following the Fontan operation. There are conflicting data regarding the closure of the venovenous collateral (VVC) vessels post-Fontan. The embolization of these VVC in older patients may be associated with decreased survival. We describe a rare fistula draining a right-sided hepatic vein connected to a hepatic venous plexus to a right-sided pulmonary venous atrium in a child with visceral heterotaxy. The patient presented with severe hypoxemia following the Fontan operation. The fistula was successfully occluded by an AMPLATZER™ Vascular Plug II to resolve the hypoxemia and improve the hemodynamic status. Approach to venovenous collaterals in older patients with mild cyanosis after the Fontan operation may differ from that in younger children with severe hypoxemia and intrahepatic VVC. Patients with profound cyanosis due to intrahepatic to atrial connection may benefit from the occlusion of these connections. Percutaneous closure of hepatic to atrial connection with significant hypoxemia following appropriate hemodynamic assessment may be beneficial.

Data on the rate of progression of aortic stenosis (AS) in women are limited. We retrospectively studied 95 female patients (age 75 ± 13 yrs) with aortic valve area (AVA) <2.0 cm2 (mild AS 1.5-1.9 cm2, moderate AS 1.0-1.4 cm2, severe AS <1.0 cm2). All patients underwent serial transthoracic echocardiography. We determined annual AVA decrease (rate of AS progression) by 3 approaches, each of which was applied to the entire cohort: 1) as a single group; 2) in the 3 subgroups of mild, moderate and severe AS; and 3) in the rapid and slower progressors. Study endpoints were aortic valve replacement (AVR) and all-cause mortality. The mean duration of follow-up was 4.5 ± 2.9 years. Mean rate of reduction in AVA for the total study group was 0.14 ± 0.16 cm2/yr and was directly related to presence of hypertension and baseline AVA, and inversely related to follow-up duration (all p<0.05). The annualized decrease in AVA for each of the subgroups of mild, moderate and severe AS at baseline was 0.21±0.31 cm2, 0.13±0.11 cm2, 0.11±0.09 cm2, respectively (p<0.0001). Rapid progression of AS (decrease in AVA =0.20 cm2/yr) occurred in 21% of patients (n=20) and was associated with baseline hypertension (p=0.03) and inversely related to follow-up duration (p=0.0007). Rapid progressors had shorter follow-up than slower progressors (20 vs. 42 mos, p=0.002). Event-free survival with end-points of death (n=65) or surgical/transcatheter AVR (n=24) at 1, 3, and 5 years, respectively, was 93%, 66% and 40% for mild AS; 96%, 72% and 48% for moderate AS; and 93%, 38% and 24% for severe AS. Thus, event-free survival at 5 years in patients with baseline severe AS was approximately half that of patients with AS of mild or moderate severity. In addition, event-free survival at 1 year in slower progressors was 92% and in rapid progressors was 70%.

Sitosterolemia is an ultra-rare autosomal recessive dyslipidemia characterized by mutations in genes encoding the ATP-binding cassette (ABC) G5/8 transporters. We describe the case of a 20-month-old female presenting with xanthomas and serum low density lipoprotein cholesterol of 657 mg/dL. Diagnostic workup revealed a previously undescribed sitosterolemia-causing mutation. After elimination of dietary sterols and initiation of ezetimibe therapy, the patient’s xanthomas resolved, and serum low density lipoprotein cholesterol was reduced to 104 mg/dL. Importantly, pathologically elevated serum phytosterols were found in each of the proband’s heterozygous parents. Elevated phytosterols, an established cause of atherosclerosis, are typically unrevealed by standard lipid testing. As heterozygous mutations for ABCG5/8 are relatively common, this has implications for a broader population than the ultra-rare sitosterolemia cohort. Thus, insights gleaned from this case highlight underappreciated matters in the prevention of atherosclerotic disease in both heterozygous and homozygous carriers alike.

Introduction: Left atrial appendage (LAA) thrombus in atrial tachyarrhythmias is one of the principal causes of stroke. Prevalence and strategies to thrombus resolution has recently been described in the era of the direct oral anticoagulants (DOAC). The aim of the study was to determine the prevalence and strategies to resolve previous LAA thrombus during regular oral antithrombotic therapy in preparation to perform atrial fibrillation (AF) ablation and/or LAA closure. Methods: Between January 2011 and December 2020 we prospectively followed 23 patients (5.39%) that showed LAA thrombus formation. Persistent AF occurred in 13 (56.52%), median age 72.39 years, 15 (65.22%) females, median CHA2DS2VASC of 4.13, HASBLED of 2.28, 17 (73.91%) with hypertension, (52.17%) with coronary disease, 9 (39.13%) had priors’ thromboembolic events, 7 (30.43%) with heart failure and Diabetes. Diagnosis was by transesophageal echocardiogram (TEE) in 20 (86.96%) and the rest by computed angiotomography. Rivaroxaban was used in 11 (47.83%), Dabigatran in 6 (26.09%), 5 (21.74%) with therapeutic range Warfarin and 1 (4.34%) with Apixaban. Main strategy of treatment was to change mechanism of action of antithrombotic medication in association to an antiplatelet drug, Clopidogrel 75mg a day, and perform a TEE at 90 days after. Results: Complete resolution of the LAA thrombus was achieved in 18 (78.26%) patients in first medical therapeutic change. Of the remaining a second approach with medical therapy adjustment with off-label dose prescription associated with Clopidogrel showed complete resolution in 3 (13.04%) totalizing a success rate of 91.30% for all patients (p value of 0.001 for treatment success). The failure of the antithrombotic plus antiplatelet therapy occurred in 2 (8.7%) patients, one with LAA sludge and other with a huge thrombus in all LAA and part of left atrium. Conclusion: Modification of the mechanism of action of direct oral anticoagulants in association with Clopidogrel demonstrates to be successful in a large number of patients with previous resistant left atrial thrombus with and secure since the low adverse event rates.

With the recent rapid growth in transcatheter mitral and tricuspid valve interventions, it has become increasingly important to understand detailed anatomy of the valves. In this study, we investigated the similarities, differences, and associations between the dimensions of the atrioventricular valves in a sheep model, as sheep heart valves have a similar morphology to human valves. A systematic dissection of twenty-five sheep hearts was performed, with annular circumference measurement, and sub-valvular anatomy documentation. There was a significant association (r=0.865; p=0.007) between the circumference of the mitral and tricuspid annuli. Authors also identified significantly more chordae tendinea in the subvalvular mitral apparatus compared to the tricuspid valve (15.8±1.2 vs. 13.9±1.5; p<0.001). In conclusion, there is a significant association between the size of mitral and tricuspid valve annuli, and the morphology of leaflets and subvalvular apparatus is different between the two valves. These findings could have important implications in transcatheter device design, sizing, and optimal intervention timing.