Pulsed field ablation improves atrial arrhythmia burden, quality of life in AF
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Key takeaways:
- Pulsed field ablation reduced atrial arrhythmia burden at 12 months in patients with atrial fibrillation.
- Those with low atrial arrhythmia burden had better quality of life.
In patients with atrial fibrillation, pulsed field ablation was associated with reduced atrial arrhythmia burden and improved quality of life, according to new data from the PULSED AF trial.
As Healio previously reported, in the main results of PULSED AF, a pulsed field ablation system (PulseSelect, Medtronic) was associated with a low rate of adverse events and was comparably effective to established AF ablation strategies. Atul Verma, MD, head of cardiology at McGill University Health Centre in Montreal, presented an analysis of effect of pulsed field ablation on atrial arrhythmia burden and quality of life in the PULSED AF cohort at Heart Rhythm 2023.
The primary outcome of PULSED AF was freedom from atrial arrhythmia recurrence of at least 30 seconds after a 90-day blanking period, but measurement of that is highly dependent on monitoring strategy, so some experts said they believe that improvement in atrial arrhythmia burden is a better measure of clinical success, Verma said during a press conference.
“With the 30-second endpoint, a lot of the variability of the results being reported may simply be due to the monitoring strategy being employed in these studies,” Verma told Healio. “Furthermore, we have known for a long time that the 30-second endpoint may be arbitrary and really doesn’t reflect how well the patients are actually doing. Those were the motivations behind this study.”
To demonstrate the inconsistency of the 30-second endpoint, the researchers “simulated three different monitoring methods, and we showed that the results in the same patients could vary by 20%, which is a huge number,” Verma told Healio.
The cohort included 300 patients, half of whom had persistent AF and the other half of whom had paroxysmal AF, who had failed antiarrhythmic drug therapy. The outcome of interest was atrial arrhythmia burden between the 90-day blanking period and 12 months.
Verma said atrial arrhythmia burden was calculated as the greater of either of the following:
- total duration of AF on all available Holter monitors divided by total duration of all available Holter monitors times 100; and
- number of weeks with at least one transtelephonic monitor reading showing atrial arrhythmia recurrence divided by number of weeks with at least one transtelephonic monitor reading times 100.
The second method is similar to the time-in-therapeutic range metric used to measure warfarin concentration in patients with AF, Verma said during the press conference. “Think of it as time in sinus rhythm,” he said.
Between 90 days and 12 months, 69% of patients with paroxysmal AF and 62% of patients with persistent AF had no atrial arrhythmia burden, whereas 87% of those with paroxysmal AF and 82% of those with persistent AF had atrial arrhythmia burden of less than 10%, the researchers found.
When the researchers measured time in atrial arrhythmia, they found that 83% of those with paroxysmal AF and 75% of those with persistent AF experienced 1 week or less of AF recurrence based on transtelephonic monitoring, with 70% of the paroxysmal AF group and 62% of the persistent AF group having no recurrence. In addition, they found that 96% of those with paroxysmal AF and 90% of those with persistent AF had less than 30 minutes per day of atrial arrhythmias detected on Holter monitoring, with 92% of the paroxysmal AF group and 87% of the persistent AF group having no atrial arrhythmias detected on Holter monitoring.
“On average, those recurrences were very short, either less than 1 week by TTM monitoring or less than 30 minutes by Holter monitoring,” Verma told Healio.
Based on results from the Atrial Fibrillation Effect on Quality of Life Questionnaire administered at baseline and at 12 months, the persistent AF group had clinically meaningful improvement, defined as an increase of at least 19 points, regardless of AF burden, but the paroxysmal AF group had clinically meaningful improvement only if their AF burden was less than 10%, Verma said.
“What does this mean? Probably a lot of the patients [with persistent AF] had a pre-ablation burden of 70% to 90%, so even if you bring it down to 40%, that is a big change for the patient,” Verma said during the press conference.
Increasing atrial arrhythmia burden was associated with increased repeat ablations (P = .0003 for paroxysmal AF; P = .0004 for persistent AF) and cardioversion (P = .001 for paroxysmal AF; P = .003 for persistent AF), according to the researchers. The difference in ED visits and hospitalization was not statistically significant, “but we found that most patients were not getting into the hospital or the ER until their AF burdens were in the 20% to 40% range,” Verma said.
“It’s very hard to mandate a monitoring strategy for a study, so when an [electrophysiologist] sees a result reported, they should immediately ask what was the monitoring strategy and how stringent was it,” Verma told Healio. “More studies should report atrial arrhythmia burden, or estimates of it based on their monitoring strategies, so that the community can get a better idea of how to interpret the data.”
The data “show that pulsed field ablation is a very effective treatment,” Verma told Healio. “This emphasizes how effective it is using an endpoint that is relevant to patient outcomes.”
Perspective
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The impact of reducing AF burden on improvement in quality of life is individualized. The benefit that a patient will derive from any rhythm control therapy will depend on the patient’s baseline clinical situation. Patients with persistent AF had a QOL improvement even with a post-ablation AF burden > 40%. It may be that a patient with persistent AF who now has paroxysmal AF due to some type of therapy, while deemed a failure using standard statistical methods such as a Kaplan Meier survival curve for recurrent AF, might be considered successful from the patient’s perspective.
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Verma A, et al. Late Breaking Clinical Trials and Science – Ablation. Presented at: Heart Rhythm 2023; May 19-21, 2023; New Orleans (hybrid meeting).
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