Liraglutide attenuates angiotensin II-induced aortic dissection and aortic aneurysm via inhibiting M1 macrophage polarization in APOE -/- mice

BACKGROUND

Aortic Aneurysm and Dissection (AAD) are severe cardiovascular conditions with potentially lethal consequences such as aortic rupture. Existing studies suggest that liraglutide, a long-acting glucagon-like peptide receptor (GLP-1R) agonist, offers protective benefits across various cardiovascular diseases. However, the efficacy of liraglutide in mitigating AAD development is yet to be definitively elucidated.

METHODS

Ang II (Angiotension II) infusion of APOE-/- mouse model with intraperitoneal injection of liraglutide (200 μg/kg) to study the role of GLP-1R in AAD formation. Bone Marrow Derived Macrophages (BMDM) and Raw264.7 were incubated with LPS, liraglutide, exendin 9-39 or LY294002 alone or in combination. SMC phenotype switching was examined in a macrophage and vascular smooth muscle cell (VSMC) co-culture system. An array of analytical methods, including Western Blot, Immunofluorescence Staining, Enzyme-LinkedImmunosorbent Assay, Real-Time Quantitative Polymerase Chain Reaction, RNA-seq, and so on were employed.

RESULTS

Our investigation revealed a significant increase in M1 macrophage polarization and GLP-1R expression in aortas of AD patients and Ang II-induced AAD APOE-/- mice. Administering liraglutide in APOE-/- mice notably reduced Ang II-induced AAD incidence and mortality. It was found that liraglutide inhibits M1 macrophage polarization primarily via GLP-1R activation, and subsequently modulates vascular smooth muscle cell phenotypic switching was the primary mechanism. RNA-Seq and subsequent KEGG enrichment analysis identified CXCL3, regulated by the PI3K/AKT signaling pathway, as a key element in liraglutide's modulation of M1 macrophage polarization.

CONCLUSION

Our study found liraglutide exhibits protective effects against AAD by modulating M1 macrophage polarization, suppressing CXCL3 expression through the PI3K/AKT signaling pathway. This makes it a promising therapeutic target for AAD, offering a new avenue in AAD management.

S-adenosylmethionine attenuates angiotensin II-induced aortic dissection formation by inhibiting vascular smooth muscle cell phenotypic switch and autophagy

It is well known that aortic dissection (AD) is a very aggressive class of vascular diseases. S-adenosylmethionine (SAM) is an autophagy inhibitor with anti-inflammatory and anti-oxidative stress effects; however, the role of SAM in AD is unknown. In this study, we constructed an animal model of AD using subcutaneous minipump continuous infusion of AngII-induced ApoE-/-mice and a cytopathic model using AngII-induced primary vascular smooth muscle cells (VSMCs) to investigate the possible role of SAM in AD. The results showed that mice in the AngII + SAM group had significantly lower AD incidence, significantly prolonged survival, and reduced vascular elastic fiber disruption compared with mice in the AngII group. In addition, SAM significantly inhibited autophagy in vivo and in vitro. Meanwhile, SAM also inhibited the cellular phenotypic switch, mainly by up regulating the expression levels of contractile marker proteins [α-smooth muscle actin (α-SMA) and smooth muscle 22α (SM22α)] and down regulating the expression levels of synthetic marker proteins [osteoblast protein (OPN), matrix metalloproteinase-2 (MMP2), and matrix metalloproteinase-9 (MMP9)]. Molecularly, SAM inhibited AD formation mainly by activating the PI3K/AKT/mTOR signaling pathway. Using a PI3K inhibitor (LY294002) significantly reversed the protective effect of SAM in AngII-induced mice and VSMCs.Our study demonstrates the protective effect of SAM on mice under AngII-induced AD for the first time. SAM prevented AD formation mainly by inhibiting cellular phenotypic switch and autophagy, and activation of the PI3K/AKT/mTOR signaling pathway is a possible molecular mechanism. Thus, SAM may be a novel strategy for the treatment of AD.

