Substrate Imaging Before Catheter Ablation of Ventricular Tachycardia: Risk Prediction for Acute Hemodynamic Decompensation

BACKGROUND

The PAINESD (Pulmonary disease, Age, Ischemic cardiomyopathy, NYHA functional class, Ejection fraction, Storm, Diabetes mellitus) risk score has been validated as a predictor of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing ventricular tachycardia (VT) ablation. Whether the addition of total scar volume (TSV) determined by preprocedure computed tomography imaging provides additional risk stratification has not been previously investigated.

OBJECTIVES

The purpose of this study was to evaluate the impact of TSV on the risk of AHD and its adjunctive benefit to the PAINESD score newly modified as Pulmonary disease, Age, Ischemic cardiomyopathy, NYHA class, Ejection fraction, Storm, Scar volume, Diabetes mellitus (PAINES2D) based on the addition of scar volumes.

METHODS

This was a retrospective analysis of all index VT ablations at a quaternary care center from 2017 to 2022. Associations between TSV and AHD were evaluated among patients with structural heart disease.

RESULTS

Among 61 patients with TSV data, 13 (21%) had periprocedural AHD. TSV and PAINESD were independently associated with AHD risk. Both TSV and PAINESD were associated with AHD (P = 0.016 vs P = 0.053, respectively). The highest TSV tertile (≥37.30 mL) showed significant association with AHD (P = 0.018; OR: 4.80) compared to the other tertiles. The PAINESD and PAINES2D scores had significant impact on AHD (P = 0.046 and P = 0.010, respectively). The PAINES2D score had a greater impact on AHD compared to PAINESD (area under the curve: 0.73; P = 0.011; 95% CI: 0.56-0.91 and area under the curve: 0.67; P = 0.058; 95% CI: 0.49-0.85, respectively).

CONCLUSIONS

Addition of TSV to a modified PAINESD score, PAINES2D, enhances risk prediction of AHD. Further prospective study is needed to assess benefit in various cardiomyopathy populations undergoing VT ablation.

Forward-Solution Noninvasive Computational Arrhythmia Mapping: The VMAP Study

BACKGROUND

The accuracy of noninvasive arrhythmia source localization using a forward-solution computational mapping system has not yet been evaluated in blinded, multicenter analysis. This study tested the hypothesis that a computational mapping system incorporating a comprehensive arrhythmia simulation library would provide accurate localization of the site-of-origin for atrial and ventricular arrhythmias and pacing using 12-lead ECG data when compared with the gold standard of invasive electrophysiology study and ablation.

METHODS

The VMAP study (Vectorcardiographic Mapping of Arrhythmogenic Probability) was a blinded, multicenter evaluation with final data analysis performed by an independent core laboratory. Eligible episodes included atrial and ventricular: tachycardia, fibrillation, pacing, premature atrial and ventricular complexes, and orthodromic atrioventricular reentrant tachycardia. Mapping system results were compared with the gold standard site of successful ablation or pacing during electrophysiology study and ablation. Mapping time was assessed from time-stamped logs. Prespecified performance goals were used for statistical comparisons.

RESULTS

A total of 255 episodes from 225 patients were enrolled from 4 centers. Regional accuracy for ventricular tachycardia and premature ventricular complexes in patients without significant structural heart disease (n=75, primary end point) was 98.7% (95% CI, 96.0%-100%; P<0.001 to reject predefined H0 <0.80). Regional accuracy for all episodes (secondary end point 1) was 96.9% (95% CI, 94.7%-99.0%; P<0.001 to reject predefined H0 <0.75). Accuracy for the exact or neighboring segment for all episodes (secondary end point 2) was 97.3% (95% CI, 95.2%-99.3%; P<0.001 to reject predefined H0 <0.70). Median spatial accuracy was 15 mm (n=255, interquartile range, 7-25 mm). The mapping process was completed in a median of 0.8 minutes (interquartile range, 0.4-1.4 minutes).

CONCLUSIONS

Computational ECG mapping using a forward-solution approach exceeded prespecified accuracy goals for arrhythmia and pacing localization. Spatial accuracy analysis demonstrated clinically actionable results. This rapid, noninvasive mapping technology may facilitate catheter-based and noninvasive targeted arrhythmia therapies.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04559061.

Role of Electrical Delay in Cardiac Resynchronization Therapy Response

Traditionally, left ventricular (LV) lead position was guided by anatomic criteria of pacing from the lateral wall of the LV. However, large trials showed little effect of LV lead position on outcomes, other than noting worse outcomes with apical positions. Given the poor correlation of cardiac resynchronization therapy (CRT) outcomes with anatomically guided LV lead placement, focus shifted toward more physiologic predictors such as targeting the areas of delayed mechanical and electrical activation. Measures of left ventricular delay and interventricular delay are strong predictors of CRT response.

Deep learning model to quantify left atrium volume on routine non-contrast chest CT and predict adverse outcomes

BACKGROUND

Low-dose computed tomography (LDCT) are performed routinely for lung cancer screening. However, a large amount of nonpulmonary data from these scans remains unassessed. We aimed to validate a deep learning model to automatically segment and measure left atrial (LA) volumes from routine NCCT and evaluate prediction of cardiovascular outcomes.

