Economic impact of contact force sensing in catheter ablation for atrial fibrillation.

AIMS: The TactiCath Contact Force Ablation Catheter Study for Atrial Fibrillation (TOCCASTAR) clinical trial compared clinical outcomes using a contact force (CF) sensing ablation catheter (TactiCath) with a catheter that lacked CF measurement. This analysis links recorded events in the TOCCASTAR study and a large claims database, IBM MarketScan®, to determine the economic impact of using CF sensing during atrial fibrillation (AF) ablation. METHODS AND RESULTS: Clinical events including repeat ablation, use of antiarrhythmic drugs, hospitalization, perforation, pericarditis, pneumothorax, pulmonary edema, pulmonary vein stenosis, tamponade, and vascular access complications were adjudicated in the year after ablation. CF was characterized as optimal if greater than or equal to 90% lesion was performed with greater than or equal to 10 g of CF. A probabilistic 1:1 linkage was created for subjects in MarketScan® with the same events in the year after ablation, and the cost was evaluated over 10 000 iterations. Of the 279 subjects in TOCCASTAR, 145 were ablated using CF (57% with optimal CF), and 134 were ablated without CF. In the MarketScan® cohort, 9811 subjects who underwent AF ablation were used to determine events and costs. For subjects ablated with optimal CF, total cost was $19 271 ± 3705 in the year after ablation. For ablation lacking CF measurement, cost was $22 673 ± 3079 (difference of $3402, P < .001). In 73% of simulations, optimal CF was associated with lower cost in the year after ablation. CONCLUSION: Compared to ablation without CF, there was a decrease in healthcare cost of $3402 per subject in the first year after the procedure when optimal CF was used.

Novel automated point collection software facilitates rapid, high-density electroanatomical mapping with multiple catheter types.

INTRODUCTION: Manual, point-by-point electroanatomical mapping requires the operator to directly evaluate each point during map construction. Consequently, point collection can be a slow process. An automated 3D mapping system was developed with the goal of improving key mapping metrics, including map completion time and point density. METHODS: Automated 3D mapping software that includes morphology and cycle length discrimination functions for surface and intracardiac electrograms was developed. In five swine, electroanatomical maps (EAMs) of all four cardiac chambers were generated in sinus rhythm. Four catheters were used: two different four-pole ablation catheters, a 20-pole circular catheter, and a 64-pole basket catheter. Automated and manual 3D mapping were compared for 12 different catheter-chamber combinations (paired sets of 10 maps for most combinations, for a total of 156 maps). RESULTS: Automated 3D mapping produced more than twofold increase in the number of points per map, as compared with manual 3D mapping (P ≤0.007 for all catheter-chamber combinations tested). Automated 3D mapping also reduced map completion time by an average of 29% (P < 0.05 for all comparisons). The amount of manual editing of the maps acquired with automated 3D mapping was minimal. CONCLUSION: Automated 3D mapping with the open-platform mapping software described in this study is significantly faster than manual, point-by-point 3D mapping. This resulted in shorter mapping time and higher point density. The morphology discrimination functions effectively excluded ectopic beats during mapping in sinus rhythm and allowed for rapid mapping of intermittent ventricular ectopic beats.

Randomized, Controlled Trial of the Safety and Effectiveness of a Contact Force-Sensing Irrigated Catheter for Ablation of Paroxysmal Atrial Fibrillation: Results of the TactiCath Contact Force Ablation Catheter Study for Atrial Fibrillation (TOCCASTAR) Study.

BACKGROUND: Contact force (CF) is a major determinant of lesion size and transmurality and has the potential to improve efficacy of atrial fibrillation ablation. This study sought to evaluate the safety and effectiveness of a novel irrigated radiofrequency ablation catheter that measures real-time CF in the treatment of patients with paroxysmal atrial fibrillation. METHODS AND RESULTS: A total of 300 patients with symptomatic, drug-refractory, paroxysmal atrial fibrillation were enrolled in a prospective, multicenter, randomized, controlled trial and randomized to radiofrequency ablation with either a novel CF-sensing catheter or a non-CF catheter (control). The primary effectiveness end point consisted of acute electrical isolation of all pulmonary veins and freedom from recurrent symptomatic atrial arrhythmia off all antiarrhythmic drugs at 12 months. The primary safety end point included device-related serious adverse events. End points were powered to show noninferiority. All pulmonary veins were isolated in both groups. Effectiveness was achieved in 67.8% and 69.4% of subjects in the CF and control arms, respectively (absolute difference, -1.6%; lower limit of 1-sided 95% confidence interval, -10.7%; P=0.0073 for noninferiority). When the CF arm was stratified into optimal CF (≥90% ablations with ≥10 g) and nonoptimal CF groups, effectiveness was achieved in 75.9% versus 58.1%, respectively (P=0.018). The primary safety end point occurred in 1.97% and 1.40% of CF patients and control subjects, respectively (absolute difference, 0.57%; upper limit of 1-sided 95% confidence interval, 3.61%; P=0.0004 for noninferiority). CONCLUSIONS: The CF ablation catheter met the primary safety and effectiveness end points. Additionally, optimal CF was associated with improved effectiveness. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT01278953.

