Real-time local impedance monitoring to assess tissue lesion during pulmonary vein isolation: a new tool for AF ablation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Di Cori ◽  
L Segreti ◽  
G Zucchelli ◽  
S Viani ◽  
F Tarasco ◽  
...  

Abstract Background Contact force catheter ablation is the gold standard for treatment of atrial fibrillation (AF). Local tissue impedance (LI) evaluation has been recently studied to evaluate lesion formation during radiofrequency ablation. Purpose Aim of the study was to assess the outcomes of an irrigated catether with LI alghorithm compared to contact force (CF)-sensing catheters in the treatment of symptomatic AF. Methods A prospective, single-center, nonrandomized study was conducted, to compare outcomes between CF-AF ablation (Group 1) and LI-AF ablation (Group 2). For Group 1 ablation was performed using the Carto 3© System with the SmartTouch SF catheter and, as ablation target, an ablation index value of 500 anterior and 400 posterior. For Group 2, ablation was performed using the Rhythmia™ System with novel ablation catheter with a dedicated algorithm (DirectSense) used to measure LI at the distal electrode of this catheter. An absolute impedance drop greater than 20Ω was used at each targeted. According to the Close Protocol, ablation included a point by point pulmonary vein isolation (PVI) with an Inter-lesion space ≤5 mm in both Groups. Procedural endpoint was PVI, with confirmed bidirectional block. Results A total of 116 patients were enrolled, 59 patients in Group 1 (CF) and 57 in Group 2 (LI), 65 (63%) with a paroxismal AF and 36 (37%) with a persistent AF. Baseline patients features were not different between groups (P=ns). LI-Group showed a comparable procedural time (180±89 vs 180±56, P=0.59) but with a longer fluoroscopy time (20±12 vs 13±9 min, P=0.002). Wide antral isolation was more often observed in CF-Group (95% vs 80%, P=0.022), while LI-Group 2 required frequently additional right or left carina ablation (28% vs 14%, P=0.013). The mean LI was 106±14Ω prior to ablation and 92.5±11Ω after ablation (mean LI drop of 13.5±8Ω) during a median RF time of 26 [19–34] sec for each ablation spot. No steam pops or complications during the procedures were reported. The acute procedural success was 100%, with all PVs successfully isolated in all study patients. Regarding safety, only minor vascular complications were observed (5%), without differences between groups (p=0.97). During follow up, 9-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 86% in Group 1 and 75% in Group 2 (P=0.2). Conclusions An LI-guided PV ablation strategy seems to be safe and effective, with acute and mid-term outcomes comparable to the current contact force strategy. LI monitoring could be a promising complementary parameter to evaluate not only wall contact but also lesion formation during power delivery. Procedural Outcomes Funding Acknowledgement Type of funding source: None

EP Europace ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 1197-1205
Author(s):  
Shu-Nan He ◽  
Ying Tian ◽  
Liang Shi ◽  
Yan-Jiang Wang ◽  
Bo-Qia Xie ◽  
...  

Abstract Aims Circumferential pulmonary vein isolation can be effective as sole treatment for persistent atrial fibrillation. However, identifying those patients who will respond to this therapy remains a challenge. We investigated the clinical value of the sequential low-dose ibutilide test for identifying patients with persistent atrial fibrillation in whom pulmonary vein isolation is effective as sole therapy. Methods and results In a prospective cohort of 180 consecutive patients with persistent atrial fibrillation, intravenous low-dose (0.004 mg/kg) ibutilide was administered 3 days before ablation and after the completion of circumferential pulmonary vein isolation. In patients in whom ibutilide did not terminate atrial fibrillation pre-procedurally, but successfully terminated it intraprocedurally, no further atrial substrate modification was performed. Pre-procedural low-dose ibutilide failed to terminate the arrhythmia in all patients with persistent atrial fibrillation, while pulmonary vein isolation ± low-dose ibutilide terminated persistent atrial fibrillation in 55 (30.6%) of them (PsAF group 1). The remaining 125 (69.4%) patients underwent electrogram-based ablation (PsAF Group 2). The control group comprised 379 consecutive patients with paroxysmal atrial fibrillation who underwent pulmonary vein isolation over the same period. At 24 months follow-up, 39 (70.9%) patients in PsAF Group 1 and 276 (72.8%) patients in the control group were free from atrial tachyarrhythmias (P = NS); the arrhythmia-free rates in both groups were higher than that in PsAF group 2 (58.4%, P = 0.005). Conclusion The sequential low-dose ibutilide test is a simple method for identifying patients with persistent atrial fibrillation in whom pulmonary vein isolation alone is an appropriate treatment strategy.


