Positive Clinical Benefit on Patient Care, Quality of Life, and Symptoms After Contact Force-Guided Radiofrequency Ablation in Persistent Atrial Fibrillation: Analyses From the PRECEPT Prospective Multicenter Study.

BACKGROUND: There is limited evidence on the long-term clinical benefits of catheter ablation in patients with persistent atrial fibrillation. METHODS: PRECEPT was a prospective, multicenter, single-arm Food and Drug Administration-regulated investigational device exemption clinical study. Patients were followed up to 15 months after ablation. Outcomes included use of antiarrhythmic drugs, rate of cardioversions and cardiovascular hospitalization, Atrial Fibrillation Effect on Quality-of-Life score, and Canadian Cardiovascular Society Severity of Atrial Fibrillation score. RESULTS: A total of 333 enrolled persistent atrial fibrillation patients underwent ablation. The cardioversion rate decreased by 83% at the 9- to 15-month follow-up. Antiarrhythmic drug utilization decreased by 69% at 12 to 15 months post-ablation. The Kaplan-Meier estimate of freedom from cardiovascular hospitalization was 84.2% (95% CI, 80.2%-88.2%) at 15 months. Consistent improvements in mean Atrial Fibrillation Effect on Quality-of-Life composite (+50.0) were seen at 6 months, sustained at 15 months, and exceeded the minimum clinically important difference. Improvements in Atrial Fibrillation Effect on Quality-of-Life scores were significantly better among participants without documented atrial arrhythmia recurrences. By Canadian Cardiovascular Society Severity of Atrial Fibrillation symptom classification, >80% of patients were asymptomatic (class 0) at 15 months post-ablation compared with only 0.7% at baseline. CONCLUSIONS: Contact force-guided radiofrequency ablation of persistent atrial fibrillation was associated with a significant decrease in antiarrhythmic drug use, cardioversion rate, and hospitalization. Clinically meaningful improvements in quality of life were observed in all patients. The majority of the patients (>80%) were asymptomatic at 15 months post-ablation. The positive clinical impact of improved quality of life and reduced health care utilization may help with shared decision-making in persistent atrial fibrillation treatment. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02817776.

Persistent Atrial Fibrillation Ablation With Contact Force-Sensing Catheter: The Prospective Multicenter PRECEPT Trial.

OBJECTIVES: This study sought to evaluate the safety and effectiveness of catheter ablation of persistent atrial fibrillation (PsAF) using a porous tip contact force-sensing catheter. BACKGROUND: Although the safety and effectiveness of catheter ablation of paroxysmal atrial fibrillation are established, there are limited data on outcomes in patients with PsAF. As such, no ablation catheter is currently approved by the Food and Drug Administration for PsAF ablation. METHODS: The prospective, multicenter, nonrandomized PRECEPT (Prospective Review of the Safety and Effectiveness of the THERMOCOOL SMARTTOUCH SF Catheter Evaluated for Treating Symptomatic PersistenT AF) study was conducted at 27 sites in the United States and Canada. Enrollment criteria included documented symptomatic PsAF and nonresponse or intolerance to ≥1 antiarrhythmic drug (Class I or III). An individualized treatment approach was used including pulmonary vein isolation with ablation of additional targets permitted at the investigators' discretion. To optimize treatment outcomes, a 3-month post-ablation medication adjustment period followed by a 3-month therapy consolidation period were included. Arrhythmia recurrences were stringently monitored by monthly and symptomatic transtelephonic monitoring, electrocardiography, and Holter monitoring for up to 15 months after ablation. RESULTS: Of 381 enrolled participants, 348 had the investigational catheter inserted and underwent ablation. The primary adverse event rate was 4.1% (15 events in 14 participants). Kaplan-Meier analyses estimated a primary effectiveness success rate of 61.7% and a clinical success rate of 80.4% at 15 months. CONCLUSIONS: The results demonstrate the clinical safety and effectiveness of PsAF ablation using contact force-sensing technologies. The primary adverse event was within the expected range and similar to those reported in historical studies of paroxysmal AF ablation. (Prospective Review of the Safety and Effectiveness of the THERMOCOOL SMARTTOUCH SF Catheter Evaluated for Treating Symptomatic PersistenT AF; NCT02817776).