Aortic Stress Activates an Adaptive Program in Thoracic Aortic Smooth Muscle Cells That Maintains Aortic Strength and Protects Against Aneurysm and Dissection in Mice

BACKGROUND

When aortic cells are under stress, such as increased hemodynamic pressure, they adapt to the environment by modifying their functions, allowing the aorta to maintain its strength. To understand the regulation of this adaptive response, we examined transcriptomic and epigenomic programs in aortic smooth muscle cells (SMCs) during the adaptive response to AngII (angiotensin II) infusion and determined its importance in protecting against aortic aneurysm and dissection (AAD).

METHODS

We performed single-cell RNA sequencing and single-cell sequencing assay for transposase-accessible chromatin (scATAC-seq) analyses in a mouse model of sporadic AAD induced by AngII infusion. We also examined the direct effects of YAP (yes-associated protein) on the SMC adaptive response in vitro. The role of YAP in AAD development was further evaluated in AngII-infused mice with SMC-specific Yap deletion.

RESULTS

In wild-type mice, AngII infusion increased medial thickness in the thoracic aorta. Single-cell RNA sequencing analysis revealed an adaptive response in thoracic SMCs characterized by upregulated genes with roles in wound healing, elastin and collagen production, proliferation, migration, cytoskeleton organization, cell-matrix focal adhesion, and PI3K-PKB/Akt (phosphoinositide-3-kinase-protein kinase B/Akt) and TGF-β (transforming growth factor beta) signaling. ScATAC-seq analysis showed increased chromatin accessibility at regulatory regions of adaptive genes and revealed the mechanical sensor YAP/transcriptional enhanced associate domains as a top candidate transcription complex driving the expression of these genes (eg, Lox, Col5a2, Tgfb2). In cultured human aortic SMCs, cyclic stretch activated YAP, which directly bound to adaptive gene regulatory regions (eg, Lox) and increased their transcript abundance. SMC-specific Yap deletion in mice compromised this adaptive response in SMCs, leading to an increased AAD incidence.

CONCLUSIONS

Aortic stress triggers the systemic epigenetic induction of an adaptive response (eg, wound healing, proliferation, matrix organization) in thoracic aortic SMCs that depends on functional biomechanical signal transduction (eg, YAP signaling). Our study highlights the importance of the adaptive response in maintaining aortic homeostasis and preventing AAD in mice.

Inhibition on CXCL5 reduces aortic matrix metalloproteinase 9 expression and protects against acute aortic dissection

Acute aortic dissection (AAD) is an acute inflammatory vascular condition associated with significant morbidity and mortality. Depletion of neutrophils can attenuate the development of AAD. The CXC-motif chemokine 5 (CXCL5) can attract and activate neutrophils. This study aimed to investigate whether direct inhibition of CXCL5 could protect against AAD formation. A set of AAD animal models was designed using an angiotensin II infusion for 3 days after treatment with the lysyl oxidase inhibitor beta-aminopropionitrile for 4 weeks in 4-week-old male BALB/c mice. While AAD developed successfully in all the animals, approximately 31% of the mice died before sacrifice. The morphological changes at different time points during the experimental period indicated that angiotensin II could trigger AAD formation in this model. CXCL5 protein expression in the aorta tissue was increased after treatment with angiotensin II. Moreover, the ex vivo and in vitro study showed that vascular smooth muscle cells and monocytes isolated from the animals could generate CXCL5. CXCL5 inhibition by a specific monoclonal antibody significantly decreased the severity of AAD evaluated by ultrasound, aorta wet weight, and en face assay. The immunohistochemical analysis showed that the aortic tissues from AAD mice had higher expressions of matrix metalloproteinase (MMP) 9 and neutrophil-positive areas in the medial layer compared to control mice. Treatment with a CXCL5 antibody reduced MMP9 and neutrophil expressions as well as neutrophil and CXCL5 double-positive areas compared to untreated AAD mice. In conclusion, direct inhibition on CXCL5 reduced aortic MMP9 expression as well as neutrophil infiltration and attenuated the development of AAD, suggesting the mechanistic role of CXCL5 in neutrophil-triggered AAD. CXCL5 may be a potential therapeutic target for AAD.

