Decreased device related thrombus and enhanced neo-endocardial tissue maturation with a new generation left atrial appendage closure (LAAC) device. An anticoagulation and antiplatelet free canin study

Introduction

Device related thrombus (DRT) has been reported in up to 7% of patients post LAAC even while on anticoagulation. Clinical predictors of DRT are poorly understood and may be related to patient, procedural and device factors. A next generation WATCHMAN LAAC device (NG) is identical in shape and geometry to the current WATCHMAN FLX device (CW) but has a device coating designed to make it hemocompatible and less thrombogenic.

Objective

To evaluate the incidence and burden of WM surface thrombus formation as detected longitudinally by TEE and at necropsy in a canine model implanted with the NG device.

Methods

The study included 12 canine (6 implanted with CW and 6 implanted with NG) that underwent serial TEE follow up at 14, 28 and 45 days to evaluate surface thrombus on WM face. This was a challenged canine model designed to induce thrombus with no anticoagulation or antiplatelet use throughout the study. D-dimer levels were measured at 7 days and 45 days and compared to baseline measurements.

Results

All devices were successfully implanted. TEE follow up at 14 days showed noticeably reduced thrombus burden on the NG device compared to CW (fig.1) with even further diminution by 28 days in the NG (6/6) as compared to only in 1/6 in the CW group (fig.2). After 45 days in-life, the post-fixation trim en-face images show a smooth, glistening neoendocardial covering (absence of acute thrombus material) in all (6/6) NG compared to only 2/6 in the CW (fig.3). The CW had 3/6 devices with exuberant, bulging calcified thrombus mass one of which was considered to be a mobile DRT. D Dimer levels at 7 and 45 days were significantly lower relative to baseline in the NG compared to CW.

Conclusion

The NG device compared to the CW device was associated with markedly less thrombus formation at 14 days and no thrombus formation at 28 days post implant on no anticoagulant and no antiplatelet therapy along with a more mature uniform tissue coverage at 45 days. The WATCHMAN FLX Pro device coating is a promising step to reduce DRT even without the use of anticoagulation and antiplatelets and merits further investigation in human studies.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific

Associations and outcomes of cardiovascular calcifications by computed tomography in atrial fibrillation patients

Background

Coronary (CAC), mitral annular (MAC), aortic valve (AVC) and thoracic aortic (TAC) calcifications are known imaging biomarkers for cardiovascular risk in the general population. Despite this, their prognostic value are not well established in atrial fibrillation (AF) patients who have elevated risk for cardiovascular events.

Purpose

We assessed the associated factors and outcomes of cardiovascular calcifications detected by computed tomography (CT) in AF patients undergoing pulmonary vein isolation (PVI).

Methods

Consecutive AF patients enrolled in a prospective PVI registry during 2014–2018 with CT performed within 1-year of their procedure were reviewed for the presence of cardiovascular calcifications on CT. Risk factors and outcomes for each type of cardiovascular calcifications were analyzed in univariable and multivariable regression models.

Results

Amongst 3604 AF patients, there were 2238 (62.1%), 308 (8.6%), 572 (15.9%) and 1048 (29.1%) patients with CAC, MAC, AVC and TAC respectively. Factors independently associated with these cardiovascular calcifications are listed in Table 1. During mean follow-up of 2.8±1.6 years, there were 97 (2.7%) all-cause deaths, and 158 (4.4%) major adverse cardiovascular events (MACE). Forest plots of unadjusted and adjusted hazards ratios of cardiovascular calcifications at predicting these outcomes are shown in Figure 1.

Conclusion

Cardiovascular calcifications especially CAC are prevalent in AF patients, and share common risk factors with cardiovascular events, except for female being protective for CAC and AVC but having higher risk of MAC and TAC. Although all cardiovascular calcifications were associated with death and MACE in unadjusted analyses, only CAC remained so for both outcomes in adjusted analyses.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Heart Foundation of New Zealand Table 1Figure 1

Screening for high utilizing somatizing patients using a prediction rule derived from the management information system of an HMO: a preliminary study

BACKGROUND

Somatization is a common, costly problem with great morbidity, but there has been no effective screening method to identify these patients and target them for treatment.

