Novel ablation strategy superior to PVI for persistent AF

A three-step ablation strategy that systematically targets multiple proarrhythmogenic atrial structures appeared superior to pulmonary vein isolation (PVI) alone in patients with persistent atrial fibrillation (AF), according to 10-month results of a new study presented at EHRA 2023.

Eighty-four percent of patients treated with the Marshall Plan ablation were free from AF or atrial tachycardia (AT) at 10 months compared with 69 percent in patients treated with the conventional PVI, reported study author Dr Thomas Pambrun from the Centre Hospitalier Universitaire de Bordeaux in France. Follow up will continue until 12 months.

Redo procedures can be abated

Complete PVI is the cornerstone of AF ablation. However, success rate with PVI is only about 65–70 percent. With the more-comprehensive Marshall Plan ablation, physicians can fend off roughly 15 out of every 100 patients requiring a second ablation, said Pambrun.

“With the Marshall Plan, it takes an hour longer to perform. But for those 15 patients, we can cut down redo ablations,” he pointed out. “This is promising as more redo procedures with traditional PVI carry the risks of stroke, tamponade, and other adverse events.”

PVI or Marshall Plan

Patients with symptomatic, persistent AF were randomly assigned to PVI alone or the Marshall Plan ablation. Their average age was 67 years; 21 were women. The primary endpoint was recurrence of AF or AT lasting >30 seconds at 12 months (including a 3-month blanking period) after a single ablation procedure.

Total radiofrequency time was significantly longer with PVI compared with the Marshall Plan (29 minutes vs 23 minutes; p<0.001). The full lesion set was completed in 88 percent of patients receiving the Marshall Plan and 98 percent of those undergoing PVI alone.

In the intention-to-treat analysis, the recurrence of AF/AT >30 seconds after 10 months was significantly higher in the PVI alone group (18 vs 9; p= 0.038).

Important takeaway

When investigators performed a redo ablation (nine patients in the PVI-only group and six patients in the Marshall Plan group), they found that the pulmonary veins were completely isolated in all patients treated with PVI.

“This is an important point. It means we have no more gaps to close and there is no more room for improvement in these patients,” said Pambrun.

By comparison, all six patients in the Marshall Plan group had identifiable spaces in the lesion set, “which means we can have an improvement in these patients even after we closed the gaps,” he explained.

In terms of complications, there was one massive groin hematoma reported in a patient ablated with the Marshall Plan.

Discussant Dr Gerhard Hindricks from the Leipzig Heart Center, Germany said the trial gets at the root of an important question: What can be done in addition to PVI to improve outcomes in patients with persistent AF?

Different strategies have been shown to be effective, but none of those have been tested in a randomized clinical trial, he added. “With the Marshall Plan, we can expect an improved outcome in our patients.”

The 12-month results are eagerly awaited and need to be confirmed in a multicentre trial.