Lesion Size and Safety Comparison Between the Novel Flex Tip on the FlexAbility Ablation Catheter and the Solid Tips on the ThermoCool and ThermoCool SF Ablation Catheters.

INTRODUCTION: Next-generation catheters have been developed to reduce irrigation volume and preserve power delivery. A novel design uses a flexible tip (FlexAbility™ catheter) that directs flow to the contact surface. Because of recent safety issues with new catheters, we undertook a study in a canine heart with 3 irrigated catheters to compare efficacy and safety. METHODS: Endocardial ablation was performed by 2 independent operators in 12 anesthetized canines with the FlexAbility (St. Jude Medical), ThermoCool™ (Biosense Webster), and ThermoCool™ SF (Biosense Webster) catheters. Endocardial RF lesions were delivered with each catheter in all 4 chambers of each animal for 52 ± 16 seconds. Each chamber was randomized to receive ablation from one catheter with recording of safety events. Cardiac pathology was performed with triphenyl tetrazolium chloride stain. RESULTS: Average lesion dimensions were not significantly different between the 3 catheters. FlexAbility™ demonstrated a lower risk of steam pops relative to ThermoCool SF (P-value = 0.013) despite equal mean power and radiofrequency time. High-temperature generator shutdowns were observed with FlexAbility™ but not with either ThermoCool catheter. High-temperature shutdowns were associated with larger average impedance drops (28.5 ohms vs. 19 ohms) without compromising lesion size. CONCLUSIONS: The FlexAbility™ tip is safe and effective with no significant difference in lesion sizes compared to both standard ThermoCool and ThermoCool SF. FlexAbility™ has a significantly lower risk of steam pops compared to ThermoCool SF in a beating heart as defined predominantly by an abrupt rise of impedance.

Radiofrequency ablation of drug refractory ventricular tachycardia related to cocaine use: a feasibility, safety, and efficacy study.

BACKGROUND: Cocaine use is a known but rare cause of cardiac arrhythmias. Ventricular arrhythmias related to cocaine may not respond to antiarrhythmic drugs and may need treatment with radiofrequency ablation. OBJECTIVES: We describe the clinical and electrophysiological characteristics of cocaine-related ventricular tachycardia (VT) from a multicenter registry. METHODS: Subjects presenting with VT related to cocaine use and being considered for radiofrequency ablation have been included in the study. Patients who were refractory to maximal medical therapy underwent radiofrequency ablation of the VT. Clinical, procedural variables, efficacy, and safety outcomes were assessed. RESULTS: A total of 14 subjects met study criteria (age 44 ± 13, range 18- to 68-year-old with 79% male, 71% Caucasian). MRI showed evidence of scar only in 43% of patients (6/14). The mechanism of VT was focal in 50% (n = 7) and scar related reentry in 50% (n = 7) based on 3D mapping. The mean VT cycle length was 429 ± 96 milliseconds. The site of origin was epicardial in 16% (3/18) of VTs. Most clinical VTs were hemodynamically stable (75%). Mean ejection fraction at the time of admission was 44 ± 14%. Duration of procedure was 289 ± 50 minutes. One subject developed pericardial tamponade requiring drainage. At 18 ± 11 months follow-up, freedom from arrhythmia was seen in 86% (1 case lost to follow-up and 2 died). CONCLUSION: Radiofrequency ablation is not only feasible but also safe and effective in patients who have drug refractory VT related to chronic cocaine use.

Catheter ablation of ventricular arrhythmias: targets, tactics, and tools.

