Early ablation of newly diagnosed paroxysmal atrial fibrillation (NEWPaAF) versus newly diagnosed persistent atrial fibrillation (NEWPeAF): Comparison of patient populations and ablation outcomes

INTRODUCTION

Little is known about very early atrial fibrillation (AF) ablation after first AF detection.

METHODS

We evaluated patients with AF ablation <4 months from newly diagnosed paroxysmal AF (NEWPaAF) and newly diagnosed persistent AF (NEWPeAF). We compared the two patient populations and compared ablation outcomes to those undergoing later ablation.

RESULTS

Ablation was done <4 months from AF diagnosis in 353 patients (135 = paroxysmal, 218 = persistent). Early ablation outcome was best for NEWPaAF versus NEWPeAF for initial (p = 0.030) but not final (p = 0.102) ablation. Despite recent AF diagnosis in both groups, they were clinically quite different. NEWPaAF patients were younger (64.3 ± 13.0 vs. 67.3 ± 10.9, p = 0.0020), failed fewer drugs (0.39 vs. 0.60, p = 0.007), had smaller LA size (4.12 ± 0.58 vs. 4.48 ± 0.59 cm, p < 0.0001), lower BMI (28.8 ± 5.0 vs. 30.3 ± 6.0, p = 0.016), and less CAD (3.7% vs. 11.5%, p = 0.007), cardiomyopathies (2.2% vs. 22.9%, p = 0.0001), hypertension (46.7% vs. 67.4%, p < 0.0001), diabetes (8.1% vs. 17.4%, p = 0.011) and sleep apnea (20.0% vs. 30.3%, p = 0.031). For NEWPaAF, early ablation AF-free outcome was no better than later ablation (p = 0.314). For NEWPeAF, AF-free outcomes were better for early ablation than later ablation (p < 0.0001). Delaying ablation allowed more strokes/TIAs in both AF types (paroxysmal p = 0.014, persistent p < 0.0001).

CONCLUSIONS

Patients presenting for early ablation after newly diagnosed persistent AF have more pre-existing comorbidities and worse initial ablation outcomes than patients with NEWPaAF. For NEWPaAF, there was no advantage to early ablation, as long as the AF remained paroxysmal. For NEWPeAF, early ablation gave better outcomes than later ablation and they should undergo early ablation. For both AF types, waiting was associated with more neurologic events, suggesting all patients should consider earlier ablation.

Very long term outcomes of atrial fibrillation ablation

BACKGROUND

Little is known about the very long term durability of atrial fibrillation (AF) ablation.

OBJECTIVE

The purpose of this study was to evaluate very long term AF ablation outcomes.

METHODS

We followed 5200 patients undergoing 7145 ablation procedures. We evaluated outcomes after single and multiple ablation procedures for paroxysmal (PAF; 33.6%), persistent (PeAF; 56.4%), and long-standing (LsAF; 9.9%) AF. We compared 3 ablation eras by initial ablation catheter: early (101 patients) using solid big tip (SBT) catheters (October 2003 to December 2005), intermediate (2143 patients) using open irrigated tip (OIT) catheters (December 2005 to August 2016), and contemporary (2956 patients) using contact force (CF) catheters (March 2014 to December 2021).

RESULTS

AF freedom at 5, 10, and 15 years was as follows: initial ablation: PAF 67.8%, 56.3%, 47.6%; PeAF 46.6%, 35.6%, 26.5%; and LsAF 30.4%, 18.0%, 3.4%; final ablation: PAF 80.3%, 72.6%, 62.5%; PeAF 60.1%, 50.2%, 42.5%; and LsAF 43.4%, 32.0%, 20.6%. For PAF and PeAF, CF ablation procedures were better than OIT ablation procedures (P < .0001) and both were better than SBT ablation procedures (P < .001). LsAF had no outcome improvement over the eras. The 8-year success rate after final ablation for CF, OIT, and SBT catheter eras was as follows: PAF 79.1%, 71.8%, 60.0%; PeAF 55.9%, 50.7%, 38.0%; and LsAF 42.7%, 36.2%, 31.8%. Highest AF recurrence was in the first 2 years, with a 2- to 15-year recurrence of 2%/yr. Success predictors after initial and final ablation procedures were younger age, smaller left atrium, shorter AF duration, male sex, less persistent AF, lower CHA₂DS₂-VASc score, fewer drugs failed, and more recent catheter era.

