Marshall-Plan Ablation Strategy Versus Pulmonary Vein Isolation in Persistent AF: A Randomized Controlled Trial

Abstract

Background: Beyond pulmonary vein (PV) isolation, the optimal ablation strategy for persistent atrial fibrillation (AF) remains poorly defined. The purpose of this study was to compare 2 ablation strategies in the treatment of patients with persistent AF: a comprehensive ablation strategy based on anatomic considerations versus PV isolation alone.

Methods: The Marshall-Plan trial is a prospective, randomized, parallel-group, controlled clinical trial of superiority conducted at the Bordeaux University Hospital. Consecutive patients with symptomatic, documented persistent AF were included and randomized into 2 arms: Marshall-Plan consisting of PV isolation with additional ablation including vein of Marshall ethanol infusion, and lines of block at the mitral, dome, and cavotricuspid isthmuses versus PV isolation alone. The main outcome was the 1-year freedom from any arrhythmia (atrial fibrillation/atrial tachycardia >30 seconds) after a single ablation procedure with or without any antiarrhythmic medication at 12 months.

Results: A total of 120 patients were included (age 65±8 years; 21 women). Two patients were excluded from analysis. All PVs were successfully isolated in both groups. In the Marshall-Plan group, vein of Marshall ethanol infusion was completed in 57 (97%) patients. Conduction block across linear lesions was obtained in 93%, 92%, and 93% of the mitral, dome, and cavotricuspid isthmuses, respectively. The full lesion set was successfully completed in 52 (88%) patients in the Marshall-Plan group and 59 (100%) patients in the PV isolation group. At 12 months, freedom from recurrence of atrial arrhythmia >30 seconds after 1 ablation procedure, with or without antiarrhythmic medication, had occurred in 51 of the 59 (86.4%) patients assigned to the Marshall-Plan approach, and 39 of the 59 (66.1%) patients assigned to PV isolation only (P=0.012).

Conclusions: In this prospective randomized controlled trial, the Marshall-Plan strategy was significantly superior to a PV isolation strategy at 12 months.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04206982.

Keywords: cardiac arrhythmia; ethanol; heart; human; pulmonary veins; tachycardia; therapeutics.

Figure 1.

Marshall-Plan lesion set. The figure shows the 3 systematic step plus 1 supplemental step in case of gap in the left atrial (LA) lines of the Marshall-Plan ablation strategy. Step 1: ethanol infusion in the vein of Marshall (VOM); Step 2: pulmonary vein (PV) isolation. The ablation points represented in light red indicate that radiofrequency application overlapping with ethanol-induced low voltage area were reduced in time. Step 3: linear lesion completion at the mitral, dome, and cavotricuspid isthmuses. It includes systematic coronary sinus (CS) ablation at the atrial aspect at the level of the endocardial line. Supplemental step: if the mitral line is not blocked after step 3, ablation at the CS free wall is performed if required. If the roof line is not blocked after step 3, creation of a floor line is performed between the lowest part of the PV encirclements.

Figure 2.

Study flowchart. Consecutive patients with symptomatic documented persistent atrial fibrillation (AF) were included and randomized in 2 arms: Marshall-Plan vs pulmonary vein (PV) isolation.

Figure 3.

Freedom from atrial fibrillation. The graph shows Kaplan-Meier estimates of freedom from any documented arrhythmias (atrial fibrillation [AF]/atrial tachycardia [AT] >30 seconds). A, After a single ablation procedure with or without antiarrhythmic medication at 12 months. B, After a single ablation procedures without antiarrhythmic medication at 12 months. C, After 1 or 2 ablation procedures without antiarrhythmic medication at 12 months. There were significant differences between groups in favor of the Marshall-Plan strategy (P=0.012, P=0.022, and P=0.011, respectively).

Figure 4.

Mode of arrhythmia recurrence during follow-up. Distribution of the mode of arrhythmia recurrence in both group. AF indicates atrial fibrillation; AT, atrial tachycardia; Parox AF, paroxysmal AF; and pers AF, persistent AF.

Figure 5.

Evolution of the left atrial function after ablation. A, A-wave velocity (cm/s) at post-ablation, 3- and 12-month for all the patients included in the Marshall-Plan group (blue line) and pulmonary vein (PV) isolation (red line; mean±SD). Right panel: A-wave velocity (cm/s) at post ablation, 3- and 12-month for patients in atrial fibrillation (AF) at the beginning of the procedure (mean±SD) and for patients in sinus rhythm (SR) at the beginning of the procedure (mean±SD) included in the Marshall-Plan group (blue line) and PV isolation (red line). B, Transmitral flow velocity assessment for a patient from the Marshall-Plan group and in AF at inclusion. Note the evolution of the A-wave velocity from 36 cm/s at day 1 post-ablation to 80 cm/s at 12-month post-ablation.