Stand-Alone Pulmonary Vein Isolation Versus Pulmonary Vein Isolation With Additional Substrate Modification as Index Ablation Procedures in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation

Abstract

C atheter ablation has become a routine treatment option for patients experiencing symptomatic paroxysmal atrial fibrillation (AF). Long-term clinical success rates of ≤80% after 5 years have been reported for the treatment of paroxysmal AF by initial stand-alone pulmonary vein isolation (PVI) as the accepted cornerstone of all AF ablation strategies; however, to achieve permanent PVI, multiple procedures are often required. 1,2 In contrast, the results for ablation of persistent AF are less convincing. 3 The optimal strategy for persistent AF is not known, and previous studies investigating more extensive ablation strategies in addition to PVI demonstrated heterogeneous results. [4][5][6][7][8][9][10][11][12] The recently published STAR AF 2 trial (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial) compared initial stand-alone PVI to PVI with additional ablation of complex fractionated atrial electrograms (CFAEs) or additional linear ablation and could not demonstrate a superior outcome for the additional ablation strategies. 13 The prospective and randomized Alster-Lost-AF © 2017 American Heart Association, Inc. Original ArticleBackground-Pulmonary vein isolation (PVI) for persistent atrial fibrillation is associated with limited success rates and often requires multiple procedures to maintain stable sinus rhythm. In the prospective and randomized Alster-Lost-AF trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation), we sought to assess, in patients with symptomatic persistent or long-standing persistent atrial fibrillation, the outcomes of initial ablative strategies comprising either stand-alone PVI (PVI-only approach) or a stepwise approach of PVI followed by complex fractionated atrial electrogram ablation and linear ablation (Substrate-modification approach). Methods and Results-Patients were randomized 1:1 to stand-alone PVI or PVI plus substrate modification. The primary study end point was freedom from recurrence of any atrial tachyarrhythmia, outside a 90-day blanking period, at 12 months. A total of 124 patients were enrolled, with 118 patients included in the analysis (61 in the PVI-only group, 57 in the Substrate-modification group). Atrial tachyarrhythmias recurred in 28 PVI-only group patients and 24 Substratemodification group patients, for 1-year freedom from tachyarrhythmia recurrence after a single ablation procedure of 54% (95% confidence interval, 43%-68%) in the PVI-only and 57% (95% confidence interval, 46%-72%) in the Substratemodification group (P=0.86). Twenty-four patients in the PVI-only group (39%) and 18 in the Substrate-modification group (32%) were without arrhythmia recurrence and off antiarrhythmic drug therapy at the end of the 12-month follow-up. Conclusions-In

Year in Review in Cardiac Electrophysiology

“…The value of atrial substrate ablation in addition to PVI versus PVI alone was assessed in a clinical trial, 18 which randomized 118 patients with persistent and longstanding persistent AF to undergo PVI alone or PVI with substrate modification targeting complex fractionated atrial electrograms and linear ablation. The 1-year freedom from atrial arrhythmia rates was comparable between the groups (54% in PVI alone versus 57% in PVI+substrate).…”

The extent of complex fractionated atrial electrograms in the left atrium reflects age‐related electrical remodeling in patients with persistent atrial fibrillation

“…However, it remains unknown whether complete elimination of CFAE area might cause a similar outcome, or whether age or extent of CFAEs itself are not associated with clinical outcome after catheter ablation. Several recent randomized clinical trials, including the RASTA study, STAR AF II, CHASE AF, and Alster‐Lost‐AF trial, revealed no clinical benefits of extensive adjuvant ablation at CFAE area beyond PV isolation . Nademanee has commented earlier that only very low voltage CFAEs responsible for scar regions in the atrium are important for targeting.…”

Long‐term outcomes of catheter ablation in patients with longstanding persistent atrial fibrillation lasting less than 2 years

“…Even if LA wall structural remodeling and fibrosis have been linked to worse ablation outcomes, strategies based on substrate modification in addition to PVAI have apparently failed to provide an advantage over PVAI alone …”