METHODS

We retrospectively evaluated 273 patients (median age 69 years, 55.5% male) who underwent LDCT for lung cancer screening. LA volumes were quantified by three expert cardiothoracic radiologists and a prototype AI algorithm. LA volumes were then indexed to the body surface area (BSA). Expert and AI LA volume index (LAVi) were compared and used to predict cardiovascular outcomes within five years. Logistic regression with appropriate univariate statistics were used for modelling outcomes.

RESULTS

There was excellent correlation between AI and expert results with an LAV intraclass correlation of 0.950 (0.936-0.960). Bland-Altman plot demonstrated the AI underestimated LAVi by a mean 5.86 ​mL/m². AI-LAVi was associated with new-onset atrial fibrillation (AUC 0.86; OR 1.12, 95% CI 1.08-1.18, p ​< ​0.001), HF hospitalization (AUC 0.90; OR 1.07, 95% CI 1.04-1.13, p ​< ​0.001), and MACCE (AUC 0.68; OR 1.04, 95% CI 1.01-1.07, p ​= ​0.01).

CONCLUSION

This novel deep learning algorithm for automated measurement of LA volume on lung cancer screening scans had excellent agreement with manual quantification. AI-LAVi is significantly associated with increased risk of new-onset atrial fibrillation, HF hospitalization, and major adverse cardiac and cerebrovascular events within 5 years.

Patient characteristics, care patterns, and outcomes of atrial fibrillation associated hospitalizations in patients with chronic kidney disease and end-stage renal disease

BACKGROUND

Chronic Kidney Disease (CKD) and end-stage renal disease (ESRD) are associated with poor outcomes in patients with cardiovascular disease. There is a paucity of contemporary data on in-hospital outcomes and care patterns of atrial fibrillation (AF) associated hospitalizations CKD and ESRD.

METHODS

Outcomes and care patterns were evaluated in GWTG-AFIB database (Jan 2013-Dec 2018), including in-hospital mortality, use of a rhythm control strategy, and oral anticoagulation (OAC) prescription at discharge among eligible patients. Generalized logistic regression models with generalized estimating equations were used to ascertain differences in outcomes. Hospital-level variation in OAC prescription and rhythm control was also evaluated.

RESULTS

Among 50,154 patients from 105 hospitals the median age was 70 years (interquartile range 61-79) and 47.3% were women. The prevalence of CKD was 36.0% while that of ESRD was 1.6%. Among eligible patients, discharge OAC prescription rates were 93.6% for CKD and 89.1% for ESRD. After adjustment, CKD and ESRD were associated with higher in-hospital mortality (odds ratio [OR] 3.08, 95% confidence interval [CI] 1.57-6.03 for ESRD and OR 2.02, 95% CI 1.52-2.67 for CKD), lower odds of OAC prescription at discharge (OR 0.59, 95% CI 0.44-0.79 for ESRD and OR 0.84, 95% CI 0.75-0.94 for CKD) compared with normal renal function. CKD was associated with lower utilization of rhythm control strategy (OR 0.92, 95% CI 0.87-0.98) with no significant difference between ESRD and normal renal function (OR 1.32, 95% CI 0.79-1.11). There was large hospital-level variation in OAC prescription at discharge (MOR 2.34, 95% CI 2.05-2.76) and utilization of a rhythm control strategy (MOR 2.69, 95% CI 2.34-3.21).

CONCLUSIONS

CKD/ESRD is associated with higher in-hospital mortality, less frequent rhythm control, and less OAC prescription among patients hospitalized for AF. There is wide hospital-level variation in utilization of a rhythm control strategy and OAC prescription at discharge highlighting potential opportunities to improve care and outcomes for these patients, and better define standards of care in this patient population.

Evaluating outcomes of same-day discharge after catheter ablation for atrial fibrillation in a real-world cohort

Background

As same-day discharge (SDD) after catheter ablation (CA) for atrial fibrillation (AF) is increasingly utilized, it is important to further investigate this approach.

Objective

To investigate the safety and efficacy of SDD after CA for AF in a large nationwide administrative sample.

Methods

The IBM MarketScan Commercial Claims and Encounters database was used to identify adult patients under 65 years undergoing CA for AF (2016-2020). Eligible patients were indexed to date of first CA and classified into SDD or overnight stay (ONS) groups based on length of service. A 1:3 propensity score matching was used to create comparable SDD:ONS samples. Study outcomes were CA-related complications within 30 days after index procedure and AF recurrence within 1 year. Cox proportional hazards models were estimated for outcome comparison.

Results

In the postmatch 30-day cohort, there were 1610 SDD and 4637 ONS patients with mean age 56.1 (± 7.6) years. There was no significant difference in composite 30-day postprocedural complication rate between SDD and ONS groups (2.7% vs 2.8%, respectively; P = .884). The most common complications were cerebrovascular events (0.7% vs 0.7%; P = .948), vascular access events (0.6% vs 0.6%; P = .935), and pericardial complications (0.6% vs 0.5%; P = .921). Further, no significant difference in composite AF recurrence rate at 1 year was observed among SDD and ONS groups (10.2% vs 8.8%; hazard ratio = 1.167; 95% confidence interval 0.935-1.455; P = .172).