Atrial fibrillation ablation with a spring sensor-irrigated contact force-sensing catheter compared with other ablation catheters: systematic literature review and meta-analysis.

OBJECTIVES: The objective of our review was to systematically assess available evidence on the effectiveness, safety and efficiency of a spring sensor-irrigated contact force (CF) catheter (THERMOCOOL SMARTTOUCH Catheter (ST)) for percutaneous ablation of paroxysmal or persistent atrial fibrillation (AF), compared with other ablation catheters, or with the ST with the operator blinded to CF data. DESIGN: Systematic literature review and meta-analysis. BACKGROUND: Emerging evidence suggests improved clinical outcomes of AF ablation using CF-sensing catheters; however, reviews to date have included data from multiple, distinct CF technologies. METHODS: We conducted a systematic review and meta-analysis of published studies comparing the use of ST versus other ablation catheters for the treatment of AF. A comprehensive search of electronic and manual sources was conducted. The primary endpoint was freedom from recurrent atrial tachyarrhythmia (AT) at 12 months. Procedural and safety data were also analysed. RESULTS: Thirty-four studies enrolling 5004 patients were eligible. The use of ST was associated with increased odds of freedom from AT at 12 months (71.0%vs60.8%; OR 1.454, 95% CI 1.12 to 1.88, p=0.004) over the comparator group, and the effect size was most evident in paroxysmal AF patients (75.6%vs64.7%; OR 1.560, 95% CI 1.09 to 2.24, p=0.015). Procedure and fluoroscopy times were shorter with ST (p=0.05 and p<0.01, respectively, vs comparator groups). The reduction in procedure time is estimated at 15.5 min (9.0%), and fluoroscopy time 4.8 min (18.7%). Complication rates, including cardiac tamponade, did not differ between groups. CONCLUSIONS: Compared with the use of other catheters, AF ablation using the CF-sensing ST catheter for AF is associated with improved success rates, shorter procedure and fluoroscopy times and similar safety profile.

Economic impact of atrial fibrillation ablation with radiofrequency contact force catheter versus cryoballoon catheter.

AIM: To compare health utilization among atrial fibrillation (AF) patients undergoing ablation with a contact force-sensing (CF) catheter versus a cryoballoon (CB) catheter. METHODS: AF patients who underwent ablation using the CF catheter (THERMOCOOL SMARTTOUCH® catheter) or CB catheter (Arctic Front™/Arctic Front Advance™ catheter) were identified from the Premier Healthcare database. Propensity score analyses were used to evaluate cost, length of stay and readmissions. RESULTS: The CF catheter (n = 1409) was associated with significantly lower total (∼7%) and supply (∼13%) costs and a significantly lower likelihood of 4-12 month all-cause and CV-related readmission compared with the CB catheter (n = 2306). CONCLUSION: Differential health utilization outcomes are associated with the CF catheter versus the CB catheter in AF ablation.

Healthcare Utilization and Quality of Life Improvement after Ablation for Paroxysmal AF in Younger and Older Patients.

BACKGROUND: Atrial fibrillation (AF) prevalence increases significantly with age. Little is known about the effect of AF ablation on quality of life and healthcare utilization in the elderly. The objective of this study was to quantify the healthcare utilization and quality of life benefits of catheter ablation for AF, for patients ≥65 years compared to patients <65 years. METHODS: Two multicenter U.S. registry studies enrolled patients with paroxysmal AF. Baseline characteristics and acute outcomes were collected for 736 patients receiving catheter ablation with the Navistar® ThermoCool® SF Catheter (Biosense Webster, Inc., Diamond Bar, CA, USA). Healthcare utilization and quality of life outcomes were collected through 1 year postablation for 508 patients. RESULTS: The rates of acute pulmonary vein isolation were high and similar between patients ≥65 years and <65 years (97.5% vs 95.8%, P = 0.2130). Length of stay for the index procedure was similar between age groups with 82.2% of the older group and 83.2% of the younger group having one-day hospitalization. Disease-specific quality of life instrument scores improved significantly and similarly for older and younger patients at 1 year postablation, compared to baseline. AF-related hospitalizations and emergency department visits were similar or lower in older patients compared to younger patients, as reported at 1 year postablation. CONCLUSION: For older patients undergoing catheter ablation for paroxysmal AF, healthcare utilization parameters were lower or not significantly different than for younger patients, and quality of life outcomes were similarly improved. These findings support the use of catheter ablation as a treatment option in older patients with paroxysmal AF.