PURPOSE OF REVIEW: Drug-refractory ventricular tachycardia in the setting of structural heart disease results in frequent implantable cardioverter defibrillator therapies and an increased risk of heart failure. Management requires catheter ablation procedures for effective suppression of the arrhythmia. RECENT FINDINGS: Imaging and electroanatomic mapping technologies provide new insights into the myocardial structural abnormalities responsible for ventricular tachycardia. Integration of imaging data with three-dimensional mapping systems coupled with improved targeting of abnormal electrical signals may improve the ablation outcomes. New ablation tools show promise for the effective ablation of previously unreachable myocardial ventricular tachycardia circuits. SUMMARY: Catheter ablation procedures have evolved over the last 2 decades. Improved technology may contribute to more widespread utilization of catheter ablation in the future.

Comparison of electroanatomical mapping systems: accuracy in left atrial mapping.

BACKGROUND: Current 3D mapping systems have difficulty rendering complex cardiac structures. Different electroanatomical mapping software has been recently developed which uses a mathematical algorithm to improve interpolation between mapped points and delineation of closely spaced structures. This study tested the feasibility and accuracy of this software in comparison to traditional software. METHODS: In vivo 3D impedance-based mapping using a multielectrode catheter with a single geometry point cloud was performed in the left atria and pulmonary veins (PV) in 23 patients undergoing catheter ablation for atrial fibrillation. The maps were analyzed with traditional (NavX, St. Jude Medical, Minnetonka, MN, USA), either with or without multichamber mapping versus St. Jude OneModel™ software and dimensions of cardiac chambers in human studies were compared to preprocedural computed tomographic (CT) or magnetic resonance (MR) scans to determine the relative accuracy of the maps. RESULTS: Maps created by the OneModel software provided greater detail of complex cardiac structures compared to traditional software. Comparison of the left atrial/pulmonary vein electroanatomical maps with the CT and MR scans as reference standard demonstrated significantly less error in measurement of all PV ostial long- and short-axis dimensions, inter-PV distance, and ridge width (left PV to left atrial appendage) with the OneModel versus traditional software (P < 0.001 for all dimensions measured). CONCLUSIONS: The OneModel software produces maps that are more accurate in rendering complex cardiac structures compared to traditional software.

Safe and effective delivery of high-power, short-duration radiofrequency ablation lesions with a flexible-tip ablation catheter.

Background: High-power, short-duration (HPSD) radiofrequency ablation (RFA) may reduce ablation time. Concerns that catheter-mounted thermocouples (TCs) can underestimate tissue temperature, resulting in elevated risk of steam pop formation, potentially limit widespread adoption of HPSD ablation. Objective: The purpose of this study was to compare the safety and efficacy of HPSD and low-power, long-duration (LPLD) RFA in the context of pulmonary vein isolation (PVI). Methods: An open-irrigated ablation catheter with a contact force sensor and a flexible-tip electrode containing a TC at its distal end (TactiFlexTM Ablation Catheter, Sensor EnabledTM, Abbott) was used to isolate the left pulmonary veins (PVs) in 12 canines with HPSD RFA (50 W for 10 seconds) and LPLD RFA (30 W for a maximum of 60 seconds). PVI was assessed at 30 minutes and 28 ± 3 days postablation. Computed tomographic scans were performed to assess PV stenosis after RFA. Lesions were evaluated with histopathology. Results: A total of 545 ablations were delivered: 252 with LPLD (0 steam pops) and 293 with HPSD RFA (2 steam pops) (P = .501). Ablation time required to achieve PVI was >3-fold shorter for HPSD than for LPLD RFA (P = .001). All 24 PVs were isolated 30 minutes after ablation, with 12/12 LPLD-ablated and 11/12 HPSD-ablated PVs still isolated at follow-up. Histopathology revealed transmural ablations for HPSD and LPLD RFA. No major adverse events occurred. Conclusion: An investigational ablation catheter effectively delivered RFA lesions. Ablation time required to achieve PVI with HPSD with this catheter was >3-fold shorter than with LPLD RFA.

The role of percutaneous left ventricular assist devices during ventricular tachycardia ablation.

