LAAO Over Meds in AF? Demographic, Clinical Factors Are at Play

Use of left atrial appendage occlusion (LAAO) for stroke prevention in patients with atrial fibrillation (AF) has increased rapidly in the United States since the technology was first approved in 2015, though there are numerous demographic and clinical factors that appear to influence the likelihood of undergoing the procedure, according to an analysis of Medicare claims data.

For instance, factors associated with complications from oral anticoagulation—like prior intracranial, GI, or other extracranial bleeding, coagulopathy, and falls—were tied to greater odds of LAAO, researchers led by Kueiyu Joshua Lin, MD, ScD (Brigham and Women’s Hospital, Boston, MA), report.

Conversely, certain demographic factors—like age over 85, Black race, and female sex—signaled a lower likelihood of undergoing the procedure versus starting on oral anticoagulation.

Lin cautioned that the study, published recently online in Circulation: Cardiovascular Quality and Outcomes, is descriptive, saying that it cannot be used to draw any conclusions about causality.

The takeaway, then, is that “the uptake of LAAO increased very rapidly from 2015 to 2020, so clearly this newer [intervention] is getting more and more attention, and we anticipate it to be used more widely,” Lin said.

Moreover, patient characteristics associated with use of LAAO will evolve over time as physicians gain more experience with the procedure and patients become more aware of it as an option for stroke prevention, he added. “We anticipate a wider patient population will be receiving this procedure, and it is important to watch the patient demographics over time and monitor the potential trends in disparities in receiving this newer cardiac device.”

Commenting for TCTMD via email, Douglas Darden, MD (Kansas City Heart Rhythm Institute, Overland Park, KS), said, “While the majority of LAAO studies focus on procedural complications, this study provides valuable insight into an important concept: the real-world decision-making process in choosing LAAO over initiating anticoagulation.”

Rapid Uptake of LAAO

LAAO first became commercially available to US physicians when the Food and Drug Administration approved the Watchman device (Boston Scientific) in March 2015. Since then, LAAO has been increasingly used as an alternative to oral anticoagulation to prevent stroke in patients with AF, but there are few data that reflect the characteristics that clinicians are using on an everyday basis to guide use of the procedure.

To explore that area, Lin et al examined Medicare claims data spanning March 15, 2015, to December 31, 2020, on patients with AF who were 65 or older, had a CHA₂DS₂-VASc score of at least 2 for men and 3 for women, and were treated with either implantation of an LAAO device or first-time initiation of an oral anticoagulant. The analysis included 30,058 LAAO recipients (mean age 78; 42.1% women) and 792,600 first-time users of an oral anticoagulant (mean age 78; 53.3% women).

Of the patients receiving either of those treatments for prevention of stroke during the study period, the proportion who underwent an LAAO procedure increased from 0.52% to 9.32%, which translated into a much greater likelihood of getting the device in 2020 than in 2015 (adjusted OR 13.64; 95% CI 12.56-14.81).

Both demographic and clinical factors were associated with the likelihood of receiving LAAO versus oral anticoagulation. The findings in relation to age were mixed. Compared with the youngest group (ages 65 to 75), those ages > 75 to 85 had greater odds of undergoing the procedure (adjusted OR 1.27; 95% CI 1.24-1.31), whereas the oldest patients (> 85 years) were less likely to receive the intervention (adjusted OR 0.84; 95% CI 0.80-0.88).

It could be, Lin speculated, that clinicians were more likely to want to avoid anticoagulation-associated complications in older patients by preferentially treating them with LAAO, but only up to a certain age. In the oldest patients, who are likely to be frail also, clinicians might have wanted to avoid the potential complications of an invasive procedure.

Female sex also was associated with lower odds of LAAO versus oral anticoagulation (adjusted OR 0.74; 95% CI 0.71-0.76). That finding was consistent in both the first half and the latter half of the study period, although women made up a greater proportion of patients undergoing LAAO as time went on.

As a potential explanation for the lower likelihood of LAAO among women, Lin speculated that physicians could have been responding to findings of other studies showing that women are more prone to complications after implantable cardiac electronic device placement—possibly due to physiological or anatomical differences between the sexes—and have a higher rate of in-hospital adverse events compared with men after LAAO.

“It is conceivable that these findings could lead to some providers’ hesitancy in performing LAAO procedures in women,” Lin said.

Potential racial disparities were observed as well. Compared with white patients, those who were Black (OR 0.63; 95% CI 0.58-0.68) or “other” (OR 0.73; 95% CI 0.69-0.79) were less likely to undergo LAAO during the study period. Lin said it’s possible that patients with nonwhite race are more likely to be treated at centers with lower LAAO volumes and less experience, or that reports of worse procedural outcomes among minority patients are influencing use of the intervention.

“This trend about a potential racial disparity needs to be closely monitored,” he said.

Numerous other factors were associated with lower odds of LAAO, too, including Medicaid eligibility (a proxy for low socioeconomic status), frailty, cancer, fractures, venous thromboembolism, arterial embolism, acute kidney injury, liver dysfunction, a history of coronary bypass surgery, and receipt of P2Y12 inhibitors. On the flip side, congestive heart failure, hypertension, chronic kidney disease, peptic ulcer disease, obesity, and anemia signaled a greater likelihood of undergoing the procedure.

No Simple Solutions to Potential Disparities

Darden said the reasons for the differences in use of LAAO between groups are not clear, noting that “socioeconomic, racial, and sex disparities have been described not only in the LAAO literature but for most cardiovascular procedures.”

It could be, he added, that “limited access to subspecialty care, lack of awareness of [the] indications among providers, insurance coverage challenges, or even implicit bias among healthcare providers may be playing a role. There may be an unconscious decision to avoid invasive procedures in those who may be at higher risk, which may include old age, females, or frailty.”

Where disparities exist, “there are no simple solutions to correct [them], but awareness is the first step to mitigate these issues,” Darden said.

Like Lin, however, he cautioned against drawing firm conclusions from this observational study. “For instance, patients that are less likely to undergo LAAO as identified by this study may have a significantly higher risk of up-front procedural risks and adverse outcomes following the procedure,” Darden said. “This is not answered by this study but has been demonstrated by other studies. There are countless factors that are left unaccounted for in registry data that all influence the decision to choose medical care.”

The next steps, he said, are randomized trials to compare LAAO with oral anticoagulation, especially in high-risk cohorts. “While current data suggests these seemingly higher-risk populations, such as older age, frailty, and women, are at increased risk of complications undergoing LAAO, we still need long-term data for adequate comparisons.”