Snare Device for LAA Closure Safe, Effective in Small A-fib Study

Use of a percutaneous snare device to close the left atrial appendage (LAA) and prevent stroke in patients with atrial fibrillation (A-fib) appears to be safe, with a high degree of procedural success, according to a small study published online January 11, 2013, ahead of print in the American Journal of Cardiology.

Investigators led by Ali Massumi, MD, of the Texas Heart Institute (Houston, TX), used the Lariat device (SentreHeart, Redwood City, CA) in 21 A-fib patients from February 2011 to February 2012. The device, which consists of a snare with a pre-tied suture that is guided epicardially over the LAA, was approved for use by the US Food and Drug Administration in 2009. All patients had CHADS₂ scores ≥ 2 and contraindications to anticoagulation.

High Procedural Success, Few Complications

Intraoperative success was confirmed by left atrial angiography and transesophageal echocardiographic (TEE) color Doppler flow. Successful LAA exclusion, evaluated by follow-up TEE, was achieved in all 20 of the patients in whom it was attempted. (One patient did not undergo the procedure due to LAA thrombus seen on intraprocedural TEE.) The mean procedure time was 82.9 ± 21.0 minutes (range, 48-129). Average fluoroscopy time was 39 ± 30 minutes, and the average contrast load was 82 ± 34 mL.

Before the procedure, 45% of patients were receiving warfarin. This number fell to 15% after the procedure.

At mean follow up of 96 ± 77 days, the LAA remained excluded in all patients who underwent follow-up TEE (n = 17). No color Doppler flow was noted in 16 of these patients, while 1 had the same degree of trace residual flow intraoperatively and 11 months after the procedure. In 6 patients (35%), a small pouch with smooth walls at the opening of the LAA was noted. Excluded LAAs appeared to have shrunk on cardiac CT, and no new strokes or cerebrovascular events were reported.

“With proper patient selection, the percutaneous exclusion of the LAA with the Lariat device can be performed effectively and safely in most patients,” the authors write.

Complications included perforation of the right ventricle with tamponade requiring emergency surgery, repeat pericardiocentesis to treat pericardial effusion with tamponade physiology, and prolonged intubation because of COPD exacerbation and urinary tract sepsis (each seen in 1 patient). All 20 patients were discharged after an average of 3.7 ± 3.0 days (range, 1-11).

Three patients required hospitalization for pericarditis less than 1 month after the procedure. One of these patients also had moderate pericardial effusion that required pericardial drainage, and the other 2 were treated conservatively.

Lariat Obviates Need for Device Sizing, Anticoagulation

In another early, single-center experience with the device published in the Journal of the American College of Cardiology, researchers found a high rate of successful LAA closure with minimal access complications or periprocedural adverse events in 89 nonvalvular A-fib patients.

Although the current study was small and not randomized, in comparing the results with those of the PROTECT AF trial, the authors note that the rate of complete LAA occlusion with no peridevice flow was only 59% at 45 days and 68% at 12 months. “The higher occlusion rate associated with the Lariat device may be because suture better accommodates various LAA sizes and shapes than does the [Watchman device], which must be sized for each patient and may not fit well in noncircular LAA orifices,” they explain. “Also, in contrast to occlusion techniques that require the implantation of intracardiac devices, LAA exclusion with the Lariat leaves no portion of the device in contact with the bloodstream. Therefore, no anticoagulation is needed except during the procedure. Furthermore, unlike endocardial devices, the Lariat poses essentially no risk for device embolization or device-associated thrombus.”

As for the small residual pouches found after the procedure in some Lariat patients, the authors say these “have had no apparent clinical significance.”

But they stress that no conclusions can be drawn about the efficacy of the device for stroke prevention compared with long-term anticoagulation or other LAA exclusion techniques. “Experience with many more patients and longer follow-up are necessary to demonstrate the efficacy of this novel technique and to refine its indications and contraindications to maximize patient safety,” they conclude.

Study Details

Successful LAA occlusion was defined as less than 5-mm residual flow, which is similar to the definition used in the large, randomized PROTECT-AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation) trial, in which an implanted percutaneous device was used to close the LAA.

 

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Source:
Massumi A, Chelu MG, Nazeri A, et al. Initial experience with a novel percutaneous left atrial appendage exclusion device in patients with atrial fibrillation, increased stroke risk, and contraindications to anticoagulation. Am J Cardiol. 2013;Epub ahead of print.

 

 

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