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% (Ptrend <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% (Ptrend <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.

Novel Low-Voltage MultiPulse Therapy to Terminate Atrial Fibrillation.

OBJECTIVES: This first-in-human feasibility study was undertaken to translate the novel low-voltage MultiPulse Therapy (MPT) (Cardialen, Inc., Minneapolis, Minnesota), which was previously been shown to be effective in preclinical studies in terminating atrial fibrillation (AF), into clinical use. BACKGROUND: Current treatment options for AF, the most common arrhythmia in clinical practice, have limited success. Previous attempts at treating AF by using implantable devices have been limited by the painful nature of high-voltage shocks. METHODS: Forty-two patients undergoing AF ablation were recruited at 6 investigational centers worldwide. Before ablation, electrode catheters were placed in the coronary sinus, right and/or left atrium, for recording and stimulation. After the induction of AF, MPT, which consists of up to a 3-stage sequence of far- and near-field stimulation pulses of varied amplitude, duration, and interpulse timing, was delivered via temporary intracardiac leads. MPT parameters and delivery methods were iteratively optimized. RESULTS: In the 14 patients from the efficacy phase, MPT terminated 37 of 52 (71%) of AF episodes, with the lowest median energy of 0.36 J (interquartile range [IQR]: 0.14 to 1.21 J) and voltage of 42.5 V (IQR: 25 to 75 V). Overall, 38% of AF terminations occurred within 2 seconds of MPT delivery (p < 0.0001). Shorter time between AF induction and MPT predicted success of MPT in terminating AF (p < 0.001). CONCLUSIONS: MPT effectively terminated AF at voltages and energies known to be well tolerated or painless in some patients. Our results support further studies of the concept of implanted devices for early AF conversion to reduce AF burden, symptoms, and progression.

Evaluation of left ventricular systolic function using synchronized analysis of heart sounds and the electrocardiogram.

BACKGROUND: Heart failure is a major health concern and often requires echocardiography to confirm the diagnosis. We introduce a new method that uses a wearable heart sound and electrocardiogram (ECG) device that can be used in the outpatient setting. OBJECTIVE: The purpose of this study was to determine the value of synchronized analysis of heart sounds and ECG in identifying patients with depressed left ventricular ejection fraction (dLVEF) <50%. METHODS: One hundred eighty-nine patients (76 with dLVEF; 113 with normal ejection fraction) were enrolled. All were admitted to the hospital because of dyspnea or chest discomfort. N-Terminal pro-B-type natriuretic peptide (NT-proBNP) was measured in all patients. LVEF was determined by echocardiography. Heart sound and ECG signals were simultaneously recorded using the wearable synchronized phonocardiogram and ECG device. Heart sound and ECG signals were automatically analyzed using wavelet analysis and utilized to determine electromechanical activation time (EMAT), EMAT/RR, S1-S2 time, and S1-S2/RR. RESULTS: EMAT in the dLVEF group was significantly higher than that in the control group (159.82 ± 83 ms vs 91.58 ± 28 ms). Pearson correlation test showed a negative correlation between EMAT and LVEF (r = -0.449; P <.001). Receiver operating characteristic curve analysis demonstrated that the sensitivity and specificity of EMAT ≥104 ms for the diagnosis of EF <50% were 92.1% and 92%, respectively. Patients with intermediate NT-proBNP values were identified as dLVEF by EMAT ≥104 ms, with sensitivity of 93.5% and specificity of 92.8%. CONCLUSION: The heart sound and ECG signal index EMAT contributes to the diagnosis of EF <50% and is especially helpful in patients with an inconclusive NT-proBNP value.

High-power, short-duration atrial fibrillation ablations using contact force sensing catheters: Outcomes and predictors of success including posterior wall isolation.

