Acute post-procedural inducibility is a poor predictor of clinical outcomes in high-risk patients (PAINESD > 17) undergoing scar-related ventricular tachycardia ablation.

AIMS: Ventricular tachycardia (VT) non-inducibility in response to programmed ventricular stimulation (PVS) is a widely used procedural endpoint for VT ablation despite inconclusive evidence with respect to clinical outcomes in high-risk patients. The aim is to determine the utility of acute post-ablation VT inducibility as a predictor of VT recurrence, mortality, or mortality equivalent in high-risk patients. METHODS AND RESULTS: We conducted a retrospective analysis of high-risk patients (defined as PAINESD > 17) who underwent scar-related VT ablation at our institution between July 2010 and July 2022. Patients' response to PVS (post-procedure) was categorized into three groups: Group A, no clinical VT or VT with cycle length > 240 ms inducible; Group B, only non-clinical VT with cycle length > 240 ms induced; and Group C, all other outcomes (including cases where no PVS was performed). The combined primary endpoint included death, durable left ventricular assist device placement, and cardiac transplant (Cox analysis). Ventricular tachycardia recurrence was considered a secondary endpoint (competing risk analysis). Of the 1677 VT ablation cases, 123 cases met the inclusion criteria for analysis. During a 19-month median follow-up time (interquartile range 4-43 months), 82 (66.7%) patients experienced the composite primary endpoint. There was no difference between Groups A and C with respect to the primary [hazard ratio (HR) = 1.21 (0.94-1.57), P = 0.145] or secondary [HR = 1.18 (0.91-1.54), P = 0.210] outcomes. These findings persisted after multivariate adjustments. The size of Group B (n = 13) did not permit meaningful statistical analysis. CONCLUSION: The results of post-ablation PVS do not significantly correlate with long-term outcomes in high-risk (PAINESD > 17) VT ablation patients.

Cryoballoon pulmonary vein isolation versus radiofrequency ablation of the pulmonary veins and left atrial posterior wall: Patient-reported outcomes.

BACKGROUND: Data are lacking on patient-reported outcomes (PRO) following cryoballoon ablation (CBA) versus radiofrequency ablation (RFA). We sought to evaluate QoL and clinical outcomes of cryoballoon pulmonary vein isolation only (CRYO-PVI-ONLY) versus RFA with PVI and posterior wall isolation (RF-PVI+PWI) in a large prospective PRO registry. METHODS: Patients who underwent AF ablation (2013-2016) at our institution were enrolled in an automated, prospectively maintained PRO registry. CRYO-PVI-ONLY patients were matched (1:1) with RF-PVI+PWI patients based on age, gender, and type of AF (paroxysmal vs. persistent). QoL and clinical outcomes were assessed using PRO surveys at baseline and at 1-year. The atrial fibrillation symptom severity scale (AFSSS) was the measure for QoL. Additionally, we assessed patient-reported clinical improvement, arrhythmia recurrence, and AF burden (as indicated by AF frequency and duration scores). RESULTS: A total of 296 patients were included (148 in each group, 72% paroxysmal). By PRO, a significant improvement in QoL was observed in the overall study population and was comparable between CRYO-PVI-ONLY and RF-PVI+PWI (baseline median AFSSS of 11.5 and 11; reduced to 2 and 4 at 1 year, respectively; p = 0.44). Similarly, the proportion of patients who reported improvement in their overall QoL and AF related symptoms was high and similar between the study groups [92% (CRYO-PVI-ONLY) vs. 92.8% (RF-PVI+PWI); p = 0.88]. Arrhythmia recurrence was significantly more common in the CRYO-PVI-ONLY group (39.7%) compared to RF-PVI+PWI (27.7 %); p = 0.03. Comparable results were observed in paroxysmal and persistent AF. CONCLUSION: CRYO-PVI-ONLY and RF-PVI+PWI resulted in comparable improvements in patient reported outcomes including QoL and AF burden; with RF-PVI+PWI being more effective at reducing recurrences.

Paroxysmal atrial fibrillation ablation with a novel temperature-controlled CF-sensing catheter: Q-FFICIENCY clinical and healthcare utilization benefits.