Conclusion

In a large, propensity-matched, real-world sample, SDD appears to be safe and have similar outcomes compared with overnight observation following CA for AF.

Same-day discharge after catheter ablation in patients with atrial fibrillation in a large nationwide administrative claims database

BACKGROUND

Catheter ablation (CA) is a common treatment for atrial fibrillation (AF). This study evaluated outcomes of same day discharge (SDD) versus overnight stay (ONS) among AF patients undergoing outpatient CA.

METHODS

The Optum SES Clinformatics Extended Data Mart database was used to identify patients ≥18 years of age undergoing outpatient CA for AF (2016-2020). Eligible patients were indexed to the date of first CA and classified into SDD and ONS groups based on the length of service. A 1:3 propensity score matching was used to create comparable SDD:ONS samples. The primary safety outcome was CA-related complications within 30 days of index procedure. The primary efficacy outcome was AF recurrence within 1 year. Cox proportional hazards models were estimated for outcome comparison.

RESULTS

In the postmatch 30-day cohort for safety evaluation, there were 6600 patients (1660 [25.2%] SDD; 4940 [74.8%] ONS), with a mean age of 66.6 years. There was no significant difference in the 30-day composite rate of postablation complications (4.7% [78/1660] vs. 3.8% [187/4940]; p = 0.100) and 1-year composite rate of AF recurrence (14.3% [142/996] vs. 14.5% [430/2972]; p = 0.705) between the SDD and ONS groups.

CONCLUSION

This study demonstrated that SDD following CA to treat patients with AF is safe, with low rates of postablation complications and AF recurrence, which were comparable to rates in patients with an ONS after CA.

Electrical delays in quadripolar leads with cardiac resynchronization therapy

BACKGROUND

Pacing at sites of late intraventricular activation (QLV) or long interventricular conduction (right ventricle [RV]-left ventricular [LV]) have been associated with improved cardiac resynchronization therapy (CRT) outcomes. Quadripolar leads improve CRT outcomes by allowing for electrical repositioning to optimize pacing sites. However, little is known regarding the effect of such repositioning on electrical delay.

OBJECTIVE

Determine the relationship between different electrical bipoles from a quadripolar lead and measures of electrical delay.

METHODS

Forty-six patients underwent CRT with a quadripolar lead. The RV-LV and QLV intervals were measured for both the proximal and distal bipoles and the difference (Δ) between bipoles for each measure were calculated. Multivariate analyses were performed to identify predictors of electrical delays.

RESULTS

This was a typical CRT population with a mean age of 65 years and ejection fraction of 27%, with left bundle branch block (LBBB) present in 70%. The regression model for ΔQLV was significant (p = .05), with both gender (p = .008) and LBBB status (p = .020) significant predictors. The overall regression model for ΔRV-LV was not significant. ΔQLV and ΔRV-LV were significant among LBBB patients. Among non-LBBB, only ΔRV-LV was significant (mean: 7.2 ms, p = .006). ΔRV-LV versus ΔQLV were strongly correlated in LBBB (R²  = .92) but not non-LBBB (R²  = .06).

CONCLUSION

In LBBB, ΔRV-LV and ΔQLV are closely correlated suggesting that the proximal bipole and thus basal LV pacing sites should be selected when feasible. Greater variation in activation pattern is present in non-LBBB, so pacing sites should be individualized.

Impact of age on catheter ablation of premature ventricular contractions

INTRODUCTION

Catheter ablation (CA) of frequent premature ventricular contractions (PVC) is increasingly performed in older patients as the population ages. The aim of this study was to assess the impact of age on procedural characteristics, safety and efficacy on PVC ablations.

METHODS

Consecutive patients with symptomatic PVCs undergoing CA between 2015 and 2020 were evaluated. Acute ablation success was defined as the elimination of PVCs at the end of the procedure. Sustained success was defined as an elimination of symptoms, and ≥80% reduction of PVC burden determined by Holter-electrocardiogram during long-term follow. Patients were sub-grouped based on age (<65 vs. ≥65 years).

RESULTS

A total of 114 patients were enrolled (median age 64 years, 71% males) and followed up for a median duration of 228 days. Baseline and procedural data were similar in both age groups. A left-sided origin of PVCs was more frequently observed in the elderly patient group compared to younger patients (83% vs. 67%; p = .04). The median procedure time was significantly shorter in elderly patients (160 vs. 193 min; p = .02). The rates of both acute (86% vs. 92%; p = .32) and sustained success (70% vs. 71%; p = .90) were similar between groups. Complications rates (3.7%) did not differ between the two groups.

CONCLUSION

In a large series of patients with a variety of underlying arrhythmia substrates, similar rates of acute procedural success, complications, and ventricular arrhythmia-free-survival were observed after CA of PVCs. Older age alone should not be a reason to withhold CA of PVCs.