BACKGROUND: Little is known about the long-term outcomes and predictors of success of high-power, short-duration (HPSD) contact force (CF) atrial fibrillation (AF) ablations. OBJECTIVE: The purpose of this study was to determine long-term freedom from AF and predictors of freedom from AF for 50-W, 5- to 15-second CF ablation. METHODS: We examined 4-year outcomes and predictors of freedom from AF after AF ablation for 1250 consecutive patients undergoing HPSD CF ablations. RESULTS: Patient demographics were age 66.6 ± 10.5 years, female 30.9%, left atrial (LA) size 4.26 ± 0.66 cm, paroxysmal AF 35.7%, persistent AF 56.6%, and longstanding AF 7.7%. Initial ablation times were procedure 114.2 ± 45.9 minutes, fluoroscopy 15.5 ± 11.5 minutes, and total radiofrequency 20.6 ± 7.7 minutes. TactiCath was used in 47.7%, SmartTouch in 52.3%, and posterior wall isolation (PWI) was performed in 34%. Four-year freedom from AF after multiple ablations were paroxysmal AF 87.0%, persistent AF 71.9%, and longstanding AF 64.9%. Single procedure success was 74.9% for TactiCath, 64.7% for SmartTouch (P <.001), and 73.0% for no PWI vs 58.9% for PWI (P <.0001). PWI did not change outcomes for paroxysmal AF but had worse outcomes for nonparoxysmal AF. Multivariate analysis showed 6 independent predictors of worse outcome after initial ablation: older age (P = .014), female gender (P <.0001), persistent AF (P = .0001), larger LA size (P <.001), PWI (P = .049), and use of SmartTouch vs TactiCath catheter (P = .007). Redo ablations were performed in 13.8%, and the outcome was better when more veins had reconnected after the initial ablation and when AF was paroxysmal. CONCLUSION: Analysis revealed 6 independent predictors of outcome for HPSD CF. At redo ablations, the outcome was better if more veins had reconnected and could be re-isolated.

Catheter ablation for failed surgical maze: comparison of cut and sew vs. non-cut and sew maze.

PURPOSE: To compare findings in patients undergoing atrial fibrillation(AF) and/or atrial flutter(AFl) ablation after failed cut and sew (CS) vs. non-cut and sew (NCS) surgical maze. METHODS: We compared 10 patients with prior CS to 25 with prior NCS maze undergoing catheter ablation after failed maze. RESULTS: Patient demographics: Age 68.3 ± 8.7 CS vs. 68.2 ± 9.2 NCS(P = 0.977), male 70% CS vs. 72% NCS(P = 1.000), LA size 5.11 ± 0.60 cm CS vs. 4.54 ± 0.92 cm NCS(P = 0.096), sternotomy 100% CS vs. 64% of NCS(P = 0.036). Concomitant heart surgery in 100% CS and 68% NCS(P = 0.073). NCS used radiofrequency 84%, cryoablation 8%, microwave 4%, and ultrasound 4%. All maze operations targeted pulmonary vein (PV) isolation. The maze also targeted the mitral isthmus 100% CS vs. 36% NCS(P = 0.001) and the tricuspid isthmus 90% CS vs. 40% NCS (P = 0.018). Maze failure arrhythmia mechanism was AF 0% CS and 56% NCS (P = 0.0006). Nine CS pts failed for AFl and 1 for RA tachycardia. For NCS pts, 11 failed for AFl. CS isolated 94% of PVs and NCS isolated only 26% of PVs (P < 0.0005). At EPS, clinical and induced arrhythmias were ablated and non-isolated PVs were isolated. After final ablation, arrhythmia-free rates were 60% for CS and 52% for NCS (P = 0.723) after 2.99 ± 2.35 years. CONCLUSIONS: After failed surgical maze, CS isolated nearly all PVs and NCS never isolated all PVs and the clinical rhythm was more frequently AF for NCS and AFl for CS. CS remains the surgical gold standard for durable PV isolation.

Low complication rates using high power (45-50 W) for short duration for atrial fibrillation ablations.

