Citations

Diastolic mitral valve regurgitation is a rare phenomenon described in patients with atrioventricular conduction abnormalities, severe left ventricular systolic or diastolic dysfunction with regional wall motion dyssynchrony, or severe acute aortic valve regurgitation. The presence of diastolic mitral valve regurgitation in acute aortic regurgitation due to endocarditis suggests critical severity requiring urgent surgical valve replacement. We describe a case of diastolic mitral regurgitation in the setting of complex native mitral-aortic valve endocarditis in a patient in normal sinus rhythm and review the etiologic mechanisms of this phenomenon, echocardiographic assessment, and therapeutic implications for hemodynamic management.

SummaryCoronary endothelial‐dependent microvascular dysfunction, an early reversible stage of coronary artery disease (CAD), is associated with poor clinical outcome. The current study investigated whether coronary artery distensibility index (CDI) is associated with: (i) coronary endothelial‐dependent microvascular dysfunction and (ii) vulnerable plaque composition among subjects with non‐obstructive CAD. Seventy‐four subjects with non‐obstructive CAD (luminal stenosis <30%) were studied. In 20 subjects with and without coronary endothelial‐dependent microvascular dysfunction, coronary flow reserve (CFR) of target segment during intracoronary (IC) infusion of acetylcholine (Ach) and bolus injection of adenosine as well as CDI at rest of corresponding target segment were measured. In 54 subjects, plaque compositions and CDI at rest of 154 non‐obstructive coronary segments as well as proximal segment without disease were measured by intravascular ultrasound (IVUS). CDI was defined as: [(Early‐diastolic cross‐sectional‐area (CSA) – End‐diastolic CSA of target segment)/(end‐diastolic CSA of target segment × coronary‐pulse‐pressure) × 103]. There is a direct association between endothelial dysfunction and impaired CDI of a coronary segment both in the given coronary segment and corresponding microvessels in which a strong agreement between CDI and CFR Ach (r2 = 0·85, P = 0·0001) was observed. Multivariable regression‐analysis showed that CDI was an independent predictor of the vulnerable plaque characteristics. The risk of impaired CDI was 125% higher in segments with necrotic core and 60% higher in segments with fibrofatty components as compared to normal segments (P = 0·001). In conclusions, the current study reveals that impaired CDI is an endothelial‐dependent process of both given coronary segment and corresponding microvessels and is associated with vulnerable plaque composition.

Background and purpose Mechanisms of both healing and complications, including spontaneous aneurysm rupture, remain unclear following flow diverter treatment. The aim of this study was to compare gene expression of various key molecules involved in the healing of aneurysms, between aneurysms treated with microcoils and flow diverters. Methods Saccular aneurysms were created in rabbits. Aneurysms were treated with coils (n=6) or flow diverters (n=6). Aneurysms were harvested at 4 weeks following treatment and used for gene expression and zymography experiments. Genes with a fold change of 1.2 or more were considered upregulated whereas those with a fold change of 0.8 or less were considered downregulated. Results All coil embolized aneurysms were completely occluded at follow-up. Two aneurysms were occluded and the remaining four samples were incompletely occluded in the flow diverter treated group. The following genes were expressed at lower levels in the flow diverter group compared with the coiled aneurysm group: proteinases (matrix metalloproteinases 2 and 9), cellular markers (endothelial nitric oxide synthase and smooth muscle actin), and structural proteins (collagens and fibronectin). Genes related to inflammation (tumor necrosis factor α and monocyte chemoattractant protein 1) were upregulated in flow diverter treated aneurysms compared with coil embolized aneurysms. Notably, the enzymatic activity of active matrix metalloproteinase 9 was high in aneurysms treated with flow diverters. Conclusions Our findings may provide improved understanding of rupture risk and healing following aneurysm treatment and inform development of therapies aimed at lowering rupture risk and accelerating healing.

Marfan syndrome is the most common inherited disorder of connective tissue affecting multiple organ systems. Identification of the facial, ocular and skeletal features should prompt referral for aortic imaging since sudden death by aortic dissection and rupture remains a major cause of death in patients with unrecognized Marfan syndrome. Echocardiography is recommended as the initial imaging test, and once a dilated aortic root is identified magnetic resonance or computed tomography should be done to assess the entire aorta. Prophylactic aortic root replacement is safe and has been demonstrated to improve life expectancy in patients with Marfan syndrome. Medical therapy for Marfan syndrome includes the use of beta blockers in older children and adults with an enlarged aorta. Addition of angiotensin receptor antagonists has been shown to slow the progression of aortic root dilation compared to beta blockers alone. Lifelong and regular follow up in a center for specialized care is important for patients with Marfan syndrome. We present a case of a patient with clinical features of Marfan syndrome and discuss possible therapeutic interventions for her dilated aorta.