Ventricular tachycardia (VT) is a common but serious arrhythmia that significantly adds to the morbidity and mortality of patients with structural heart disease. Percutaneous catheter ablation has evolved to be standard therapy to prevent recurrent implantable cardioverter defibrillator shocks from VT in patients on antiarrhythmia medications. Procedural outcomes in patients with structural heart disease are often limited by haemodynamically unstable VT. Although substrate- and pace-mapping techniques have become increasingly popular for VT ablation, these approaches can often times may not address inducible clinical and non-clinical VTs. Activation and entrainment mapping can help the operator target VT exit sites in a precise fashion minimizing the amount of radiofrequency ablation needed for a successful ablation. An evolving alternative strategy that allows induction and mapping of VT in the setting of severe cardiomyopathy and haemodynamic instability is through maintaining perfusion with a percutaneous ventricular assist device (pVAD). This review will discuss these pVAD technologies, distinguish technical applications of use, highlight the published clinical experience, provide a clinical approach for support device selection, and discuss use of these technologies with current mapping and navigational systems.

Efficacy and safety of ventricular tachycardia ablation with mechanical circulatory support compared with substrate-based ablation techniques.

AIMS: Catheter ablation of ventricular tachycardia (VT) can be limited by haemodynamic instability. In these cases, substrate-based ablation is typically performed. An alternative is to perform activation and entrainment mapping during VT supported by a percutaneous left ventricular assist device (pVAD). We sought to compare the complication and success rates of pVAD-assisted VT ablation with scar-based techniques. METHODS AND RESULTS: Thirteen consecutive patients with haemodynamically unstable VT underwent pVAD-assisted ablation (pVAD group) and were retrospectively compared with 18-matched patients undergoing a substrate-based VT ablation (non-pVAD group). There was no significant difference in age or ejection fraction between the groups although pVAD patients tended to have more shocks in the preceding months. Procedure times were longer for the pVAD group. The number of monomorphic VTs induced was greater in the pVAD group (3.2 vs. 1.6, P= 0.04); however, after ablation, there was no difference in inducibility between the pVAD and non-pVAD group (10 of 13 vs. 12 of 18; 77 vs. 67%, P = 0.69). There was no difference in acute complications including stroke or death. At 9 ± 3 months, 1-year freedom from implantable cardioverter-defibrillator (ICD) shocks/therapies for sustained VT were similar (P= 0.96). In multivariable analysis, the absence of atrial fibrillation (hazard ratio=0.15, P= 0.04) was associated with a lower incidence of ICD shocks. CONCLUSIONS: In high-risk patients, pVAD-assisted VT ablation guided by activation and entrainment mapping is a feasible alternative to substrate mapping and allows outcomes comparable to substrate mapping.

Emerging role of artificial intelligence in cardiac electrophysiology.

Artificial intelligence (AI) and machine learning (ML) have significantly impacted the field of cardiovascular medicine, especially cardiac electrophysiology (EP), on multiple fronts. The goal of this review is to familiarize readers with the field of AI and ML and their emerging role in EP. The current review is divided into 3 sections. In the first section, we discuss the definitions and basics of AI, ML, and big data. In the second section, we discuss their application to EP in the context of detection, prediction, and management of arrhythmias. Finally, we discuss the regulatory issues, challenges, and future directions of AI in EP.

Treatment of a malpositioned transcutaneous ventricular pacing lead in the left ventricle via direct aortic puncture.

An 81-year-old woman with progressive cough was hospitalized 2 weeks following transcutaneous pacemaker implantation. Imaging revealed an absent brachiocephalic vein and aberrant course of a ventricular lead into the aorta with implantation into the left ventricle. We describe the unusual anatomic course, diagnosis, and surgical extraction of a malpositioned pacer lead.

Incidence, risk factors, and consequences of new-onset atrial fibrillation following epicardial ablation for ventricular tachycardia.