BACKGROUND: Many centers use radiofrequency (RF) energy at 25-35 W for 30-60 seconds. There is a safety concern about using higher power, especially on the posterior wall. OBJECTIVE: The purpose of this study was to examine complication rates for atrial fibrillation (AF) ablations performed with high-power, short-duration RF energy. METHODS: We examined the complication rates of 4 experienced centers performing AF ablations at RF powers from 45-50 W for 2-15 seconds per lesion. In total, 13,974 ablations were performed in 10,284 patients. On the posterior wall, 11,436 ablations used 45-50 W for 2-10 seconds, and 2538 ablations used power reduced to 35 W for 20 seconds. Esophageal temperature monitoring was used in 13,858 (99.2%). RESULTS: Demographics were age 64 ± 11 years, male 68%, left atrial size 4.4 ± 0.7 cm, paroxysmal AF 37%, persistent AF 42%, longstanding AF 20%, antiarrhythmic drugs failed 1.4 ± 0.7, hypertension 54%, diabetes 15%, previous cerebrovascular accident/transient ischemic attack 7%, and CHA2DS2-VASc score 2.1 ± 1.4. Procedural time was 116 ± 41 minutes. Complications were death in 2 (0.014%; 1 due to stroke and 1 due to atrioesophageal fistula), pericardial tamponade in 33 (0.24%; 26 tapped, 7 surgical), strokes <48 hours in 6 (0.043%), strokes 48 hours-30 days in 6 (0.043%), pulmonary vein stenosis requiring intervention in 2 (0.014%), phrenic nerve paralysis in 2 (0.014%; both resolved), steam pops 2 (0.014%) without complications, and catheter char 0 (0.00%). There was 1 atrioesophageal fistula in 11,436 ablations using power 45-50 W on the posterior wall and 3 in 2538 ablated with 35 W on the posterior wall (P = .021), although 2 of the 3 had no esophageal monitoring during a fluoroless procedure. CONCLUSION: AF ablations can be performed at 45-50 W for short durations with very low complication rates. High-power, short-duration ablations have the potential to shorten procedural and total RF times and create more localized and durable lesions.

Impact of obesity on atrial fibrillation ablation: Patient characteristics, long-term outcomes, and complications.

BACKGROUND: There is an association between obesity and atrial fibrillation (AF). The impact of obesity on AF ablation procedures is unclear. OBJECTIVE: The purpose of this study was to evaluate the influence of body mass index (BMI) on patient characteristics, long-term ablation outcomes, and procedural complications. METHODS: We evaluated 2715 patients undergoing 3742 AF ablation procedures. BMI was ≥30 kg/m2 in 1058 (39%) and ≥40 kg/m2 in 129 (4.8%). Patients were grouped by BMI ranges (<25, 25-<30, 30-<35, 35-<40, and ≥40 kg/m2). RESULTS: As BMI increased from <25 to ≥40 kg/m2, age decreased from 65.3 ± 11.2 to 61.2 ± 9.2 years (P < .001), left atrial size increased from 3.91 ± 0.68 to 4.72 ± 0.62 cm (P < .005), and CHADS2 scores increased from 1.24 ± 1.10 to 1.62 ± 1.09 (P < .001). As BMI increased, paroxysmal AF decreased from 48.0% to 16.3% (P < .0001) and there was an increase in dilated cardiomyopathy (from 7.6% to 12.4%; P < .0001), hypertension (from 41.0% to 72.9%; P < .0001), diabetes (from 4.3% to 23.3%; P < .0001), and sleep apnea (from 7.0% to 46.9%; P < .0001). For the entire cohort, for BMI ≥35 kg/m2 the 5-year ablation freedom from AF decreased from 67%-72% to 57% (P = .036). For paroxysmal AF, when BMI was ≥40 kg/m2 ablation success decreased from 79%-82% to 60% (P = .064), and for persistent AF, when BMI was ≥35 kg/m2 ablation success decreased from 64%-70% to 52%-57% (P = .021). For long-standing AF, there was no impact of BMI on outcomes (P = .624). In multivariate analysis, BMI ≥35 kg/m2 predicted worse outcomes (P = .036). Higher BMI did not impact major complication rates (P = .336). However, when BMI was ≥40 kg/m2, minor (from 2.1% to 4.4%; P = .035) and total (from 3.5% to 6.7%; P = .023) complications increased. CONCLUSION: In patients undergoing AF ablation, increasing BMI is associated with more patient comorbidities and more persistent and long-standing AF. BMI ≥35 kg/m2 adversely impacts ablation outcomes, and BMI ≥40 kg/m2 increases minor complications.

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.

Retrieval of the Leadless Cardiac Pacemaker: A Multicenter Experience.