Current progress of fluoroquinolones-increased risk of aortic aneurysm and dissection

Aortic aneurysm (AA) and aortic dissection (AD) are major life-threatening diseases around the world. AA is a localized or diffuse dilation of the aorta, while AD is the separation of the layers creating a false lumen within the aortic wall. Fluoroquinolones (FQ) remain one of the most important kind of antibiotics and have a wider clinical use and broad antibacterial spectrum. FQ were also reported to treat infected AA. The most common adverse events (AEs) of FQ are mild and reversible, like headaches, diarrhea and nausea. Due to FQ-related serious AEs, such as tendonitis and tendon rupture, chondrotoxicity, or retinal detachment, QT-prolongation and dysglycemia, the United States Food and Drug Administration (FDA) issued a black box warning for FQ for systemic use in 2016 and updated warnings for FQ several times since then. Of note, in December 2018, FDA issued several "black box warnings" against FQ with the latest safety announcement warning about an increased risk of ruptures in the aorta blood vessel in certain patients. Recently, many studies have indicated an association between FQ and an increase risk of AA and AD. However, the exact mechanism of FQ-induced AA/AD remains unclear. This review aims to highlight the latest research progress of the alarming association between FQ and AA/AD. Moreover, molecular mechanisms of FQ in increasing risk of AA and AD are explored. Hopefully, this review can provide novel insights into FQ-increased the risk of AA/AD and a starting place for stewardship interventions.

Inhibition of HIPK2 Alleviates Thoracic Aortic Disease in Mice With Progressively Severe Marfan Syndrome

Objective

Despite considerable research, the goal of finding nonsurgical remedies against thoracic aortic aneurysm and acute aortic dissection remains elusive. We sought to identify a novel aortic PK (protein kinase) that can be pharmacologically targeted to mitigate aneurysmal disease in a well-established mouse model of early-onset progressively severe Marfan syndrome (MFS).

Approach and Results

Computational analyses of transcriptomic data derived from the ascending aorta of MFS mice predicted a probable association between thoracic aortic aneurysm and acute aortic dissection development and the multifunctional, stress-activated HIPK2 (homeodomain-interacting protein kinase 2). Consistent with this prediction, Hipk2 gene inactivation significantly extended the survival of MFS mice by slowing aneurysm growth and delaying transmural rupture. HIPK2 also ranked among the top predicted PKs in computational analyses of DEGs (differentially expressed genes) in the dilated aorta of 3 MFS patients, which strengthened the clinical relevance of the experimental finding. Additional in silico analyses of the human and mouse data sets identified the TGF (transforming growth factor)-β/Smad3 signaling pathway as a potential target of HIPK2 in the MFS aorta. Chronic treatment of MFS mice with an allosteric inhibitor of HIPK2-mediated stimulation of Smad3 signaling validated this prediction by mitigating thoracic aortic aneurysm and acute aortic dissection pathology and partially improving aortic material stiffness.

Conclusions

HIPK2 is a previously unrecognized determinant of aneurysmal disease and an attractive new target for antithoracic aortic aneurysm and acute aortic dissection multidrug therapy.

Anesthesia in Parturients Presenting with Marfan Syndrome

BACKGROUND

Pregnant women with Marfan syndrome (MS) have a high risk of aortic dissection around delivery and their optimal management requires a multi-disciplinary approach, including proper cardio-obstetric care and adequate pain management during labor, which may be difficult due to the high prevalence of dural ectasia (DE) in these patients.

OBJECTIVES

To evaluate the multidisciplinary management of MS patients during labor.

METHODS

Nineteen pregnant women (31 pregnancies) with MS were followed by a multi-disciplinary team (cardiologist, obstetrician, anesthesiologist) prior to delivery.