INTRODUCTION: The prospective, nonrandomized, multicenter Q-FFICIENCY study demonstrated the safety and 12-month efficacy of paroxysmal atrial fibrillation (AF) ablation with the novel QDOT MICRO temperature-controlled, contact force-sensing, radiofrequency (RF) catheter. Participants underwent pulmonary vein isolation with very high-power short-duration (vHPSD) mode (90 W, ≤4 s) alone or combined with conventional-power temperature-controlled (CPTC) mode (25-50 W). This study aimed to assess quality-of-life (QOL) and healthcare utilization (HCU) benefits experienced by Q-FFICIENCY study participants. METHODS: Besides evaluating procedural efficiency, QOL and HCU were assessed through 12 months postablation via Atrial Fibrillation Effect on Quality-of-Life Tool (AFEQT) score, antiarrhythmic drug (AAD) use, and incidence of cardioversion and cardiovascular hospitalization. RESULTS: Of 191 participants enrolled, 166 were ablated with the new catheter. Compared to baseline, statistically significant, clinically meaningful improvements in composite and subcategories of AFEQT scores were observed at 3 months and sustained through 12 months (12-month increase, 29.3-44.2 points). Class I/III AAD use decreased from 97.6% (162/166) at baseline to 19.6% (31/158) during Months 6-12, representing a significant 79.9% reduction. The cardioversion rate significantly declined by 93.9% from 31.3% (12 months preablation) to 1.9% (evaluation period). One-year Kaplan-Meier estimates of freedom from all-cause and cardiovascular hospitalization were 80.9% (95% confidence interval [CI], 74.8%-86.9%) and 88.8% (95% CI, 84.0%-93.7%), respectively. CONCLUSIONS: Paroxysmal AF ablation with the novel temperature-controlled RF catheter in vHPSD mode, alone or with CPTC mode, led to clinically meaningful improvement in QOL and significant reduction in AAD use, cardioversion, and cardiovascular hospitalization.

Impact of redo ablation for atrial fibrillation on patient-reported outcomes and quality of life.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF) is frequently used for the purpose of rhythm control and improved quality of life (QoL). Although success rates are high, a significant proportion of patients require redo ablation. Data are scarce on patient-centered outcomes and QoL in patients undergoing redo AF ablation. We aimed to assess QoL and clinical outcomes using a large prospectively maintained patient-reported outcomes (PRO) registry. METHODS: All patients undergoing redo AF ablation (2013-2016) at our center were enrolled in a prospective registry for outcomes and assessed for QoL using automated PRO surveys (baseline, 3 and 6 months after ablation, every 6 months thereafter). Data were collected over 3 years of follow-up. The atrial fibrillation symptom severity scale (AFSSS) was used as the main measure for QoL. Additional variables included patient-reported improvement, AF burden, and AF-related healthcare utilization including emergency room (ER) visits and hospitalizations. RESULTS: A total of 848 patients were included (28% females, mean age 63.8, 51% persistent AF). By automated PRO, significant improvement in QoL was noted (baseline median AFSSS of 12 [5-18] and ranged between 2 and 4 on subsequent assessments; p < .0001), with ≥70%of patients reported remarkable improvement in their AF-related symptoms. The proportion of patients in AF at the time of baseline survey was 36%, and this decreased to <8% across all time points during follow-up (p < .0001). AF burden was significantly reduced (including frequency and duration of episodes; p < .0001), with an associated decrease in healthcare utilization after 6 months from the time of ablation (including ER visits and hospitalizations; p < .0001). The proportion of patients on anticoagulants or antiarrhythmics decreased on follow-up across all time points (p < .0001 for all variables). CONCLUSION: Most patients derive significant QoL benefit from redo AF ablation; with reduction of both AF burden and healthcare utilization.

Impact of obesity on catheter ablation of atrial fibrillation: Patient characteristics, procedural complications, outcomes, and quality of life.

