Positive Outcomes Following Left Atrial Appendage Closure with Amplatzer Plug in High-Risk Patients with Atrial Fibrillation

Retrospective analysis of real-world outcomes supports the use of the Amplatzer cardiac plug (ACP) for left atrial appendage closure in atrial fibrillation (AF) patients with a very high risk of stroke or serious bleeds.

Investigators studied a single facility’s records on 96 consecutive AF patients whose surgeons used the ACP for appendage closure. Those patients had a median baseline CHA₂DS₂-VASc score of 5 and a median baseline HAS-BLED score of 3. All procedures resulted in fully closed appendages, and complications were rare. Just 7.3% of the patients showed any immediate signs of complications: 4.2% experienced pericardial effusion, 2.1% experienced some sort of thromboembolic event, and 1.0% experienced device embolization.

Follow-up with patients detected another 3 thromboembolic events and thrombus formation on the devices inside 2 patients, but among the 70% of patients who underwent transesophageal echocardiography during follow-up exams, no leaks were detected. Appendage closure was complete.

“The prevention of thromboembolism is the most important therapeutic goal in patients with AF. Vitamin K antagonists effectively reduce strokes rates, but as individual stroke and bleeding risks increase in parallel, physicians face a therapeutic dilemma concerning their use in very high stroke and bleeding risk patients,” the study authors wrote in Cardiology and Therapy. “Because left atrial appendage closure makes long-term oral anticoagulation unnecessary, patients with very high stroke and bleeding risks should benefit most from this therapy.”

The analysis was designed to determine whether the ACP was safe and effective enough in such patients to produce these theoretical benefits by simultaneously reducing the risk of both major bleeds and thromboembolic events — all without introducing significant new dangers related to the surgery or the device.

The trial did not compare the ACP directly against any sort of oral anticoagulation, but the investigators wrote that the patients who underwent appendage closure did fare significantly better than they would expect from identical patients who got no treatment.

Among the 89 patients (92.7%) who participated in some form of follow-up (median duration: 9 months), the annual rate of thromboembolic events was 3.2% — significantly lower than the 6.7% to 10.0% that prior studies have found in untreated patients with similar baseline characteristics. The investigators calculated the rate ratio incidence for thromboembolic events for ACP patients at 0.32 (95% confidence interval [CI], 0.07-0.94) of that for untreated patients.

The investigators did not compare the rate of thromboembolic events among trial patients with the rate expected from similar patients on different forms of anticoagulation, but they did compare the rate of actual bleeds to the expected rate of bleeds in warfarin users. Only 1 major bleed was detected among trial uses, so the annualized rate of major bleeds was 1.1%. The annual bleeding risk among warfarin users with a HAS-BLED score of 3 falls somewhere between 3.74% and 5.8%, wrote the investigators, who calculated the reduction of bleeding risk to be anywhere from 70% to 81%. That said, the number of patients in the trial was too small to demonstrate a significant reduction in bleeds. The investigators calculated the rate ratio of serious bleeds among ACP patients at 0.18 (95% CI, 0.00-1.03) of warfarin users.

“The sample size of the study was small and no inference about comparative outcomes can be made due to lack of a control group,” the investigators wrote. “Randomized controlled trials are needed for further validation of the results.”