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Published on: February 28, 2012
Clinical Implications of CT-detected Hypoattenuation Thickening on Left Atrial Appendage Occlusion Devices
Xavier Iriart1, Gregoire Blanc1, Xavier Paul Bouteiller1
1From the IHU Liryc, CHU/Univ Bordeaux/Inserm 1045, IHU Liryc, Electrophysiology and Heart Modelling Institute, Bordeaux University Foundation, Inserm U1045, Avenue de Magellan, 33604 Pessac, France (X.I., X.P.B., A.B., J.B.T., H.C.); Department of Cardiac Imaging, CHU Bordeaux, Pessac, France (B.L., S.S.C., H.C.); Department of Pediatric and Adult Congenital Heart Disease, M3C National Reference Centre, Bordeaux University Hospital, Bordeaux-Pessac, France (X.I., B.B., C.V., J.B.T.); and Department of Cardiology, CHU de Toulouse, Toulouse, France (G.B., M.E.).
Insights
Hypoattenuation thickening (HAT) after left atrial appendage occlusion (LAAO) is common. High-grade HAT indicates increased stroke risk, while low-grade HAT suggests favorable outcomes, aiding clinical management decisions.
Area of Science:
- Cardiology
- Radiology
- Medical Imaging
Background:
- Hypoattenuation thickening (HAT) is a frequent finding on CT scans post-left atrial appendage occlusion (LAAO).
- The clinical significance of HAT in patients undergoing LAAO requires further investigation.
Purpose of the Study:
- To determine the association between the grade of HAT observed on follow-up CT scans and clinical characteristics.
- To evaluate the relationship between HAT grade and patient outcomes after LAAO.
Main Methods:
- A prospective study included 412 patients with atrial fibrillation and high stroke risk (CHA2DS2-VASc score ≥4) who underwent LAAO.
- Follow-up CT images were analyzed by two radiologists to classify HAT as low-grade or high-grade.
- Statistical analyses, including multinomial logistic regression and Cox proportional hazard models, were used to assess associations.
Main Results:
- Low-grade HAT was observed in 23.8% and high-grade HAT in 5.1% of patients.
- High-grade HAT correlated with increased antithrombotic drug discontinuation (OR, 9.5) and a higher risk of stroke (HR, 4.6).
- Low-grade HAT was associated with a lower likelihood of persistent left atrial appendage patency (OR, 0.46).
Conclusions:
- Low-grade HAT is more common than high-grade HAT after LAAO.
- High-grade HAT is a significant predictor of adverse outcomes, including stroke.
- HAT grading on follow-up CT can provide valuable prognostic information for LAAO patients.
Abstract:
Background At follow-up CT after left atrial appendage occlusion (LAAO), hypoattenuation thickening (HAT) on the atrial aspect of the device is a common finding but the clinical implications require further study. Purpose To assess the association of HAT grade at follow-up CT with clinical characteristics and outcomes in patients who underwent LAAO. Materials and Methods This prospective study included consecutive participants with atrial fibrillation and who were at high risk for stroke (CHA2DS2-VASc score ≥4) who underwent LAAO and were administered pacifier or nonpacifier devices at two French medical centers between January 2012 and November 2020. Postprocedure CT images were evaluated by two radiologists in consensus and device-specific interpretation algorithms were applied to classify HAT as low grade (low suspicion of thrombosis) or high grade (high suspicion of thrombosis). The association between HAT grade and clinical characteristics was assessed using multinomial logistic regression, and variables associated with risk of stroke were assessed using a Cox proportional hazard model. Results This study included 412 participants (mean age, 76 years ± 8 [SD]; 284 male participants) who underwent follow-up CT at a mean of 4.2 months ± 1.7 after LAAO. Low-grade and high-grade HAT were depicted in 98 of 412 (23.8%) and 21 of 412 (5.1%) participants, respectively. High-grade HAT was associated with higher odds of antithrombotic drug discontinuation during follow-up (odds ratio, 9.5; 95% CI: 3.1, 29.1; P < .001), whereas low-grade HAT was associated with lower odds of persisting left atrial appendage patency (odds ratio, 0.46; 95% CI: 0.27, 0.79; P = .005). During a median follow-up of 17 months (IQR, 11-41 months), stroke occurred in 24 of 412 (5.8%) participants. High-grade HAT was associated with stroke (hazard ratio, 4.6; 95% CI: 1.5, 14.0; P = .008) and low-grade HAT (P = .62) was not. Conclusion Low-grade HAT was a more common finding at CT performed after LAAO CT (24%) than was high-grade HAT (5%), but it was associated with more favorable outcomes than high-grade HAT, which was associated with higher stroke risk. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Choe in this issue.
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