Long-Term Success of Irrigated Radiofrequency Catheter Ablation of Sustained Ventricular Tachycardia: Post-Approval THERMOCOOL VT Trial.

BACKGROUND: Radiofrequency catheter ablation is used to treat recurrent ventricular tachycardia (VT). OBJECTIVES: This study evaluated long-term safety and effectiveness of radiofrequency catheter ablation using an open-irrigated catheter. METHODS: Patients with sustained monomorphic ventricular tachycardia associated with coronary disease were analyzed for cardiovascular-specific adverse events within 7 days of treatment, hospitalization duration, 6-month sustained monomorphic ventricular tachycardia recurrence, quality of life measured by the Hospital Anxiety and Depression Scale, long-term (1-, 2-, and 3-year) survival, symptomatic VT control, and amiodarone use. RESULTS: Overall, 249 patients, mean age 67.4 years, were enrolled. The cardiovascular-specific adverse events rate was 3.9% (9 of 233) with no strokes. Noninducibility of targeted VT was achieved in 75.9% of patients. Post-ablation median hospitalization was 2 days. At 6 months, 62.0% (114 of 184) of patients had no sustained monomorphic ventricular tachycardia recurrence; the proportion of patients with implantable cardioverter-defibrillator shocks decreased from 81.2% to 26.8% (p < 0.0001); the frequency of VT in implantable cardioverter-defibrillator patients with recurrences was reduced by ≥50% in 63.8% of patients; and the proportion with normal Hospital Anxiety and Depression Scale scores increased from 48.8% to 69.1% (p < 0.001). Patient-reported VT remained steady for 1, 2, and 3 years at 22.7%, 29.8%, and 24.1%, respectively. Amiodarone use and hospitalization decreased from 55% and 77.2% pre-ablation to 23.3% and 30.7%, 18.5% and 36.7%, 17.7% and 31.3% at 1, 2, and 3 years, respectively. CONCLUSIONS: Radiofrequency catheter ablation reduced implantable cardioverter-defibrillator shocks and VT episodes and improved quality of life at 6 months. A steady 3-year nonrecurrence rate with reduced amiodarone use and hospitalizations indicate improved long-term outcomes. (NaviStar ThermoCool Catheter for Endocardial RF Ablation in Patients With Ventricular Tachycardia [THERMOCOOL VT]; NCT00412607).

Relationship Between Catheter Stability and 12-Month Success After Pulmonary Vein Isolation: A Subanalysis of the SMART-AF Trial.

OBJECTIVES: This study sought to assess the correlation between catheter and tissue contact force (CF) stability and 12-month clinical success for atrial fibrillation (AF) ablation. BACKGROUND: The SMART-AF (Thermocool Smarttouch Catheter for the Treatment of Symptomatic Paroxysmal Atrial Fibrillation) multicenter trial provided a robust dataset of AF ablation procedures, using the CF sensing ablation catheter. METHODS: CF and CF stability were correlated with 12-month success for drug-refractory symptomatic AF ablation. CF stability was assessed by stability of ablation parameters (CF, time, location stability) over 3-dimensional electroanatomic maps of pulmonary veins (PVs) using a new proprietary software module and the percentage of time within investigator-selected CF ranges. Available data for potential "PV gaps" were retrospectively identified when stability criteria were not met and were correlated with 12-month success. RESULTS: Average CF categories of 0 to 10, 10 to 20, and >20 g were associated with 12-month success rates of 90%, 70%, and 70%, respectively; thus, higher average CF did not correlate with treatment success. An exploratory univariate analysis showed significantly higher success rates with a CF of 6.5 to 10.3 g than with <6.5 g (odds ratio: 2.95; 95% confidence interval: 1.13 to 7.72; p = 0.028) but a CF >10 g did not improve success. When stable CF was applied ≥73% of the time within the preselected CF range, success improved. A receiver operating characteristic curve analysis revealed that PV gaps exceeding 10.6-mm distance significantly correlated with 12-month failure. CONCLUSIONS: In the SMART-AF trial, CF stability with sufficient CF was most predictive of optimal 12-month success. (Thermocool Smarttouch Catheter for the Treatment of Symptomatic Paroxysmal Atrial Fibrillation [SMART-AF]; NCT01385202).