INTRODUCTION: We sought to determine the incidence, predictors, and consequences of new-onset atrial fibrillation (AF) following epicardial ventricular tachycardia (VT) ablation. METHODS AND RESULTS: A total of 41 patients with no prior history of AF underwent epicardial VT ablation via a percutaneous subxiphoid approach. All patients were monitored continuously for 3 days following ablation and then via implantable cardiac defibrillator (ICD) or Holter monitoring. Mean age was 70.0 ± 11.3 years and mean ejection fraction was 30.3 ± 16.6%. In seven (17%) patients, the right ventricle (RV) was punctured during access with subsequent needle withdrawal without requiring surgical repair. Thirty patients (73%) were treated with amiodarone following ablation. Post-ablation, eight (19.5%) patients had documented new-onset AF within 7 days. All AF patients had clinical symptoms of pericarditis. One patient with AF was maintained on amiodarone post-procedure. Complications of AF included three patients who received inappropriate ICD shocks and one patient who developed a large, left atrial appendage clot. Acutely, all patients responded to short-term medical therapy or electrical cardioversion. At 18.0 ± 9.0 months of follow-up, no patient had recurrence of AF, and all were off antiarrhythmic drugs. One patient had typical atrial flutter requiring catheter ablation. Risk factors for AF included lack of amiodarone immediately after ablation (12.5 vs. 87.9%, P < 0.001), RV puncture (50.0 vs. 9.1%, P = 0.02), and epicardial ablation time >10 min (62.5 vs. 3.0%, P < 0.001). CONCLUSIONS: Atrial fibrillation after epicardial ablation is common and can lead to ICD shocks and atrial thrombus formation. Short-term antiarrhythmic drug therapy and ICD reprogramming should be considered after epicardial VT ablation.

Sonication of explanted cardiac rhythm management devices for the diagnosis of pocket infections and asymptomatic bacterial colonization.

BACKGROUND: Correct diagnosis of the causative organism is critical for the treatment of pacemaker and defibrillator pocket infections. No gold standard for this exists, although swab and tissue cultures are frequently used. The purpose of this study was to determine the value of ultrasonication of explanted generators in the diagnosis of pocket infections and asymptomatic bacterial colonization. METHODS: Samples were prospectively collected during pacemaker and defibrillator generator extractions for elective replacements, upgrades, or pocket infections. The devices were placed in an ultrasonicator for 5 minutes and the fluid sent for culture, along with swab and tissue cultures. RESULTS: Eighty-two patients with pacemakers (n = 46) or defibrillators (n = 36) underwent generator explantation, 66 of these for elective reasons and 16 for pocket infection. In patients with pocket infection, 15 (94%) received a definitive bacterial diagnosis using a combination of all three-culture modalities. Cultures were positive in 15 sonicated fluid, 13 tissue, and 11 swab samples, with Staphylococcus aureus and other skin flora commonly seen. In asymptomatic patients, 14 (21%) had positive cultures. Cultures were positive in 11 sonicated fluid, eight tissue, and two swab samples. Skin flora was commonly seen, but three of the sonicated fluid cultures grew gram-negative rods. No patients with asymptomatic colonization developed clinical infection during the follow-up period. CONCLUSIONS: Ultrasonication is an inexpensive and simple technique that improves the bacteriologic diagnosis of device pocket infections. It also identifies a significant proportion of patients with asymptomatic colonization, although this is not a marker of future pocket infection.

Ranolazine reduces ventricular tachycardia burden and ICD shocks in patients with drug-refractory ICD shocks.

BACKGROUND: There are limited options for patients who present with antiarrhythmic-drug (AAD)-refractory ventricular tachycardia (VT) with recurrent implantable cardioverter defibrillator (ICD) shocks. Ranolazine is a drug that exerts antianginal and antiischemic effects and also acts as an antiarrhythmic in isolation and in combination with other class III medications. Ranolazine may be an option for recurrent AAD-refractory ICD shocks secondary to VT, but its efficacy, outcomes, and tolerance are unknown. METHODS AND RESULTS: Twelve patients (age 65 ± 9.7 years) were treated with ranolazine. Eleven (92%) were male, and 10 (83%) had ischemic heart disease with an average ejection fraction of 0.34 ± 0.13. All patients were on a class III AAD (11 amiodarone, one sotalol), with six (50%) receiving mexilitene or lidocaine. Five patients had a prior ablation and two were referred for a VT ablation at the index presentation. The QRS increased nonsignificantly from 128 ± 31 ms to 133 ± 31 ms, and the QTc increased nonsignificantly from 486 ± 32 ms to 495 ± 31 ms after ranolazine initiation. Over a follow-up of 6 ± 6 months, 11 (92%) patients had a significant reduction in VT and no ICD shocks were observed. VT ablation was not required in those referred. In two patients, gastrointestinal side effects limited long-term use. Of these two patients, one died due to progressive heart failure. In one patient, severe hypoglycemia limited dosing to 500 mg daily, but this was sufficient for VT control. CONCLUSION: Ranolazine proved effective in reducing VT burden and ICD shocks in patients with AAD-refractory VT. Ranolazine should be further tested for this indication and considered for clinical application when other options have proven ineffective.

