, and death 0.21‰). Age, female sex, a dilated left atrium, procedure duration, and the use of radiofrequency energy were independently associated with the composite endpoint of all severe complications. Among patients experiencing tamponade, 13% required cardiac surgery. Ninety-three percent of patients with complications were discharged directly home after a median length of stay of 5 days (Q1-Q3: 3-7 days). CONCLUSIONS: This large worldwide collaborative study highlighted that tamponade, stroke, cardiac arrest, esophageal fistula, and death are rare after AF ablation. Older age, female sex, procedure duration, a dilated left atrium, and the use of radiofrequency energy were associated with severe complications in this multinational cohort. One in 8 patients with tamponade required cardiac surgery.

Safety and feasibility of intravenous sotalol loading for the prevention of ventricular arrhythmias.

BACKGROUND: The use of intravenous (IV) sotalol loading following recent U.S. Food and Drug Administration (FDA) approval of a 1-day loading protocol has reduced the obligatory 3-day hospital stay for sotalol initiation when given orally. Several studies have recently demonstrated the safety and feasibility of IV loading for patients with atrial arrhythmias. However, there is a paucity of data on the feasibility and safety of IV sotalol loading for patients with ventricular arrhythmias. This study aims to assess the safety, feasibility, and length of stay (LOS) outcomes of IV sotalol loading for the prevention of ventricular arrhythmias. METHODS: A retrospective analysis was performed of all patients undergoing IV sotalol loading and oral sotalol initiation for ventricular arrhythmias, or IV sotalol loading for atrial arrhythmias between August 2021 and December 2023 at Northwestern University. Baseline characteristics, success of sotalol initiation/loading, changes in heart rate (HR) and QT/QTc, safety, and LOS were compared between patients undergoing sotalol loading/initiation for ventricular arrhythmias (IV vs. PO) and between patients undergoing IV sotalol loading for ventricular arrhythmias vs. for atrial arrhythmias. RESULTS: A total of 28 patients underwent sotalol loading/initiation for ventricular arrhythmias (N = 15 IV and N = 13 PO) and 41 patients underwent IV sotalol loading for atrial arrhythmias. Baseline characteristics of congestive heart failure history and left ventricular ejection fraction were worse in the ventricular arrhythmias group. There was no significant difference in the successful completion of IV sotalol loading for ventricular arrhythmias compared to oral sotalol initiation for ventricular arrhythmias or IV sotalol loading for atrial arrhythmias (86.7% vs. 92.3% vs. 90.2%, p = 0.88). There was a significant increase in ΔQTc following IV sotalol infusion for ventricular arrhythmias compared to following PO sotalol initiation for ventricular arrhythmias (46.4 ± 29.2 ms vs. 8.9 ± 32.6 ms, p = 0.004) and following IV sotalol infusion for atrial arrhythmias (46.4 ± 29.2 ms vs. 24.0 ± 25.1 ms, p = 0.018). ΔHR following IV sotalol infusion for ventricular arrhythmias was similar to ΔHR following PO sotalol initiation for ventricular arrhythmias and ΔHR following IV sotalol infusion for atrial arrhythmias (- 7.5 ± 8.7 bpm vs. - 8.5 ± 13.9 bpm vs. - 8.3 ± 13.2 bpm, p = 0.87). There were no significant differences in discontinuation for QTc prolongation (6.7% vs. 1.7% vs. 2.4%, p = 0.64) and bradycardia (13.3% vs. 7.7% vs. 9.8%, p = 0.88) between IV sotalol loading for ventricular arrhythmias, PO sotalol initiation for ventricular arrhythmias, and IV sotalol loading for atrial arrhythmias. There were no instances of hypotension, life-threatening ventricular arrhythmias, heart failure, or death. Length of stay was significantly shorter for IV sotalol loading compared to PO sotalol initiation for ventricular arrhythmias (1.1 ± 0.36 days vs. 4.2 ± 1.0 days, p < 0.0001). CONCLUSION: IV sotalol loading appears feasible and safe for use in ventricular arrhythmias and results in a decreased length of stay. Despite increased comorbidities and greater increase in QTc interval following IV sotalol infusion in the ventricular arrhythmias group, there were no significant differences in successful completion of loading or adverse outcomes when compared to PO sotalol initiation for ventricular arrhythmias and IV loading for atrial arrhythmias.

Impact of Atrial Fibrillation Burden on Health Care Costs and Utilization.

