Preprocedural CT Can Improve LAAO Success Rate

Dee Dee Wang, MD

The addition of preprocedural 3D computed tomography (CT) imaging could improve procedural success rates in patients undergoing left atrial appendage occlusion (LAAO).

A retrospective analysis of nearly 500 Watchman implantations at a single medical center, data from the study provide insight into the impact of including 3D CT imaging as part of the preprocedural planning, with results suggesting use of 3D CT imaging was associated with increased device implantation rates, shorter procedural times, and less frequent changes in device sizes.

“The standard method for imaging the heart to guide LAAO procedures is 2-dimensional transesophageal echocardiogram, which uses ultrasound waves to make a detailed picture of the heart,” said senior investigator Dee Dee Wang, MD, director of structural heart imaging at Henry Ford Hospital, in a statement. “This study aimed to assess the value of adding 3-dimensional CT imaging to that process, versus using only TEE imaging, to make that detailed picture. Our findings indicate significant benefit by adding CT imaging, which uses x-ray to help create a more comprehensive 3Dimensional image of the heart.”

As the popularity of LAAO procedures with the Watchman device has exploded since approval in March 2015, research related to LAAO has shifted from the plausibility of the procedure to avenues for optimizing uptake. With this in mind, Wang and a team of colleagues sought to assess whether use of additional CT preprocedural planning could improve procedural success compared to stand-alone transesophageal echocardiogram (TEE) guidance. To do so, investigators designed their research endeavor as a retrospective analysis of data from all LAAO using the Watchman device performed at a single center from May 2015-December 2019.

The primary outcome of interest was the rate of successful device implantation without major peri-device leaks, which was defined as a leak greater than 5 mm. Secondary outcomes of interest included major adverse events, total procedural time, radiation dose, total contrast used, number and types of delivery sheath used, number of devices used, number of partial recaptures, and risk of significant peri‐device leak, and device‐related thrombus at follow‐up imaging.

Overall, 485 Watchman implantations were identified for inclusion in the investigators’ analyses. Of these, 328 used additional CT preprocedural planning and 157 used stand-alone TEE guidance. Compared to those in the stand-alone TEE guidance arm, patients in the CT group had a significantly lower BMI (28.7±6.2 vs 30.9±6.8; P=.001) and higher HAS‐BLED score (3.2±1.0 vs 2.9±1.0; P=.006). However, there were no significant differences observed in their baseline clinical profiles, including the baseline creatinine levels.

Upon analysis, results indicated additional preprocedural CT planning was associated with a significantly higher successful device implantation rate (98.5% vs 94.9%; P=0.02), a shorter procedural time (median, 45.5 vs 51.0 minutes; P=.03), and a less frequent change of device size (5.6% vs 12.1%; P=.01) and particularly device upsize (4% vs 9.4%; P=.02). Investigators pointed out there was no significant difference in the risk of major adverse events (2.1% vs 1.9%; P=.87). Additionally, only 1 significant peri‐device leak (0.2%) and 5 device‐related thrombi were detected in follow‐up (1.2%), with no intergroup differences observed.

“CT imaging allows us to take all guesswork out of device implantation. We know that we can safely close the appendage and have a success of 98% when imaging is available,” said William O’Neill, MD, director of the Henry Ford Center for Structural Disease.

This study, “Additive Value of Preprocedural Computed Tomography Planning Versus Stand‐Alone Transesophageal Echocardiogram Guidance to Left Atrial Appendage Occlusion: Comparison of Real‐World Practice,” was published in the Journal of the American Heart Association.