Dr George VilanilamGeorge Vilanilam, MBBS
While the use of left atrial appendage closure (LAAC) increased 40-fold from 2005 to 2014, data suggests that patients who underwent LAAC were less likely to be those with a higher Charlson Comorbidity Index (CCI), or have a history of stroke or major bleeds.

Patients receiving LAAC were more likely to be younger, male, white, have private insurance, and treated in urban-teaching hospitals. Ultimately, the investigators, including George Vilanilam, MBBS, research fellow, Department of Radiology, Mayo Clinic Jacksonville, included 15,549 hospitalizations including LAAC in patients with atrial fibrillation (AF). From 2005 to 2014, the proportion of LAAC increased from 0.01% to 0.46%, respectively (P <.001).

The data were presented at the American Academy of Neurology (AAN) Annual Meeting in Philadelphia, Pennsylvania. To find out more about the background that prompted this exploration of trends in the use of LAAC, NeurologyLive® spoke with Vilanilam about the findings.

NeurologyLive®: What’s the importance of this work?

George Vilanilam, MBBS: We wanted to describe the national trends and predictors in the use of LAAC among hospitalized AF patients with a CHA2DS2Vasc score ≥2 over the last 9 years. Left atrial appendage is one of the underlying etymologies for AF. Obviously, AF by itself is a factor for embolic stroke. There have been closure devices, there have been closure surgeries, so this has been in the literature for the last so many years. This is what we were trying to see.

We wanted to see the trend of patients was, or who were more likely to have closure among AF patients. Now another thing to know about AF patients is the CHA2DS2VASc score, which is a well-known score which is used to determine the risk of thrombotic events. So, the moment a patient is diagnosed with AF, we calculate their CHA2DS2VASc and we see how likely they are to have a thrombotic event in the future. Now, based on that, we have a scoring system and traditionally, or according to literature, patients with a score of 2 and above ought to be anticoagulated.

Patients who have a CHA2DS2VASc score of 0 are not anti-coagulated, patients with 1 may or may not be, and patients with 2 and 3 have to be anticoagulated, according to treatment guidelines. This is a cohort of patients and we looked at how many of them had an appendage closure. Now, why this is important is because there were previous trials, the PROTECT-AF trial and the PREVAIL trial, which showed a noninferiority of LAAC as compared to warfarin. Relatively little is known about regarding the utilization of LAAC in patients with CHA2DS2-VASc greater than or equal to 2, because why would you do closure for someone who is already eligible for warfarin, so that fear is a question. So that’s what we wanted to study.

Could you provide some background information for the study?

We included all patients with an age ≥18 who had AF and were candidates for anticoagulation in the US from 2005 to 2014. This is using the national inpatient sample database. And we tried to look for predictors that showed a certain group of patients had higher predictors for LAAC or those who had a low prediction. And we had about 6 million hospitalizations for which about 0.23%, or 15,000 patients have LAAC.

What were the findings?

What we saw was the proportion of people who used LAAC, increased from 0.01%  to 0.46%—that’s about 40-fold from 2005 to 2014 and this is a very significant number. Once we did market verifiable studies, we found that the adjusted odds of LAAC was higher with the younger age. So, patients who are younger were most likely to get the closure device as well as those of white race, and those of male sex, and those who have private insurance, and additionally those who had hospitalization in urban teaching hospitals. They’re more likely to have LAAC implants or LAAC closure surgeries. Those who even had a CHA2DS2VASc ≥4 had increased prediction of LAAC.

On the other hand, we also looked at the CCI, a scoring system for their level of comorbidity. Those who had a higher comorbidity index were less likely to have LAAC, and that makes sense because, with comorbidities, you don’t want to subject them to anesthesia and surgical complications. Those who have an ischemic stroke—they were less likely. Those who had an internal hemorrhage, and history with major bleeding, they’re also associated with a lower chance of LAAC.

Even after what we had expected—a patient who is eligible for anticoagulation, if they get the appendage closure device, they don’t need to be anticoagulated. This is why we’re doing the whole thing. It’s because if the patient is eligible for anticoagulation and if the patient has an atrial left appendage, then why don’t we just close that area either in surgery or using a device and avoid anticoagulation at all? This is what we would like to see, and this is we are also doing a prospective study on this.

Were any of the results unexpected?

For us, we were not surprised by the results. We obviously expected healthier patients, younger patients, and those with better insurance and those in urban teaching hospitals to have surgeries and have these procedures. It did not surprise us. We were really hoping that this would encourage more research in this field so that we can move and transition away from anticoagulants into more of these closure devices.

What’s the impact of this data on the clinical community?

I think it makes sense that most of these surgeries or closure devices are more common in younger patients and patients who have private insurance or at an urban teaching hospital. It makes a lot of sense, on the other hand, that patients with a higher risk of bleeding, patients who have had bleeding, or patients who had a history of stroke—they’re less likely to be on closure devices. This is also because there is a small window period at the moment when we get the closure device, or we do the closure surgery, there are still the first few months where we have to continue anticoagulation. This might increase the risk of bleeding and, probably, that’s why patients were not given an appendage closure with a history of bleeding.

I think the most important thing here was to see who got the elected appendage closure and to see the trend. This actually gave us historical data to proceed for a more prospective study that we are currently conducting.

Are there any plans for subgroup analysis or additional study?

Our main aim in the study was to see if we could study left atrial appendage devices in general. Left atrial appendage devices are a new thing—I believe they were introduced after 2010, maybe 2012, 2013. After that left atrial appendage devices were released, we wanted to do a study of devices. But because we only had access to data in 2014, that was not possible, which is why we looked at patients who had left appendage closure in general. This would include surgeries, any kind of closure, which might also include a few device implants.

The important thing is if we can avoid anticoagulation in patients who already have a high risk of bleeding. In younger patients who have fewer comorbidities—in such patients, this might be a great alternative to LAAC by itself or devices. Potentially, in the future, they’re great alternatives and if you ask a younger person—if they would rather have a small procedure to treat their AF versus being on anticoagulants for life, I’m sure a lot of people would prefer the small procedure. These are not extensive procedures, the appendage itself is a very, very limited procedure. I would imagine that going forward into the future, we want to reduce the amount of anticoagulation—or lifetime anticoagulation—and move forward into this minimally invasive surgery so we can have LAAC devices which will be much more beneficial.

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REFERENCE
Badi M, Vilanilam G, Markovic D, et al. Disparities, Predictors and Trends of Left Atrial Appendage Closure Among Hospitalized Patients with Atrial Fibrillation in the United States. Neurology. 2019;92:(15 Supplement). P4.6-017.