BACKGROUND: Integrating patient-specific cardiac implantable electronic device (CIED)-detected atrial fibrillation (AF) burden with measures of health care cost and utilization allows for an accurate assessment of the AF-related impact on health care use. OBJECTIVES: The goal of this study was to assess the incremental cost of device-recognized AF vs no AF; compare relative costs of paroxysmal atrial fibrillation (pAF), persistent atrial fibrillation (PeAF), and permanent atrial fibrillation (PermAF) AF; and evaluate rates and sources of health care utilization between cohorts. METHODS: Using the de-identified Optum Clinformatics U.S. claims database (2015-2020) linked with the Medtronic CareLink database, CIED patients were identified who transmitted data ≥6 months postimplantation. Annualized per-patient costs in follow-up were analyzed from insurance claims and adjusted to 2020 U.S. dollars. Costs and rates of health care utilization were compared between patients with no AF and those with device-recognized pAF, PeAF, and PermAF. Analyses were adjusted for geographical region, insurance type, CHA2DS2-VASc score, and implantation year. RESULTS: Of 21,391 patients (mean age 72.9 ± 10.9 years; 56.3% male) analyzed, 7,798 (36.5%) had device-recognized AF. The incremental annualized increased cost in those with AF was $12,789 ± $161,749 per patient, driven by increased rates of health care encounters, adverse clinical events associated with AF, and AF-specific interventions. Among those with AF, PeAF was associated with the highest cost, driven by increased rates of inpatient and outpatient hospitalization encounters, heart failure hospitalizations, and AF-specific interventions. CONCLUSIONS: Presence of device-recognized AF was associated with increased health care cost. Among those with AF, patients with PeAF had the highest health care costs. Mechanisms for cost differentials include both disease-specific consequences and physician-directed interventions.

Associations of Circulating Vascular Cell Adhesion Molecule-1 and Intercellular Adhesion Molecule-1 With Long-Term Cardiac Function.

BACKGROUND: Although VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1) have been associated with incident heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF), the associations of VCAM-1 and ICAM-1 with sensitive measures of cardiac structure/function are unclear. The objective of this study is to evaluate associations between VCAM-1, ICAM-1, and measures of cardiac structure and function as potential pathways through which cellular adhesion molecules promote HFpEF and AF risk. METHODS AND RESULTS: In MESA (Multi-Ethnic Study of Atherosclerosis), we evaluated the associations of circulating VCAM-1 and ICAM-1 at examination 2 (2002-2004) with measures of cardiac structure/function on cardiac magnetic resonance imaging at examination 5 (2010-2011) after multivariable adjustment. Mediation analysis of left atrial (LA) strain on the association between VCAM-1 or ICAM-1 and AF or HFpEF was also performed. Overall, 2304 individuals (63±10 years; 47% men) with VCAM-1 or ICAM-1, cardiac magnetic resonance imaging, and covariate data were included in analysis. Higher VCAM-1 and ICAM-1 were associated with lower LA peak longitudinal strain and worse global circumferential left ventricular strain but were not associated with left ventricular myocardial scar or interstitial fibrosis. Lower LA peak longitudinal strain mediated 8% (95% CI, 2-30) of the relationship between VCAM-1 and HFpEF and 9% (95% CI, 2-21) of the relationship between VCAM-1 and AF. CONCLUSIONS: Higher VCAM-1 and ICAM-1 were associated with lower LA function and left ventricular systolic function but were not associated with myocardial scar or interstitial fibrosis. VCAM-1 and ICAM-1 may promote HFpEF and AF risk through impaired LA reservoir function.

Aortic Regurgitation and Heart Failure: Advances in Diagnosis, Management, and Interventions.

This review discusses the contemporary clinical evaluation and management of patients with comorbid aortic regurgitation (AR) and heart failure (HF) (AR-HF). Importantly, as clinical HF exists along the spectrum of AR severity, the present review also details novel strategies to detect early signs of HF before the clinical syndrome ensues. Indeed, there may be a vulnerable cohort of AR patients who benefit from early detection and management of HF. Additionally, while the mainstay of operative management for AR has historically been surgical aortic valve replacement, this review discusses alternate procedures that may be beneficial in high-risk cohorts.

"Pill-in-Pocket" anticoagulation for stroke prevention in atrial fibrillation.

Uninterrupted anticoagulation for atrial fibrillation (AF), regardless of AF burden, is deeply rooted in practice since the early anticoagulation trials. However, uninterrupted anticoagulation is not without risks, and may not be beneficial for allcomers with a history of AF. Indeed, contemporary data that support a critical duration threshold of AF that benefits from anticoagulation, and a temporal association between stroke and multihour AF episodes, compel the study of a more targeted approach to AF anticoagulation. In this review, we discuss data that support further investigation of "pill in the pocket" anticoagulation for AF, and introduce the pivotal Rhythm Evaluation for Anticoagulation Therapy for Atrial Fibrillation (REACT-AF) trial that will robustly evaluate this strategy.

