Non-endocardial radiofrequency ablation of premature ventricular complexes (NERA-PVC): safety, efficacy and outcome

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Radiofrequency ablation (RF) is a well-established treatment for of premature ventricular complexes (PVCs) It is not uncommon to perform radiofrequency ablation of PVCs arising from epicardial/intramural localization, in particular those arising from the LV summit and aortic sinuses of Valsalva. PURPOSE: The aim is to investigate safety, efficacy, and outcome of PVCs radiofrequency ablation through a non-endocardial approach including high power and long duration RF applications. METHODS: We defined Non-Endocardial Radiofrequency Ablation (NERA) a procedure in which at least one RF site has been identified into the coronary venous system, aortic sinuses of Valsalva, inter-leaflet triangle or pulmonary cusps. We selected the study population from a series of consecutive patients who underwent radiofrequency ablation of PVCs from January 2017-May 2022, in whom at least one RF application has been realized according to the definition. RESULTS: During the study period, 399 patients underwent PVCs RF and 46 fulfilled the inclusion criteria (age: 59±13 years; 33, 72% males; mean LVEF:46±12%, mean PVC burden 26±10 %). The total number of NERA sites was 55: 15(27%) coronary venous system, 9(16%) right coronary cusp, 10(18%) left coronary cusp, 18 (33%) interleaflet triangle between right and left coronary cusp and 3 (5%) left pulmonary cusp. In 18 (39%) patients a multisite ablation was performed. Mean power during RF was 37±9 W (15-50) with median of 40W. Mean duration of single RF was 88±72 seconds (30-304) (median: 58 seconds). In 63% of the patients high power (40W or more) and in 55% long duration (>60 seconds) application was delivered in at least one of the ablation spots. Procedural success was achieved in 37 patients (80%). No complications related with RF site were observed. Multisite RF was significantly associated with procedural failure (OR 8,27; CI 1,48– 46,31; p=0,01). During follow up, mean PVCs burden was 7,3±9%, with a mean and median burden reduction (Δ) of 69±41% and 96%. The rate of event-free survival was 69%. Multisite RF and coronary venous system RF were predictors of recurrence (HR 3,81; 95% CI 1,14–12,66; p=0,02 and HR 3,88; 95% CI 1,23 – 12,27; p=0,01), while procedural success was protective (HR 0.1; CI 0.03 - 0.33, p < 0.001). After multivariate Cox proportional hazard analysis, coronary venous system RF was associated with higher VA recurrences during follow up (HR 2.71, CI 0.83 - 8.85, p= 0,09), while procedural success confirmed his protective role (HR 0.13, CI 0.04-0.42, p < 0,001). CONCLUSION: Radiofrequency ablation from non-endocardial sites is a safe and effective procedure, even using high power and/or long duration RF. Nevertheless long term outcomes are still characterized by a recurrence rate higher than in purely endocardial PVC ablation. [Figure: see text] [Figure: see text]