Concern of growing leaks over time
People with long-standing persistent atrial fibrillation (Afib) tended to have larger left atrial appendages (LAAs) that required larger occlusion devices and were associated with more residual leaks, a single-center study of Watchman recipients found.
With continuous Afib lasting over a year, their ostial diameters were about 2-3 mm wider and LAA depths 3-5 mm deeper depending on the angle of transesophageal echocardiography (TEE). As such, these patients typically got the larger 27-, 30-, or 33-mm occlusion devices more often (77% vs 46% of controls, P=0.003).
This group went from a similar rate of peridevice leaks immediately after device implantation (9% vs 2%, P=0.14) to having more moderate leaks (3-5 mm) at 6-week follow-up (27% vs 4%, P=0.04), according to Gagan Singh, MD, and colleagues at the University of California, Davis, reporting in a study published in JACC: Cardiovascular Interventions.
Despite having more moderate leaks, these patients did not suffer more deaths, strokes, or myocardial infarctions (MIs) at 1 year, the researchers reported.
"Admittedly, all the leaks noted in this and other series are not 'significant' and remain <5 mm out to 6 weeks of follow-up. Based on the present series and the available published reports, nonsignificant leaks have not been associated with adverse clinical events," Singh's group noted.
"However, whether these leaks continue to enlarge over time, particularly in the LSPAF [long-standing persistent Afib], is a valid concern based on our findings and deserves special attention on follow-up investigations," the researchers maintained.
Explanations for the moderate leakage in long-standing Afib may include anatomic remodeling of the left atrium and LAA from ongoing Afib, hemodynamic changes along with loss of a distensible LAA reservoir, and an acutely contracted LAA at the time of implant that later relaxes, Singh and colleagues suggested.
Device undersizing was probably not the issue as there was no difference in 6-week compression rates between arms, the team said.
The study included 101 consecutive Watchman cases performed under general anesthesia with 2-D TEE and fluoroscopic guidance. The mean age of the patients in the cohort was 76, and 65% were men. Average CHA2DS2-VASc and HAS-BLED scores were 4.4 and 4.1, respectively.
Patients with long-standing Afib typically had lower ejection fractions, more mitral regurgitation, and greater left atrial volumes and left ventricular dimensions.
The use of larger devices was not accompanied by increased procedural complications such as thromboembolic events, pericardial effusions, or device embolization, the operators found.
Nevertheless, the study authors acknowledged the single-center nature of their study and the lack of long-term TEE follow-up.
That device sizing was not performed with 3-D TEE or CT was another weakness, as these modalities provide larger measurements and can help prevent device undersizing and subsequent peridevice leak.
"Hopefully, with the increasing use of 3-dimensional imaging modalities for LAA assessment and device sizing, together with increased operator experience and refinement in device design, the occurrence of significant PDL [peridevice leak] may decrease in the future," said a trio led by Adel Aminian, MD, of Centre Hospitalier Universitaire de Charleroi, Belgium, writing in an accompanying editorial.
"Patients with LSPAF may have LAA sizes that are too large for percutaneous LAA occlusion with current commercially available devices and therefore warrant detailed baseline measurements prior to embarking on LAA occlusion," the editorialists concluded.
Moreover, they noted, the findings of Singh and colleagues should be replicated in larger prospective series.
Singh disclosed being an educational consultant and speaker for Boston Scientific.
Aminian reported proctoring and consulting for Abbott and Boston Scientific.
JACC: Cardiovascular Interventions
Source Reference: Glassy MS, et al "Watchman occlusion in long-standing persistent atrial fibrillation: larger left atrial appendages with greater residual leak" JACC Cardiovasc Interv 2019; DOI: 10.1016/j.jcin.2019.04.007.
JACC: Cardiovascular Interventions
Source Reference: Aminian A, et al "Are patients with long-standing persistent atrial fibrillation at higher risk with left atrial appendage occlusion?" JACC Cardiovasc Interv 2019; DOI: 10.1016/j.jcin.2019.04.022.
Rad the original article on Medpage Today: With Chronic Afib, LAAs Get Bigger With More Occluder Leaks