Cardiac Computed Tomography Angiography for Device-Related Thrombus Assessment After WATCHMAN FLX™ Occluder Device Implantation: A Single-Center Retrospective Observational Study.

BACKGROUND/PURPOSE: Device-related thrombosis (DRT) is one of the greatest challenges of transcatheter left atrial appendage device occlusion. Due to the invasive nature of transesophageal echocardiography (TEE), cardiac computed tomography angiography (CCTA) is being increasingly utilized in several centers for assessing adequate left atrial appendage closure and monitoring for DRT. There is a paucity of data regarding the standardized definition of DRT on CCTA for the WATCHMAN FLX™ device. METHODS/MATERIALS: A retrospective review was conducted on 43 patients receiving WATCHMAN FLX™ device implantation with CCTA performed at the first follow-up at our institution. A comparative review of DRT predictors was performed on 10 patients who had both CCTA and TEE at the time of follow-up. RESULTS: Hypoattenuated thickening (HAT) was a common finding on CCTA and was noted to be present in 95.35% of the patients. The combination of a large device size, peridevice gap >4 mm, and HAT located on the device gutter and 1 shoulder were characteristics present on CCTA observed in 2 patients with confirmed DRT on TEE. CONCLUSION: CCTA is a noninvasive imaging modality for DRT monitoring, with guidelines still in development. We report potential predictors of DRT on CCTA. Additional studies are needed to further determine standardized parameters for DRT detection on CCTA and the significance of HAT with multimodality correlation.

CT assessment of the left atrial appendage post-transcatheter occlusion - A systematic review and meta analysis.

BACKGROUND: Transesophageal echocardiography (TEE) is the standard imaging modality used to assess the left atrial appendage (LAA) after transcatheter device occlusion. Cardiac computed tomography angiography (CCTA) offers an alternative non-invasive modality in these patients. We aimed to conduct a comparison of the two modalities. METHODS: We performed a comprehensive systematic review of the current literature pertaining to CCTA to establish its usefulness during follow-up for patients undergoing LAA device closure. Studies that reported the prevalence of inadequate LAA closure on both CCTA and TEE were further evaluated in a meta-analysis. 19 studies were used in the systematic review, and six studies were used in the meta-analysis. RESULTS: The use of CCTA was associated with a higher likelihood of detecting LAA patency than the use of TEE (OR, 2.79, 95% CI 1.34-5.80, p â€‹= â€‹0.006, I2 â€‹= â€‹70.4%). There was no significant difference in the prevalence of peridevice gap ≥5 â€‹mm (OR, 3.04, 95% CI 0.70-13.17, p â€‹= â€‹0.13, I2 â€‹= â€‹0%) between the two modalities. Studies that reported LAA assessment in early and delayed phase techniques detected a 25%-50% higher prevalence of LAA patency on the delayed imaging. CONCLUSION: CCTA can be used as an alternative to TEE for LAA assessment post occlusion. Standardized CCTA acquisition and interpretation protocols should be developed for clinical practice.

Cardiac MRI assessment of myocardial perfusion.

Coronary artery disease is the most common cause of mortality and morbidity around the globe. Assessment of myocardial perfusion to diagnose ischemia is commonly performed in symptomatic patients prior to referral for cardiac catheterization. Among other noninvasive imaging modalities, cardiac MRI (CMR) is emerging as a highly sensitive and specific test for myocardial ischemia and infarction. Resting perfusion on CMR is used to evaluate for microvascular obstruction, which is shown to predict adverse left ventricular remodeling and cardiac events after acute myocardial infarction. This article summarizes the current understanding of CMR perfusion.

Sex-specific biatrial volumetric measurements obtained with use of multidetector computed tomography in subjects with and without coronary artery disease.

Atrial volumetric measurement has proven clinical implications. Advances in cardiac imaging, notably the precision enabled by multidetector computed tomography (MDCT), herald the need for new criteria of what constitutes normal volumetric measurements. With use of 64-slice MDCT, we compared the atrial volumes in healthy individuals with those in individuals with coronary artery disease. By means of manual segmentation, we measured biatrial volume in 686 participants who underwent retrospective electrocardiographic-gated MDCT angiographic evaluation. The study population included a control group of 203 persons with no cardiac abnormalities, and a study group of 483 patients with obstructive coronary artery disease. All variables were compared between men and women and between the groups. We found a significant difference in left atrial end-systolic and end-diastolic volumes between men and women in the control group (P <0.05); however, right atrial volumes were similar. In comparison with the entire control group, the coronary artery disease group had significantly higher left atrial volume, significantly lower right atrial stroke volume, and significantly lower biatrial ejection fraction, except for left atrial ejection fraction in men. Right atrial volume and left atrial stroke volume were not significantly different. The results imply that a sex-specific reference value is necessary for left atrial volumetric evaluation, and that left atrial volume and biatrial ejection fraction (excluding left atrial ejection fraction in men) might be useful during diagnosis and prognosis in patients who have coronary artery disease.