INTRODUCTION: Obesity is a well-known risk factor for atrial fibrillation (AF). We aim to evaluate the effect of baseline obesity on procedural complications, AF recurrence, and symptoms following catheter ablation (CA). METHODS: All consecutive patients undergoing AF ablation (2013-2021) at our center were enrolled in a prospective registry. The study included all consecutive patients with available data on body mass index (BMI). Primary endpoint was AF recurrence based on electrocardiographic documentation. Patients were categorized into five groups according to their baseline BMI. Patients survey at baseline and at follow-up were used to calculate AF symptom severity score (AFSS) as well as AF burden (mean of AF duration score and AF frequency score; scale 0: no AF to 10: continuous and 9 frequencies/durations in between). Patients were scheduled for follow-up visits with 12-lead electrocardiogram at 3, 6, and 12 months after ablation, and every 6 months thereafter. RESULTS: A total of 5841 patients were included (17% normal weight, 34% overweight, 27% Class I, 13% Class II, and 9% Class III obesity). Major procedural complications were low (1.5%) among all BMI subgroups. At 3 years AF recurrence was the highest in Class III obesity patients (48%) followed by Class II (43%), whereas Class I, normal, and overweight had similar results with lower recurrence (35%). In multivariable analyses, Class III obesity (BMI ≥ 40) was independently associated with increased risk for AF recurrence (hazard ratio, 1.30; confidence interval, 1.06-1.60; p = .01), whereas other groups had similar risk in comparison to normal weight. Baseline AFSS was lowest in normal weight, and highest in Obesity-III, median (interquartile range) 10 (5-16) versus 15 (10-21). In all groups, CA resulted in a significant improvement in their AFSS with a similar magnitude among the groups. At follow-up, AF burden was minimal and did not differ significantly between the groups. CONCLUSION: AF ablation is safe with a low complication rate across all BMI groups. Morbid obesity (BMI ≥ 40) was significantly associated with reduced AF ablation success. However, ablation resulted in improvement in QoL including reduction of the AFSS, and AF burden regardless of BMI.

Outcomes of atrial fibrillation ablation in patients with or without silent pulmonary veins from prior ablation procedure.

INTRODUCTION: Pulmonary venous (PV) electrical recovery underlies most arrhythmia recurrences after atrial fibrillation (AF) ablation. Little is known about procedural profiles and outcomes of patients with electrically silent PVs upon redo ablation for AF. METHODS: In a prospectively maintained registry, we enrolled 838 consecutive patients (2013-2016) undergoing redo ablation procedures. Ablation procedures targeted the PVs, the PV antra, and non-PV sites at operators' discretion. Procedural profiles and clinical outcomes were assessed. The primary outcome was freedom from AF after a 3-month blanking period. The secondary outcome was improvement in quality of life. RESULTS: Most patients undergoing redo AF ablation (n = 684, 82%) had PV reconnection while the remaining 154 (18%) had electrically silent PVs. Patients with recurrent AF and electrically silent PVs were older (66 vs. 64 years, p = .02), had more prior ablation procedures (median 2 IQR 1-3 vs 1 IQR 1-2 p = .001), were more likely to have non-paroxysmal AF (62% vs. 49%, p = .004) and atrial flutter (48% vs. 29%, p = .001) and had significantly larger left atrial volumes (89 vs. 81 ml, p = .003). Patients with silent PVs underwent a more extensive non-PV ablation strategies with antral extension of prior ablation sets in addition to ablation of the roof, appendage, inferior to the right PVs, peri-mitral flutter lines, cavotricuspid isthmus lines and ablation in the coronary sinus. Upon one year of follow-up, patients with electrically silent PVs were less likely to remain free from recurrent atrial arrhythmias (64% vs. 76%, p = .008). Regardless of PV reconnection status, redo ablation resulted in improvement in quality of life. CONCLUSION: Rhythm control with extensive ablation allowed maintenance of sinus rhythm in about two thirds of patients with silent PVs during redo AF ablation procedures. Regardless of PV reconnection status, redo ablation resulted in improvement in quality of life. This remains a challenging group of patients, highlighting the need to better understand non-PV mediated AF.

Bayesian network meta-analysis comparing cryoablation, radiofrequency ablation, and antiarrhythmic drugs as initial therapies for atrial fibrillation.