CONCLUSION

After year 2, there is 2%/yr recurrence rate for all AF types. Ablation success is best in the CF catheter era, intermediate in the OIT era, and worst in the SBT era. Over the ablation eras, outcomes improved for PAF and PeAF but not for LsAF. We should follow patients indefinitely after ablation. We need an understanding of how to better ablate more persistent AF.

Internationally validated score to predict the outcome of non-paroxysmal atrial fibrillation ablation: the 'FLAME score'

Background

The clinical effectiveness of ablating non-paroxysmal atrial fibrillation (non-PAF) relies on proper patient selection. We developed and validated a scoring system to predict non-PAF ablation outcomes.

Methods

Data on 416 non-PAF ablations were analysed using binary logistic regression at a London centre. Identified preprocedural variables, which independently predicted freedom from atrial tachyarrhythmia. Twenty-one possible predictive variables and a model with c-statistic 0.751—explained outcome variation in London at mean follow-up 12±3 months. An additive point score (range 0–9) was developed—the FLAME score: female=1; long-lasting persistent atrial fibrillation=1; left atrial diameter in mm: 40 to <45 = 1, 45 to <50 = 2, 50 to <55=3, ≥55 =4; mitral regurgitation (MR) mild to moderate=1; extreme comorbidity=2. Extreme comorbidities include severe MR, moderate mitral stenosis, mitral replacement, hypertrophic cardiomyopathy or congenital heart disease.

Results

The FLAME score was applied to data (882 non-PAF ablations) at a Californian centre, and predicted the outcome of both single (p<0.0001) and multiple (p<0.0001) procedures. For first ablation (follow-up 2.1 years (median, IQR 1.0–4.1)), FLAME score: 0–1 predicts 62% success, 2–4 44% and ≥5 29% (P_trend <0.0001). After the final ablation (mean procedures: 1.4±0.6, follow-up 1.8 years (median, IQR 0.8–3.6)), FLAME score: 0–1 predicts 81% success, 2–4 65% and ≥5 44% (P_trend <0.0001).

Conclusions

FLAME score is easily calculated, derived in London, and predicted single and multiple procedural outcomes for non-PAF ablations in California. In patients with a high score, even multiple procedures are usually ineffective.

Ablation of atypical atrial flutters using ultra high density-activation sequence mapping

PURPOSE

The purpose of this study was to evaluate ultra high density-activation sequence mapping (UHD-ASM) for ablating atypical atrial flutters.

METHODS

For 23 patients with 31 atypical atrial flutters (AAF), we created UHD-ASM.

RESULTS

Demographics age = 65.3 ± 8.5 years, male = 78%, left atrial size = 4.66 ± 0.64 cm, redo ablation 20/23(87%). AAF were left atrial in 30 (97%). For each AAF, 1273 ± 697 points were used for UHD-ASM. Time to create and interpret the UHD-ASM was 20 ± 11 min. For every AAF, the entire circuit was identified. Thirty (97%) were macroreentry. AAF cycle length was 267 ± 49 ms, and the circuit length was 138 ± 38 mm (range 35-187). Macroreentry atrial flutters took varied pathways, but each had an area of slow conduction (ASC) averaging 16 ± 6 mm (range 6-29) in length. Entrainment was not utilized. We targeted the ASC and ablation terminated AAF directly in 19/31 (61.3%) and altered AAF activation in 7/31 (22.6%), all of which terminated directly with additional mapping/ablation. AAF degenerated to atrial fibrillation in 2/31 (6.5%) with RF and could not be reinduced after ASC ablation. Median time from initial ablation to AAF termination was 64 s. Thus, 28/31 (90.3%) terminated with RF energy and/or could not be reinduced after ASC ablation. At 1 year of follow-up, 77% were free of atrial tachycardia or atrial flutter and 61% were free of all atrial arrhythmias.

