Implant success and safety of left atrial appendage closure with the WATCHMAN device: peri-procedural outcomes from the EWOLUTION registry

Abstract

Aims: Left atrial appendage closure is a non-pharmacological alternative for stroke prevention in high-risk patients with non-valvular atrial fibrillation. The objective of the multicentre EWOLUTION registry was to obtain clinical data on procedural success and complications, and long-term patient outcomes, including bleeding and incidence of stroke/transient ischaemic attack (TIA). Here, we report on the peri-procedural outcomes of up to 30 days.

Methods and results: Baseline/implant data are available for 1021 subjects. Subjects in the study were at high risk of stroke (average CHADS2 score: 2.8 ± 1.3, CHA2DS2-VASc: 4.5 ± 1.6) and moderate-to-high risk of bleeding (average HAS-BLED score: 2.3 ± 1.2). Almost half of the subjects (45.4%) had a history of TIA, ischaemic stroke, or haemorrhagic stroke; 62% of patients were deemed unsuitable for novel oral anticoagulant by their physician. The device was successfully deployed in 98.5% of patients with no flow or minimal residual flow achieved in 99.3% of implanted patients. Twenty-eight subjects experienced 31 serious adverse events (SAEs) within 1 day of the procedure. The overall 30-day mortality rate was 0.7%. The most common SAE occurring within 30 days of the procedure was major bleeding requiring transfusion. Incidence of SAEs within 30 days was significantly lower for subjects deemed to be ineligible for oral anticoagulation therapy (OAT) compared with those eligible for OAT (6.5 vs. 10.2%, P = 0.042).

Conclusion: Left atrial appendage closure with the WATCHMAN device has a high success rate in complete LAAC with low peri-procedural risk, even in a population with a higher risk of stroke and bleeding, and multiple co-morbidities. Improvement in implantation techniques has led to a reduction of peri-procedural complications previously limiting the net clinical benefit of the procedure.

Keywords: Atrial fibrillation; Left atrial appendage; Stroke.

Figure 1

Implant success in EWOLUTION when compared with prior WATCHMAN studies.

Figure 2

Serious procedure-/device-related events through 7 days in EWOLUTION when compared with prior WATCHMAN studies.

Figure 3

Subgroup results—serious adverse events through 7 days. The percentage (95% confidence interval) of the number of subjects experiencing events is displayed along the horizontal axis, separately for each subgroup defined by baseline characteristics. P -values are based on log-rank tests. OAT, oral anticoagulation therapy.

Figure 4

Subgroup results—serious procedure-/device-related events through 7 days. The percentage (95% confidence interval) of the number of subjects experiencing events is displayed along the horizontal axis, separately for each subgroup defined by baseline characteristics. P -values are based on log-rank tests. OAT, oral anticoagulation therapy.

Figure 5

Subgroup results for serious adverse events through 30 days. The percentage (95% confidence interval) of the number of subjects experiencing events is displayed along the horizontal axis, separately for each subgroup defined by baseline characteristics. P -values are based on log-rank tests. OAT, oral anticoagulation therapy.

Figure 6

Subgroup results for procedure-/device-related serious adverse events through 30 days. The percentage (95% confidence interval) of the number of subjects experiencing events is displayed along the horizontal axis, separately for each subgroup defined by baseline characteristics. P -values are based on log-rank tests. OAT, oral anticoagulation therapy.