Validation of the SCALE-CryoAF risk model to predict very late return of atrial fibrillation after cryoballoon ablation.

BACKGROUND: To date, few risk models have been validated to predict recurrent atrial fibrillation (AF) >1 year after ablation. The SCALE-CryoAF score was previously derived to predict very late return of AF (VLRAF) >1 year following cryoballoon ablation (CBA), with strong predictive ability. In this study, we aim to validate the SCALE-CryoAF score for VLRAF after CBA in a novel patient cohort. METHODS: Retrospective analysis of a prospectively maintained single-center database was performed. Inclusion criteria were pulmonary vein isolation using CBA 2017-2020. Exclusion criteria included prior ablation, <1-year follow-up, lack of pre-CBA echocardiogram, additional ablation lesion sets, and documented AF recurrence 90-365 days post-CBA. The area under the curve (AUC) of SCALE-CryoAF was compared to the derivation value and other established risk models. RESULTS: Among 469 CBA performed, 241 (61% male, 62.8 ±11.7 years old) cases were included in analysis. There were 37 (15.4%) patients who developed VLRAF. Patients with VLRAF had a higher SCALE-CryoAF score (VLRAF 5.4 ± 2.7; no VLRAF 3.1 ± 2.9; p<0.001). SCALE-CryoAF was linearly associated with VLRAF (y=14.35x-11.72, R2=0.99), and a score > 5 had a 32.7% risk of VLRAF. The SCALE-CryoAF risk model predicted VLRAF with an AUC of 0.74, which was similar to the derivation value (AUCderivation: 0.73) and statistically superior to MB-LATER, CHA2DS2-VASc, and CHADS2 scores. CONCLUSIONS: The current analysis validates the ability of SCALE-CryoAF to predict VLRAF after CBA in a novel patient cohort. Patients with a high SCALE-CryoAF score should be monitored closely for recurrent AF >1 year following CBA.

Subcutaneous implantable cardioverter-defibrillator implantation position predicts successful defibrillation in obese and non-obese patients.

BACKGROUND: Subcutaneous implantable cardioverter-defibrillators (S-ICD) are an alternative to transvenous ICDs for patients without a need for cardiac pacing. Obese patients have been proposed to be at higher risk for conversion failure with S-ICDs due to subcutaneous fat underneath the device. Optimal device positioning may promote equivalent outcomes between obese and non-obese patients by minimizing the effects of excess adipose tissue. METHODS: A retrospective analysis of patients undergoing defibrillation testing at the time of S-ICD implantation was performed. The primary endpoint was the rate of successful conversion of ventricular fibrillation (VF) at the time of implant. The secondary endpoint was shock impedance. RESULTS: A total of 184 patients were included in the study. The rate of successful conversion of VF was 90.3% for obese patients (n = 72) and 96.4% for non-obese patients (n = 112) (p = 0.086). Compared to non-obese patients, obese patients had a higher mean PRAETORIAN score (78.5 ± 58.1 vs. 48.8 ± 35.5, p < 0.001) and higher measured mean impedance (82.0 ohms ± 26.5 vs. 69.8 ohms ± 19.3, p < 0.001). Patients with a PRAETORIAN score < 90 all had successful defibrillation testing regardless of BMI. CONCLUSIONS: In this study, a PRAETORIAN score < 90 was associated with a 100% success rate of defibrillation testing following S-ICD implantation regardless of patient body mass index (BMI). Thus, the impact of obesity on impedance and the risk of failed shocks may be minimized with close attention to implantation technique to achieve a low PRAETORIAN score.

Comparison of data quality and monitoring completion rates between clinic and self-applied ECG patches.

BACKGROUND: Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, direct-to-patient, self-applied ECG patch use has substantially increased. There are limited data comparing clinic with self-applied electrocardiogram (ECG) patches. OBJECTIVE: The purpose of this study was to compare rates of ECG patch return, percentages of time patches yielded analyzable data (analyzable time), and percentages of prescribed time ECG patches were worn between clinic and self-applied ECG patches before and during COVID-19. METHODS: A retrospective analysis of patients prescribed an ECG patch during "pre-COVID" (March 1, 2019, through March 1, 2020) and "COVID" (April 4, 2020, through April 1, 2021) years was performed. ECG patch return rates, mean percentages of analyzable time, and mean percentages of prescribed wear time were compared between clinic and self-applied groups. RESULTS: Among the 29,093 ECG patch prescriptions (19% COVID self-applied), the COVID self-applied group had a lower return rate (90.8%) than did both clinic-applied groups (COVID: 97.1%; pre-COVID: 98.1%; P < .001). Among the 28,048 ECG patches (17.5% self-applied) returned for analysis, the COVID self-applied group demonstrated a lower mean percentage of analyzable time (95.9% ± 8.2%) than did both clinic-applied groups (COVID: 96.6% ± 6.6%; pre-COVID 96.6% ± 7.4%; P < .001). There were no differences in the mean percentage of prescribed wear time between groups (pre-COVID clinic-applied: 96.7% ± 34.3%; COVID clinic-applied: 97.4% ± 39.8%; COVID self-applied: 98.1% ± 52.1%; P = .09). CONCLUSION: Self-applied ECG patches were returned at a lower rate and had a statistically lower percentage of analyzable time than clinic-applied patches. However, there were no differences between groups in mean percentages of prescribed wear time, and mean percentages of analyzable time were >95% in all groups.