CONCLUSIONS

Using rapidly acquired UHD-ASM, the entire AAF circuit as well as the target ASC could be identified. Most AAF were left atrial macroreentry. Ablation of the ASC or microreentry focuses directly terminated or eliminated AAF in 90.3% without the need for entrainment mapping.

Peri-procedural interrupted oral anticoagulation for atrial fibrillation ablation: comparison of aspirin, warfarin, dabigatran, and rivaroxaban

Aims

Atrial fibrillation ablation requires peri-procedural oral anticoagulation (OAC) to prevent thromboembolic events. There are several options for OAC. We evaluate peri-procedural AF ablation complications using a variety of peri-procedural OACs.

Methods and results

We examined peri-procedural OAC and groin, bleeding, and thromboembolic complications for 2334 consecutive AF ablations using open irrigated-tip radiofrequency (RF) catheters. Pre-ablation OAC was warfarin in 1113 (47.7%), dabigatran 426 (18.3%), rivaroxaban 187 (8.0%), aspirin 472 (20.2%), and none 136 (5.8%). Oral anticoagulation was always interrupted and intraprocedural anticoagulation was unfractionated heparin (activated clotting time, ACT = 237 ± 26 s). Pre- and post-OAC drugs were the same for 1591 (68.2%) and were different for 743 (31.8%). Following ablation, 693 (29.7%) were treated with dabigatran and 291 (12.5%) were treated with rivaroxaban. There were no problems changing from one OAC pre-ablation to another post-ablation. Complications included 12 (0.51%) pericardial tamponades [no differences for dabigatran (P = 0.457) or rivaroxaban (P = 0.163) compared with warfarin], 12 (0.51%) groin complications [no differences for rivaroxaban (P = 0.709) and fewer for dabigatran (P = 0.041) compared with warfarin]. Only 5 of 2334 (0.21%) required blood transfusions. There were two strokes (0.086%) and no transient ischaemic attacks (TIAs) in the first 48 h post-ablation. Three additional strokes (0.13%), and two TIAs (0.086%) occurred from 48 h to 30 days. Only one stroke had a residual deficit. Compared with warfarin, the neurologic event rate was not different for dabigatran (P = 0.684) or rivaroxaban (P = 0.612).

Conclusion

Using interrupted OAC, low target intraprocedural ACT, and irrigated-tip RF, the rate of peri-procedural groin, haemorrhagic, and thromboembolic complications was extremely low. There were only minimal differences between OACs. Low-risk patients may remain on aspirin/no OAC pre-ablation. There are no problems changing from one OAC pre-ablation to another post-ablation.

Atrial fibrillation ablation using open-irrigated tip radiofrequency: experience with intraprocedural activated clotting times ≤210 seconds

BACKGROUND

Atrial fibrillation (AF) ablation procedures generally use intraprocedural activated clotting time (ACT) of >300-350 seconds to prevent thromboembolic events.

OBJECTIVE

To evaluate bleeding and thromboembolic procedural complications in patients with symptomatic AF undergoing ablation procedures with low intraprocedural ACT.

METHODS

We examined a subset of 372 of 2334 (15.9%) AF ablation procedures using open-irrigated tip radiofrequency catheters at 50 W, interrupted oral anticoagulation, and a target ACT of 225 seconds, with average ACT ≤210 seconds.

RESULTS

There were 372 ablation procedures in 339 patients with average ACT ≤210 seconds. Patient demographic characteristics were as follows: age 60.9 ± 9.4 years, men 269 (79.3%), left atrial (LA) size 4.27 ± 0.65 cm, prior stroke/transient ischemic attack 24 (7.1%), CHADS2 score 0.94 ± 0.98, and CHA2DS2-VASc score 1.53 ± 1.35. AF type was categorized as paroxysmal in 107 (31.6%), persistent in 200 (59.0%), and long-standing persistent in 32 (9.4%). Procedural and LA times were 119 ± 26 and 82 ± 24 minutes. Patients underwent preprocedure transesophageal echocardiography. The heparin bolus (8738 ± 2823 units, 93.4 mg/kg) was given after LA access, and the maintenance infusion was 1000 units/hour via a single transseptal sheath with subsequent adjustments based on ACT values. The average ACT was 202 ± 7.5 seconds per procedure, with 116 patients with average ACT <200 seconds and 16 patients with all ACTs <200 seconds. Complications occurred in 7 of 372 (1.9%) ablation procedures, including 2 pericardial tamponades (0.54%), 1 groin pseudoaneurysm (0.27%), and 1 pulmonary embolus, several weeks postablation. There were no other bleeding events and no strokes/transient ischemic attacks or systemic thromboemboli.