Guideline-Concordant Antiarrhythmic Drug Use in the Get With The Guidelines-Atrial Fibrillation Registry

BACKGROUND

Antiarrhythmic drug (AAD) therapy for atrial fibrillation (AF) can be associated with both proarrhythmic and noncardiovascular toxicities. Practice guidelines recommend tailored AAD therapy for AF based on patient-specific characteristics, such as coronary artery disease and heart failure, to minimize adverse events. However, current prescription patterns for specific AADs and the degree to which these guidelines are followed in practice are unknown.

METHODS

Patients enrolled in the Get With The Guidelines-Atrial Fibrillation registry with a primary diagnosis of AF discharged on an AAD between January 2014 and November 2018 were included. We analyzed rates of prescription of each AAD in several subgroups including those without structural heart disease. We classified AAD use as guideline concordant or nonguideline concordant based on 6 criteria derived from the American Heart Association/American College of Cardiology/Heart Rhythm Society AF guidelines. Guideline concordance for amiodarone was not considered applicable, since its use is not specifically contraindicated in the guidelines for reasons such as structural heart disease or renal function. We analyzed guideline-concordant AAD use by specific patient and hospital characteristics, and regional and temporal trends.

RESULTS

Among 21 921 patients from 123 sites, the median age was 69 years, 46% female and 51% had paroxysmal AF. The most commonly prescribed AAD was amiodarone (38%). Sotalol (23.2%) and dofetilide (19.2%) were each more commonly prescribed than either flecainide (9.8%) or propafenone (4.8%). Overall guideline-concordant AAD prescription at discharge was 84%. Guideline-concordant AAD use by drug was as follows: dofetilide 93%, sotalol 66%, flecainide 68%, propafenone 48%, and dronedarone 80%. There was variability in rate of guideline-concordant AAD use by hospital and geographic region.

CONCLUSIONS

Amiodarone remains the most commonly prescribed AAD for AF followed by sotalol and dofetilide. Rates of guideline-concordant AAD use were high, and there was significant variability by specific drugs, hospitals, and regions, highlighting opportunities for additional quality improvement.

Catheter ablation and healthcare utilization and cost among patients with paroxysmal versus persistent atrial fibrillation

Background

Ablation reduces atrial fibrillation (AF) burden and improves health-related quality of life. The relationship between ablation, healthcare utilization, and AF type (paroxysmal AF [PAF] vs persistent AF [PsAF]) remains unclear.

Objective

To compare changes in AF-related healthcare utilization and costs from preablation to postablation among patients with PAF and PsAF.

Methods

Patients (2794 PAF, 1909 PsAF) undergoing ablation (2016–2018) were identified using the Optum database. Outcomes included inpatient admissions, emergency department (ED) visits, office visits, cardioversion, and antiarrhythmic drug (AAD) use. Costs (2018 US$) and outcomes were compared for the year before/after ablation using the McNemar test and Wilcoxon signed rank test.

Results

Compared to PAF patients, PsAF patients were older (68.6 ± 9.0 years vs 67.4 ± 9.9 years, P < .0001), were less commonly female (36.3% vs 44.1%, P < .0001), and more commonly had a CHA₂DS₂-VASc ≥ 3(71.2% vs 62.7%, P < .0001). The 12-month postablation costs were lower for AF-specific inpatient admissions (PAF -28%, PsAF -33%), ED visits (PAF -76%, PsAF -70%), AAD prescription fills (PAF -25%, PsAF -7%), and cardioversions (PAF -59%, PsAF -55%) as compared to 12 months before ablation. Although these reductions were observed for both PAF and PsAF patients, absolute costs remained higher for PsAF. Total AF costs were higher during the 1 year after ablation vs before ablation (PAF: 11%, P < .0001; PsAF: 10%, P < .0001) owing to repeat ablation. However, in the 18-month follow-up analysis, postablation costs were overall reduced (PAF: 35%, P < .0001; PsAF: 34%, P < .0001), despite including costs from repeat ablation.

Conclusion

Significant reductions in healthcare utilization and costs were observed among PAF and PsAF patients undergoing ablation. These data suggest a strategy of earlier ablation may reduce long-term healthcare utilization and costs.

Healthcare utilization and cost in patients with atrial fibrillation and heart failure undergoing catheter ablation

Background

Catheter ablation is an effective treatment for patients with atrial fibrillation (AF) and heart failure (HF). However, little is known about how healthcare utilization and cost change after ablation in this population. We sought to determine healthcare utilization and cost patterns among patients with AF and HF undergoing ablation.

Methods

Using a large United States administrative database, we identified (n = 1568) treated with ablation with a primary and secondary diagnosis of AF and HF, respectively, were evaluated 1‐year pre‐ and postablation for outcomes including inpatient admissions (AF or HF), emergency department (ED) visits, cardioversions, length of stay (LOS), and cost. A secondary analysis was extended to 3‐years postablation.

