Epicardial adipose tissue (EAT) is a fat depot located between the myocardium and the visceral layer of the epicardium, which, owing to its location, can influence surrounding tissues and can act as a local transducer of systemic inflammation. The mechanisms upon which such influence depends on are however unclear. Given the role EAT undoubtedly has in the scheme of cardiovascular diseases (CVDs), understanding the impact of its cellular components is of upmost importance. Extracellular vesicles (EVs) constitute promising candidates to fill the gap in the knowledge concerning the unexplored mechanisms through which EAT promotes onset and progression of CVDs. Owing to their ability of transporting active biomolecules, EAT-derived EVs have been reported to be actively involved in the pathogenesis of ischemia/reperfusion injury, coronary atherosclerosis, heart failure, and atrial fibrillation. Exploring the precise functions EVs exert in this context may aid in connecting the dots between EAT and CVDs.
Although associated with left heart pathologies, functional tricuspid regurgitation (FTR) is often left untreated during left heart surgery. Hence, owing to its degenerative character, reoperation is often needed, encompassing an impressive (25% to 35%) mortality rate. Thus transcatheter approaches to FTR are raising great interest. The authors evaluated the post-treatment effectiveness of the edge-to-edge technique using the percutaneous mitral valve repair device in an ex vivo pulsatile model of FTR. The devices were implanted in 11 porcine hearts simulating FTR. In each heart, single-clip treatments involved grasping leaflet pairs in the medial or commissural position (6 combinations). Two-clip treatments were then performed considering all possible 15 combinations of leaflet pairs and medial/commissural grasping. Cardiac output, mean pulmonary pressure, and mean diastolic valve pressure gradient were evaluated in physiological and simulated pathological conditions (FTR), and post-treatments. Grasping the septal and anterior leaflets allowed for the best post-procedural outcome, ensuring a complete re-establishment of physiological-like hemodynamics. Septal and posterior grasping induced a significant recovery from FTR, although less marked. Conversely, grasping the anterior and posterior leaflets did not reduce FTR, and was detrimental in some specific cases. This experimental work demonstrated that the transcatheter edge-to-edge repair technique is a feasible approach for FTR. The study investigated this approach to develop a selective, specific structural intervention methodology for treating FTR, considering the several biomechanical factors that alter proper functionality of valvular substructures. These results can be used to guide the development of edge-to-edge repair techniques in treatment of FTR.
BackgroundA longer-arm clip design for transcatheter edge-to-edge repair of mitral and tricuspid valves could be beneficial in treating complex valve pathologies. Its hemodynamic effects and usability are unknown. This study aims to assess its new design in an ex-vivo beating heart model.MethodsThe long-arm clip was implanted in porcine left (n = 14) and right (n = 6) hearts with induced degenerative mitral regurgitation and functional tricuspid regurgitation, respectively. Hemodynamic conditions were assessed at baseline, pathology and post-treatment. Usability and grasping quality were evaluated during simulated treatment.ResultsMitral valve treatment significantly increased cardiac output (p < 0.001) and decreased mean left atrial pressure during ventricular systole (p = 0.001) with respect to pathological conditions. Tricuspid treatment with grasping involving septal leaflet significantly increased cardiac output (posterior-septal grasping: p = 0.006; anterior-septal grasping: p = 0.04). There was no significant increase of transvalvular gradient pressure nor tissue damage.ConclusionLong-arm clip treatment was feasible in porcine hearts, it effectively reduced regurgitation and did not significantly increase the transvalvular pressure gradient.AbbreviationsMV, mitral valve; DMR, degenerative mitral regurgitation; FTR, functional tricuspid regurgitation; TV, tricuspid valve; XTR Clip, long-arm clip; P2, posterior middle scallop of mitral valve; MRF, mitral regurgitation fraction; A-P, medial grasping of anterior and posterior leaflets; A-S, medial grasping of anterior and septal leaflets; P-S, medial grasping of posterior and septal leaflets; COs, systemic cardiac output; COp, pulmonary cardiac output; AoP, mean aortic pressure; PAP, mean pulmonary artery pressure; LAP, mean left atrial pressure; LAPsyst, mean left atrial pressure during ventricular systole; Δpm, mean diastolic pressure gradient across mitral valve; Δpt, mean diastolic pressure gradient across tricuspid valve; APd, mid-systole mitral antero-posterior distance; CI, confidence interval
Acute aortic dissection in pregnancy is a rare event and rarer still in healthy young women; however, women with a bicuspid aortic valve or the Marfan syndrome are at a higher risk of dissection. The relationship between pregnancy and aortic dissection is still unclear. We describe the cases of two women with no history of cardiovascular disease who developed an acute aortic type A dissection within a few days after term delivery. Surgical repair was performed with ascending aorta replacement and aortic valve sparing. In both cases, the dissection was diagnosed within a few days following cesarean section done neither because of fetal or maternal distress. To date, only one case of type A and two cases of type B aortic dissection following cesarean section have been reported. Compared with spontaneous delivery, scheduled cesarean section, as in our cases, allows for better control of hemodynamic parameters and should protect against aortic dissection. Postoperative screening for inherent connective tissue disorders detected no mutations within the fibrillin and collagen gene chromosome in either patient. Postoperative recovery was uneventful, and the patients were discharged on postoperative days 7 and 8, respectively.
Objective: Phasic blood flow dynamics and wall shear stress (WSS) have the potential to directly modulate endothelial responses, playing an important role in the development of bypass graft occlusion.This study compares phasic blood flow velocity patterns and WSS of the left internal thoracic artery (LITA) used as a composite Y-graft (27 patients, Y-group) and as a single graft (24 patients, S-group) on the left anterior descending (LAD) coronary artery.Methods: An intravascular Doppler-tipped guide wire was used for postoperative analysis of phasic blood flow velocity.Flow velocities were recorded proximally and distally into the LITA in both groups.Digitalized spectral velocities were acquired to compute systolic peak velocity, diastolic peak velocity, and average peak velocity.The ratio of diastolic to systolic peak velocity was computed (DSVR).WSS was calculated from graft flow velocity and vessel diameter.Results: Proximal LITA in Y-group had greater average peak velocity (APV) ( p = 0.000), DSVR ( p = 0.026), flow volume ( p = 0.000), WSS ( p = 0.02), and diameter (0.019) than S-group.There were not significant differences for the distal LITA between the two groups.Conclusions: The LITA shows a marked adaptability to flow dynamics.The proximal tract of the LITA in Y-group is able to match increased flow requirements, probably through the release of endothelial vasoactive mediators.Flow velocity spectra acquired in the proximal LITA in Y-group resemble the biphasic coronary artery pattern with a clear diastolic predominance.This pattern is probably consequence of the increase of blood flow due to the lower vascular resistance of the Y-graft system and to the active dilatation of the LITA.