RESULTS

Two patients had kyphoscoliosis; none had previous spine surgery nor complaints compatible with DE. In eight pregnancies (7 patients), aortic root diameter (ARd) before pregnancy was 40 to 46 mm. In this high-risk group, one patient underwent elective termination, two underwent an urgent cesarean section (CS) under general anesthesia, and five had elective CS; two under general anesthesia (GA), and three under spinal anesthesia. In 23 pregnancies (12 patients), ARd was < 40 mm. In this non-high-risk group three pregnancies (1 patient) were electively terminated. Of the remaining 20 deliveries (11 patients), 14 were vaginal deliveries, 9 with epidural analgesia and 5 without. Six patients had a CS; four under GA and two2 under spinal anesthesia. There were no epidural placement failures and no failed responses. There were 2 cases of aortic dissection, unrelated to the anesthetic management.

CONCLUSIONS

The optimal anesthetic strategy during labor in MS patients should be decided by a multi-disciplinary team. Anesthetic complications due to DE were not encountered during neuraxial block.

Concerns About Fluoroquinolones and Aortic Aneurysm

Recent research indicates that all adults may be at risk for aortic aneurysm after fluoroquinolone use, not only those with aortic aneurysm risk factors.

Postpartum Stanford type B aortic dissection in a woman with Loeys-Dietz syndrome who underwent a prophylactic aortic root replacement before conception: A case report

OBJECTIVE

Loeys-Dietz syndrome (LDS) is associated with a higher risk of aortic dissections (ADs) during pregnancy and postpartum. However, there is limited evidence about the perinatal management of LDS patients who have undergone prophylactic aortic root replacements (ARRs) before conception.

CASE REPORT

We present the case of a 28-year-old nulliparous pregnant woman with LDS with a pathogenic variant within exon 5 of TGFBR2 (c.1379G > T, p.[Arg460Leu]), who underwent an ARR at 20 years of age. Cardiac echocardiography did not show any significant changes in the aorta during pregnancy, and her blood pressure remained normal. She had a cesarean section at 37 weeks of gestation. She developed an acute Stanford type B AD extending from the aortic arch to the infrarenal aorta 8 days postpartum and underwent a total arch replacement.

CONCLUSION

This case report suggests that patients with LDS after prophylactic ARRs still possess a risk for Stanford type B ADs.

Smooth Muscle Sirtuin 1 Blocks Thoracic Aortic Aneurysm/Dissection Development in Mice

PURPOSE

Advancing age is the major risk factor for thoracic aortic aneurysm/dissection (TAAD). However, the causative link between age-related molecules and TAAD remains elusive. Here, we investigated the role of Sirtuin 1 (SIRT1, also known as class III histone deacetylase), the best studied member of the longevity-related Sirtuin family, in TAAD development in vivo.

METHODS

We used male smooth muscle-specific SIRT1 transgenic (ST-Tg) mice, smooth muscle-specific SIRT1 knockout (ST-KO) mice, and their wild-type (WT) littermates on a C57BL/6J background to establish a TAAD model induced by oral administration of 3-aminopropionitrile fumarate (BAPN). We analyzed the incidence and fatality rates of TAAD in the groups. We examined matrix metallopeptidase 2 (MMP2) and MMP9 expression in aortas or cultured A7r5 cells via western blotting and real-time polymerase chain reaction (PCR). We performed chromatin immunoprecipitation (ChIP) to clarify the epigenetic mechanism of SIRT1-regulated MMP2 expression in vascular smooth muscle cells (VSMCs).

RESULTS

BAPN treatment markedly increased the incidence of TAAD in WT mice but caused less disease in ST-Tg mice. Moreover, ST-KO mice had the highest BAPN-induced TAAD fatality rate of all the groups. Mechanistically, SIRT1 overexpression resulted in lower MMP2 and MMP9 expression after BAPN treatment in both mouse aortas and cultured A7r5 cells. The downregulation of BAPN-induced MMP2 expression by SIRT1 was mediated by deacetylation of histone H3 lysine 9 (H3K9) on the Mmp2 promoter in the A7r5 cells.

CONCLUSION

Our findings suggest that SIRT1 expression in SMCs protects against TAAD and could be a novel therapeutic target for TAAD management.