Impact of atrial fibrillation ablation on activity minutes in patients with cardiac implantable electronic devices.

BACKGROUND: Impaired quality of life due to atrial fibrillation (AF), which often includes decreased activity level, is an indication for ablation. However, the impact of ablation for AF on activity is poorly understood. OBJECTIVE: The purpose of this study was to assess the impact of ablation on activity minutes per day using continuous accelerometer data from cardiac implantable electronic devices (CIEDs). METHODS: Using the Optum® Health Record dataset (2007-2019) linked with the Medtronic CareLink® database, we identified patients who had a CIED with AF detection and accelerometer capabilities. Patients with a device that transmitted heart rhythm and activity data ≥3 months before and ≥12 months after ablation were included in analysis. The associations between ablation and activity minutes were assessed for each CIED type. RESULTS: Of 4297 eligible patients who underwent AF ablation, 409 (9.5%) (65% male; age 67.3 ± 9.8 years; 64% paroxysmal AF) were included in analysis. The average AF burden and activity minutes per day preablation were 30.9% ± 37.4% and 175 ± 99 minutes, respectively. After ablation, relative AF burden decreased by 75.1% ± 53.2% (P <.001). There was no change in activity minutes per day after ablation in the entire cohort (average change -0.10 ± 36.2 minutes; P = .96). There were also no clinically significant changes in activity minutes postablation in subgroups based on CIED, season of ablation, quartile of AF burden change, and quartile of age at the time of ablation. CONCLUSION: There were no clinically significant changes in activity minutes per day in patients with CIEDs after ablation for AF.

Impact of pre-ablation weight loss on the success of catheter ablation for atrial fibrillation.

INTRODUCTION: Obesity is an established risk factor for recurrent atrial fibrillation (AF) after ablation. The impact of pre-procedure weight changes on freedom from AF (FFAF) after ablation in obese and nonobese patients is unknown. METHODS: A single-center retrospective cohort study of patients undergoing pulmonary vein isolation was performed. Before ablation, all candidates were encouraged to adopt healthy lifestyle habits according to American Heart Association guidelines, including weight loss, by their physician. The primary endpoint was FFAF through 1-year after completion of the 3-month blanking period. RESULTS: Of the 601 patients (68% male; average age 62.1 ± 10.3 years) included in analysis, 234 patients (38.9%) were obese (body mass index ≥ 30) and 315 (52.4%) had paroxysmal AF. FFAF was observed in 420 patients (69.9%) at 15 months. Percent change in weight that occurred during the year before ablation independently predicted FFAF through 15-months in all patients (adjusted odds ratio = 1.17, 95% confidence interval: 1.11-1.23). Subgroup analyses based on paroxysmal vs persistent AF, presence of obesity, and history of prior ablation were performed. Percent change in weight over the year before ablation was independently associated with FFAF in all subgroups except nonobese patients with persistent AF. CONCLUSION: Pre-ablation weight loss was associated with FFAF in both obese and nonobese patients. Further studies are needed to define the optimal approach to weight loss before AF ablation.

Left Atrial Myopathy in Atrial Fibrillation and Heart Failure: Clinical Implications, Mechanisms, and Therapeutic Targets.

PURPOSE OF REVIEW: This review discusses the mechanisms, clinical implications, and treatments of left atrial (LA) myopathy in comorbid atrial fibrillation (AF) and heart failure (HF) across the spectrum of ejection fraction. RECENT FINDINGS: AF and HF are highly comorbid conditions. Left atrial (LA) myopathy, characterized by impairments in LA structure, function, or electrical conduction, plays a fundamental role in the development of both AF and HF with preserved ejection fraction (AF-HFpEF) along with AF and HF with reduced ejection fraction (AF-HFrEF). While the nature of LA myopathy in AF-HFpEF is unique from that of AF-HFrEF, LA myopathy also leads to progression of both of these conditions. There may be a vulnerable cohort of AF-HF patients who have a disproportionate degree of LA myopathy compared with left ventricular (LV) dysfunction. Further investigations are required to identify therapies to improve LA function in this cohort.