LAA Excision Disappoints in Persistent-AF Surgical Ablation

Patrice Wendling

May 07, 2016

SAN FRANCISCO, CA — Contrary to prior results, left atrial appendage (LAA) excision did not tamp down atrial fibrillation (AF) recurrence when added to ablation with pulmonary vein isolation (PVI) in patients with persistent AF in a randomized trial[1].

After 18 months of follow-up, freedom from any AF recurrence after a single ablation procedure occurred in 89.7% of patients undergoing PVI plus LAA excision and 87.2% with PVI alone (hazard ratio [HR] 0.79; P=0.61).

These results held across all secondary outcomes, and complication rates were also similar.

"This study included relatively healthy and low-risk patients, and we cannot generalize the results to patients with significant comorbidities," principal investigator Dr Alexander Romanov (State Research Institute of Circulation Pathology, Novosibirsk, Russian Federation) said during a late-breaking clinical-trial session at the Heart Rhythm Society (HRS) 2016 Scientific Sessions.

A limitation of the study was that not all participating centers had the capacity for cardiac monitor insertion, so the primary end point was assessed with conventional 24-hour Holter monitoring, he noted.

Session moderator Dr John Day (Intermountain Healthcare, Salt Lake City, UT) told heartwire from Medscape the study is interesting because other data show that LAA is an important target in persistent AF, but that he was somewhat suspicious.

"It's an outlier. If I had seen a 70% success rate in both arms or 60%, I would have felt a little bit better that maybe isolating the left atrial appendage doesn't help, but the success rate was so high in both arms for a persistent atrial fibrillation group, I want to see more data," he said.

Dr Vivek Reddy (Cleveland Clinic, OH), who also was not involved in the trial, agreed, pointing out that in the BELIEF trial, which supports LAA isolation in long-standing persistent AF, the event rate in the control arm was much lower than the 87% reported here.

"You always wonder about what exactly is the patient cohort; persistent, how persistent were they, how long; we need to know that information. But having said that, what this shows is that at least in this persistent population it makes no sense to address the appendage as a first procedure," he told heartwire .

Patient Characteristics

The investigators evenly randomized 176 patients who had AF for 4 years to receive video-assisted thoracoscopic surgical ablation with PVI plus ganglionic plexus and poster box lesion set (77% men) or the same procedure plus LAA excision (81% men). Persistent AF >6 months was present in 78% and 82%, respectively. AF burden by 24-hour Holter was 85% in the control and 83% in the LAA group.

The procedure was successful in all patients, and there was no difference in procedure times (P=0.81).

AF burden was significantly reduced at 6 months postablation with both procedures (P<0.001) and remained relatively unchanged until the end of follow-up. "The two groups had similar burden throughout," Romanov said.

At 18 months, 78.2% of the LAA arm and 75.6% of the control arm were free of AF without antiarrhythmic drugs (AADs) (HR 0.87, P=0.72).

The co–primary end point of freedom from any atrial tachyarrhythmias after a single procedure without any AADs occurred in 73.6% with LAA and 70.9% with PVI alone (HR 0.88; P=0.73).

Rates of documented AF or atrial arrhythmia after two procedures with or without AAD were also similar, he said.

Five patients, including two in the LAA arm, required conversion to median sternotomy for bleeding. Stroke occurred in one patient in each arm and transient ischemic attack in three controls and one LAA patient. There was only one death, due to metastatic cancer in an LAA patient 6 months after the procedure.

"As study data refer to the follow-up period of 18 months after the ablation procedure, results cannot be extrapolated to the long-term maintenance of sinus rhythm or prevention of thromboembolic events," Romanov said.

Romanov reported being on the speaker's bureau for Medtronic and financial relationships with Biosense Webster and Boston Scientific. Disclosures for the coauthors are listed in the abstract.

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