Study Suggests Benefits of Preoperative CT for Left Atrial Appendage Occlusion Procedures

(Editor’s note: This article has been adapted from its original publication on our sister site Practical Cardiology.)

Preoperative planning with 3D computed tomography (CT) imaging may be beneficial for surgeons looking to improve the success and efficiency of procedures for left atrial appendage occlusion (LAAO).

In a recently published retrospective analysis of nearly 500 Watchman (Boston Scientific) implantations, researchers found that preoperative use of 3D CT not only facilitated higher procedure success rates in comparison to standalone transesophageal echocardiogram (TEE), it also reduced procedure time and implant size changes.

“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 the study’s senior investigator Dee Dee Wang, MD, the 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 three-dimensional image of the heart.”

For the retrospective review of 485 Watchman implantation procedures, the study authors noted 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.

Out of the 485 Watchman implantations, additional CT preoperative planning was used for 328 procedures and surgeons used stand-alone TEE guidance in 157 cases. 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 (rate) of 98 percent when imaging is available,” said William O’Neill, MD, director of the Henry Ford Center for Structural Disease.