CONCLUSION

Using open-irrigated tip radiofrequency catheters at 50 W and preablation transesophageal echocardiography as well as infusing maintenance heparin through a single transseptal sheath, AF ablation can be performed safely despite ACT averaging ≤210 seconds. While we are not advocating target ACTs this low, our data suggest that long ACTs may not be absolutely necessary for preventing thromboembolic events. Lower target ACTs may potentially reduce bleeding complications.

Discontinuing anticoagulation following successful atrial fibrillation ablation in patients with prior strokes

Purpose

This study was conducted to examine the outcomes in patients with prior stroke/transient ischemic attack (CVA/TIA) after atrial fibrillation (AF) ablation and the feasibility of discontinuing oral anticoagulation (OAC).

Methods

This study examined long-term outcomes following AF ablations in 108 patients with a history of prior thromboembolic CVA/TIA. Because of risks of OAC, we frequently discontinue OAC in these patients after successful ablation. These patients understand the risks/benefits of discontinuing OAC and remain on OAC for a longer time following successful AF ablation, compared to our patients without prior CVA/TIA.

Results

Patient age was 66.2 ± 9.0 years with an average CHADS₂ score = 3.0 ± 0.9 and CHA₂DS₂-VASc score = 4.1 ± 1.4. Following 1.24 ablations, 71 (65.7 %) patients were AF free 2.8 ± 1.6 (median 2.3) years after their last ablation. OAC was discontinued in 55/71 (77.5 %) patients an average of 7.3 months following the final ablation. These 55 patients had 2.2 ± 1.3 (median 1.8) years of follow-up off of OAC. Kaplan–Meier analysis suggests little AF recurrence >1 year following initial or final ablations, suggesting that 1 year post successful ablation may be the appropriate time to consider discontinuing OAC. Thirty-seven patients had AF postablation, and 32/37 (86.5 %) remained on OAC. One patient with a mechanical valve had a stroke despite OAC. Bleeding occurred in 8.3 % of patients on OAC and 0 % of patients off OAC (P = 0.027).

Conclusions

Patients with prior CVA/TIAs, who undergo successful AF ablation, have a low incidence of subsequent thromboembolic events. Most patients who appear AF free postablation may be able to discontinue OAC after successful ablation with a low thromboembolic risk and with a reduced bleeding risk.

Comparison of CHADS2 and CHA2DS2-VASC anticoagulation recommendations: evaluation in a cohort of atrial fibrillation ablation patients

Aims

Atrial fibrillation (AF) is associated with a high incidence of strokes/thromboembolism. The CHADS₂ score assigns points for several clinical variables to identify stroke risk. The CHA₂DS₂-VAS_C score uses the same variables but also incorporates age 65 to 74, female gender, and vascular disease in an effort to provide a more refined risk of stroke/thromboembolism. We aimed to examine oral anticoagulation (OAC) recommendations for a cohort of patients undergoing AF ablation depending upon whether thrombo-embolic risk was determined by the CHADS₂ or CHA₂DS₂-VAS_C score.

