Multimodality Imaging for Left Atrial Appendage Closure: Practical Guidance Across Preprocedural, Intraprocedural, and Postprocedural Phases

Left atrial appendage closure is an increasingly used stroke prevention therapy for patients with atrial fibrillation who are unable to maintain long-term anticoagulation. Imaging quality and consistency are central to procedural safety and long-term outcomes, yet practice varies widely across centers. This review presents a practical, phase-based multimodality imaging framework intended to provide guidance and minimum standards for image acquisition and interpretation across all phases of left atrial appendage closure care, including preprocedural planning and thrombus exclusion, intraprocedural guidance and complication detection, and postprocedural surveillance for device-related thrombus and peridevice leak. Because sizing rules, sealing mechanisms, and leak patterns differ between the 2 contemporary platforms, device-specific considerations for the Watchman and Amulet systems are addressed throughout. Transesophageal echocardiography remains the reference standard for thrombus detection and procedural guidance, while cardiac computed tomography offers high spatial resolution, detailed 3-dimensional characterization, and complementary leak assessment, with optimal modality selection influenced by patient characteristics, operator expertise, and institutional resources. Intracardiac echocardiography and mini transesophageal echocardiographic support anesthesia-sparing workflows. Standardized device-related thrombus and peridevice leak classification and harmonized imaging protocols can enhance reproducibility and facilitate cross-center comparisons. Emerging technologies including computed tomography first workflows, 4-dimensional imaging, AI applications, and computational modeling further advance precision planning and surveillance.