BACKGROUND: Antiarrhythmic drugs (AADs) and catheter ablation are first line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus AADs as an early rhythm strategy. OBJECTIVE: To assess the safety and efficacy of cryoablation versus radiofrequency ablation (RFA) versus AADs as a first line therapy of PAF. METHODS: MEDLINE, Embase, Scopus and CENTRAL were searched to retrieve randomized clinical trials (RCTs) comparing cryoablation, RFA or AADs to one another as first line therapies for atrial fibrillation (AF). The primary outcome was overall freedom from arrhythmia recurrence (AF, atrial flutter [AFL], atrial tachycardia). Secondary outcomes included freedom from symptomatic arrhythmia recurrence, hospitalization, and serious adverse events. A random-effects Bayesian network meta-analysis was used to calculate odds ratios (OR) and 95% credible intervals (CrI). RESULTS: Six RCTs (N = 1212) met the inclusion criteria (605 AADs, 365 Cryoablation, and 245 RFA). Compared with AADs, overall recurrence was reduced with RFA (OR: 0.31; 95% CrI: 0.10-0.71) and cryoablation (OR: 0.39; 95% CrI: 0.16-1.00). Comparing ablation (cryoablation and RFA) with AADs in respect to freedom from symptomatic AF recurrence, neither cryoablation (OR: 0.35; 95% CrI: 0.06-1.96) nor RFA (OR: 0.34; 95% CrI: 0.07-1.27) resulted in statistically significant reductions individually compared to AADs, though pooled ablation with both technologies showed lower odds of arrhythmia recurrence (OR: 0.35; 95% CrI: 0.13-0.79). In terms of serious adverse events rates, neither cryoablation (OR: 0.77; 95% CrI: 0.44-1.39) nor RFA (OR: 1.45; 95% CrI: 0.67-3.23) were significantly different to AADs. RFA resulted in a statistically significant reduction in hospitalizations compared to AAD (OR: 0.08; 95% CrI: 0.01-0.99), whereas cryoablation did not (OR: 0.77; 95% CrI: 0.44-1.39). The surface under the cumulative ranking curve showed RFA to be the most effective treatment at reducing overall rates of recurrence, symptomatic recurrence and hospitalizations; whereas cryoablation was most likely to reduce serious adverse events. CONCLUSION: Cryoablation and RFA are both effective and safe first line therapies for AF compared to AADs, with RFA being the most effective at reducing recurrences.

Efficacy and Safety of Catheter Ablation vs Antiarrhythmic Drugs as Initial Therapy for Management of Symptomatic Paroxysmal Atrial Fibrillation: A Meta-Analysis.

BACKGROUND: Catheter ablation is an effective treatment for atrial fibrillation (AF), primarily performed in patients who fail antiarrhythmic drugs. Whether early catheter ablation, as first-line therapy, is associated with improved clinical outcomes remains unclear. METHODS: Electronic databases (PubMed, Scopus, Embase) were searched until March 28th, 2021. Randomized controlled trials (RCTs) compared catheter ablation vs antiarrhythmic drug therapy as first-line therapy were included. The primary outcome of interest was the first documented recurrence of any atrial tachyarrhythmia (symptomatic or asymptomatic; AF, atrial flutter, and atrial tachycardia). Secondary outcomes included symptomatic atrial tachyarrhythmia (AF, atrial flutter, and atrial tachycardia) and serious adverse events. Unadjusted risk ratios (RR) were calculated from dichotomous data using Mantel Haenszel (M-H) random-effects with statistical significance considered if the confidence interval (CI) excludes one and p < 0.05. RESULTS: A total of six RCTs with 1212 patients (Ablation n = 609; Antiarrhythmic n = 603) were included. Follow- up period ranged from 1-2 years. Patients who underwent ablation were less likely to experience any recurrent atrial tachyarrhythmia when compared to patients receiving antiarrhythmic drugs (RR 0.63; 95% CI 0.55-0.73; p < 0.00001). Symptomatic atrial tachyarrhythmia was also lower in the ablation arm (RR 0.53; 95% CI 0.32-0.87; p = 0.01). No statistically significant differences were noted for overall any type of adverse events (RR 0.93; 95% CI 0.68-1.27; p = 0.64) and cardiovascular adverse events (RR 0.90; 95% CI 0.56-1.44; p = 0.65) respectively. CONCLUSIONS: Catheter ablation, as first-line therapy, was associated with a significantly lower rate of tachyarrhythmia recurrence compared to conventional antiarrhythmic drugs, with a similar adverse effect risk profile. These findings support a catheter ablation strategy as first-line therapy among patients with symptomatic paroxysmal atrial fibrillation.

The utility of a novel mapping algorithm utilizing vectors and global pattern of propagation for scar-related atrial tachycardias.