Methods and results

For 1411 patients we compared OAC recommendations for each of these risk stratification schemes to one of the three OAC strategies: (i) NO-OAC, (ii) CONSIDER-OAC, and (iii) DEFINITE-OAC. Compared with the CHADS₂ score, the CHA₂DS₂-VAS_C score reduced NO-OAC from 40.3 to 21.8% and CONSIDER-OAC from 36.6 to 27.9% while increasing DEFINITE-OAC from 23.0 to 50.2% of patients. Age 65 to 74 and female gender accounted for 95.2% and vascular disease for only 4.8% of recommendations for more aggressive OAC using CHA₂DS₂-VAS_C. Most vascular disease occurred in patients with higher CHADS₂ scores already recommended for DEFINITE-OAC (P < 0.0001). Reclassifying 30 females of age <65 with a CHA₂DS₂-VAS_C score of 1 to the NO-OAC group had minimal effect on the overall recommendations.

Conclusion

Compared with the CHADS₂ score, in our AF ablation population, the CHA₂DS₂-VAS_C score markedly increases the number of AF patients for whom OAC is recommended. It will be important to determine by randomized trials if this major paradigm shift to greater use of OAC using the CHA₂DS₂-VAS_C scoring improves patient outcomes.

Physician-controlled costs: the choice of equipment used for atrial fibrillation ablation

Purpose

Atrial fibrillation (AF) ablation uses expensive technology and equipment. Physicians have considerable latitude over equipment choice. Average Medicare reimbursement is $10,338 for uncomplicated AF ablations. The purpose of this study is to evaluate the cost of special equipment chosen by physicians to perform AF ablation.

Methods

We obtained the list price cost of special capital equipment and of disposable equipment (intracardiac ultrasound probes, transseptal needles/sheaths, and ablation/recording catheters) commonly used for radiofrequency (RF) AF ablation. We also evaluated the equipment cost of using robotic magnetic navigation and cryoablation. Then we evaluated costs for several physician equipment choice scenarios.

Results

Using open irrigated-tip catheters, the lowest estimated cost-per-case for manual RF ablation of AF was $6,637, and the highest estimated cost of manual RF ablation was $12,603. Assuming 200 AF ablations/year and a 6-year magnet life, the cost-per-case of using magnetic navigation ablation ranged from $12,261–$15,464. The cost-per-case using cryoballoons alone ranged from $12,847–$15,320, and if focal cryoablation or RF touch-up is needed, cryoablation cost increased to $15,942–$22,284.

Conclusions

Physicians have many choices in AF ablation equipment. Equipment costs in our arbitrary scenarios range from $6,637 to $22,284 per case. More important than the specific cost of each scenario is the concept that these are physician-driven costs, and as such, physicians will need to determine if more expensive technologies increase procedural efficacy and/or patient safety enough to justify the greater procedural equipment costs.

Atrial arrhythmia burden on long-term monitoring in asymptomatic patients late after atrial fibrillation ablation

Patients appearing free of atrial fibrillation (AF) based on limited electrocardiographic monitoring/clinical history late after ablation may still have a large silent AF burden and thus have failed ablations and may be at risk of thromboembolism. We evaluated long-term monitoring (LTM; 7 days or 1 year) in 203 patients off antiarrhythmic drugs who were clinically free of AF >1 year after ablation. A 7-day monitor was done in 186 and 17 had pacemakers in whom the most recent year was analyzed. Arrhythmia recurrence was >30 seconds of AF, flutter, or tachycardia. LTM was done 3.1 ± 1.3 years (range 1.1 to 7.3) after the last ablation. AF recurred in only 8 of 186 (4.3%) on 7-day monitoring. One had persistent AF. For the other 7, AF burden was 0.0075% to 3.34% with 3 of 7 having an AF burden ≤0.037%. AF recurred in 4 of 17 patients (23.5%) with pacemakers. The 4 patients with pacemakers and AF had a 1-year AF burden of 0.0037% to 0.16%. Given the longer duration of monitoring, pacemakers detected more AF than 7-day monitors (p <0.011). AF duration before ablation was the only predictor of AF recurrence on LTM (p = 0.01). In patients with symptomatic AF who appeared free of AF on clinical grounds an average of 3 years after ablation, AF burden on LTM was low. In conclusion, monitoring by implanted devices detects more AF than 7-day monitors, most patients exceeding the failure definition of >30 seconds have a small AF burden, and when using LTM for follow-up the definition of "ablation failure" may be better described by an AF burden >0.5% rather than a single 30-second arrhythmia recurrence.