Pulmonary vein isolation using "contact force" ablation: the effect on dormant conduction and long-term freedom from recurrent atrial fibrillation--a prospective study.

BACKGROUND: Atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) is associated with PV to left atrium reconduction. Effective lesion creation necessitates adequate contact force between the ablation catheter and myocardium. OBJECTIVE: The purpose of this study was to study the utility of contact force-guided ablation on immediate and long-term outcomes. METHODS: Seventy-five patients with highly symptomatic paroxysmal AF underwent wide circumferential PVI using an irrigated-tip radiofrequency catheter. In 25 patients, ablation was guided by real-time contact force measurements (CF group; SmartTouch, Biosense Webster). A control group of 50 patients underwent PVI using a standard nonforce sensing catheter (standard group; ThermoCool, Biosense Webster). After PVI, all patients underwent adenosine testing to unmask dormant conduction. Patients were followed up at 3, 6, and 12 months and by transtelephonic monitoring as well. RESULTS: Dormant conduction was unmasked and subsequently eliminated in 4 PV pairs (8%; 16% of patients) in the CF group and 35 PV pairs (35%; 52% of patients) in the standard group (P = .0004 per PV pair; P = .0029 per patient). The single-procedure, off-antiarrhythmic drug freedom from recurrent atrial arrhythmias at 1 year was 88% in the CF group vs 66% in the standard group (P = .047). Procedure duration and fluoroscopy time were significantly longer in the CF group (P = .0038 and P = .0001, respectively). CONCLUSION: The use of real-time contact force guidance results in a significant reduction in the prevalence of dormant conduction with improved long-term freedom from recurrent arrhythmias. The utility of a contact force-guided approach requires evaluation in a long-term prospective randomized study.

Acute safety of an open-irrigated ablation catheter with 56-hole porous tip for radiofrequency ablation of paroxysmal atrial fibrillation: analysis from 2 observational registry studies.

INTRODUCTION: This report presents safety data on the use of a new open-irrigation radiofrequency ablation (RFA) catheter with a 56-hole porous tip in 742 patients enrolled in 2 US prospective, multicenter observational registry studies representing real-world use of the catheter. METHODS: This analysis is comprised of patients who underwent RFA of drug-refractory recurrent symptomatic paroxysmal atrial fibrillation (AF). Acute adverse events (AEs) were collected and categorized by seriousness, timing, and relatedness, with 7 days of follow-up data in one study and at least 120 days of data from a 1-year follow-up in the other. Acute serious adverse events (SAEs) that were identified as potentially related to the device and/or procedure were adjudicated by an independent safety committee. RESULTS: A total of 30 patients (4.0%) in the combined studies experienced an acute SAE related to the device and/or procedure, which was similar in the subset of patients age 65 and over (4.2%). These SAEs included 1.2% cardiac tamponade/perforation, 0.7% pericarditis, 0.5% pulmonary events, and 0.8% vascular access complications. No myocardial infarction, stroke, transient ischemic attack, or atrioesophageal fistulas within 7 days postprocedure were reported. In the study with extended follow-up, 1 pulmonary vein stenosis and 1 esophageal injury were seen beyond 7 days postprocedure (0.2% each). There were no device or procedure related deaths. CONCLUSION: Results from 2 large observational studies demonstrated that a new porous tip RFA catheter was safe for the treatment of drug refractory, recurrent, symptomatic paroxysmal AF, including treatment of older patients (≥65 years).

Pulmonary vein isolation using a pace-capture-guided versus an adenosine-guided approach: effect on dormant conduction and long-term freedom from recurrent atrial fibrillation--a prospective study.