BACKGROUND: Activation maps of scar-related atrial tachycardias (AT) can be challenging to interpret due to difficulty in inaccurate annotation of electrograms, and an arbitrarily predefined mapping window. A novel mapping software integrating vector data and applying an algorithmic solution taking into consideration global activation pattern has been recently described (Coherent™, Biosense Webster "Investigational"). OBJECTIVE: We aimed to assess the investigational algorithm to determine the mechanism of AT compared with the standard algorithm. METHODS: This study included patients who underwent ablation of scar-related AT using the Carto 3 and the standard activation algorithm. The mapping data were analyzed retrospectively using the investigational algorithm, and the mechanisms were evaluated by two independent electrophysiologists. RESULTS: A total of 77 scar-related AT activation maps were analyzed (89.6% left atrium, median tachycardia cycle length of 273 ms). Of those, 67 cases with a confirmed mechanism of arrhythmia were used to compare the activation software. The actual mechanism of the arrhythmia was more likely to be identified with the investigational algorithm (67.2% vs. 44.8%, p = .009). In five patients with dual-loop circuits, 3/5 (60%) were correctly identified by the investigational algorithm compared to 0/5 (0%) with the standard software. The reduced atrial voltage was prone to lead to less capable identification of mechanism (p for trend: .05). The investigational algorithm showed higher inter-reviewer agreement (Cohen's kappa .62 vs. .47). CONCLUSIONS: In patients with scar-related ATs, activation mapping algorithms integrating vector data and "best-fit" propagation solution may help in identifying the mechanism and the successful site of termination.

Cardiac Implantable Electronic Device Therapy in Heart Failure.

The population of patients with heart failure continues to grow, which introduced significant challenges in clinical practice related to the management of cardiac arrhythmia and advanced heart failure syndromes. Device therapy has increasingly become essential in the management of life-threatening arrhythmia and clinical heart failure in this population. This review will discuss the use of cardiac implantable electronic devices in heart failure with primary focus on sudden cardiac death prevention and cardiac resynchronization, including published evidence and evolving technologies.

Impact of risk-factor modification on arrhythmia recurrence among morbidly obese patients undergoing atrial fibrillation ablation.

BACKGROUND: Morbid obesity is associated with prohibitively high arrhythmia recurrence rates following atrial fibrillation (AF) ablation. DESIGN: This was a single-center study comprising 239 patients with morbid obesity and symptomatic paroxysmal or persistent AF undergoing AF ablation compared to 239 patients with a body mass index less than 30 kg/m2 matched based on age, sex, ejection fraction, AF type, presence and type of heart failure, and left atrial volume index. METHODS: Our primary outcome of interest was arrhythmia recurrence. RESULTS: During a mean follow-up of 29 months, arrhythmia recurrence was observed in 65% of the morbidly obese cohort compared to 27% of the control group (P < .0001). Among those with morbid obesity, sleep apnea screening, and treatment (91% vs 40%; P < .0001), blood pressure control (62% vs 53%; P = .001), glycemic control (85% vs 56%; P = .004), and weight loss more than equal to 5% (33% vs 57% in those who lost less than 5% and 83% in those who gained weight, P < .0001) were associated with lower arrhythmia recurrence. Recurrent arrhythmia was observed in one (4%) patient who accomplished all four goals, compared to 36% who achieved 3 of 4, 85% who modified 2 of 4%, and 97% of those who modified zero or one risk-factor. Risk-factor modification (RFM) was also associated with substantial reductions in the need for repeat ablation or direct-current cardioversion and arrhythmia-related hospitalization (P < .0001). CONCLUSION: RFM through pragmatic noninvasive means such as blood pressure and glycemic control, sleep apnea screening and treatment, and weight loss is associated with substantially lower rates of recurrent arrhythmia among morbidly obese patients undergoing AF ablation.

Predictors of long-term outcomes greater than 10 years after cardiac resynchronization therapy implantation.

