Study Indicates Snare Device for LAA Closure Should Only Be Used in Highest-Risk Patients

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Procedural success of left atrial appendage (LAA) closure for stroke prevention with a snare device, though “high,” is limited by the occurrence of major bleeding, according to a study in the August 12, 2014, issue of the Journal of the American College of Cardiology. Until adequate safety and postprocedure management processes can be confirmed, use of the device should be limited to high-risk patients who are unable to undergo other LAA occlusion therapies, researchers say. 

Average procedure duration was 76.6 minutes. The device could not be delivered in 9 patients—due to pericardial adhesions, challenging anatomy, or emergency surgery—with an overall rate of device success (defined as suture deployment and < 5 mm leak by post-procedure transesophageal echocardiography) of 94%. 

Overall procedural success (primary endpoint; defined device success plus lack of major complications at discharge) was 86% but hampered by a relatively high rate of major bleeding (9.1%) driven by the need for transfusion (4.5%). Additionally, emergency surgery was required in 3 patients (2%) and one patient died in-hospital 19 days after the procedure due to respiratory failure, sepsis, and subsequent pneumonia. Significant pericardial effusion was seen in 16 patients (10%) and pleural effusion in 4 (3%).

After a median follow-up period of 112 days in 87% of patients, the composite outcome of death, MI, or stroke occurred in 4 patients (2.9%). TEE measurements post-procedure (n = 63) showed complete LAA closure in 92% and a leak of less than 5 mm in the remaining patients. However, at follow-up (n = 50) TEE showed complete closure in 79% with less than 5-mm leak in 14% and larger leaks in 6%. 

The incidence of left atrial thrombus originating near the LAA occlusion was 5% with TEE follow-up out to 104 days post-procedure. 

Patient Characteristics Drive Outcomes

Dr. Price and colleagues acknowledge that their patient population was older and sicker than those in previous studies of Lariat, which “may have contributed in part to a greater rate of complications,” they write.

Still, the 3% rate of unanticipated pericardial adhesions, which was the most common cause of aborted procedures, was consistent with previous research, the authors say. 

Pericardial effusion is “unique to the Lariat procedure,” they explain. But “whether the incidence of serious pericardial effusion can be reduced with increasing operator experience and technical refinements… remains to be determined.” 

The authors attribute the high rate of late leak to patient selection and operator experience, “although this is speculative.” 

‘Not Ready for Prime Time’

Going one step further, Gerhard Hindricks, MD, of the University of Leipzig (Leipzig, Germany), and colleagues, state plainly in an editorial accompanying the study, that “at present, the Lariat technique for LAA occlusion is certainly not ready for prime time.” 

Because of the “limited experience” of the operators and the retrospective nature of the study, they say that little can be gleaned from the research. Furthermore, they question why a patient should undergo this technique “instead of the established occlusion with a permanent device or by means of minimally invasive surgery.” 

Additionally, in a telephone interview with TCTMD, Ali Massumi, MD, of the Texas Heart Institute (Houston, TX), said the Lariat procedure has such a steep learning curve that a center should perform at minimum 25 such procedures before being considered minimally experienced. 

“Overall, this procedure is not something that's going to suddenly become very commonplace or very frequently performed because it takes a lot of training,” he said. “It is not without complications. While I think it is good that they have the experience in 154 patients, the study has to be read with consideration.” 

Since the authors did not describe how they selected patients or judged anatomy to be suitable, Dr. Massumi said, it is hard to trust the results. Per his experience and ongoing research with the device, he commented that “the paper is good but not reflective of the data. We have our own paper where… our numbers in terms of leak and complications are better.” 

Lariat vs Watchman

Dr. Hindricks and colleagues write that the Lariat procedure “should be reserved only for very well-selected patients with substantial thromboembolic and bleeding risk.” 

Expanding Lariat procedures to non-optimal candidates under ‘compassionate use’ should be avoided as much as possible, Dr. Massumi said. But with the still pending approval by the US Food and Drug Administration of the Watchman device (Boston Scientific, Natick, MA), the “ingenious” Lariat is the only percutaneous option currently available, he said, cautioning that it should “only be used in the right patients with the right indications by the right people.” 

If Watchman is approved, Lariat would still be “number one,” Dr. Massumi added, given the positive results he has seen in his research. “It is very important to have a second option because right now we don't have it,” he said. 

In a telephone interview with TCTMD, Randall J. Lee, MD, PhD, of the University of California-San Francisco (San Francisco, CA), said that because it does not leave any implants behind, the Lariat procedure is “the most elegant” compared with Watchman and other approaches to LAA closure. 

But it is not totally feasible to pit the 2 closure devices against each other. “I don't think it’s this versus the Watchman,” he said. “It’s [about] selecting the proper patient and which therapy is suitable.” 

From an electrophysiology angle, Dr. Lee said, there are other reasons why Lariat is beneficial. “Beside preventing stroke, it also isolates the left atrial appendage and may benefit or improve pulmonary vein isolation procedures. So you could see it as an adjunctive therapy,” he suggested.

Sources:
1. Price MJ, Gibson DN, Yakubov SJ, et al. Early safety and efficacy of percutaneous left atrial appendage suture ligation: results from the US Transcatheter LAA Ligation Consortium. J Am Coll Cardiol. 2014;Epub ahead of print.

2. Dagres N, Rolf S, Hindricks G. Percutaneous left atrial appendage suture ligation: not ready for prime time [editorial]. J Am Coll Cardiol. 2014;Epub ahead of print.

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