A validated mouse model capable of recapitulating the protective effects of female sex hormones on ascending aortic aneurysms and dissections (AADs)

Fewer females develop AADs (ascending aortic aneurysms and dissections) and the reasons for this protection remain poorly understood. The present study seeks to develop a mouse model that may be utilized to address this sexual dimorphism. Adult normolipidemic mice were challenged with BAPN (β-aminopropionitrile), AngII (angiotensin II), or BAPN + AngII. An initial protocol optimization found that 0.2% BAPN in drinking water plus AngII-infusion at 1,000 ng kg-1  min-1 produced favorable rates of AAD rupture (~50%) and dilation (~40%) in 28 days. Using these dosages, further experiments revealed that BAPN is toxic to naïve mature aortas and it acted synergistically with AngII to promote aortic tears and dissections. BAPN + AngII provoked early infiltration of myeloid cells and subsequent recruitment of lymphoid cells to the aortic wall. AADs established with BAPN + AngII, but not AngII alone, continued to expand after the cessation of AngII-infusion. This indefinite growth precipitated a 61% increase in the AAD diameter in 56 days. More importantly, with the optimized protocol, significant differences in AAD dilation (p = .012) and medial degeneration (p = .036) were detected between male and female mice. Treatment of ovariectomized mice with estradiol protected AAD formation (p = .014). In summary, this study developed a powerful mouse AAD model that can be used to study the sexual dimorphism in AAD formation.

Melatonin protects against thoracic aortic aneurysm and dissection through SIRT1-dependent regulation of oxidative stress and vascular smooth muscle cell loss

Melatonin functions as an endogenous protective molecule in multiple vascular diseases, whereas its effects on thoracic aortic aneurysm and dissection (TAAD) and underlying mechanisms have not been reported. In this study, TAAD mouse model was successfully induced by β-aminopropionitrile fumarate (BAPN). We found that melatonin treatment remarkably prevented the deterioration of TAAD, evidenced by decreased incidence, ameliorated aneurysmal dilation and vascular stiffness, improved aortic morphology, and inhibited elastin degradation, macrophage infiltration, and matrix metalloproteinase expression. Moreover, melatonin blunted oxidative stress damage and vascular smooth muscle cell (VSMC) loss. Notably, BAPN induced a decrease in SIRT1 expression and activity of mouse aorta, whereas melatonin treatment reversed it. Further mechanistic study demonstrated that blocking SIRT1 signaling partially inhibited these beneficial effects of melatonin on TAAD. Additionally, the melatonin receptor was involved in this phenomenon. Our study is the first to report that melatonin exerts therapeutic effects against TAAD by reducing oxidative stress and VSMC loss via activation of SIRT1 signaling in a receptor-dependent manner, thus suggesting a novel therapeutic strategy for TAAD.

Inhibition of Marfan Syndrome Aortic Root Dilation by Losartan: Role of Angiotensin II Receptor Type 1-Independent Activation of Endothelial Function

Marfan syndrome (MFS) is a genetic disorder that frequently leads to aortic root dissection and aneurysm. Despite promising preclinical and pilot clinical data, a recent large-scale study using antihypertensive angiotensin II (AngII) receptor type 1 (ATR1) blocker losartan has failed to meet expectations at preventing MFS-associated aortic root dilation, casting doubts about optimal therapy. To study the deleterious role of normal ATR1 signaling in aortic root widening, we generated MFS mice lacking ATR1a expression in an attempt to preserve protective ATR2 signaling. Despite being hypotensive and resistant to AngII vasopressor effects, MFS/ATR1a-null mice showed unabated aortic root enlargement and remained fully responsive to losartan, confirming that blood pressure lowering is of minor therapeutic value in MFS and that losartan's antiremodeling properties may be ATR1 independent. Having shown that MFS causes endothelial dysfunction and that losartan can activate endothelial function in mice and patients, we found that nitric oxide synthase (NOS) inhibition renders losartan therapeutically inactive, whereas multiple transgenic and pharmacologic models of endothelial NOS activation block aortic root dilation by correcting extracellular signal-regulated kinase signaling. In vitro, losartan can increase endothelial NO release in the absence of AngII and correct MFS NO levels in vivo. Our data suggest that increased protective endothelial function, rather than ATR1 inhibition or blood pressure lowering, might be of therapeutic significance in preventing aortic root disease in MFS.