BACKGROUND: Cardiac resynchronization therapy (CRT) is indicated in patients with medically refractory heart failure and wide QRS duration. While much is known about predictors of left ventricular (LV) remodeling after CRT implantation and short-term mortality, limited data exist on long-term outcomes after CRT placement. METHODS: We retrospectively reviewed all patients undergoing CRT implantation at our center between 2003 and 2008 and examined mortality using institutional electronic records, social security death index, and online obituary search. We included only patients with preimplant echoes with LV ejection fraction (LVEF) 35% or below. Variable selection was performed using stepwise regression and models were compared using goodness-of-fit criteria. A final model was validated with the bootstrap regression method. RESULTS: Out of the 877 CRT patients undergoing implantation during this time, 287 (32.7%) survived longer than 10 years. Significant (P < .05) predictors of survival in our multivariate model were age, left ventricular diastolic diameter, sex, presence of nonischemic vs ischemic cardiomyopathy, QRS duration, atrial fibrillation, BNP levels, and creatinine levels at the time of CRT implantation. A model using the odds ratios from these variables had a receiver operating curve with an area under the curve score of 0.816 (standard error, 0.019) at predicting survival or freedom from LVAD or heart transplant for longer than 10 years after CRT implantation. The specificity for factors 3 or above and 5 or above was 68% and 77%, respectively. CONCLUSION: A large proportion of patients are still alive 10 years after CRT implantation. Variables at the time of CRT implant can help provide prognostic information to patients and electrophysiologists to determine the long-term benefit and survival of patients after CRT implantation.

The gap between what patients know and desire to learn about their cardiac implantable electronic devices.

BACKGROUND: Advancement of digital technology now allows patients to have access to data from their cardiac implantable electronic devices (CIEDs). However, patients' understanding regarding CIED data and perceived personal usability remain unclear. The present study is a prospective survey to examine patients' understanding of their CIEDs and their perception of what is important. METHODS: We screened 400 patients between July and December 2018 who presented to our outpatient clinic for a CIED interrogation. Patients received a one-page questionnaire asking baseline demographics, their perception about their own knowledge about their device, and multiple-choice questions in seven basic categories: type of CIED, original indication, functionality, manufacturer, number of active leads, estimated battery life, and number of shocks received. We compared these answers to their interrogation reports to assess accuracy. We also asked participants what they would like to be aware of regarding their CIED. RESULTS: From this cohort, 344 of 400 (86%) (62.9 ± 12.8 years and 64 % males) agreed to take the survey and were included in the analysis. At baseline, 63.2% agreed or strongly agreed that they were knowledgeable about their devices. The overwhelming majority of patients demonstrated CIED knowledge deficits in at least one content area (n = 294, 86%), or more than two content areas (n = 176, 51%). Patients agreed or strongly agreed that they had a desire to have information regarding each of the following: battery life (84%), activity level (79%), heart rate trend (75%), and ventricular arrhythmias (74%). CONCLUSION: There is a large discrepancy in patients' level of knowledge regarding their CIEDs and their wish to know more details. Future technologies should satisfy providers' goals to educate their patients with basic information and fulfill patients' desire to obtain more data from their CIEDs.

Burden and consequences of retained cardiovascular implantable electronic device lead fragments after heart transplantation.

We performed a retrospective review of 402 consecutive patients who underwent heart transplantation at our institution between January 2009 and March 2017. A retained cardiovascular implantable electronic device (CIED) fragment was identified after transplantation in 49 of the 301 patients (16.2%) with CIED at baseline. Patients with retained fragments had leads with longer dwell times (median 2596 [1982, 3389] vs 1384 [610, 2202] days, P < .001), higher prevalence of previously abandoned leads (14.3% vs 2.8%, P = .003), and dual-coil defibrillator leads (98% vs 81%, P = .001) compared with patients without retained fragments. Five patients (10%) with retained CIED fragments underwent magnetic resonance imaging without adverse events. There was no difference in overall mortality between patients with and without CIED fragments (12% vs 11%, P = .81) Patients with retained fragments located in the superior vena cava had significantly higher fluoroscopic times (3.3 vs 2.9 minutes, P = .024) during subsequent endomyocardial biopsies. In a competing risk analysis, presence of a retained CIED fragment was associated with upper extremity deep venous thrombosis (sub hazard ratio [HR] 2.19, 95% confidence interval [CI] 1.17-4.10, P = .014) but not bloodstream infection after adjusting for potential confounders. In summary, retained CIED fragments are common after heart transplantation, and are associated with longer radiation exposure during biopsy procedures and upper extremity deep venous thrombosis.