Results

Reductions were observed in AF‐related admissions (64%), LOS (65%), cardioversions (52%), ED visits (51%, all values, p < .0001), and HF‐related admissions (22%, p = .01). There was a 40% reduction in inpatient admission cost ($4165 preablation to $2510 postablation, p < .0001). In a sensitivity analysis excluding repeat‐ablation patients, a greater reduction in overall AF management cost was observed compared to the full cohort (−43% vs. −2%). Comparing 1‐year pre‐ to 3‐years postablation, both total mean AF‐management cost ($850 per‐patient per‐month 1‐year pre‐ to $546 3‐years postablation, p < .0001) and AF‐related healthcare utilization was reduced.

Conclusions

Catheter ablation in patients with AF and HF resulted in significant reductions in healthcare utilization and cost through 3‐years of follow‐up. This reduction was observed regardless of whether repeat ablation was performed, reflecting the positive impact of ablation on longer term cost reduction.

Electromagnetic interference from left ventricular assist devices in patients with subcutaneous implantable cardioverter-defibrillators

INTRODUCTION

Interactions of left ventricular assist devices (LVADs) with transvenous implantable cardioverter-defibrillator systems (ICDs) have been widely reported. However, less is known regarding the impact of electromagnetic interference (EMI) from LVADs on subcutaneous ICD function.

METHODS AND RESULTS

A comprehensive literature search was performed on PubMed, Cochrane central registry, and Google Scholar using the search terms "subcutaneous implantable cardioverter-defibrillator and left ventricular assist devices," "electromagnetic interference, LVAD, and subcutaneous ICD," "EMI and S-ICD," and "inappropriate shocks, LVAD, and ICD." Demographic and programming data were extracted from the reports and authors as needed. A total of seven cases of EMI in LVAD patients with subcutaneous ICD (S-ICD) devices were found. In addition three previously unreported cases from our center were included. All cases involved either a heartware ventricular assist device or HeartMate III LVAD with a pre-existing S-ICD. In all patients, both the primary and secondary vectors had inappropriate sensing due to EMI. Three patients were reprogramed to the alternate vector with appropriate sensing. The S-ICD was either inactivated or replaced with a transvenous device in six patients. A single patient was left sensing in the alternate vector. There were no reports of inability to interrogate S-ICD systems in patients with LVADs.

CONCLUSION

The risk of inappropriate shocks from LVADs should be considered in pre-existing patients with S-ICD, particularly when the heartware ventricular assist device or HeartMate III LVAD device is present. Reprogramming of the sensing vector can occasionally avoid this issue but often the S-ICD needs to be inactivated.

Intracardiac echocardiography use and outcomes after catheter ablation of ventricular tachycardia

Aim: To compare outcomes among patients with implantable cardioverter defibrillator/cardiac resynchronization therapy-defibrillator undergoing outpatient ventricular tachycardia (VT) catheter ablation using intracardiac echocardiography (ICE) versus no ICE. Patients & methods: Patients were classified into ICE (n = 1143)/non-ICE (n = 1677) groups based on ICE procedure codes. Patients in each group were propensity matched on study covariates. Survival analyses were used to assess outcomes. To examine residual confounding, falsification outcomes were evaluated. Results: ICE patients had a 24% lower risk of all-cause readmissions, 24% lower risk of cardiovascular-related and 20% lower risk of VT-related readmissions compared with non-ICE patients. Falsification analyses for ICE use association were nonsignificant. Conclusion: Patients with implantable cardioverter defibrillator/cardiac resynchronization therapy-defibrillator undergoing VT ablation with ICE use had significantly lower likelihood of VT-related readmission.

Persistent Asthma Is Associated With Increased Risk for Incident Atrial Fibrillation in the MESA

BACKGROUND

Asthma and atrial fibrillation (AF) share an underlying inflammatory pathophysiology. We hypothesized that persistent asthmatics are at higher risk for developing AF and that this association would be attenuated by adjustment for baseline markers of systemic inflammation.

METHODS

The MESA (Multi-Ethnic Study of Atherosclerosis) is a prospective longitudinal study of adults free of cardiovascular disease at baseline. Presence of asthma was determined at exam 1. Persistent asthma was defined as asthma requiring use of controller medications. Intermittent asthma was defined as asthma without use of controller medications. Participants were followed for a median of 12.9 (interquartile range, 10-13.6) years for incident AF. Multivariable Cox regression models were used to assess associations of asthma subtype and AF.

RESULTS

The 6615 participants were a mean (SD) 62.0 (10.2) years old (47% male, 27% black, 12% Chinese, and 22% Hispanic). AF incidence rates were 0.11 (95% CI, 0.01-0.12) events/10 person-years for nonasthmatics, 0.11 (95% CI, 0.08-0.14) events/10 person-years for intermittent asthmatics, and 0.19 (95% CI, 0.120.49) events/10 person-years for persistent asthmatics (log-rank P=0.008). In risk-factor adjusted models, persistent asthmatics had a greater risk of incident AF (hazard ratio, 1.49 [95% CI, 1.03-2.14], P=0.03). IL (Interleukin)-6 (hazard ratio, 1.26 [95% CI, 1.13-1.42]), TNF (tumor necrosis factor)-α receptor 1 (hazard ratio, 1.09 [95% CI, 1.08-1.11]) and D-dimer (hazard ratio, 1.10 [95% CI, 1.02-1.20]) predicted incident AF, but the relationship between asthma and incident AF was not attenuated by adjustment for any inflammation marker (IL-6, CRP [C-reactive protein], TNF-α R1, D-dimer, and fibrinogen).