Preventing a Catastrophe: Increasing Awareness of Loeys-Dietz Syndrome

Loeys-Dietz syndrome is a genetic disorder that predisposes patients to aortic aneurysms. If left untreated, the natural history of the associated aortopathy often culminates in fatal aortic dissection. We describe the case of a 21-year-old man who was diagnosed with Loeys-Dietz syndrome after 2 family members died of aortic dissection. This case highlights the importance of increased physician awareness of this syndrome, which can play a crucial role in preventing premature sudden cardiac death caused by aortic catastrophe.

Rapamycin prevents thoracic aortic aneurysm and dissection in mice

OBJECTIVE

The purpose of this study was to investigate whether rapamycin inhibits the development of thoracic aortic aneurysm and dissection (TAAD) in mice.

METHODS

Three-week-old C57BL/6J male mice were fed a normal diet and randomized into a control group (n = 6), β-aminopropionitrile fumarate (BAPN) group (Gp A; n = 15), BAPN plus rapamycin (5 mg) group (Gp B; n = 8), and BAPN plus rapamycin (10 mg) group (Gp C; n = 8). Gp A, Gp B, and Gp C were administered BAPN (1 g/kg/d) for 4 weeks. One week after BAPN administration, Gp B and Gp C were treated with rapamycin (5 mg/kg/d or 10 mg/kg/d) through gavage for 21 days. Thoracic aortas were harvested for Western blot and immunofluorescence staining at day 14 and for morphologic and histologic analyses at day 28.

RESULTS

BAPN treatment induced TAAD formation in mice. The incidence of TAAD in control, Gp A, Gp B, and Gp C mice was 0%, 80%, 25%, and 37.5%, respectively. Smaller thoracic aortic diameters (ascending aorta and arch) were observed in Gp B and Gp C mice than in Gp A mice (Gp B vs Gp A: ascending aorta, ex vivo, 1.07 ± 0.21 mm vs 1.80 ± 0.67 mm [P < .05]; aortic arch, ex vivo, 1.51 ± 0.40 mm vs 2.70 ± 1.06 mm [P < .05]; Gp C vs Gp A: ascending aortas, ex vivo, 1.10 ± 0.33 mm vs 1.80 ± 0.67 mm [P < .05]; aortic arch, ex vivo, 1.55 ± 0.56 mm vs 2.70 ± 1.06 mm [P < .05]). TAAD mice exhibited elastin fragmentation, abundant inflammatory cell infiltration, and significantly increased matrix metalloproteinase production in the aorta, and rapamycin treatment alleviated these changes. The protein levels of p-S6K and p-S6 in TAAD aortic tissues increased significantly, whereas they were suppressed by rapamycin.

CONCLUSIONS

Rapamycin suppressed TAAD formation, probably by inhibition of mechanistic target of rapamycin signaling and reduction of inflammatory cell infiltration and matrix metalloproteinase 9 production. Targeting of the mechanistic target of rapamycin signaling pathway using rapamycin may be a favorable modulation for the clinical treatment of TAAD.

Increased risk of aortic aneurysm and dissection in patients with Sjögren's syndrome: a nationwide population-based cohort study in Taiwan

OBJECTIVES

Sjögren's syndrome (SS) is a systemic autoimmune disorder. Several molecular pathways and the activation of matrix metalloproteinases associated with the pathogenesis of SS participate in the initiation and progression of aortic aneurysm (AA) and aortic dissection (AD). In this study, we aimed to evaluate whether patients with SS exhibit an increased risk of AA or AD.