Repeat ablation or medical management alone for recurrent arrhythmias after ablation of persistent atrial fibrillation.

INTRODUCTION: Management of persistent atrial fibrillation (PersAF) remains challenging, and many patients are left on medical therapy after a failed first ablation. In patients with recurrent symptomatic arrhythmias after PersAF ablation, we aimed to compare outcomes of repeat ablation and medical therapy versus medical therapy alone. METHODS AND RESULTS: All 682 consecutive patients with recurrent symptomatic arrhythmia after a first ablation for PersAF at our institution (2005-2012) were included. Repeat ablation with continuation of medical therapy was performed in 364 patients (Group 1) and 318 were only medically managed (Group 2). The outcome of interest was freedom from arrhythmia recurrence beyond a 3-month blanking period. Separate analyses were performed to assess this endpoint totally off antiarrhythmics (primary endpoint) or alternatively with/without use of antiarrhythmics (secondary endpoint). Over a median follow-up of 26 months, 41.5% of Group 1 patients met the primary endpoint and remained free from arrhythmia recurrence off antiarrhythmics (vs. 14.5% in Group 2, P < 0.0001). At last follow-up, antiarrhythmics continued to be required for rhythm control in 40.1% and 46.2% of patients in Groups 1 and 2, respectively (P < 0.0001). The secondary endpoint was met in 60.2% versus 32.1% of patients in Groups 1 and 2, respectively (P < 0.0001). In multivariable Cox analyses, repeat ablation was associated with significant reduction in arrhythmia recurrences compared to medical therapy alone (HR 0.48, 95% CI 0.35-0.65, P < 0.0001). CONCLUSION: In patients with recurrent symptomatic arrhythmia after ablation of PersAF, repeat ablation was associated with significant reduction in arrhythmia recurrences compared to routine medical therapy alone.

Removal of subcutaneous defibrillator shocking coils: Lessons to learn for future extraction of subcutaneous defibrillator systems.

BACKGROUND: Subcutaneous shocking coils (SQC) have been used to lower defibrillation thresholds in certain patient populations. There are limited data regarding the extraction complexity of these leads. The goal of this study is to describe our SQC extraction experience and identify challenges that may be of importance with the increase in utilization and extraction of fully subcutaneous defibrillator systems. METHODS: We studied consecutive patients who underwent lead removal at our institution during which a Medtronic 6996SQ (Medtronic plc, Minneapolis, MN, USA) was removed RESULTS: Twenty-one patients (54.5 ± 14 years, 85.7% male) underwent procedures where at least one lead removed was a SQC. Mean ejection fraction was 27.7% and 11 patients had prior ventricular arrhythmia. Median SQC age was 177 days and the age of the oldest SQC removed was 3,041 days. Infection was the indication for removal in 14 patients. One removal was performed surgically and 20 were completed percutaneously. Three procedures required additional incisions beyond the device pocket and tie-down sleeve to complete the SQC lead removal due to dense adhesions. One removal procedure required the use of a laser sheath to relieve fibrosis. Complications in this group did not appear related to SQC removal. CONCLUSIONS: Drawing from our SQC removal experience, there may be a need for additional incisions and extra tools to complete removal of older subcutaneous implantable cardioverter defibrillator leads.

Persistent Atrial Fibrillation Ablation With or Without Contact Force Sensing.

INTRODUCTION: Arrhythmia recurrences remain common after ablation of persistent atrial fibrillation (PersAF). Contact force (CF)-sensing catheters have been introduced for objective assessment of contact during radiofrequency application and have been suggested to improve outcomes in ablation of paroxysmal AF, but little is known about their role in PersAF ablation. We aimed to compare the procedural profiles and outcomes of (PersAF) ablation with or without using CF-sensing catheters. METHODS: All consecutive patients undergoing first time ablation for PersAF between April 2014 and January 2015 at the Cleveland Clinic were included. Substrate modification was performed in addition to isolation of the pulmonary veins. Success rates were determined off antiarrhythmics over 1 year of follow-up. RESULTS: The study included 174 patients (77 CF and 97 non-CF). Ablation with CF-sensing catheters resulted in shorter procedures (median 204 vs. 216 minutes, P = 0.04) and shorter fluoroscopy time (36 vs. 48 minutes, P = 0.0005), without statistical difference in radiation dose (225 vs. 270 milligrays, P = 0.1). Arrhythmia recurrences were less likely to be observed in the CF-sensing group (27.6% vs. 46.4%, P = 0.01, log-rank P = 0.004). In multivariable Cox analyses, the use of CF-sensing catheters was associated with a lower risk of arrhythmia recurrence (hazard ratio 0.49, 95% confidence interval 0.27-0.85, P = 0.01). CONCLUSIONS: Compared to non-CF sensing, the use of CF-sensing catheters for PersAF ablation is associated with shorter procedures, shorter fluoroscopy time, and reduction in arrhythmia recurrences.