2020 ◽  
Vol 13 (9) ◽  
Author(s):  
Zak Loring ◽  
DaJuanicia N. Holmes ◽  
Roland A. Matsouaka ◽  
Anne B. Curtis ◽  
John D. Day ◽  
...  

Background: Catheter ablation is an increasingly used treatment for symptomatic atrial fibrillation (AF). However, there are limited prospective, nationwide data on patient selection and procedural characteristics. This study describes patient characteristics, techniques, treatment patterns, and safety outcomes of patients undergoing AF ablation. Methods: A total of 3139 patients undergoing AF ablation between 2016 and 2018 in the Get With The Guidelines-Atrial Fibrillation registry from 24 US centers were included. Patient demographics, medical history, procedural details, and complications were abstracted. Differences between paroxysmal and patients with persistent AF were compared using Pearson χ 2 and Wilcoxon rank-sum tests. Results: Patients undergoing AF ablation were predominantly male (63.9%) and White (93.2%) with a median age of 65. Hypertension was the most common comorbidity (67.6%), and patients with persistent AF had more comorbidities than patients with paroxysmal AF. Drug refractory, paroxysmal AF was the most common ablation indication (class I, 53.6%) followed by drug refractory, persistent AF (class I, 41.8%). Radiofrequency ablation with contact force sensing was the most common ablation modality (70.5%); 23.7% of patients underwent cryoballoon ablation. Pulmonary vein isolation was performed in 94.6% of de novo ablations; the most common adjunctive lesions included left atrial roof or posterior/inferior lines, and cavotricuspid isthmus ablation. Complications were uncommon (5.1%) and were life-threatening in 0.7% of cases. Conclusions: More than 98% of AF ablations among participating sites are performed for class I or class IIA indications. Contact force-guided radiofrequency ablation is the dominant technique and pulmonary vein isolation the principal lesion set. In-hospital complications are uncommon and rarely life-threatening.


EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
P Kupo ◽  
R Pap ◽  
G Bencsik ◽  
M Kohari ◽  
A Benak ◽  
...  

Abstract Background The most common complications of electrophysiology (EP) procedures are related to vascular access. Purpose Our study aimed to compare the ultrasound (US)-guided (Group 1) vs. palpation-based (Group 2) technique for femoral venous access in atrial fibrillation (AF) ablation procedures. Methods Between January 2018 and October 2019, 355 patients undergoing pulmonary vein isolation (PVI) on uninterrupted anticoagulant treatment were included. They were allocated to Group 1 or 2 based on which of the two procedure rooms their procedure was scheduled in, with only one of the rooms equipped with an US machine including an 8 MHz linear transducer. Major and minor complications and the rate of prolonged hospitalization were compared in the two groups. Major vascular complication was defined as groin hematoma, arteriovenous fistula, or pseudoaneurysm. Hematoma was considered as a major vascular complication if it met type 2 or higher Bleeding Academic Research Consortium (BARC) criteria (requiring nonsurgical, medical intervention by a health care professional; leading to hospitalization or increased level of care, or prompting evacuation). Results Of the 355 patients 105 were allocated to Group 1 and 250 included in Group 2. Compared to the standard technique, the use of US significantly reduced both major (from 5.60% to 0.95%, p = 0.047) and minor (from 6.40% to 0.95%, p = 0.029) vascular complications. The absolute risk reduction (ARR) of minor/major vascular complications was 10.10% equated to a relative risk reduction (RRR) of 84.13%, and a number needed to treat (NNT) of 10 to prevent one bleeding event. No difference was found for the rate of prolonged hospitalization (5.04% vs. 0.95%, p = 0.119). Conclusion With the use of US for the femoral vein puncture in patients undergoing PVI procedure the rate of both major and minor vascular complications were lower.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
A Azul Freitas ◽  
P Sousa ◽  
V Goncalves ◽  
C Ferreira ◽  
S Martinho ◽  
...  