METHODS

We conducted a retrospective cohort study using a database extracted from Taiwan's National Health Insurance Research Database. All medical conditions for each case and control were categorised using the International Classification of Diseases, Ninth Revision. HRs and 95% CIs for associations between SS and AA/AD were estimated using Cox regression and adjusted for comorbidities.

RESULTS

Our analyses included 10 941 SS cases and 43 764 propensity score-matched controls. Compared with the controls, the patients with SS exhibited a significantly increased risk of developing an AA or AD (adjusted HR=3.642, p<0.001). Subgroup analysis revealed that compared with patients without SS, patients with primary and secondary SS both exhibited a significantly increased risk of developing AA or AD (adjusted HR=1.753, p=0.042; adjusted HR=3.693, p<0.001).

CONCLUSION

Patients with SS exhibit increased risks of developing AA or AD, and healthcare professionals should be aware of this risk when treating patients with SS. Increased aortic surveillance may be required for patients with SS.

Post-Transcriptional Control of Tropoelastin in Aortic Smooth Muscle Cells Affects Aortic Dissection Onset

Aortic dissection (AD) is a catastrophic disease with high mortality and morbidity, characterized with fragmentation of elastin and loss of smooth muscle cells. Although AD has been largely attributable to polymorphisms defect in the elastin-coding gene, tropoelastin (TE), other undermined factors also appear to play roles in AD onset. Here, we investigated the effects of post-transcriptional control of TE by microRNAs (miRNAs) on elastin levels in aortic smooth muscle cells (ASMC). We found that miR-144-3p is a miRNA that targets TE mRNA in both human and mouse. Bioinformatics analyses and dual luciferase reporter assay showed that miR-144-3p inhibited protein translation of TE, through binding to the 3'-UTR of the TE mRNA. Interestingly, higher miR-144-3p levels and lower TE were detected in the ASMC obtained from AD patients, compared to those from non-AD controls. In a mouse model for human AD, infusion of adeno-associated viruses (serotype 6) carrying antisense for miR-144-3p (as-miR-144-3p) under CAG promoter significantly reduced the incidence and severity of AD, seemingly through enhancement of TE levels in ASMC. Thus, our data suggest an essential role of miR-144-3p on the pathogenesis of AD.

Efficacy and safety of the Shexiang Baoxin Pill for the treatment of coronary artery disease not amenable to revascularisation: study protocol for a randomised, placebo-controlled, double-blinded trial

INTRODUCTION

Coronary artery disease (CAD) not amenable to revascularisation indicates that the coronary arteries have severe diffuse lesions or calcifications, or that CAD is complicated with severe multiple-organ disease. Currently, Western medicines available for the treatment of CAD not amenable to revascularisation are limited. Shexiang Baoxin Pill (SBP), a type of Chinese patent medicine, has been widely used to treat CAD in China for many years. Previous studies have shown that long-term administration of SBP (1-2 pills three times daily, for at least 6 months) for treatment of CAD is effective and safe, with a significant, long-term effect. This study aims to evaluate the efficacy and safety of SBP in patients with CAD not amenable to revascularisation.

METHODS AND ANALYSIS

This is a multicentre, randomised, double-blinded, placebo-controlled clinical trial. A total of 440 participants will be randomly allocated to two groups: the intervention group and the placebo group. Based on conventional treatment with Western medicine, the intervention group will be treated with SBP and the placebo group will be treated with SBP placebo. The primary outcomes include major adverse cardiovascular events (including angina, acute myocardial infarction, pulmonary embolism and aortic dissection). The secondary outcomes include C reactive protein, B-type natriuretic peptide, ECG, echocardiographic parameters (ejection fraction percentage and the E/A ratio) and hospital readmission rates due to CAD. Assessments will be performed at baseline (before randomisation) and at 24 weeks after randomisation.

ETHICS AND DISSEMINATION

The protocol has been approved by the Research Ethics Committee of Guang'anmen Hospital, China Academy of Chinese Medical Sciences in Beijing, China (reference: 2016-129-KY-01). The results of this study will be published in a peer-reviewed journal and will be used as a basis for a multisite trial.

