«Complete» and «incomplete» ablation lines for radiofrequency isolation of the pulmonary veins - is there a difference in reconnection and clinical efficacy?

Purpose. To compare the effect of the completed and incomplete ablation lines on the permanent isolation of the pulmonary veins (PV) during intracardiac electrophysiological (EP) examination 3 months after the operation, as well as to assess the frequency of recurrence of atrial fibrillation (AF) and its relationship with the reconnection in the PV.

Methods. From January to December 2016, 60 patients with paroxysmal AF selected and operated. Patients were randomized into two groups in a 1:1 ratio. In the first group, after achieving isolation of PV, radiofrequency (RF) exposure continued until an anatomically continuous line of ablation was created. In the second group, after receiving electrical isolation of all PV, RF ablation was interrupted regardless of the anatomical completeness of the ablation line. After 3 months in a planned manner (regardless of clinical status), an endocardial EP study was performed to check the consistency of the input and output block of excitation in each PV and, if necessary, repeated RF ablation of the reconnection sites.

Results. A total of 53 people completed the study. In the first group intracardiac EP examination was performed on 29 patients, in the second group - on 24 patients. In the first group 4 patients retained isolation of all PV (13.8%), and in the second group - 5 (20.8%). No significant difference between the groups was obtained (p = 0.267). Sinus rhythm 3 months after the first procedure was observed in 28 patients (52.8%), of which 78.5% had reconnection in at least one PV. The recurrence rate of AF between the groups did not differ (OR 0.488 95% CI 0.162-1.460 p = 0.563) In the first group after 15 months the sinus rhythm was observed in 19 of 29 patients (65.5%), in the second group in 18 of 24 patients (75%). Differences are not statistically significant (OR 0.633 95% CI 0.191-2.103 p = 0.612)

Conclusions: in our study, there was no significant difference in the frequency of reconnection and the clinical efficacy of RF isolation of PV in groups with complete and incomplete ablation lines.

1. Haissaguerre M, Jais P, Shah DC, et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998;339(10): 659-66 DOI: 10.1056/NEJM199809033391003.

2. Hakalahti A, Biancari F, Nielsen JC, et al. Radiofrequency ablation vs. antiarrhythmic drug therapy as first line treatment of symptomatic atrial fibrillation: systematic review and meta-analysis. Europace. 2015;17: 370-378. DOI: 10.1093/europace/euu376.

3. Revishvili ASh, Lyubkina EV, Labartkava EZ. Radiofrequency isolation of the left atrium or ablation of the pulmonary veins with atrial fibrillation: advantages and disadvantages of various approaches. Annals of arrhythmology. 2005;2: 64-75 (In Russ).

4. Cappato R, Calkins H, Chen SA, et al. Updated worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circ Arrhythm Electrophysiol. 2010;3: 32-38. DOI: 10.1161/CIRCEP.109.859116.

5. Kozlov AV, Durmanov SS. The role of various catheter treatment strategies for atrial fibrillation in improving clinical outcomes. Journal of Creative cardiology. 2017;11(4): 348-360 (In Russ) DOI: 10.24022/1997-3187-2017-11-4-348-360.

6. Gerstenfeld EP, Callans DJ, Dixit S, et al. Incidence and location of focal atrial fibrillation triggers in patients undergoing repeat pulmonary vein isolation: implications for ablation strategies. J Cardiovasc Electrophysiol. 2003;14: 685-690. DOI: 10.1046/j.1540-8167.2003.03013.x.

7. Nanthakumar K, Plumb VJ, Epstein AE, et al. Resumption of electrical conduction in previously isolated pulmonary veins: rationale for a different strategy? Circulation. 2004; 109: 1226-1229 DOI:10.1161/01.CIR.0000121423.78120.49.

8. Kottkamp H, Tanner H, Kobza R, et al. Time courses and quantitative analysis of atrial fibrillation episode number and duration after circular plus linear left atrial lesions: trigger elimination or substrate modification: early or delayed cure? J Am Coll Cardiol. 2004;44: 869-877. DOI: 10.1016/j.jacc.2004.04.049.

9. Hocini M, Sanders P, Haïssaguerre M. et al. Prevalence of pulmonary vein disconnection after anatomical ablation for atrial fibril-lation: consequences of wide atrial encircling of the pulmonary veins. Eur Heart J. 2005;26: 696- 704. DOI: 10.1093/eurheartj/ehi096.

10. Pablo B. Nery, Daniel Belliveau, Girish M. Nair et al. Relationship between pulmonary vein reconnection and atrial fibrillation recurrence a systematic review and meta-analysis. JACC: Clinical Electrophysiology. 2016;2(4): 474-483 DOI:10.1016/j.jacep.2016.02.003.

11. Kuck K-H, Hoffmann BA, Ernst S, et al. Impact of complete versus incomplete circumferential lines around the pulmonary veins during catheter ablation of paroxysmal atrial fibrillation. Circ Arrhythm Electrophysiol. 2016;9:e003337 DOI: 10.1161/CIRCEP.115.003337.

12. Phlips T, Taghji P, Duytschaever M. Improving procedural and one-year outcome after contact force-guided pulmonary vein isolation: the role of interlesion distance, ablation index, and contact force variability in the ‘CLOSE’-protocol. Europace. 2018 Nov 1;20: 419-427. DOI:10.1093/europace/eux376

13. Weerasooriya R1, Jaïs P, Haïssaguerre M. Dissociated pulmonary vein arrhythmia: Incidence and characteristics. Pacing Clin Electrophysiol. 2003. 26:941. DOI: 10.1046/j.1540-8167.2003.02583.x.

14. Ganesan AN, Shipp NJ, Brooks AG, et al. Longterm outcomes of catheter ablation of atrial fibrillation: a systematic review and meta-analysis. J Am Heart Assoc. 2013;2(2):e004549. DOI: 10.1161/JAHA.112.004549.

15. Katritsis DG, Pokushalov E, Romanov A, et al. Autonomic denervation added to pulmonary vein isolation for paroxysmal atrial fibrillation: a ran-domized clinical trial. J Am Coll Cardiol. 2013;62: 2318-25 DOI: 10.1016/j.jacc.2013.06.053.

16. Narayan SM, Krummen DE, Clopton P, et al. Direct or coincidental elimination of stable rotors or focal sources may explain successful atrial fibrillation ablation: on-treatment analysis of the CONFIRM trial (Conventional ablation for AF with or without focal impulse and rotor modulation). J Am Coll Cardiol. 2013;62: 138-47. DOI: 10.1016/j.jacc.2013.03.021.