CONCLUSIONS

In a large multiethnic cohort with nearly 13 years follow-up, persistent asthma was associated with increased risk for incident AF. This association was not attenuated by adjustment for baseline inflammatory biomarkers.

Real-world outcomes of ventricular tachycardia catheter ablation with versus without intracardiac echocardiography

INTRODUCTION

By providing real-time monitoring of catheter-tissue interface and for complications, intracardiac echocardiography (ICE) during catheter ablation for ventricular tachycardia (VT) may improve outcomes. To test this hypothesis, we compared 12-month readmission rates (all-cause, cardiovascular [CV]-related, and VT-related), repeat ablation, and complications among patients with VT with structural heart disease undergoing ablation with versus without ICE.

METHODS AND RESULTS

Using the 2008-2017 IBM MarketScan Commercial and Medicare Supplemental databases, patients with a history of implantable cardioverter defibrillator/cardiac resynchronization therapy (ICD/CRT-D) who underwent VT ablation with and without ICE use were identified. Propensity matching was performed and regression analysis was used to compare outcomes. After matching, 1324 patients were identified (ICE: 662; non-ICE: 662). The rate of 12-month VT-related readmission (18.13% vs 22.51%; P < .05) and repeat VT ablation (14.35% vs 19.34%; P = .02) postindex discharge were lower among patients in the ICE group compared with the non-ICE group, with a 24% lower risk of 12-month VT-related readmission (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.58-0.99) and a 30% lower risk of repeat ablation (OR, 0.70; 95% CI, 0.52-0.93) vs non-ICE group. The 12-month all-cause (44.56% vs 43.20%; P = .62) and CV-related readmissions (35.20% vs 32.93%; P = 0.38) and complication rates were not significantly different between the two groups.

CONCLUSIONS

VT ablation using ICE was associated with a lower likelihood of 12-month VT-related readmission and repeat ablation compared with non-ICE patients.

Outcomes During Intended Fluoroscopy-free Ablation in Adults and Children

Electroanatomic mapping (EAM) systems facilitate the elimination of fluoroscopy during electrophysiologic (EP) studies and ablations. The rate and predictors of fluoroscopy requirements while attempting fluoroscopy-free (FF) ablations are unclear. This study aimed (1) to investigate the rates of fluoroscopic use and acute success in patients initially referred for FF ablation and (2) to identify procedural characteristics associated with fluoroscopic use in patients in whom FF ablation was initially planned (IFF). We performed a retrospective review of all patients who underwent IFF EP study or ablation between 2010 and 2013. Patient and procedural characteristics were compared between those with successful FF procedures and those who subsequently required fluoroscopy during their procedure. An FF EP study with or without ablation was performed in 124 patients during 138 procedures for either supraventricular or idiopathic ventricular arrhythmias. Of the 138 procedures, 105 of them were performed without fluoroscopy. In the remaining 33 cases, fluoroscopy was used for an average of 1.21 minutes ± 1.18 minutes. Acute procedural success was achieved in 97% of both FF and fluoroscopy procedures. The primary reason for fluoroscopy use was as a guide for transseptal puncture. There were no significant differences between FF and fluoroscopy procedures with respect to catheter placement time or complication rate. In conclusion, in this single-center study of IFF procedures, despite careful case selection for IFF ablation, 24% of IFF cases ultimately required minimal fluoroscopy. Fluoroscopy and FF procedures had similar rates of procedural success and complications. Additional large prospective studies are required to further investigate the safety and efficacy of FF ablations.

Impact of a novel protocol for atrial fibrillation management in outpatient gastrointestinal endoscopic procedures: a retrospective cohort study

BACKGROUND

Atrial fibrillation (AF) may result in procedure cancellations and emergency department (ED) referrals for patients presenting for outpatient GI endoscopic procedures. Such cancellations and referrals delay patient care and can lead to inefficient use of resources.

METHODS

All consecutive patients presenting in AF for a colonoscopy or upper endoscopy to the University of Wisconsin Digestive Health Center between October 2013 and September 2014 were defined as the pre-intervention group (Group 1). In 2015, a protocol was initiated for peri-procedural management of patients presenting in AF, new onset or previously known. All consecutive patients after initiation of the protocol from October 2015 to September 2016 were analyzed as the post intervention group (Group 2). Patients with heart failure, hypotension, or chest pain were excluded from the protocol.

RESULTS

One hundred nine and 141 patients were included in Groups 1 and Group 2, respectively. Following protocol initiation, patients were less likely to present to the ED (6.4% Group 1 vs. 1.4% Group 2, RR 0.22, p = 0.04). There was also a trend towards a reduction in procedure cancelations (5.5% Group 1 vs. 1.4% Group 2, RR 0.26, p = 0.08). All attempted procedures were completed and there were no complications in the intervention group.

