DECAAF II: AF, Fibrosis Ablation Falls Short, but Signs of Hope
The addition of image-guided atrial fibrosis ablation did not vastly decrease the likelihood of recurrence relative to pulmonary vein isolation (PVI) by myself in sufferers with remedy-resistant atrial fibrillation (AFib), in step with results of an scheme-to-contend with prognosis of the randomized DECAAF II trial.
However, there became as soon as a vital assist for the addition of image-guided ablation in the subgroup of sufferers with stage I or II fibrosis, and that’s a clinically meaningful finding, Nassir F. Marrouche, MD, reported at the annual congress of the European Society of Cardiology.
“Sufferers at early phases [of fibrosis] seem to complete effectively whenever you stop a lawful job protecting the myopathy [with scar formation], and which shall be a extremely crucial message,” acknowledged Dr. Marrouche, the main investigator.
The underlying hypothesis of the DECAAF trial became as soon as that ablation guided with MRI imaging would expose superior to PVI by myself in the remedy of resistant AF. There were 843 people randomized at 44 companies. At baseline, all underwent a leisurely gadolinium-enhancement MRI, one intention that permits detection of fibrotic tissue.
After randomization, those in the control crew underwent customary of care PVI by myself. These in the intervention crew underwent ablation of areas of the atrium printed to be fibrotic on the MRI scan as well to PVI.
5 Percent Possibility Reduction No longer Fundamental
After a median apply-up of 12 months, recurrence of AFib, which became as soon as the foremost endpoint, became as soon as seen in 43% in the intervention crew and 46.1% in the control crew. The relative 5% low cost for remedy became as soon as not statistically vital (hazard ratio, 0.95; 95% self belief interval, 0.778-1.17; P = .63).
As segment of the study about protocol, MRI became as soon as repeated 3 months after remedy in all sufferers. This authorised the investigators to retain in ideas the extent of scar formation in relation to the fibrosis covered in the intervention crew. Unbiased reviewers rated this coverage on phases from 1 to five, with 5 representing complete coverage.
On this prognosis, it became as soon as came across that ablation resulted in higher phases of lesion formation in those with early phases of disease, defined as stage I or II fibrosis, but decrease phases in evolved phases.
“The more myopathy, the more disease, the less likelihood of lesion formation,” reported Dr. Marrouche, professor of remedy in the half of cardiology at Tulane College, Sleek Orleans.
Attributed to the elevated phases of fibrosis coverage, the likelihood of AF recurrence over the route of apply-up became as soon as vastly diminished in the intervention relative to the control crew on as-treated prognosis in sufferers who had stage I or II fibrosis at baseline (HR 0.841, 95% CI, 0.732-0.968; P < .05).
Subgroup Knowledge Referred to as Clinically Fundamental
“This has gargantuan implications going forward,” Dr. Marrouche maintained. In the context of a series of old trials, including DECAAF I, which associated evolved fibrosis with higher likelihood of failing ablation, DECAAF II affords the groundwork for “the attach and the intention to ablate.”
Taken together, the DECAAF knowledge recommend that there is not any price in ablating evolved fibrosis. Due to the unpleasant scar formation desired to decrease likelihood of AF recurrence, there must always not any advantages to outweigh the a minute elevated likelihood of strokes and numerous unfavorable events seen amongst the intervention crew in the DECAAF II trial, in step with Dr. Marrouche.
“If the fibrosis is evolved, stop PVI finest,” he acknowledged.
“DECAAF tells you to center of attention on early disease,” he acknowledged. Requested if he would now be aware these knowledge to remedy of sufferers with early fibrosis, he replied, “Certain, that’s what I’m concluding.”
A total lot of aspects of the style of DECAAF II, such because the usage of a apply-up MRI to assess ablation at 3 months, were praised by Paul J. Wang, MD, director, Stanford Cardiac Arrhythmia Provider, Stanford (Calif.) College, but he did not accept as true with Dr. Marrouche’s interpretation. This integrated the contention that scar formation became another time straightforward to complete in sufferers with less atrial fibrosis.
DECAAF II Is No longer a Definite Trial
Constant with his reading of the correlation coefficients, expressed as an r price, which were 0.237 and nil.493 for the low- and high-fibrosis teams, respectively, “the adaptation in lesion formation in low- and high-fibrosis teams seems refined to expose,” Dr. Wang pointed out.
Besides to, “the authors recommend that the failure to complete a lawful ablation lesion could memoir for the AFib recurrence,” acknowledged Dr. Wang, editor-in-chief of the American Heart Affiliation’s Circulation: Arrhythmia and Electrophysiology. However, resulting from the many numerous doable variables influencing this likelihood, “that is refined to expose.”
Finally, despite a assist seen amongst sufferers with a low level of fibrosis that became as soon as known in an as-treated subgroup, “DECAAF II joins the a gargantuan more than a number of of studies [evaluating the addition of an intervention relative to PVI alone] which maintain not completed the foremost endpoint,” Dr. Wang concluded.
An ESC-invited discussant, Christophe Leclercq, MD, chief of cardiology at Centre Hospitalier Universitaire, Rennes, France, made the same point. He acknowledged several old studies maintain made the concept that of attaining elevated ablation to decrease AF recurrence “pleasing,” but this “became as soon as not confirmed in DECAAF II.”
He additionally would not endorse MRI-guided ablation in resistant AFib amongst sufferers with early disease.
“There became as soon as a particular result seen in those with a low stage of fibrosis, but there were additionally more issues in those present process MRI-guided ablation,” he acknowledged.
Dr. Marrouche studies monetary relationships with Abbott, which supplied funding for this study about. Dr. Wang had no disclosures. Dr. Leclercq reported monetary relationships with Boston Scientific, Medtronic, Sorin Community, and St. Jude Medical.
This article at the foundation seemed on MDedge.com, segment of the Medscape Authentic Community.