BACKGROUND: Atrial fibrillation recurrence after pulmonary vein (PV) isolation is associated with PV to left atrium reconduction. We prospectively studied the use of 2 procedural techniques designed to facilitate identification of residual gaps within the index ablation line. METHODS AND RESULTS: After wide circumferential PV isolation, 40 patients received additional ablation targeted at locations of left atrial capture during high-output pacing (pace-capture group), while 40 patients underwent adenosine testing with targeted ablation at sites of dormant conduction (adenosine group). Patients were followed up at 3, 6, and 12 months. After PV isolation, high-output pace-capture was documented in 39 PVs (25%; 50% of patients) in the pace-capture group. Dormant conduction was unmasked in 34 PVs (22%; 53% of patients) in the adenosine group. A subset of 25 patients in the pace-capture group underwent adenosine testing without targeted ablation of dormant conduction. In these patients, only 10 out of 86 PVs (11.6%; 24% of patients) demonstrated dormant conduction after the elimination of local pace-capture. At a follow-up of 329±124 days, the single procedure off antiarrhythmic drug freedom from recurrent atrial fibrillation was 67.5% in the adenosine group and 65.0% in the pace-capture group (P=0.814). Procedure duration and fluoroscopy time were significantly longer in the pace-capture group (P=0.002 and P<0.001), whereas radiofrequency ablation time was comparable (P=0.192). CONCLUSIONS: The use of high-output pacing post-PV isolation results in a significant reduction in the incidence of dormant conduction with a comparable long-term freedom from recurrent atrial fibrillation (versus adenosine-guided ablation). The use of these approaches requires evaluation in a long-term prospective randomized study. [corrected].

Detection of inadvertent catheter movement into the coronary sinus ostium or middle cardiac vein by real-time impedance monitoring prior to radiofrequency ablation in the right atrial posteroseptal region.

OBJECTIVE: The objective of this study was to evaluate the use of continuous catheter impedance monitoring prior to ablation to facilitate differentiation of the coronary sinus ostium (CSO) and the middle cardiac vein (MCV) from the right atrial posteroseptal region (RPS). BACKGROUND: Empiric observations have suggested that continuous catheter impedance monitoring could differentiate the CSO and MCV from the RPS region. Radiofrequency ablation in the MCV or coronary sinus has been associated with coronary artery injury. Differentiation of these areas may be difficult with either fluoroscopy or electrogram characteristics. METHODS AND RESULTS: Continuous impedance measurements using a 4-mm Navistar (Biosense Webster) ablation catheter were conducted in 17 consecutive patients undergoing ablation for supraventricular tachycardia. The average impedance value was recorded at the right atrial septum (RS) posterior to the bundle of His, the RPS region, within 1 cm inside the CSO and in the MCV. These areas were confirmed and demarcated with 3-D mapping and biplane fluoroscopy. A significant increase in impedance was observed between the CSO (X = 146.6 ± 24.8) and RPS [Formula: see text] regions (p < 0.001). Furthermore, a significant rise in impedance was seen between the MCV [Formula: see text] and RPS and CSO, respectively (p < 0.001). No significant change in impedance was found between the RS [Formula: see text] and RPS regions. CONCLUSIONS: Continuous impedance measurements during mapping can facilitate differentiation of catheter locations inside the CSO and MCV from extracoronary sinus regions. This may reduce the risk of inadvertent coronary artery damage during the ablation procedure.

Consistency of the CFAE phenomena using custom software for automated detection of complex fractionated atrial electrograms (CFAEs) in the left atrium during atrial fibrillation.

INTRODUCTION: Complex fractionated atrial electrograms (CFAEs) have been described as a potential target for ablation of atrial fibrillation (AF). The purpose of this study is to assess the consistency of the CFAE phenomena using custom software for automated detection of CFAEs in the left atrium during AF. METHODS AND RESULTS: This prospective study included 10 patients referred for catheter ablation of symptomatic drug-refractory AF. Ten consecutive points at a single location (cluster) were acquired as electroanatomical points every 3 seconds. Atrial signals were automatically classified as CFAEs by the software algorithm. The number of intervals between 50 ms and 110 ms and in the voltage range 0.05-0.15 mV during the 2.5-second recordings was determined and referred to as the interval confidence level (ICL). A total of 2,226 points were acquired during mapping of AF. A dominant group of ICL using one of two different configurations of ICL fractionation was identified. A dominant group was defined as the ICL categorization occurring with greatest frequency in a given cluster of points. The results show the consistency ranged from 73%+/- 21 for the three-group configuration (ICL < or = 4; 4 < ICL < or = 7; ICL > 7) to 84%+/- 16 for the two-group configuration (ICL < or = 5; ICL > 5). CONCLUSION: This novel software offers an objective method for CFAE analysis during atrial fibrillation. CFAE consistency ranged from 73% to 84% with wide standard deviation. Automated detection of CFAEs may remove the pitfalls associated with subjective visual detection, thus removing one variable in comparative studies of using CFAEs as AF ablation targets.