Image integration using intracardiac ultrasound and 3D reconstruction for scar mapping and ablation of ventricular tachycardia.

BACKGROUND: Ablation of ventricular tachycardia (VT) reduces implantable cardioverter defibrillator shocks. Intracardiac ultrasound (ICE) can visualize and quantify the function of all left ventricular wall segments. We thus hypothesized that ICE could identify scar tissue and provide a guide to facilitate substrate-guided VT ablation. METHODS: Eighteen patients underwent VT ablation with real time ICE mapping from the right atrium and ventricle with online 3D-image reconstruction of scar segments. The left ventricle was also scar mapped by traditional electroanatomic mapping (CARTO) for comparison. Images from these 2 scar mapping techniques were compared to each other as well as to a preprocedure transthoracic echocardiogram. RESULTS: The average age was 65 +/- 12 years and 12 (67%) were male (15 [83%] had ischemic cardiomyopathy). Two patients (12%) had recurrence of their clinical VT (1 remained on an antiarrhythmic medication, the other had a repeat ablation) over a follow-up of 127 +/- 33 days. No periprocedural or long-term adverse events occurred. A total of 248 wall segments were analyzed. All 3 modalities were concordant in scar identification in 193 (78%) segments. The ICE segments correlated with the electroanatomic map in 213 (86%) segments versus 198 (80%), which correlated with transthoracic echocardiography and electroanatomic mapping (P = 0.046). Specifically, the ICE wall motion scores were closer to the electroanatomic mapping in the basal segments and showed a higher accuracy in ischemic heart disease. CONCLUSION: These data demonstrate that real time ICE images provide accurate chamber geometries and scar boundaries of the left ventricle. These scar borders were more accurate than transthoracic echocardiography and illustrate the feasibility of ICE for substrate-based ablation for VT.

Is paroxysmal supraventricular tachycardia truly benign? Insightful association between PSVT and stroke from a National Inpatient Database Study.

BACKGROUND: Atrial fibrillation and flutter are well-known causes of stroke. Whether other atrial arrhythmias categorized as paroxysmal supraventricular tachycardia (PSVT) are associated with stroke is less clear. We aimed to evaluate the association of PSVT with ischemic and embolic stroke and its impact on short-term outcomes in hospitalized stroke patients. METHODS: National Inpatient Sample database of the USA was used to assess the association of PSVT with ischemic stroke. Atrial fibrillation and flutter were excluded to minimize the confounding effects. The association of PSVT with stroke was evaluated using univariate and multivariate analysis. Subgroup analyses by gender, age, and stroke type were also performed. RESULTS: PSVT was associated with increased odds of overall ischemic stroke in univariate [OR 1.18 (95% CI 1.09-1.27) p < 0.001] analysis. No such association was observed in multivariate analysis (OR 1.06 (95% CI 0.98-1.14) p = 0.1) or with subgroup analysis by gender and age. However, PSVT was associated with embolic stroke in both univariate (OR 2.01 (95%CI 1.67-2.43, p < 0.001) and multivariate analysis (OR 1.7 (95%CI 1.4-2.14) p < 0.001) as well as in subgroup analyses by gender and age. Furthermore, the presence of PSVT was associated with increased mortality in embolic stroke (OR 4.11, CI 2.29 to 7.39, p < 0.001) and increased total hospital cost and length of hospital stay in all stroke types. CONCLUSIONS: PSVT is independently associated with higher prevalence of embolic stroke but not with overall ischemic stroke. Patients with embolic stroke in the presence of PSVT have worse in-hospital outcomes with increased mortality.

Temporal relationships between esophageal injury type and progression in patients undergoing atrial fibrillation catheter ablation.

