The fundamental aspect of catheter ablation for atrial fibrillation is achieving complete isolation of the pulmonary veins. Nevertheless, after two years, only 50-60% of patients maintain a sinus rhythm despite this technique. Despite numerous trials involving various ablation strategies, none have proven to be more effective than pulmonary vein isolation (PVI).

Late-breaking research presented at the EHRA 2023 scientific congress of the European Society of Cardiology (ESC) indicates that an inventive three-step ablation technique, which involves ethanol infusion of the vein of Marshall, offers better outcomes in terms of arrhythmia-free status in patients with persistent atrial fibrillation than pulmonary vein isolation (PVI) alone. The findings presented pertain to initial results at the 10-month mark, with ongoing follow-up until 12 months.

The Marshall-Plan ablation approach entails three steps: 1) PVI; 2) ethanol infusion of the vein of Marshall; and 3) a linear ablation aimed at obstructing the three primary anatomical isthmuses to the pulmonary veins (namely, the dome, mitral, and cavotricuspid isthmus lines).

The procedure prioritizes anatomical objectives that have been identified as significant in the onset or perpetuation of atrial fibrillation, but which have not been systematically addressed in combination. Previous non-randomized studies conducted by the current investigators have reported promising outcomes with the use of this technique.

In the current investigation, the Marshall-Plan ablation technique was compared to PVI alone in terms of 12-month arrhythmia-free survival. This trial of superiority was prospective, randomized, and parallel group. 120 individuals with symptomatic persistent atrial fibrillation for over a month participated in the experiment. The participants’ average age was 67, and 21 (18%) of them were female.

To receive either the Marshall-Plan or PVI alone, participants were randomly assigned. Patients performed several tests as part of the follow-up at 3, 6, 9 and 12 months, including an electrocardiogram (ECG), echocardiogram, stress test, and 24-hour Holter monitoring. Arrhythmia recurrence was detected via ECG teletransmission, with results being provided to the hospital once per week in addition to whenever the patient experienced symptoms. After a single ablation procedure, the main outcome was the recurrence of atrial fibrillation or atrial tachycardia lasting longer than 30 seconds at 12 months (including a 3-month blanking interval).

The duration of total radiofrequency time was notably longer in the PVI group (29 minutes) than in the Marshall-Plan group (23 minutes), with a statistically significant difference (p<0.001). The complete lesion set was successfully accomplished in 53 patients (88%) who underwent the Marshall-Plan technique and 59 patients (98%) who received PVI exclusively. Based on an intention-to-treat analysis, the rate of arrhythmia recurrence following an average follow-up of 10 months was significantly higher in the PVI group compared to the Marshall-Plan group (18 vs. 8 patients, respectively; p=0.026). The follow-up period will continue until the 12-month mark.

“After 10 months of follow up, the success rate in the Marshall-Plan group was significantly better (87%) compared to the PVI only group (70%),” remarks Principal investigator Dr. Nicolas Derval from the University Hospital of Bordeaux.

But, “the results are still preliminary as follow up is not completed for all patients. While the findings indicate that the Marshall-Plan strategy holds promise for patients with persistent atrial fibrillation, they need to be confirmed in a multicentre trial.”

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