BACKGROUND: Leadless cardiac pacemakers have emerged as a safe and effective alternative to conventional transvenous single-chamber ventricular pacemakers. Herein, we report a multicenter experience on the feasibility and safety of acute retrieval (<6 weeks) and chronic retrieval (>6 weeks) of the leadless cardiac pacemaker in humans. METHODS AND RESULTS: This study included patients enrolled in 3 multicenter trials, who received a leadless cardiac pacemaker implant and who subsequently underwent a device removal attempt. The overall leadless pacemaker retrieval success rate was 94%: for patients whose leadless cardiac pacemaker had been implanted for <6 weeks (acute retrieval cohort), complete retrieval was achieved in 100% (n=5/5); for those implanted for ≥ 6 weeks (chronic retrieval cohort), retrieval was achieved in 91% (n=10/11) of patients. The mean duration of time from implant to retrieval attempt was 346 days (range, 88-1188 days) in the chronic retrieval cohort, and nearly two thirds (n=7; 63%) had been implanted for >6 months before the retrieval attempt. There were no procedure-related adverse events at 30 days post retrieval procedure. CONCLUSIONS: This multicenter experience demonstrated the feasibility and safety of retrieving a chronically implanted single-chamber (right ventricle) active fixation leadless pacemaker. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifiers: NCT02051972, NCT02030418, and NCT01700244.

Predicting atrial fibrillation ablation outcome: The CAAP-AF score.

BACKGROUND: Patients with a variety of clinical presentations undergo atrial fibrillation (AF) ablation. Long-term ablation success rates can vary considerably. OBJECTIVE: The purpose of this study was to develop a clinical scoring system to predict long-term freedom from AF after ablation. METHODS: We retrospectively derived the scoring system on a development cohort (DC) of 1125 patients undergoing AF ablation and tested it prospectively in a test cohort (TC) of 937 patients undergoing AF ablation. RESULTS: The demographics of the DC patients were as follows: age 62.3 ± 10.3 years, male sex 801 (71.2%), left atrial size 4.30 ± 0.69 cm, paroxysmal AF 348 (30.9%), number of drugs failed 1.3 ± 1.1, hypertension 525 (46.7%), diabetes 100 (8.9%), prior stroke/transient ischemic attack 78 (6.9%), prior cardioversion 528 (46.9%), and CHADS2 score 0.87 ± 0.97. Multivariate analysis showed 6 independent variables predicting freedom from AF after final ablation: coronary artery disease (P = .021), atrial diameter (P = .0003), age (P = .004), persistent or long-standing AF (P < .0001), number of antiarrhythmic drugs failed (P < .0001), and female sex (P = .0001). We created a scoring system (CAAP-AF) using these 6 variables, with scores ranging from 0 to 13 points. The 2-year AF-free rates by CAAP-AF scores were as follows: 0 = 100%, 1 = 95.7%, 2 = 96.3%, 3 = 83.1%, 4 = 85.5%, 5 = 79.9%, 6 = 76.1%, 7 = 63.4%, 8 = 51.1%, 9 = 53.6%, and ≥10 = 29.1%. Ablation success decreased as CAAP-AF scores increased (P < .0001). The CAAP-AF score also predicted freedom from AF in the TC. The 2-year Kaplan-Meier AF-free rates by CAAP-AF scores were as follows: 0 = 100%, 1 = 87.0%, 2 = 89.0%, 3 = 91.6%, 4 = 90.5%, 5 = 84.4%, 6 = 70.1%, 7 = 71.0%, 8 = 60.7%, 9 = 68.9%, and ≥10 = 51.3%. As CAAP-AF scores increased, 2-year freedom from AF in the TC decreased (P < .0001). CONCLUSION: An easily determined clinical scoring system was derived retrospectively and applied prospectively. The CAAP-AF score predicted freedom from AF after ablation in both a DC and a TC of patients undergoing AF ablation. The CAAP-AF score provides a realistic AF ablation outcome expectation for individual patients.

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.

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-VASC 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-VASC 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-VASC 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-VASC. 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-VASC 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-VASC 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-VASC scoring improves patient outcomes.

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.

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 CHADS(2) 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.