Trends in atrial fibrillation ablation: have we maximized the current paradigms?

Purpose

The purpose of this study was to evaluate how atrial fibrillation (AF) ablation has evolved over time with regards to patient characteristics, procedural variables, complications, and outcomes.

Methods

We evaluated trends over time from 2003 to 2010 in clinical characteristics, procedural variables, complications, and Kaplan–Meier AF-free rates after the initial and final AF ablation in 1,125 patients undergoing 1,504 ablations.

Results

Evaluating trends from 2003 to 2010, we found that patients undergoing AF ablation became older (P < 0.0001), had higher CHADS₂ scores (P < 0.0001), and more coronary artery disease (P = 0.021), persistent AF (P < 0.0001), hypertension (P < 0.0001), and previous strokes/transient ischemic attacks (P = 0.005). Procedure times decreased from 256 ± 49 to 122 ± 28 min (P < 0.0005), fluoroscopy times decreased from 134 ± 29 to 56 ± 19 min (P < 0.0005), and major (P = 0.023), minor (P = 0.023), and total complications (P = 0.001) decreased over time. The learning curve to minimize complications was 6 years. For paroxysmal AF, initial ablation AF-free rates improved over time (P = 0.015) but improvement plateaued in recent years. For persistent AF, initial ablation AF-free rates trended toward improvement over time (P = 0.062) but also plateaued in recent years. For long-standing persistent AF (P = 0.995), there was no outcome improvement after initial ablation over time. There was no trend for improved final outcomes (including repeat ablations) over time for paroxysmal, persistent, or long-standing AF (P = 0.150 to P = 0.978).

Conclusions

Despite decreased procedural and fluoroscopy times and reduced complication rates, post-ablation freedom from AF has not improved commensurately in recent years. A better understanding of AF initiation and maintenance may be required to devise personalized approaches to AF ablation and further improve outcomes.

Prior antiarrhythmic drug use and the outcome of atrial fibrillation ablation

Aims

Atrial fibrillation (AF) ablation is generally performed after patients fail antiarrhythmic drug (AAD) therapy. Some patients have drug contraindications or choose to avoid a lifetime of drug therapy. Little is known about the impact of previous drug therapy on ablation outcomes. We evaluated AAD use before AF ablation and its impact on ablation outcomes.

Methods and results

We evaluated freedom from AF after ablation and patients' clinical characteristics by number of AADs failed in 1125 patients undergoing 1504 ablations. We also evaluated reasons why some patients did not receive prior drug therapy. Cox multivariate analysis examined factors predicting ablation failure. Patients failing more drugs before ablation were older (P = 0.001), had a longer duration of AF (P = 0.0001), were more likely female (P = 0.037), had more repeat ablations (P = 0.045), and less paroxysmal AF (P = 0.003). For patients with either paroxysmal or persistent AF, the number of drugs failed predicted AF recurrence (P = 0.0001). Other factors predicting AF recurrence following final ablation included age (P = 0.004), left atrial size (P = 0.002), female gender (P = 0.0001), and persistent AF (P = 0.0001). The reason for not receiving prior drug therapy was medical in 21.5% and patient choice in 78.5%. Number of drugs failed did not influence ablation outcome for patients with long-standing persistent AF (P = 0.352).

Conclusions

For paroxysmal and persistent AF patients undergoing ablation, those failing fewer AADs have different clinical characteristics than those who fail more drugs. Our study also suggests that the more drugs failed pre-ablation, the lower the freedom from AF post-procedure, possibly due to AF progression during drug trials.