Incidence, indications, risk factors, and survival of patients undergoing cardiac implantable electronic device implantation after open heart surgery.

AIMS: The incidence, indications, and risk factors for cardiac implantable electronic device (CIED) implantation after cardiac surgery in an era with an aging population are not well described. There are limited data about the survival of these patients compared with a non-device group. We aimed to evaluate the incidence, indications, and risk factors for postoperative CIED implantation. We also assessed survival of these patients compared with a non-device group. METHODS: We included all patients without prior CIED implantation who underwent cardiac surgery at our institution from 1996 to 2008. Characteristics associated with CIED implantation were identified by multivariable logistic regression. A propensity model was constructed to compare survival. RESULTS: A total of 39 546 patients were included in the study of which 1608 patients (4.1%) underwent postoperative CIED implantation. Conduction disease accounted for most devices, but 371 patients underwent CIED implantation for secondary prevention of ventricular arrhythmias. Risk factors associated with implantation included older age, valvular disease, atrial fibrillation, and prior surgery. The propensity-adjusted risk of early death (within 1 year) was significantly less in the device group (hazard ratio [HR] 0.38; 95% confidence interval [CI] 0.22-0.65; P = 0.0004). However, the propensity-adjusted risk of late death was significantly greater in the device group (HR 1.3; 95% CI 1.2-1.5; P = <0.0001). CONCLUSION: Despite an aging population, the incidence of CIED implantation after cardiac surgery remains low and varies by the type of operation. Follow-up suggests increased early survival but decreased late survival in patients who undergo CIED implantation compared with a non-device group.

Radiofrequency Ablation with an Enhanced-Irrigation Flexible-Tip Catheter versus a Standard-Irrigation Rigid-Tip Catheter.

BACKGROUND: The flexible-tip irrigated ablation catheter Cool Flex™ (St. Jude Medical, St. Paul, MN, USA) was introduced to enhance cooling of the catheter-tissue interface and to conform to endocardial surface with better contact. Little is known about the performance of such catheter design compared to the widely used rigid-tip catheters. METHODS: In a thigh muscle preparation, ablation using the flexible-tip and rigid-tip catheters was performed in seven pigs across a range of ablation settings and catheter orientation. Postprocedure, the thigh muscle was stained with 2,3,5-triphenyltetrazolium-chloride injected into the femoral artery. The muscle was excised, fixed with formalin, and examined grossly. RESULTS: A total of 196 lesions (95 flexible tip, 101 rigid tip) were evaluated. The flexible-tip catheter was associated with enhanced cooling of catheter-tissue interface (31.1 ± 3.3°C vs 36.3 ± 3.7°C, P = 0.0001) in both perpendicular and nonperpendicular catheter orientations. This allowed more energy delivery (37.3 ± 8.9 W vs 33.7 ± 8.1 W, P = 0.004) to targeted tissue and resulted in larger lesions (median 194.7 [interquartile range: 113.1-333.8] mm(3) vs 170.9 [88.7-261.6] mm(3) , P = 0.03) than the rigid-tip catheter with larger maximum diameter (11.1 ± 2.6 mm vs 10.3 ± 2.1 mm, P = 0.03) and larger diameter at tissue surface (10.3 ± 2.4 mm vs 9.6 ± 1.7 mm, P = 0.01). Catheter orientation during ablation affected the efficiency of rigid-tip but not the flexible-tip catheter. The use of the flexible-tip catheter was associated with significantly less char formation on tissue (none vs 5.1% with rigid tip, P = 0.009). CONCLUSION: The Cool Flex™ catheter performed better than a rigid-tip catheter with enhanced cooling, larger ablation lesions, and no charring of targeted tissue.