SIMULTANEOUS HYBRID ABLATION WITH EPI-ENDOCARDIAL MAPPING FOR THE TREATMENT OF LONG STANDING PERSISTENT ATRIAL FIBRILLATION

Abstract

BACKGROUND While the paroxysmal form of atrial fibrillation (AF) can be managed pharmaceutically with antiarrhythmic drugs or by means of catheter ablation, persistent AF and longstanding persistent atrial fibrillation (LsP-AF) have presented more of a challenge. Hybrid ablation offers a minimally invasive tailored approach for these non-paroxysmal forms of AF which are associated with a more complex substrate. Moreover, given the recent evidence of endo-epicardial electrical asynchrony that can develop in patients with PAF and LsP-AF it is necessary to extensively validate lesion transmurality. Our hybrid technique employs high-density electrical mapping of both the epicardial and endocardial surfaces allowing the team to validate endpoints of ablation in an extensive manner during the procedure which mitigates the risk of incomplete ablation lines that could create re-entrant circuits and recurrence of AF (Fig.1 A-D). METHODS AND RESULTS We describe the outcomes of 15 consecutive patients who underwent simultaneous thoracoscopic hybrid ablation with epi-endocardial mapping for the treatment of LsPAF (Fig.1 E-H). Patient outcomes were recorded at 3 months, 6 months, 1 year and last follow-up greater than 1 year for each patient. Rhythm status was obtained primarily via a 24 hr Holter monitor and if that was not available, ECG measurements were used. Table 1 lists patient and procedure characteristics: age 62.7±11 yr; mean AF duration 51.6 months [range: 14-130]; previous transcatheter (TC) ablation 3/15 (20%); previous cardioversion 12/15 (80%); box lesion set 15/15 (100%); ablation time 20 ±4 mins; surgical gaps 8/15 (53%); adverse events (bleeding/stroke/pacemaker implantation) (0%). At discharge 13/15 (86.6%) of patients were in sinus rhythm (SR) with a mean post-op stay of 3.8 ± 1.1 days. SR restoration was as follows: 3 month 14/15(93.3%), 6 month 13/15 (86.7%) SR off anti-arrhythmic drugs (AAD), 1yr 11/15 (73.3%) SR off AAD. At last follow-up (22±7 month) 13/15 (86.7%) patients were in SR with 11/15 (73.3%) patients in SR off AAD; 4 patients underwent repeat TC ablation 18±3.6 month post hybrid ablation. The same areas that were endocardially targeted as surgical gaps during the index procedure were re-ablated (3/4) and areas that were not seen as surgical gaps in the first place were ablated during the repeat TC procedure (4/4). CONCLUSION Our hybrid approach is safe, feasible and has shown successful SR restoration off AAD in 73% (11/15) of our patients at 1 year follow-up and epicardial mapping before and after endocardial ablation provided an additional means of lesion validation. While the paroxysmal form of atrial fibrillation (AF) can be managed pharmaceutically with antiarrhythmic drugs or by means of catheter ablation, persistent AF and longstanding persistent atrial fibrillation (LsP-AF) have presented more of a challenge. Hybrid ablation offers a minimally invasive tailored approach for these non-paroxysmal forms of AF which are associated with a more complex substrate. Moreover, given the recent evidence of endo-epicardial electrical asynchrony that can develop in patients with PAF and LsP-AF it is necessary to extensively validate lesion transmurality. Our hybrid technique employs high-density electrical mapping of both the epicardial and endocardial surfaces allowing the team to validate endpoints of ablation in an extensive manner during the procedure which mitigates the risk of incomplete ablation lines that could create re-entrant circuits and recurrence of AF (Fig.1 A-D). We describe the outcomes of 15 consecutive patients who underwent simultaneous thoracoscopic hybrid ablation with epi-endocardial mapping for the treatment of LsPAF (Fig.1 E-H). Patient outcomes were recorded at 3 months, 6 months, 1 year and last follow-up greater than 1 year for each patient. Rhythm status was obtained primarily via a 24 hr Holter monitor and if that was not available, ECG measurements were used. Table 1 lists patient and procedure characteristics: age 62.7±11 yr; mean AF duration 51.6 months [range: 14-130]; previous transcatheter (TC) ablation 3/15 (20%); previous cardioversion 12/15 (80%); box lesion set 15/15 (100%); ablation time 20 ±4 mins; surgical gaps 8/15 (53%); adverse events (bleeding/stroke/pacemaker implantation) (0%). At discharge 13/15 (86.6%) of patients were in sinus rhythm (SR) with a mean post-op stay of 3.8 ± 1.1 days. SR restoration was as follows: 3 month 14/15(93.3%), 6 month 13/15 (86.7%) SR off anti-arrhythmic drugs (AAD), 1yr 11/15 (73.3%) SR off AAD. At last follow-up (22±7 month) 13/15 (86.7%) patients were in SR with 11/15 (73.3%) patients in SR off AAD; 4 patients underwent repeat TC ablation 18±3.6 month post hybrid ablation. The same areas that were endocardially targeted as surgical gaps during the index procedure were re-ablated (3/4) and areas that were not seen as surgical gaps in the first place were ablated during the repeat TC procedure (4/4). Our hybrid approach is safe, feasible and has shown successful SR restoration off AAD in 73% (11/15) of our patients at 1 year follow-up and epicardial mapping before and after endocardial ablation provided an additional means of lesion validation.