Application of cardiac computed tomographic imaging and fluoroscopy fusion for guiding left atrial appendage occlusion

Objective: Evaluate the value of 3D computed tomography (CT) and CT-integrating fluoroscopy for procedural guidance during WATCHMAN implantation.

Methods: This observational study compared the clinical and procedural parameters for LAAO with and without fusion imaging. Forty-one pairs of patients-matched by procedure month and with or without the use of the image fusion system-were enrolled. Using the image fusion Advanced Workstation 4.6 software (GE Healthcare), we identified the 3D cardiac anatomy and safe zones for septal punch. The LAA orifice anatomy outlines were then projected onto the real-time fluoroscopy image during the procedure to guide all the steps of LAAO.

Results: The use of image fusion significantly reduced the procedural time, compared to the time required for the control group (44.73 ± 20.03 min vs. 63.73 ± 26.10 min, respectively; P < 0.001). When compared to the standard procedure, the use of image fusion significantly reduced both the total radiation dose (448.80 ± 556.35 mGy vs. 798.42 ± 616.34 mGy; P = 0.004) and dose area product (DAP) (38.03 ± 47.15 Gy∙cm2 vs. 67.66 ± 52.23 Gy∙cm², P = 0.004). Corresponding to the radiation dose, the contrast volume was also reduced (67.32 ± 18.65 vs. 90.98 ± 25.03 ml; P = 0.0004). During short-term follow-up at 6 months, there was only one femoral hematoma and incomplete LAA sealing (>3 mm) in either group.

Conclusions: Automated real-time integration of cardiac CT and fluoroscopy is feasible, safe, and applicable in LAAO. It may significantly reduce the radiation exposure, procedure duration, and volume of contrast media. Following these results, the potential of merging reconstructed 3D CT scans with real-time coronary angiography should be fully exploited in LAAO.