As efficient as catheter ablation will be for sufferers with paroxysmal atrial fibrillation (AF), the process that goals for pulmonary vein isolation (PVI) has met a lot much less success in these with persistent AF, when episodes final every week to a yr or extra.
To spice up catheter ablation’s possibilities for achievement in persistent AF, PVI is usually augmented with additional ablation to attain posterior wall isolation (PWI). However the add-on technique has had blended success within the literature, and a newly revealed randomized trial has finished little to enhance its file.
The addition of PWI to PVI emerged as no higher than solo PVI at suppressing atrial arrhythmias over 1 yr within the worldwide CAPLA trial, arguing towards its routine use in sufferers just like the trial entered: symptomatic with drug-refractory persistent AF present process their first AF ablation process.
Posterior wall isolation “I believe is themost widespread add on-strategy to pulmonary vein isolation in sufferers with persistent atrial fibrillation,” Peter M. Kistler, MD, the Alfred Hospital and Baker Coronary heart and Diabetes Institute, Melbourne, Australia, informed theheart.org | Medscape Cardiology. “I have been doing it for greater than 10 years,” he stated, based mostly on supportive observational research.
However given the outcomes of CAPLA, “I’d specific warning about empirically isolating the posterior wall in sufferers with persistent AF as a first-time ablation technique,” stated Kistler, who’s lead creator on the examine’s January 10 publication within the Journal of the American Medical Affiliation. He additionally offered the ends in preliminary type final August on the European Society of Cardiology (ESC) Congress 2022.
Based mostly on present proof, he stated, sufferers present process first-time ablation for persistent AF ought to obtain PVI alone. In a possible exception, nonetheless, PVI plus ablation guided by markers for sluggish conduction could also be more practical.
Within the not too long ago revealed, randomized ERASE-AF trial, for instance, PVI plus individualized ablation guided by detection of atrial low-voltage myocardium suppressed atrial arrhythmias in sufferers much like these in CAPLA.
And, probably, PVI plus PWI could also be more practical in chosen sufferers with persistent AF, reminiscent of these with the arrhythmia for longer than 12 months. The few such sufferers in CAPLA, Kistler stated, confirmed a nonsignificant pattern favoring addition of PWI however, “One all the time needs to watch out in coming to conclusions based mostly on subgroup evaluation.”
“Whereas disappointing,” states an accompanying editorial, “the failure of the CAPLA trial to display a big enchancment in outcomes is a crucial discovering that ought to name into query the present understanding of the pathophysiology of persistent AF and the restrictions of present strategies.”
Many sufferers with persistent AF don’t present left atrial structural or electrographic proof of “sluggish and heterogeneous” conduction, observes Rod Passman, MD, Northwestern College Middle for Arrhythmia Analysis and Feinberg College of Drugs, Chicago.
“The profit, due to this fact, of empirically isolating a seemingly wholesome posterior wall in all sufferers with persistent AF could also be restricted,” he writes.
CAPLA randomly assigned 338 symptomatic adults (77% male) present process a first-time ablation for persistent AF at 11 facilities in Australia, Canada, and the UK to PVI-only procedures or to ablation for PVI and PWI. Antiarrhythmic meds had been allowed for three months after the process however had been “discouraged” thereafter.
Unsurprisingly, imply procedural time was considerably shorter, by 21 minutes, among the many 168 PVI-only sufferers in comparison with the 170 getting PVI plus PWI, as was the imply ablation time, by 6 minutes. Imply fluoroscopy occasions had been comparable, nonetheless.
Profitable PVI was achieved in all sufferers, and 86% of the PVI plus PWI group had profitable PWI. “There was zero procedural mortality, with no cerebrovascular occasions or esophageal fistula,” the report states.
The first endpoint, “freedom from any documented atrial arrhythmia of greater than 30 seconds with out antiarrhythmic remedy at 12 months after a single ablation process,” was met by 53.6% of solo PVI sufferers and 52.4% of the PVI plus PWI group (P = .98) at 1 yr. Nor was there a big distinction in AF burden.
“For sufferers with symptomatic persistent AF, the CAPLA trial gives one more disappointing outcome within the seek for efficient catheter-based therapies,” Passman writes.
“Whether or not new power sources reminiscent of pulsed-field ablation or extremely–low temperature cryotherapy will present sturdy transmural lesions that translate to higher outcomes for this inhabitants stays to be seen,” he continues, “however their favorable danger profiles have supplied wanted optimism.”
Cryoablation is unlikely to enhance PWI outcomes, Kistler stated, “as a result of it’s totally troublesome to get good contact on the posterior wall with the balloon.”
However pulsed-field ablation catheters are sometimes used for PWI, “and it looks like it is fairly efficient.” Which may be as a result of they do not pose a danger for thermal harm, reminiscent of to the esophagus, he noticed, and due to this fact allow extra thorough ablations.
Kistler experiences receiving speaker charges from Abbott Medical and serving on an advisory board for Biosense Webster. Disclosures for the opposite authors are within the report. Passman experiences receiving private charges from Medtronic and Abbott Laboratories for serving on steering committees; receiving grants from Abbott Laboratories, the Nationwide Institutes of Well being, and the American Coronary heart Affiliation for analysis on atrial fibrillation; and receiving royalties from UpToDate.
JAMA. Revealed on-line January 10, 2023. Full textual content, Editorial
Observe Steve Stiles on Twitter: @SteveStiles2. For extra from theheart.org | Medscape Cardiology, observe us on Twitter and Fb.