BACKGROUND: Currently, little is known about the onset, natural progression, and management of esophageal injuries after atrial fibrillation (AF) ablation. OBJECTIVES: We sought to provide a systematic review on esophageal injury after AF ablation and identify temporal relationships between various types of esophageal lesions, their progression, and clinical outcomes. METHODS: A comprehensive search of PubMed and Web of Science was conducted until September 21, 2017. All AF ablation patients who underwent upper gastrointestinal endoscopy within 1 week of the procedure were included. Patients with esophageal lesions were classified into 3 types by using our novel Kansas City classification: type 1: erythema; type 2a: superficial ulcers; type 2b: deep ulcers; type 3a: perforation without communication with the atria; and type 3b: perforation with atrioesophageal fistula. RESULTS: Thirty studies met our inclusion criteria. Of the 4473 patients, 3921 underwent upper gastrointestinal evaluation. The overall incidence of esophageal injuries was 15% (570). There were 206 type 1 lesions (36%), 222 type 2a lesions (39%), and 142 type 2b lesions (25%). Six of 142 type 2b lesions (4.2%) progressed further to type 3, of which, 5 were type 3a and 1 was type 3b. All type 1 and type 2a and most type 2b lesions resolved with conservative management. One type 3a and 1 type 3b lesions were fatal. CONCLUSION: Based on our classification, all type 1 and most type 2 lesions resolved with conservative management. A small percentage (4.2% [6 of 142]) of type 2b lesions progressed to perforation and/or fistula formation, and these patients need to be followed closely.

Characterization of the mitral isthmus for atrial fibrillation ablation using intracardiac ultrasound from within the coronary sinus.

BACKGROUND: Atrial fibrillation (AF) ablation involving the mitral isthmus and/or the coronary sinus (CS) may result in circumflex artery (Cx) or other collateral structure damage. OBJECTIVE: The purpose of this study was to investigate the feasibility of intracardiac echocardiographic (ICE) imaging from within the CS to characterize mitral isthmus anatomy and guide ablation. METHODS: A 9-Fr sheath was introduced into the CS of 30 patients before AF ablation. A 9-Fr rotational ICE catheter was then advanced within the sheath to the distal CS adjacent to the lateral left atrial (LA) wall. Serial cross-sectional images to document the relations of the LA, Cx, CS, esophagus, and pericardium were obtained at multiple points within the CS during a pullback to the CS ostium. RESULTS: The Cx was identified in 62/150 positions in 25/30 patients. The median (range) of the LA-Cx distance was 3.3 mm (0.7-19.6 mm), and the median CS-Cx distance was 2.0 mm (0.4-9.7 mm). The esophagus was seen in 36/150 positions in 17/30 patients. The median CS-esophagus distance was 4.0 mm (1.4-16.2 mm). The proximity of the Cx and esophagus to the LA and CS varied considerably. The median CS-mitral annulus distance was 11.9 mm (4.1-21.6 mm). After CS cannulation, the ICE imaging took 5 +/- 2 minutes and required 120 +/- 60 seconds of fluoroscopy. CONCLUSIONS: Mitral isthmus anatomy can be accurately characterized by rotational ICE imaging from within the CS. There is great variability in the location and proximity of the Cx, CS, esophagus, and pericardium to the LA. Real-time identification of these structures could help to plan ablation strategies and potentially reduce complications.

Stroke and Cardiovascular Events After Ablation or Antiarrhythmic Drugs for Treatment of Patients With Atrial Fibrillation.

Catheter ablation and antiarrhythmic drugs (AADs) are the most common rhythm-control strategies for atrial fibrillation (AF). Data comparing the rate of stroke and cardiovascular events between the treatment strategies are limited. Therefore, this observational study uses claims data to compare rate of cardiovascular hospitalization and stroke for patients with AF treated with ablation or AADs. Patients in the MarketScan dataset with AF between January 2010 and December 2014 were categorized in the ablation group if an atrial catheter ablation was performed, or in the AAD group if a relevant AAD was prescribed for AF but no ablation was performed. One year of history was required, and the index event was selected as the most recent ablation or AAD prescription closest to January 1, 2013. A 2:1 propensity score match was performed for age, gender, co-morbidities, and total medical cost in the year before index event. Outcomes included thromboembolic event (ischemic stroke, transient ischemic attack, or systemic embolism) and all cardiovascular hospitalizations. Of the 164,639 patients in the AAD group, 29,456 were matched to the 14,728 ablation patients. There were no significant differences in age (64 ± 10 in both groups), gender (58% male), or CHA2DS2-VASc score (3.2 ± 1.3). Risk of hospitalization with primary diagnosis of thromboembolic event was 41% greater in the AADs group (p < 0.001), and cardiovascular hospitalizations were 13% more likely (p < 0.001). In conclusion, patients treated with catheter ablation of AF have lower risk of thromboembolic events and cardiovascular hospitalizations than a matched cohort of patients managed with AADs.