Left atrial appendage closure (LAAC) via implanted device was associated with a decreased risk of admission for stroke, compared with the expected risk without anticoagulation therapy, according to a study published in the Journal of the American Medical Association (JAMA).
Authored by Rajesh Kabra (University of Tennessee Health Science Center, Memphis, USA) et al, the population-based cohort study concluded that although LAAC provides an attractive non-pharmacological option for stroke prevention in patients with atrial fibrillation (AF), who are not candidates for long-term anticoagulation therapy, further prospective long-term real-world studies are needed to monitor its safety and efficacy.
In the study, Kabra and colleagues note that anticoagulation therapy is the cornerstone for stroke prevention in patients with AF, although LAAC devices have emerged as non-pharmacological alternatives for stroke prevention. The Watchman device [Boston Scientific] was the first LAAC device compared with warfarin in two randomised clinical trials—PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) and PREVAIL (Prospective Randomized Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long‐Term Warfarin).
To date, real-world data outside clinical trials regarding the use and outcomes of LAAC devices are limited, Kabra and colleagues note, adding that the present study seeks to address this gap by examining the post-procedural outcomes of mortality, hospital readmissions, and ischaemic stroke.
Medicare inpatient claims for 13,627 patients aged older than 65 years with a diagnosis of atrial fibrillation who underwent LAAC with an implanted device from January 2015 to November 2017 were assessed. Mortality rates during the index admission and for one-year after LAAC were investigated, and the 30-day readmission rate and the primary reasons for readmission were also examined. In addition, the likelihood of hospitalisation for ischaemic stroke within 180 days among 9,231 patients for whom six months of follow-up data were available was evaluated.
Among the 13,627 patients undergoing LAAC, the mean age was 78.0 years, 9,406 (69.0%) were older than 75 years, 11,980 (87.9%) were white, and 5,630 (41.3%) were women. The mean CHA2DS2-VASc score was 4.3 (1.4). Twenty-eight patients (0.2%) died during the index admission. Mortality rates were 0.6% (80 patients) at 30 days, 1.9% (262 patients) at 90 days, 4% (547 patients) at 180 days, and 7.5% (1027 patients) at 365 days. The 30-day readmission rate among 13,599 patients discharged alive was 9.4% (1,284 patients). Among 92,31 patients with six months of follow-up data, 111 (1.2%) experienced readmission for ischaemic stroke or transient ischaemic attack within 180 days of discharge.
Kabra and colleagues also further examined mortality and readmission rates for stroke and transient ischaemic attack by CHA2DS2–VASc score, noting that all outcomes were more frequent among patients with higher CHA2DS2–VASc scores. In particular, Kabra and colleagues note, among those with higher CHA2DS2–VASc scores, mortality rates were higher within 90 days (score 0–3, 1.1%; score 4–5, 1.8%, score 6, 3.5%; p< .001), within 180 days (score 0–3, 2.3%; score 4–5, 3.8%; score 6, 7.1%; p<0.001), and within 365 days (score 0-3, 4.0%; score 4–5, 7.7%; score 6, 12.0%; p<0.001). The authors also compared the observed rates of ischaemic stroke after LAAC via implanted device with expected stroke rates in the absence of anticoagulation therapy according to CHA2DS2-VASc scores, using data from prior studies. They noted a 60–69% relative reduction in stroke risk after LAAC, compared with the risk in the absence of anticoagulation therapy. The most frequent primary diagnoses for readmissions within 30 days were gastrointestinal haemorrhage (134 patients [1.0%]), hypertension with complications (111 patients [0.8%]), cardiac dysrhythmias (103 patients [0.8%]), complications from a device or surgical procedure (84 patients [0.6%]), and septicaemia (68 patients [0.5%]). There were 28 readmissions (0.30%) for haemorrhagic stroke within 180 days after LAAC via implanted device.
Kabra and colleagues found that, LAAC via implanted device was associated with a decreased risk of admission for stroke compared with the expected risk without anticoagulation therapy. The risks of one-year mortality and stroke at six months were higher, they found, than those in previous randomised clinical trials, likely because the population in the current study was older and had more comorbidities and higher CHA2DS2-VASc scores. Kabra also pointed out that unlike randomised trials, the study population also included patients not eligible for warfarin.
Kabra et al concluded: “Although LAAC provides an attractive non-pharmacological option for stroke prevention in patients with AF who are not candidates for long-term anticoagulation therapy. Further prospective long-term real-world studies are needed to monitor its safety and efficacy.”