Left Atrial Implant Appears to Curb Stroke Risk in Some With Atrial Fibrillation

By David Douglas

November 09, 2019

NEW YORK (Reuters Health) - Older patients with atrial fibrillation show a reduced risk of stroke following left-atrial-appendage closure (LAAC) with an implanted device, according to a retrospective study.

This large real-world study of Medicare patients with a LAAC device, first author Dr. Rajesh Kabra told Reuters Health by email, "showed a significant decline in stroke incidence compared to the expected risk based on CHA2DS2-VASCc score," a tool that uses clinical-prediction rules to estimate stroke risk in such patients.

AF is known to up the risk of stroke as much as five times, Dr. Kabra of the University of Tennessee Health Science Center, in Memphis, and colleagues note in JAMA Network Open, online October 30. Anticoagulation therapy is the standard treatment, they add, but LAAC devices "have emerged as nonpharmacological alternatives" to agents such as warfarin.

In particular, the Watchman device from Boston Scientific has shown efficacy in two randomized trials comparing it with warfarin. However, say the researchers, "the real-world data outside clinical trials regarding the use and outcomes of LAAC devices are limited."

To investigate, they examined Medicare data on more than 13,000 patients with AF who underwent LACC with the Watchman device between 2015 and 2017. Their mean age was 78.0 years.

Mortality rates were 0.6% at 30 days, 1.9% at three months and 7.5% at one year. The 30-day readmission rate in patients discharged alive was 9.4%.

However, in the 9,231 patients with six months of follow-up data, only 111 (1.2%) experienced readmission for ischemic stroke or transient ischemic attack within 180 days of discharge.

This readmission risk, say the researchers, was significantly lower than that expected based on their mean CHA2DS2-VASc score of 4.3. According to previous work "in the absence of anticoagulation therapy (this) would yield an expected annual ischemic stroke risk of 4.8%."

This finding, Dr. Kabra added, "was comparable to what was noted in the randomized clinical studies, thereby confirming the role of LAAC in stroke prevention in AF patients who are not candidates for long-term anticoagulation."

He concluded, "We noted a higher incidence of mortality than the randomized studies, likely due to inclusion of older patients who had more co-morbidities and were more likely to be warfarin-ineligible."

The study had no commercial funding. None of the authors report ties to LAAC-device makers.

SOURCE: https://bit.ly/2JVG139

JAMA Netw Open 2019.