Comparative Assessment of Left Atrial Appendage Occlusion Devices

Background: In patients with atrial fibrillation at an elevated risk of stroke, oral anticoagulants are considered the gold standard for thromboembolic prophylaxis. However, for certain patients, anticoagulation is contraindicated. In such cases, left atrial appendage closure (LAAC) emerges as an alternative therapeutic approach. This retrospective research aimed to compare the safety and efficacy of different LAA occluders.

Methods: We included 276 patients who underwent LAAC at the University Hospital Heidelberg between 01/01/2005 and 30/06/2023. Patient data were extracted from medical records, including indication, device type and size, LAA anatomy, transthoracic and transesophageal echocardiography parameters. Data were collected up to one year post-intervention. Endpoints consisted of periprocedural success rates, residual flow, periprocedural complication rates, fluoroscopy time and implantation duration, as well as post-implantation clinical events up to 1 year.

Results: The most common indication for LAAC was a history of bleeding events. Among them, gastrointestinal bleeding was the most frequent (39.1%) followed by intracranial or intraspinal bleeding (38.0%). Occluders were successfully implanted in 95.4% of attempts and showed no significant differences among various devices. Significant residual flow (≥3mm) at 3 months after implantation was more common in occluders with a single sealing mechanism (Watchman/FLX, 21.4%) than in those with a double sealing mechanism (Amulet and ACP 0%, p=0.004). Overall, oversized occluders had less residual flow compared to those implanted as per manufacturer recommendations (7.6% vs. 30.8%, p=0.003) without a significant difference in periprocedural pericardial effusion rates (2.0% oversized vs. 2.9% manufacturer recommendation, p=0.76). Major periprocedural bleeding resulting in an aneurysma spurium or AV fistula formation was observed exclusively with Watchman 2.5 (4.5%) and ACP (7.1%). Devices did not differ significantly regarding implantation duration (p=0.12) and fluoroscopy time (p=0.37). At one year post-implantation there was no significant difference in the occurrence of ischemic strokes (p=0.54) or device-related thrombus (p=0.17, see Table).

Conclusion: All the studied occluders demonstrated comparable high rates of successful implantation. In terms of residual flow, ACP and Amulet outperformed Watchman/FLX. Ischemic strokes and device-related thrombus one year after LAAC were comparably infrequent across different occluders.

Table: Selected metrics in 284 LAAC attempts

	PLAATO (n=7)	Watchman 2.5 (n=178)	Watchman FLX (n=28)	ACP (n=28)	Amulet (n=42)	Total (n=284*)	p-value
Successful implantation	6 (85.7%)	169 (94.9%)	27 (96.4%)	28 (100%)	40 (95.2%)	271 (95.4%)	0.48
Residual flow ≥3 mm, at 3 months	nA (n=0)	19 (24.1%) (n=79)	2 (10.5%) (n=19)	0 (n=8)	0 (n=21)	21 (16.5%) (n=127)	0.019
Major periprocedural bleeding	0	8 (4.5%)	0	2 (7.1%)	0	10 (3.5%)	0.41
Ischemic stroke at 1 year	0 (n=6)	2 (2.1%) (n=96)	0  (n=7)	0 (n=23)	1 (5.9%) (n=17)	3 (2%) (n=149)	0.54
Device-related thrombus at 1 year	0 (n=6)	2 (2.1%) (n=96)	1 (14.3%) (n=7)	2 (8.7%) (n=23)	1 (5.9%) (n=17)	6 (4%) (n=149)	0.17

*In one patient, an initial LAAC attempt had to be aborted due to hemodynamic instability before a device was selected.

 

Keywords: LAAC, device safety, device efficacy