Abstract Introduction Catheter ablation has become the first-line treatment for symptomatic patients with atrial fibrillation (AF). Several approaches of substrate ablation have been used for persistent and long-standing persistent AF and the best protocol procedure is yet to be established. The purpose of this study was to evaluate the outcomes of patients submitted to catheter ablation of persistent and long-standing persistent AF adding extra-pulmonary substrate approaches to pulmonary vein isolation. Methods We retrospectively studied 67 consecutive patients referred for the first procedure of catheter ablation of persistent or long-standing persistent AF from May 2016 to October 2018. The first 27 patients were subjected to pulmonary vein isolation and complex fractionated atrial electrograms (CFAE) ablation (group 1) and the last 40 patients were subjected to a tailored approach guided by voltage map areas and CFAE (group 2). Patient characteristics, procedure details and follow-up were assessed, and predictors of recurrence were determined. Results Mean age was 59±11 years with 58% being male. During a mean follow-up of 16±6 months 27% of the patients showed AF recurrence. There were no differences in baseline characteristics of group 1 and 2. A higher recurrence rate was found in group 1 by comparison with group 2 (40.7% vs 17.5%, Log Rank X2 = 5.076, P=0.024) (Figure 1). Also, recurrence was associated with a longer AF duration, an increased baseline Brain Natriuretic Peptide (BNP), an increased left atrium (LA) volume, the presence of hyperthyroidism, the absence of sinus rhythm after procedure, the inducibility of AF post-ablation and the absence of an antiarrhythmic drug at hospital discharge. After adjustment for other confounders, the patient group (HR 5.16 [1.23–21.71] P=0.025), a long-standing AF (HR 9.09 [1.41–58.82] P=0.020), the BNP value at admission (HR 1.03 [1.01–1.05] P=0.033) and the LA volume index (HR 1.13 [1.02–1.25] P=0.017) were the only independent predictors of recurrence. Conclusion Ablation of persistent and long-standing persistent AF is feasible with good results when a substrate approach is added to pulmonary vein isolation. A tailored approach seems to be more efficient, showing best outcomes in mid-term follow-up. A long-standing AF, higher BNP value and the LA enlargement are important predictors of recurrence and should be used to better select patients and to manage follow-up. FUNDunding Acknowledgement Type of funding sources: None.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257050
Author(s):  
Nándor Szegedi ◽  
Zoltán Salló ◽  
Péter Perge ◽  
Katalin Piros ◽  
Vivien Klaudia Nagy ◽  
...  

Introduction Our pilot study aimed to evaluate the role of local impedance drop in lesion formation during pulmonary vein isolation with a novel contact force sensing ablation catheter that records local impedance as well and to find a local impedance cut-off value that predicts successful lesion formation. Materials and methods After completing point-by-point radiofrequency pulmonary vein isolation, the success of the applications was evaluated by pacing along the ablation line at 10 mA, 2 ms pulse width. Lesions were considered successful if loss of local capture was achieved. Results Out of 645 applications, 561 were successful and 84 were unsuccessful. Compared to the unsuccessful ablation points, the successful applications were shorter (p = 0.0429) and had a larger local impedance drop (p<0.0001). There was no difference between successful and unsuccessful applications in terms of mean contact force (p = 0.8571), force-time integral (p = 0.0699) and contact force range (p = 0.0519). The optimal cut-point for the local impedance drop indicating successful lesion formation was 21.80 Ohms on the anterior wall [AUC = 0.80 (0.75–0.86), p<0.0001], and 18.30 Ohms on the posterior wall [AUC = 0.77 (0.72–0.83), p<0.0001]. A local impedance drop larger than 21.80 Ohms on the anterior wall and 18.30 Ohms on the posterior wall was associated with an increased probability of effective lesion creation [OR = 11.21, 95%CI 4.22–29.81, p<0.0001; and OR = 7.91, 95%CI 3.77–16.57, p<0.0001, respectively]. Conclusion The measurement of the local impedance may predict optimal lesion formation. A local impedance drop > 21.80 Ohms on the anterior wall and > 18.30 Ohms on the posterior wall significantly increases the probability of creating a successful lesion.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Dan L Musat ◽  
Nicolle S Milstein ◽  
Jacqueline Pimienta ◽  
Advay Bhatt ◽  
Tina C Sichrovsky ◽  
...  