OBJECTIVES

We tested a hypothesis that we could identify high utilizing somatizing patients from a management information system (MIS) by total number of visits and what we termed "somatization potential," the percentage of visits for which ICD-9 primary diagnosis codes represented disorders in the musculoskeletal, nervous, or gastrointestinal systems or ill-defined complaints.

METHODS

We identified 883 high users from the MIS of a large staff model HMO as those having six or more visits during the year studied (65th percentile). A physician rater, without knowledge of hypotheses and predictors, then reviewed the medical records of these patients and identified somatizing patients (n = 122) and nonsomatizing patients (n = 761). In two-thirds of the population (the derivation set), we used logistic regression to refine our hypothesis and identify predictors of somatization available from the MIS: demographic data, all medical encounters, and primary diagnoses made by usual care physicians (ICD-9 codes). We then tested our prediction model in the remaining one-third of the population (the validation set) to validate its usefulness.

RESULTS

The derivation set contained the following significant correlates of somatization: gender, total number of visits, and percent of visits with somatization potential. The c-statistic, equivalent to the area under the ROC curve, was 0.90. In the validation set, the explanatory power was less with a still impressive c-statistic of 0.78. A predicted probability of 0.04 identified almost all somatizers, whereas a predicted probability of 0.40 identified about half of all somatizers but produced few false positives.

CONCLUSIONS

We have developed and validated a prediction model from the MIS that helps to distinguish chronic somatizing patients from other high utilizing patients. Our method requires corroboration but carries the promise of providing clinicians and health plan directors with an inexpensive, simple approach for identifying the common somatizing patient and, in turn, targeting them for treatment. The screener does not require clinicians' time.

Relation of ferritin levels to pulmonary function in patients with thalassemia major and the acute effects of transfusion

We studied 36 patients (17 males and 19 females) with thalassemia major by performing pulmonary function testing (PFT), arterial blood gas analysis (ABG), as well as determining the serum ferritin level. In addition, 19 of these patients were transfused with two units of packed cells, and a repeat ABG and PFT were performed. Twenty-three patients had normal PFTs, eleven patients (30.6%) showed a restrictive pattern (significant decrease in both TLC and DLCO), and only two patients (5.6%) showed an obstructive pattern. A significant negative correlation was found between serum ferritin and restrictive parameters, DLCO and TLC (p = 0.01 and p = 0.03, respectively). This correlation was even stronger after transfusion. Controlling for age, ferritin was still negatively correlated with DLCO (p = 0.04), but no longer with TLC. There was no correlation between age and DLCO or age and TLC; however, there was a statistically significant negative correlation between age and FVC (p = 0.003). Analysis of patients who were transfused revealed a significant decrease in forced vital capacity (89 +/- 4% vs. 74 +/- 5% of predicted; p-value < 0.001) and in maximum midexpiratory flow rate (79 +/- 4% vs. 67 +/- 5% of predicted; p-value = 0.004). For patients older than 15 yr of age, there was a statistically significant decrease in FEV1/FVC (84 +/- 2 vs. 83 +/- 2%; p-value = 0.04). The ABGs showed no significant change post-transfusion. In this study, PFT findings in thalassemia major were restrictive and correlated with serum ferritin level. Transfusion had an acute effect on the obstructive parameters of PFT.

Life experiences, response styles and mental health among mothers and children in Beirut, Lebanon

A sample of 152 women living in Beirut, Lebanon was studied to determine the relationship between life experiences, mothers' depression, and children's health and behavior. Measures of the perceived negative impact of both war and nonwar related events, measures of available social support, sociodemographic variables, coping or response strategies and displacement were used to predict mothers' depressive symptomatology and their children's health. The level of perceived negative impact of war-related events was found to be strongly associated with higher levels of depressive symptomatology among mothers. More surprising was the relative importance of experiences unrelated to the war in predicting higher levels of depressive symptoms. Among the most noteworthy of the findings was the association between the use of an emotional response style and the measure of psychological dysfunction. Finally, the level of a mother's depressive symptomatology was found to be the best predictor of her child's reported morbidity, with higher levels of symptoms associated with higher levels of morbidity.