CT-Based Preplanning Allows Abstaining from Intraprocedural TEE during Interventional Closure of the LAA in Patients with Atrial Fibrillation

OBJECTIVES

The aim of this study was to determine whether the application of a CT-based preplanning algorithm might allow abstaining from TEE during LAAC.

BACKGROUND

LAAC is an established treatment alternative for patients with atrial fibrillation. Today, most LAAC procedures are guided by TEE, which, however, leads to the need for patient sedation and might even cause direct harm to the patient. CT-based preplanning of the LAAC procedure, in combination with technical improvements in device design and interventional experience, might allow abstaining from TEE.

METHODS

Fluoro-FLX is a prospective single-center study to evaluate how often TEE leads to a procedural change during interventional LAAC if a dedicated CT planning algorithm is applied. The study hypothesis is that under these circumstances, a sole fluoroscopy-guided LAAC is an alternative to a TEE-guided approach. All procedures are preplanned by cardiac CT and, finally, guided by fluoroscopy only, while TEE is carried out in the background during the intervention for safety reasons.

RESULTS

In none of the 31 consecutive patients did TEE lead to a change in the preplanned fluoroscopy-guided LAAC (success ratio: 1.00; CI: 0.94-1.00), thereby meeting the primary endpoint (performance goal: 0.90). There were no procedure-related adverse cardiac or cerebrovascular events (no pericardial effusion, TIA, stroke, systemic embolism, device embolism, death).

CONCLUSIONS

Our data suggest that it is feasible to perform LAAC under sole fluoroscopic guidance if preplanning is performed using cardiac CT. This might be worth considering, especially in patients who are at high risk for TEE-related adverse events.

Impact of ultrasound contrast agent during transoesophageal echocardiography on the sizing of the left atrial appendage

INTRODUCTION

Interventional closure of the left atrial appendage closure (LAAC) has been established as an alternative treatment in patients with atrial fibrillation (AF) and an increased risk of stroke. So far it is unknown whether the use of ultrasound contrast agent (UCA) would influence the correct sizing of the LAA and thereby have an impact on device selection during interventional LAAC.

METHODS

Between January 2017 and April 2018, 223 transoesophageal echocardiography (TOE) examinations were prospectively performed in adult patients with non-valvular AF (Impact of the use of ultrasound contrast agent on the detection of thrombi in the left atrial appendage during transesophageal echocardiography (CONDOR) study). LAA was examined both with and without the use of UCA. The following measurements were taken at 0^o, 45^o, 90^o and 135^o: diameter of LAA ostium, maximal depth of the LAA, maximal available depth of the LAA orthogonal to the ostial plane and area of the LAA.

RESULTS

The use of UCA had no relevant influence on the size determination of the LAA. Additionally, Bland-Altman blots demonstrate a high degree of correlation between the measurements with and without UCA with no evidence for a systematic effect arising from the use of UCA. When comparing the measurements of two independent investigators, the use of UCA rather leads to a higher variability than to an improved precision.

DISCUSSION

Despite the fact that the use of UCA during TOE leads to an improved rule out of thrombi, our study shows that there is no advantageous effect of UCA on the size determination of the LAA and should therefore not be used for this purpose.

Correction to: Fusion Imaging of X-ray and Transesophageal Echocardiography Improves the Procedure of Left Atrial Appendage Closure

The article "Fusion Imaging of X-ray and Transesophageal Echocardiography Improves the Procedure of Left Atrial Appendage Closure."

Fusion Imaging of X-ray and Transesophageal Echocardiography Improves the Procedure of Left Atrial Appendage Closure

Background

Left atrial appendage closure (LAAC) is an alternative treatment strategy for patients with atrial fibrillation who are at risk for thromboembolic events and considered not suitable for oral anticoagulation (OAC). LAAC is mainly performed under the guidance of transesophageal echocardiography (TEE) and fluoroscopy. The study presented here should analyze whether fusion imaging (FI) of transesophageal echocardiography and X-ray performed during LAAC is feasible and can improve the results of the procedure.

Methods

The data presented here are from a retrospective single center study. Sample size was defined as 50 patients in which LAAC was performed without fusion imaging (control group) and 25 patients were the LAAC procedure was guided by fusion imaging (treatment group). Inclusion criteria were defined as age > 18 years and completion of an LAAC procedure defined as deployment of a WATCHMAN 2.5 LAA occluder. Study endpoints were procedure time, amount of used contrast medium, radiation dose, final position of the WATCHMAN in TEE (deviation from ideal positioning), and clinical endpoints, respectively.

Results

LAA closure was successfully performed in all patients. No case of device embolism was occurring, and none of the patients experienced a periprocedural stroke/TIA nor a systemic embolism, respectively. Mean procedure time was 15 min shorter in the group of patients where fusion imaging was applied (p < 0.001). Additionally, the use of fusion imaging was associated with a significant reduction of contrast medium (20.6 ml less than in control; p < 0.045). Regarding the final position of the WATCHMAN, no relevant differences were found between the groups.

Summary

The use of fusion imaging significantly reduced procedure time and the amount of contrast medium in patients undergoing LAAC.

Impact of ultrasound contrast agent on the detection of thrombi during transoesophageal echocardiography

Background

Atrial fibrillation (AF) carries the risk of thrombus formation in the left atrium and especially in the left atrial appendage (LAA). A transoesophageal echocardiography (TOE) is routinely performed in these patients to rule out thrombi before cardioversion or structural interventions like LAA closure or pulmonary vein isolation. However, in a certain number of cases, inconclusive results of the TOE may result. This study was performed to analyse whether the routine use of ultrasound contrast agent (UCA) has an influence on the frequency of thrombus detection.

Methods

In patients with AF who were scheduled for a subsequent interventional procedure, a TOE was initially performed without contrast agent. Then, the TOE was repeated with the use of UCA. The percentage of diagnostic findings regarding the prevalence of thrombus in the LAA with and without UCA were compared (thrombus present (T+), no thrombus (T−) and inconclusive result (T+/−)).

Results

223 patients were prospectively included into the trial. The numbers of thrombus detection were as follows: without UCA: 17 T+ (7.6%), 154 T− (69.1%), 52 T+/− (23,3%); with UCA: 16 T+ (7.2%), 179 T− (80.3%), 28 T+/− (12.6%; χ²: p<0.01). In 29 examinations (13.0%), the use of UCA had an impact on the subsequent treatment strategy.

Conclusions

The use of UCA during TOE in patients with AF has a significant impact on the subsequent patient management especially due to an improved rule out of LAA thrombi.