CONCLUSIONS

Implementation of a standardized protocol for management of atrial fibrillation in patients presenting for outpatient gastrointestinal endoscopic procedures resulted in a significant decrease in emergency department visits with an additional trend toward decreased procedural cancellations without an increased risk of complications.

P-Wave Amplitude and PR Changes in Patients With Inappropriate Sinus Tachycardia: Findings Supportive of a Central Mechanism

BACKGROUND

The mechanism of inappropriate sinus tachycardia (IST) remains incompletely understood.

METHODS AND RESULTS

We prospectively compared 3 patient groups: 11 patients with IST (IST Group), 9 control patients administered isoproterenol (Isuprel Group), and 15 patients with cristae terminalis atrial tachycardia (AT Group). P-wave amplitude in lead II and PR interval were measured at a lower and higher heart rate (HR1 and HR2, respectively). P-wave amplitude increased significantly with the increase in HR in the IST Group (0.16±0.07 mV at HR1=97±12 beats per minute versus 0.21±0.08 mV at HR2=135±21 beats per minute, P=0.001). The average increase in P-wave amplitude in the IST Group was similar to the Isuprel Group (P=0.26). PR interval significantly shortened with the increases in HR in the IST Group (146±15 ms at HR1 versus 128±16 ms at HR2, P<0.001). A similar decrease in the PR interval was noted in the Isuprel Group (P=0.6). In contrast, patients in the atrial tachycardia Group experienced PR lengthening during atrial tachycardia when compared with baseline normal sinus rhythm (153±25 ms at HR1=78±17 beats per minute versus 179±29 ms at HR2=140±28 beats per minute, P<0.01).

CONCLUSIONS

We have shown that HR increases in patients with IST were associated with an increase in P-wave amplitude in lead II and PR shortening similar to what is seen in healthy controls following isoproterenol infusion. The increase in P-wave amplitude and absence of PR lengthening in IST support an extrinsic mechanism consistent with a state of sympatho-excitation with cephalic shift in sinus node activation and enhanced atrioventricular nodal conduction.

Machine Learning Algorithm Predicts Cardiac Resynchronization Therapy Outcomes: Lessons From the COMPANION Trial

BACKGROUND

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure patients with reduced left ventricular function and intraventricular conduction delay. However, individual outcomes vary significantly. This study sought to use a machine learning algorithm to develop a model to predict outcomes after CRT.

METHODS AND RESULTS

Models were developed with machine learning algorithms to predict all-cause mortality or heart failure hospitalization at 12 months post-CRT in the COMPANION trial (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure). The best performing model was developed with the random forest algorithm. The ability of this model to predict all-cause mortality or heart failure hospitalization and all-cause mortality alone was compared with discrimination obtained using a combination of bundle branch block morphology and QRS duration. In the 595 patients with CRT-defibrillator in the COMPANION trial, 105 deaths occurred (median follow-up, 15.7 months). The survival difference across subgroups differentiated by bundle branch block morphology and QRS duration did not reach significance (P=0.08). The random forest model produced quartiles of patients with an 8-fold difference in survival between those with the highest and lowest predicted probability for events (hazard ratio, 7.96; P<0.0001). The model also discriminated the risk of the composite end point of all-cause mortality or heart failure hospitalization better than subgroups based on bundle branch block morphology and QRS duration.

CONCLUSIONS

In the COMPANION trial, a machine learning algorithm produced a model that predicted clinical outcomes after CRT. Applied before device implant, this model may better differentiate outcomes over current clinical discriminators and improve shared decision-making with patients.

Concealed Accessory Pathways with a Single Ventricular and Two Discrete Atrial Insertion Sites

BACKGROUND

Atrioventricular reciprocating tachycardia (AVRT) utilizing a concealed accessory pathway is common. It is well appreciated that some patients may have multiple accessory pathways with separate atrial and ventricular insertion sites.

METHODS

We present three cases of AVRT utilizing concealed pathways with evidence that each utilizing a single ventricular insertion and two discrete atrial insertion sites.

RESULTS

In case one, two discrete atrial insertion sites were mapped in two separate procedures, and only during the second ablation was the Kent potential identified. Ablation of the Kent potential at this site remote from the two atrial insertion sites resulted in the termination of the retrograde conduction in both pathways. Case two presented with supraventricular tachycardia (SVT) with alternating eccentric atrial activation patterns without alteration in the tachycardia cycle length. The two distinct atrial insertion sites during orthodromic AVRT and ventricular pacing were targeted and each of the two atrial insertion sites were successfully mapped and ablated. In case three, retrograde decremental conduction utilizing both atrial insertion sites was identified prior to ablation. After mapping and ablation of the first discrete atrial insertion site, tachycardia persisted utilizing the second atrial insertion site. Only after ablation of the second atrial insertion site was SVT noninducible, and VA conduction was no longer present.

CONCLUSIONS

Concealed retrograde accessory pathways with discrete atrial insertion sites may have a common ventricular insertion site. Identification and ablation of the ventricular insertion site or the separate discrete atrial insertion sites result in successful treatment.

