Clin Res Cardiol (2022). https://doi.org/10.1007/s00392-022-02002-5

Impact of additional substrate modification beyond pulmonary vein isolation on hospitalization mortality and atrial fibrillation recurrence in patients with heart failure

J. Kirchner1, C. Sohns2, L. Bergau3, P. Sommer4, D. Guckel5, G. Imnadze2, M. Khalaph2, V. Sciacca4, T. Fink2, P. Lucas2, M. Braun4, M. El Hamriti4

1Klinik für Kardiologie, Herz- und Diabeteszentrum NRW, Bad Oeynhausen; 2Elektrophysiologie/ Rhythmologie, Herz- und Diabeteszentrum NRW, Bad Oeynhausen; 3Allgemeine und Interventionelle Kardiologie/Angiologie, Herz- und Diabeteszentrum NRW, Bad Oeynhausen; 4Klinik für Elektrophysiologie/Rhythmologie, Herz- und Diabeteszentrum NRW, Bad Oeynhausen; 5Klinik für Elektrophysiologie/ Rhythmologie, Herz- und Diabeteszentrum NRW, Bad Oeynhausen;

Background: Atrial fibrillation (AF) often coexists in patients with heart failure (HF) resulting in remodeling in line with worsening of heart failure and progression of the underlying arrhythmia substrate. Patients with AF and HF benefit from catheter ablation but it remains unclear whether ablation beyond pulmonary vein isolation (PVI) might be associated with improved outcome. Aim: The purpose of this observation study was to test the hypothesis that additional substrate modification beyond PVI has beneficial effects on AF recurrence, hospitalization and mortality in patients with HF and reduced ejection fraction (HfrEF). Methods: Data from consecutive patients with AF and HFrEF who underwent AF ablation between 2017 and 2021 was analyzed and 118 patients were identified. Patients were divided into 3 subgroups based on the treatment they received: group 1: cryoballoon-guided PVI, n=33; group 2: radiofrequency (RF)-guided PVI n=28; group 3: PVI+substrate modification, n=57. Patients with RF-guided ablation approaches received ultra-high density mapping in sinus rhythm following PVI with a bipolar voltage reference interval between 0.05-0.5 mV. Substrate modification aimed to target areas of bipolar low-voltage. Patients were followed-up in our outpatient clinic. Arrhythmia recurrence was defined as AF or atrial tachycardia (AT) lasting >30s outside a three months blanking period. Primary endpoint was a composite of cardiovascular hospitalization and death within 18 months after ablation. Main secondary endpoints were, despite others, improvement of the left ventricular function and arrhythmia recurrence. Results: There were no significant differences in terms of patient baseline characteristics between the different subgroups. Mean procedure duration was 106 ±32 min in group 1, 120 ±52 min in group 2 and 143 ±53 min in group 3. We observed no procedure related complications requiring intervention. Patients from group 3 underwent the following approaches for substrate modification: anterior line n= 14, septal substrate modification n=5, roof line n= 2, posterior wall isolation n=7, box isolation of fibrotic areas in the left atrium n=11 and right atrium n=3, ablation of the cavotricuspid isthmus n= 22. After a median follow up of 358 days (range: 2-548 days), the composite primary endpoint was observed in a significantly lower proportion of patients from group 3 as compared to PVI-only approaches (RF-PVI and cryoballoon-guided PVI in combination: n=19; 33.3% vs. n=34; 55.7%; P= 0,014; %; HR: 0.55). In addition, AF recurrence was significantly lower in patients with PVI and substrate modification (PVI+substrate: n=7; 12.3% vs. RF-PVI and cryoballoon-guided PVI in combination: n=19; 31.1%; P= 0,027; HR 0.37). Mean left ventricular function significantly improved in all three subgroups (preablation: 33.6 % ± 6.3%; postablation: 40.9% ± 11.8%; P=0.01) without group-specific differences. Conclusions: Addition substrate modification beyond PVI improves cardiovascular hospitalization, death and AF recurrence in line with beneficial effects in terms of left ventricular reverse remodeling in patients with AF and HFrEF. More data from prospective multicenter trails is warranted to confirm this initial observation.

https://dgk.org/kongress_programme/jt2022/aP1522.html