Background: Pulmonary vein isolation (PVI) is a cornerstone of atrial fibrillation (AF) ablation procedures to treat symptomatic AF. Ablation success is defined by absence of AF recurrence >30 seconds. However, reduction in AF burden (AFB) is also an important endpoint. Whether patients with paroxysmal (PAF) and persistent AF (PeAF) have similar reduction in AFB post-ablation is unknown. Objective: To compare the decrease in AFB following cryoballoon (CB) PVI in patients with PAF and PeAF. Methods: We enrolled consecutive pts with an implantable loop recorder (ILR) who subsequently underwent CB PVI. All patients were followed prospectively for at least one year, or until repeat ablation; we compared AFB pre and post-ablation. Results: The cohort included had 47 patients (66 ± 10 years; 32 [68%] male; PAF [n=23, 49%]; CHA 2 DS 2 -VASc 2.7 ± 1.7, 34 [72%] on AAD at the time of ablation). A median of 136 days [IQR 280, 73; minimum of 30 days] of ILR data pre-ablation were available. The median AFB for PAF was 4.7% [IQR 0.9, 14.8] and PeAF was 6.8% [IQR 1.1, 40.4]. After excluding a 3-month post-ablation blanking period, recurrent AF occurred in 12 (52%) PAF and 11 (46%) PeAF patients. The median AFB post-ablation for PAF and PeAF cohorts was 0.03%, [IQR 0, 0.3] and 0.04%, [IQR 0, 1.1], respectively. This represents a >99% reduction in AFB. Conclusion: Although 50% of patients undergoing CB PVI for PAF or PeAF had a recurrence of AF, there was >99% reduction in AFB in both groups. These data highlight the importance of using AFB burden as a marker of therapeutic efficacy post-AF ablation.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Tilz ◽  
C L Lenz ◽  
P S Sommer ◽  
N Sawan ◽  
R Meyer-Saraei ◽  
...  

Abstract Background Based on the assumption of trigger elimination, pulmonary vein isolation (PVI) currently presents the gold standard of atrial fibrillation (AF) ablation. Recently, rapidly spinning rotors or focal impulse formation has been raised as a crucial sustaining mechanism of AF. Ablation of these rotors may potentially obviate the need for trigger elimination with PVI. Purpose This study sought to compare the safety and effectiveness of Focal Impulse and Rotor Modulation (FIRM) guided catheter ablation only with the gold standard of pulmonary vein isolation (PVI) in patients with paroxysmal AF. Methods This was a post-market, prospective, single-blinded, randomized, multi-center trial. Patients were enrolled at three centers and equally (1:1) randomized between those undergoing conventional RF ablation with PVI (PVI group) vs. those treated with FIRM-guided RF ablation without PVI (FIRM group). Data was collected at enrollment, procedure, and at 7-day, 3-month, 6-month, and 12-month follow-up visits. The study was closed early by the sponsor. At the time of study closure, any pending follow-up visits were waived. Results From February 2016 until February 2018, a total of 51 (out of a planned 170) patients (mean age 63±10.6 years, 57% male) were enrolled and randomized. Four patients withdrew from the study prior to treatment, resulting in 23 patients allocated to the FIRM group and 24 in the PVI group. Only 13 patients in the FIRM group and 11 patients in the PVI group completed the 12-month follow-up. Statistical analysis was not completed given the small number of patients. Single-procedure effectiveness (freedom from AF/atrial tachycardia recurrence after blanking period) was 52.9% (9/17) in the FIRM group and 85.7% (12/14) in the PVI group at 6 months; and 31.3% (5/16) in the FIRM group and 80% (8/10) in the PVI group at 12 months. Repeat procedures were performed in 45.8% (11/24) patients in the FIRM group and 7.4% (2/27) in the PVI group. The acute safety endpoint [freedom from procedure-related serious adverse events (SAE)] was achieved in 87% (20/23) of FIRM group patients and 100% (24/24) of PVI group patients. Procedure related SAEs occurred in three patients in the FIRM group: 1 femoral artery aneurysm and 2 injection site hematomas. No additional procedure-related SAEs were reported >7 days post-procedure. Conclusions These partial study effectiveness results reinforce the importance of PVI in paroxysmal atrial fibrillation patients and suggest that FIRM-guided ablation alone (without PVI) is not an effective strategy for treatment of paroxysmal AF in most patients. Further study is needed to understand the effectiveness of adding FIRM-guided ablation as an adjunct to PVI in this patient group. Acknowledgement/Funding Abbot


EP Europace ◽  
2019 ◽  
Vol 22 (4) ◽  
pp. 567-575 ◽  
Author(s):  
Ruhong Jiang ◽  
Minglong Chen ◽  
Bing Yang ◽  
Qiang Liu ◽  
Zuwen Zhang ◽  
...  