Comparison of Outcomes of Atrial Fibrillation in Patients With Reduced Versus Preserved Left Ventricular Ejection Fraction

Patients with newly diagnosed atrial fibrillation (AF) and a rapid ventricular response may present with a reduced left ventricular ejection fraction (LVEF). We compared long-term outcomes of these patients with those with preserved LVEF. This retrospective cohort study included 385 consecutive adults with newly diagnosed AF with rapid ventricular response, presenting to a single medical center from January 2006 to August 2014. Patients with a history of coronary artery disease or known cardiomyopathy were excluded. Patients were divided into 2 groups: those with an LVEF ≤55% (n = 147) (REF) and those with an LVEF >55% (n = 238) (PEF). Echocardiographic parameters, all-cause mortality, cardiovascular mortality, and stroke rates were compared between both groups at baseline and a minimum of 1-year follow-up. The mean age of patients was 68 ± 1.1 in REF versus 60 ± 7.4 in PEF (p = 0.39). There were no significant differences in baseline co-morbidities between both groups. The mean LVEF during the index admission was 47.7 ± 0.8% in REF versus 65.5 ± 0.3% in PEF. The average duration of follow-up was 2.8 years. Patients with REF had higher all-cause mortality (32.7% REF vs 20.6% PEF, odds ratio 2.17, p = 0.008). Patients with REF had higher rates of subsequent clinic or ER visits for AF with a rapid ventricular response (32% REF vs 22.7% PEF, p = 0.044). The incidence of stroke was similar between both groups (17% REF vs 18.9% PEF, p = 0.639). Of the patients with REF, 64% had subsequent EF recovery and had similar outcomes compared with patients with PEF. Baseline LV end-diastolic diameter predicted all-cause mortality (odds ratio 1.14, p = 0.003) in the REF group. None of the echocardiographic parameters predicted EF recovery. In conclusion, in patients with new AF with rapid ventricular response, REF was associated with higher long-term all-cause mortality. Those with subsequent LVEF recovery after medical therapy appear to have a similar prognosis compared with those with initial PEF.

Bidirectional ventricular tachycardia in cardiac sarcoidosis

A 73-year-old man with history of pulmonary sarcoidosis was found to have runs of non-sustained bidirectional ventricular tachycardia (BVT) with two different QRS morphologies on a Holter monitor. Cardiac magnetic resonance delayed gadolinium imaging revealed a region of patchy mid-myocardial enhancement within the left ventricular basal inferolateral myocardium. An 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed increased uptake in the same area, consistent with active sarcoid, with no septal involvement. Follow-up FDG-PET one year later showed disease progression with new septal involvement. Cardiac sarcoidosis, characterized by myocardial inflammation and interstitial fibrosis that can lead to conduction system disturbance and macro re-entrant arrhythmias, should be considered in differential diagnosis of BVT. BVT may indicate septal involvement with sarcoidosis before the lesions are large enough to be detected radiologically.

Restoring Sinus Rhythm Improves Baroreflex Function in Patients With Persistent Atrial Fibrillation

Background

Studies have suggested that patients with atrial fibrillation (AF) have impairment in the baroreflex. It is not clear whether these findings are the result of the associated comorbid conditions or the arrhythmia itself. We hypothesized that AF is associated with impairment in baroreflex function and that the arrhythmia itself is a contributing factor.

Methods and Results

Twenty‐four patients with persistent AF referred for cardioversion were enrolled. A second group of patients with no history of AF matched for age and left ventricular ejection fraction was identified and served as the control group. In the AF group, baroreflex gain (BRG) was measured on the day of cardioversion (Day 1) and again at 30 days post‐cardioversion (Day 30) in patients who remained in sinus rhythm (SR). The clinical characteristics of patients with AF were not different than those of the control group. The mean BRG in the AF group on Day 1 was significantly lower than the mean BRG of the control group (5.2±3.6 versus 10.8±5.5 ms/mm Hg, P<0.05). Ten patients experienced AF recurrence before the 30‐day follow‐up and 14 patients remained in SR. In the group that remained in SR, BRG increased from 4.1±3.7 ms/mm Hg on Day 1 to 7.0±6.0 ms/mm Hg on Day 30 (P<0.01).

Conclusion

We have shown that AF is associated with impairment of the baroreflex and that restoration of SR improves BRG. Our data suggest that AF might be a contributing factor to the observed impairment in BRG and that restoring SR might help improve baroreflex function.

Antiarrhythmic drugs in pregnancy

The risk of arrhythmia development or recurrence is increased during pregnancy. For those arrhythmias that are unresponsive to conservative therapy, such as vagal maneuvers or life style interventions, or that present a higher risk to the mother or fetus, medical therapy may be necessary. In each case, the patient and provider must carefully consider the risks and benefits of a particular therapy. This requires an understanding of the data regarding the safety and efficacy of any particular drug, which in some cases may be extensive and in others quite limited. Fortunately, options exist for the treatment of arrhythmias during pregnancy.