A Comparison of Cardiac Computed Tomography, Transesophageal and Intracardiac Echocardiography, and Fluoroscopy for Planning Left Atrial Appendage Closure

Surface steel ball calibration - A novel method for facilitating fluoroscopic measurement during implantation of WATCHMAN

BACKGROUND

Although the method of autocalibration or calibration based on catheter diameters was proposed for fluoroscopic measurement during percutaneous left atrial appendage occlusion (LAAO), it may be imprecise and lead to mismeasurement. We sought to investigate whether the utilization of the surface steel ball calibration (SSBC) method under fluoroscopy could facilitate the fluoroscopic measurement of the post-implanted WATCHMAN device (Boston Scientific Corporation, Natick, MA, USA) in LAAO.

METHODS

This retrospective study included 97 consecutive patients who underwent percutaneous LAAO with the WATCHMAN device. The SSBC method and sheath calibration method under fluoroscopy, and transesophageal echocardiography (TEE) were employed to measure the diameter of the post-implanted device during the LAAO procedure. The results of the three methods were then compared.

RESULTS

The success rate for procedural WATCHMAN implantation was 100 %. The mean maximal diameter of the post-implanted devices was 24.7 ± 3.1 mm, 23.5 ± 3.2 mm, and 24.2 ± 3.0 mm, as measured by the SSBC method, sheath calibration method, and TEE, respectively (all p < 0.001). The relevant coefficient of correlation between the SSBC method/TEE, SSBC method/sheath calibration method, and TEE/sheath calibration method, was 0.94, 0.93, and 0.89, respectively (all p < 0.001).

CONCLUSION

The SSBC method, when employed under fluoroscopy, demonstrated a high correlation with the sheath calibration method and TEE for measurements. It may be applied to facilitate fluoroscopic measurements during percutaneous LAAO procedures.

Computed tomography-based device-sizing in Amplatzer Amulet left atrial appendage occlusion

BACKGROUND

Amplatzer Amulet is a frequently used device for left atrial appendage occlusion (LAAO). The current sizing protocol is based on the maximum diameter of the left atrial appendage (LAA) landing zone. However, mean, perimeter-, or area-derived diameter might be more accurate measures for device sizing.

METHODS

Retrospective analysis of 150 consecutive patients undergoing LAAO is guided by pre-procedural cardiac CT. A total of 117 patients were included; 7 were excluded due to renal failure and 26 due to closure with the sandwich technique. The maximum, mean, area-, and perimeter-derived diameters of the landing zone were derived from pre-procedural cardiac CT scans, and their accuracy to predict the implanted device size was investigated. The predicted device size was determined based on the currently recommended sizing algorithm. Peri-device leak (PDL) was assessed (grade 1-3) along with the underlying mechanism.

RESULTS

Device-sizing accuracy was superior for mean, area-, and perimeter derived diameters compared with the maximal diameter, especially for eccentric landing zones. Mean difference between predicted and actually implanted device size was 0.08 mm (± 2.77), 0.30 mm (± 2.40), - 0.39 mm (± 2.43), and - 2.55 mm (± 2.57) across mean, area-derived, perimeter-derived, and maximal diameter, respectively. Grade 3 peri-device leak was seen in 8.5% of implants without a significant association to the eccentricity of the landing zone. The leading mechanism for PDL was device malalignment.

CONCLUSION

Our results indicate mean, area-, and perimeter-derived diameters of the device landing zone to perform similar and superior in device-sizing accuracy compared with the maximum diameter.

Practical guide on left atrial appendage closure for the non-implanting physician: an international consensus paper

A significant proportion of patients who suffer from atrial fibrillation (AF) and are in need of thromboembolic protection are not treated with oral anticoagulation or discontinue this treatment shortly after its initiation. This undertreatment has not improved sufficiently despite the availability of direct oral anticoagulants which are associated with less major bleeding than vitamin K antagonists. Multiple reasons account for this, including bleeding events or ischaemic strokes whilst on anticoagulation, a serious risk of bleeding events, poor treatment compliance despite best educational attempts, or aversion to drug therapy. An alternative interventional therapy, which is not associated with long-term bleeding and is as effective as vitamin K anticoagulation, was introduced over 20 years ago. Because of significant improvements in procedural safety over the years, left atrial appendage closure, predominantly achieved using a catheter-based, device implantation approach, is increasingly favoured for the prevention of thromboembolic events in patients who cannot achieve effective anticoagulation. This management strategy is well known to the interventional cardiologist/electrophysiologist but is not more widely appreciated within cardiology or internal medicine. This article introduces the devices and briefly explains the implantation technique. The indications and device follow-up are more comprehensively described. Almost all physicians who care for adult patients will have many with AF. This practical guide, written within guideline/guidance boundaries, is aimed at those non-implanting physicians who may need to refer patients for consideration of this new therapy, which is becoming increasingly popular.