Gregory Engel

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

BACKGROUNDnAblation 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.nnnMETHODSnWe 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.nnnRESULTSnInitial 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.nnnCONCLUSIONSnRepeat 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.

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.

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

BACKGROUNDnAtrial 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.nnnOBJECTIVEnThis study sought to compare a new radiofrequency (RF) transseptal needle with the standard needle.nnnMETHODSnWe 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.nnnRESULTSnThe 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).nnnCONCLUSIONnOur 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.

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

BACKGROUNDnPatients with a variety of clinical presentations undergo atrial fibrillation (AF) ablation. Long-term ablation success rates can vary considerably.nnnOBJECTIVEnThe purpose of this study was to develop a clinical scoring system to predict long-term freedom from AF after ablation.nnnMETHODSnWe 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.nnnRESULTSnThe 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).nnnCONCLUSIONnAn 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.

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.

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

PurposeThis 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).MethodsThis 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.ResultsPatient age was 66.2u2009±u20099.0xa0years with an average CHADS2 scoreu2009=u20093.0u2009±u20090.9 and CHA2DS2-VASc scoreu2009=u20094.1u2009±u20091.4. Following 1.24 ablations, 71 (65.7xa0%) patients were AF free 2.8u2009±u20091.6 (median 2.3)u2009years after their last ablation. OAC was discontinued in 55/71 (77.5xa0%) patients an average of 7.3xa0months following the final ablation. These 55 patients had 2.2u2009±u20091.3 (median 1.8)u2009years of follow-up off of OAC. Kaplan–Meier analysis suggests little AF recurrence >1xa0year following initial or final ablations, suggesting that 1xa0year post successful ablation may be the appropriate time to consider discontinuing OAC. Thirty-seven patients had AF postablation, and 32/37 (86.5xa0%) remained on OAC. One patient with a mechanical valve had a stroke despite OAC. Bleeding occurred in 8.3xa0% of patients on OAC and 0xa0% of patients off OAC (Pu2009=u20090.027).ConclusionsPatients 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.

PurposeAtrial fibrillation (AF) ablation uses expensive technology and equipment. Physicians have considerable latitude over equipment choice. Average Medicare reimbursement is

Prior antiarrhythmic drug use and the outcome of atrial fibrillation ablation

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.MethodsWe 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.ResultsUsing open irrigated-tip catheters, the lowest estimated cost-per-case for manual RF ablation of AF was

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

6,637, and the highest estimated cost of manual RF ablation was

Atrial Fibrillation Ablation: “Perpetual Motion” of Open Irrigated Tip Catheters at 50 W Is Safe and Improves Outcomes

12,603. Assuming 200 AF ablations/year and a 6-year magnet life, the cost-per-case of using magnetic navigation ablation ranged from