Novel imaging techniques of the esophagus enhancing safety of left atrial ablation.

This report describes different imaging techniques of the esophagus in four patients during radiofrequency catheter ablation of atrial fibrillation in the left atrium. A novel use of a mixture of barium cream and gadolinium diglutamate allowed esophageal imaging during magnetic resonance angiography of the left atrium and pulmonary veins. Barium cream used during computer tomography angiographic imaging of the left atrium and pulmonary veins allowed esophageal imaging. The esophagus was also imaged with an electroanatomic mapping system. Esophageal and left atrial imaging helped to avoid catheter ablation in left atrial tissue overlapping the esophagus.

Ablation therapy of supraventricular tachycardia in elderly persons.

Ablation of supraventricular tachycardia in elderly persons presents a challenging problem to electrophysiologists. Friable cardiac structures, prone to catheter perforation, comorbid cardiovascular disease, and the propensity to develop atrial fibrillation and thromboembolic complications, place these patients at high risk. Newer techniques for cardiac mapping and ablation, the establishment of precise ablation lines, and safer approaches to the ablation mechanism (particularly for atrial fibrillation) are presented in this review. In addition, a novel rapid ablation method to permanently cure atrial ventricular nodal re-entry tachycardia is demonstrated.

The effect of atrial pacing therapies on atrial tachyarrhythmia burden and frequency: results of a randomized trial in patients with bradycardia and atrial tachyarrhythmias.

OBJECTIVES: The Atrial Therapy Efficacy and Safety Trial (ATTEST) was a prospective, randomized study to evaluate preventive pacing and antitachycardia pacing (ATP) in patients with symptomatic atrial fibrillation (AF) or atrial tachycardia (AT). BACKGROUND: The effect of the combination of atrial prevention and termination algorithms on AT/AF burden and frequency in pacemaker patients is unknown. METHODS: A DDDRP pacemaker (AT500, Medtronic Inc., Minneapolis, Minnesota) with three atrial preventive pacing algorithms and two ATP algorithms was implanted in 368 patients. Patients were randomized one-month post-implant to all prevention and ATP therapies ON or OFF and followed for three months. The OFF group had DDDR pacing at a lower programmed rate of 60 ppm. The AT/AF burden and frequency were determined from daily device counters in 324 patients treated according to protocol. RESULTS: In 17,018 episodes with stored electrograms, appropriate detection was confirmed in 17,004 (99.9%). The median percentage of atrial pacing was 98% in the ON group versus 75% in the OFF group (p < 0.001). Using device-defined criteria for successful termination, ATP terminated 8,590 (54%) of 15,789 treated episodes. The median AT/AF burden during the three-month study period was 4.2 h/month ON versus 1.1 h/month OFF (p = 0.20). The median AT/AF frequency was 1.3 episodes/month ON versus 1.2 episodes/month OFF (p = 0.65). System-related, complication-free survival at four months was 90.2% (Kaplan-Meier estimate). CONCLUSIONS: This DDDRP pacemaker is safe, has accurate AT/AF detection, and provides ATP with 54% efficacy as defined by the device. The atrial prevention and termination therapies combined did not reduce AT/AF burden or frequency in this patient population.

Ablation of nonparoxysmal A-V nodal tachycardia.

The present study describes the successful radiofrequency ablation of an uncommon type of A-V nodal tachycardia. Electroanatomical mapping of the right atria was used to locate the region of the earliest atrial activation and allowed for positioning of the ablation catheter and a successful 25-watt radiofrequency burn in this area terminating the tachycardia. The ability to visualize multiple projections of pertinent intracardiac structures allows a more rapid and systematic approach by marking all ablation points even in the presence of AV block or AV dissociation. Consequently, repeated burns can be eliminated in previously treated areas by electroanatomical mapping of the earliest depolarization and leading pacemaker.