Follow-up imaging after left atrial appendage closure.Heart Rhythm. 2020 Jun 27 [Online ahead of print]HR
Because device-related thrombus (DRT) portends a poor prognosis after left atrial appendage closure with the Watchman device, surveillance transesophageal echocardiography (TEE) is recommended at 45 days and 1 year. However, oral anticoagulants are just discontinued at 45 days, rendering this early TEE unlikely to detect DRT. Indeed, DRT is most likely to occur after instituting aspirin monotherapy.
The purpose of this study was to evaluate the alternative strategy of first TEE imaging (or computed tomography) at 4 months post-Watchman implantation.
After Food and Drug Administration approval, consecutive patients undergoing Watchman implantation at 2 centers received TEE or CT at 4 months and 1 year, along with a truncated drug regimen: 6 weeks of an oral anticoagulant (or clopidogrel in a subset) plus aspirin, then 6 weeks of dual antiplatelet therapy, and finally aspirin monotherapy.
Of the 530-patient cohort (mean age 78.7±7.9 years; 65.5% male; CHA2DS2-VASc score 4.5±1.4), 465 patients (87.7%) received 4-month imaging: 83.0% (440 of 530) TEE and 4.7% (25 of 530) computed tomography. Over a median follow-up of 12 months, 16 ischemic strokes (ISs), 8 transient ischemic attacks, and 1 systemic embolization occurred. Importantly, no IS occurred between 45 days and 4 months; the sole transient ischemic attack in this period (at ∼2 months) occurred 1 week after transcatheter aortic valve replacement. DRT was detected in 2.4% (11 of 465) at 4 months and 0.9% (2 of 214) at 1 year. No IS, but 1 leg embolization, was observed after DRT detection.
Delaying first post-Watchman imaging to 4 months was associated with no IS between 45 days and 4 months, the "vulnerable" period of this follow-up strategy.