Abstract Aims The optimal procedural endpoint to achieve permanent pulmonary vein isolation (PVI) during ablation of atrial fibrillation (AF) remains unknown. We aimed to compare the impact of prolonged waiting periods and adenosine triphosphate (ATP) testing after PVI on long-term freedom from AF. Methods and results In total, 538 patients (median age 61 years, 62% male) undergoing first-time radiofrequency ablation for paroxysmal AF were randomized into four groups: Group 1 [PVI (no testing), n = 121], Group 2 (PVI + 30min waiting phase, n = 151), Group 3 (PVI+ATP, n = 131), and Group 4 (PVI + 30min+ATP, n = 135). The primary endpoint was freedom from AF. Repeat mapping to assess for late pulmonary vein (PV) reconnection was performed in patients who remained AF-free for &gt;3 years (n = 46) and in those who had repeat ablation for AF recurrence (n = 82). During initial procedure, acute PV reconnection was observed in 33%, 26%, and 42% of patients in Groups 2, 3, and 4, respectively. At 36 months, no significant differences in freedom from AF recurrence were observed among all four groups (55%, 61%, 50%, and 62% for Groups 1, 2, 3, and 4, respectively; P = 0.258). Late PV reconnection was commonly observed, with a similar incidence between patients with and without AF recurrence (74% vs. 83%; P = 0.224). Conclusion Although PVI remains the cornerstone for AF ablation, intraprocedural techniques to assess for PV reconnection did not improve long-term success. Patients without AF recurrence after 3 years exhibited similarly high rates of PV reconnection as those that underwent repeat ablation for AF recurrence. The therapeutic mechanisms of AF ablation may not be solely predicated upon durable PVI.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
Y Fujimoto ◽  
K Yodogawa ◽  
Y Iwasaki ◽  
M Hachisuka ◽  
R Mimuro ◽  
...  

Abstract Background Atrial fibrillation (AF) ablation is the most commonly performed catheter ablation (CA) procedure today. The 2015 ACC/AHA/HRS Advanced Training Statement reported that the success rate of AF ablation is higher in high-volume centers than in low-volume centers. We tested whether the procedure proficiency of each operator was associated with the outcome of AF ablation, and whether the ablation outcome depended on whether contact force (CF)-guided catheters were used or not, in a high-volume center. Methods We conducted a retrospective observational study including all AF patients who underwent radiofrequency CA with or without CF support since 2016 at our hospital. The patients who underwent CA at other hospitals or underwent a balloon or surgical ablation in the first session were excluded. Each ipsilateral pulmonary vein (PV) pair was divided into 8 segments. The reconnection numbers and sites of the PV segment were evaluated in the second session. Operators were divided into the experienced group (≥100 AF cases/year, at least every 3 years) and developing group (other than the experienced group), respectively. Results Among 728 patients who underwent an initial AF ablation and were followed for 510±306 days, 131 (90 males, 65±10 years) received a second ablation procedure and were analyzed. A total of 260 and 264 PV isolations (PVI) were performed by the experienced and developing group operators in the initial ablation, respectively. Compared to the experienced group, the developing group had a longer procedure time for the PVI (35±15 vs. 28±10 min, p<0.001), higher frequency of reconnections of the PVs (73% vs. 59%, p=0.01) and higher number of reconnection gaps (2.1±2.0 vs. 1.5±2.0, p=0.02), respectively. There were no significantly differences in the number of gaps between the catheters with and without CF (1.6±2.0 vs. 1.4±2.0, p=0.65) in the experienced group, however, in the developing group a smaller total number of gaps (1.5±1.6 vs. 2.4±2.1, p=0.006) and less frequency reconnection gaps of the posterosuperior segment of the right PV (10% vs. 45%, p=0.005) were seen with catheters with CF than without. There was no significant difference in the procedure time for the PVI between catheters with and without CF. Conclusions The operator proficiency may predict the outcome after AF ablation even in high-volume centers. It is preferable to perform PVI with a CF-sensing catheter for operators without adequate proficiency. Acknowledgement/Funding JSPS KAKENHI Grant Number JP18K15865


2013 ◽  
Vol 34 (suppl 1) ◽  
pp. P491-P491
Author(s):  
M. Kimura ◽  
S. Sasaki ◽  
D. Horiuchi ◽  
K. Sasaki ◽  
S. Owada ◽  
...  

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