Relation of early termination of persistent atrial fibrillation by cardioversion or drugs to ablation outcomes

Current ablation consensus documents define persistent atrial fibrillation (AF) as AF lasting >1 week to 1 year or AF requiring cardioversion or pharmacologic conversion in <1 week. These 2 persistent AF subgroups may have different clinical characteristics and ablation outcomes. We compared 179 patients whose persistent AF was always terminated in <1 week by cardioversion/drugs to 244 whose AF actually lasted >1 week to 1 year. Patients with AF termination in <1 week by cardioversion/drugs had smaller left atrial (LA) size (4.1 ± 0.6 vs 4.5 ± 0.7 cm, p <0.0001), a longer AF history (7.5 ± 7.5 vs 6.0 ± 7.2 years, p = 0.035), more failed drugs (1.6 ± 1.0 vs 1.3 ± 1.0, p = 0.004), lower body mass index (28.5 ± 5.5 vs 30.3 ± 5.5, p = 0.0008), and fewer cardiomyopathies (3.9% vs 11.1%, p = 0.01). Cox multivariate analysis showed that LA size (p = 0.02), female gender (p = 0.001), and coronary artery disease (p = 0.03) predict ablation failure. There was a linear relation between duration of longest AF episode and LA size (p = 0.0001). Longest AF episode duration was the only factor predicting LA size (p = 0.001). Kaplan-Meier analysis showed more patients with AF termination in <1 week by cardioversion/drugs were free of AF after ablation (p = 0.042) than those whose AF actually lasted >1 week to 1 year. Once AF lasted >1 week, duration up to 1 year did not affect ablation success. In conclusion, patients whose persistent AF is always terminated by drugs/cardioversion in <1 week have different clinical characteristics and better ablation outcomes than patients whose AF persists beyond 1 week. This suggests that maintaining sinus rhythm before ablation is beneficial and that the definition of AF2 may need revision.

Long-term results of atrial fibrillation ablation: the importance of all initial ablation failures undergoing a repeat ablation

BACKGROUND

Ablation is more successful for patients with paroxysmal atrial fibrillation (AF1) than for those with persistent (AF2) or longstanding persistent AF (AF3). Many patients fail initial ablation and undergo repeat ablations. Little is known about repeat ablation procedure times, complications, and outcomes.

METHODS

We evaluated Kaplan-Meier freedom from AF by AF type and sex for initial and repeat ablations and for final status of 843 patients undergoing 1122 ablations. We examined complications, procedure times and reasons why patients do not undergo repeat ablations. Cox multivariate analysis evaluated factors predicting ablation failure.

RESULTS

Initial ablations were more successful in AF1 than AF2 or AF3 (P < .0001) patients. For each AF type, repeat ablations were more successful than initial ablations (P = .01 to <.001). Procedure times (139.1 ± 49.1 vs 135.3 ± 45.6 minutes, P = .248) and major complications (1.66% vs 2.87%, P = .216) were similar. Women had different clinical characteristics than men, similar initial and repeat ablation success rates but lower overall success because of fewer repeat ablations (57.8% vs 68.2%, P = .047) due to patient choice (P = .028). Patients with either successful initial ablations or undergoing repeat ablations had late AF recurrence rates of 0% to 1.5% a year. Age (P = .012), larger left atria (P = .002), female sex (P = .001), AF2 (P < .0001), AF3 (P = .003), and coronary disease (P = .003) predicted failure.

CONCLUSIONS

Repeat ablations are more successful than initial ablations, have similar procedure times and complication rates, help determine final success rates, and may explain sex difference in success rates. For the best outcomes, patients should assume that a repeat ablation may be required to eliminate AF.

The use of a radiofrequency needle improves the safety and efficacy of transseptal puncture for atrial fibrillation ablation

BACKGROUND

Atrial fibrillation (AF) ablation requires transseptal puncture to gain entry to the left atrium (LA). On rare occasions, LA entry cannot be achieved or cardiac perforation results in pericardial tamponade.

OBJECTIVE

This study sought to compare a new radiofrequency (RF) transseptal needle with the standard needle.

METHODS

We evaluated 1,550 AF ablations in 1,167 patients. We compared 975 transseptal punctures done using a standard needle to 575 done using a new electrode-tipped needle attached to an RF perforation generator.

RESULTS

The rate of failure to cross the atrial septum was lower for the RF needle (1 of 575 [0.17%] vs. 12 of 975 [1.23%], P = .039) and there were fewer pericardial tamponades with the RF needle (0 of 575 [0.00%] vs. 9 of 975 [0.92%], P = .031). Multivariate analysis showed the RF needle use was the only variable associated with a lower incidence of tamponade (P = .04). Becasuse the RF needle was used later in our series, we examined our 975 standard needle punctures over time for evidence of improved operator experience that might explain the superior RF results. For the standard needle, there was no trend for improved septal crossing rates (P = .794) or fewer tamponades (P = .456) with more operator experience. Instrumentation time was shorter for the RF needle (27.1 ± 10.9 vs. 36.4 ± 17.7 minutes, P < .0001).

CONCLUSION

Our data suggest that the RF needle is superior to the standard transseptal needle. It results in shorter instrumentation times, a greater efficacy in transseptal crossing, and fewer episodes of pericardial tamponade.

Safety of lower activated clotting times during atrial fibrillation ablation using open irrigated tip catheters and a single transseptal puncture

Guidelines largely based on closed-tip catheters recommend activated clotting times (ACTs) >300 to 350 seconds during atrial fibrillation (AF) ablation to prevent thrombus and char formation. Open irrigated tip catheters (OITC) may decrease complications and permit lower ACTs. This study evaluated factors contributing to vascular and hemorrhagic complications during AF ablation with emphasis on catheter type, anticoagulation level, procedural and clinical variables, and gender. In 1,122 AF ablations we examined catheter used, ACT level, gender, and complications. Target ACTs initially were >300 seconds and were decreased to 225 seconds for the OITC. Average ACT ranges were created: <250, 250 to 299, 300 to 350, and >350 seconds. Average ACT was <250 seconds in 557 ablations (complication rate 1.62%). Cochran-Armitage analysis showed that complications increased linearly as ACT increased and peaked at 5.55% for ablations with ACTs >350 seconds (p = 0.038). Women were older (66 ± 10 vs 60 ± 10 years, p <0.001) and had more paroxysmal AF (43% vs 28%, p = 0.007) and more hypertension (50% vs 40%, p = 0.013). Women received less heparin but were over-represented in higher ACT ranges (p <0.0001) consistent with a pharmacokinetic gender difference. There was no difference in vascular or hemorrhagic complications between men and women (2.3% vs 2.9%, p = 0.668). Multivariate logistic regression showed that only use of the OITC was associated with lower complication rates (p = 0.024). In conclusion, AF ablation with the OITC is safe with a target ACT of 225 seconds.

Dobutamine stress echocardiography in preoperative and long-term postoperative risk assessment of elderly patients

The authors reviewed all negative preoperative dobutamine stress echocardiograms (DSEs) performed over a 3-year period to determine the value of negative DSE for preoperative risk assessment in elderly patients. All patients with negative DSE performed for preoperative evaluation were followed. Cardiac event rates during and after the operative procedure were determined for hard end points (nonfatal myocardial infarction, cardiac death) and soft end points (emergency room visits, hospitalization for unstable angina, congestive heart failure, coronary angioplasty, coronary artery bypass graft surgery). Results noted that DSEs were negative for ischemia in 82 preoperative evaluations. Group 1 (age >/=65; n=41) had hard and soft event rates per patient/year of 0.97% and 7.3%, while group 2 (age <65; n=41) had hard and soft event rates per patient/year of 0.81% and 10.8%. There were no significant differences in event rates between the two groups (p=NS). In conclusion, the authors found that negative DSEs predict low cardiac event rates in elderly patients during the perioperative and long-term postoperative periods, which are not significantly different from the cardiac event rates in a younger cohort.

Dual AV nodal pathway physiology after injury with radiofrequency energy in a patient without a history of reentrant tachycardia

Radiofrequency (RF) atrioventricular (AV) nodal modification has been reported to occasionally produce a proarrhythmic effect. Dual AV nodal pathway physiology in patients without reentrant tachychardia has also been reported. This case describes AV nodal modification with RF energy in an anatomically intermediate area resulting in the appearance of discontinuous antegrade conduction curves and reentry in a patient in which these were previously not present. This suggests that AV nodal injury may be a mechanism for acquired AV nodal reentry.