TRIAL REGISTRATION NUMBER

NCT03072121; Pre-results.

Beta-blockers for preventing aortic dissection in Marfan syndrome

BACKGROUND

Marfan syndrome is a hereditary disorder affecting the connective tissue and is caused by a mutation of the fibrillin-1 (FBN1) gene. It affects multiple systems of the body, most notably the cardiovascular, ocular, skeletal, dural and pulmonary systems. Aortic root dilatation is the most frequent cardiovascular manifestation and its complications, including aortic regurgitation, dissection and rupture are the main cause of morbidity and mortality.

OBJECTIVES

To assess the long-term efficacy and safety of beta-blocker therapy as compared to placebo, no treatment or surveillance only in people with Marfan syndrome.

SEARCH METHODS

We searched the following databases on 28 June 2017; CENTRAL, MEDLINE, Embase, Science Citation Index Expanded and the Conference Proceeding Citation Index - Science in the Web of Science Core Collection. We also searched the Online Metabolic and Molecular Bases of Inherited Disease (OMMBID), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 30 June 2017. We did not impose any restriction on language of publication.

SELECTION CRITERIA

All randomised controlled trials (RCTs) of at least one year in duration assessing the effects of beta-blocker monotherapy compared with placebo, no treatment or surveillance only, in people of all ages with a confirmed diagnosis of Marfan syndrome were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for inclusion, extracted data and assessed trial quality. Trial authors were contacted to obtain missing data. Dichotomous outcomes will be reported as relative risk and continuous outcomes as mean differences with 95% confidence intervals. We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

One open-label, randomised, single-centre trial including 70 participants with Marfan syndrome (aged 12 to 50 years old) met the inclusion criteria. Participants were randomly assigned to propranolol (N = 32) or no treatment (N = 38) for an average duration of 9.3 years in the control group and 10.7 years in the treatment group. The initial dose of propranolol was 10 mg four times daily and the optimal dose was reached when the heart rate remained below 100 beats per minute during exercise or the systolic time interval increased by 30%. The mean (± standard error (SE)) optimal dose of propranolol was 212 ± 68 mg given in four divided doses daily.Beta-blocker therapy did not reduce the incidence of all-cause mortality (RR 0.24, 95% CI 0.01 to 4.75; participants = 70; low-quality evidence). Mortality attributed to Marfan syndrome was not reported. Non-fatal serious adverse events were also not reported. However, study authors report on pre-defined, non-fatal clinical endpoints, which include aortic dissection, aortic regurgitation, cardiovascular surgery and congestive heart failure. Their analysis showed no difference between the treatment and control groups in these outcomes (RR 0.79, 95% CI 0.37 to 1.69; participants = 70; low-quality evidence).Beta-blocker therapy did not reduce the incidence of aortic dissection (RR 0.59, 95% CI 0.12 to 3.03), aortic regurgitation (RR 1.19, 95% CI 0.18 to 7.96), congestive heart failure (RR 1.19, 95% CI 0.18 to 7.96) or cardiovascular surgery, (RR 0.59, 95% CI 0.12 to 3.03); participants = 70; low-quality evidence.The study reports a reduced rate of aortic dilatation measured by M-mode echocardiography in the treatment group (aortic ratio mean slope: 0.084 (control) vs 0.023 (treatment), P < 0.001). The change in systolic and diastolic blood pressure, total adverse events and withdrawal due to adverse events were not reported in the treatment or control group at study end point.We judged this study to be at high risk of selection (allocation concealment) bias, performance bias, detection bias, attrition bias and selective reporting bias. The overall quality of evidence was low. We do not know whether a statistically significant reduced rate of aortic dilatation translates into clinical benefit in terms of aortic dissection or mortality.

AUTHORS' CONCLUSIONS

Based on only one, low-quality RCT comparing long-term propranolol to no treatment in people with Marfan syndrome, we could draw no definitive conclusions for clinical practice. High-quality, randomised trials are needed to evaluate the long-term efficacy of beta-blocker treatment in people with Marfan syndrome. Future trials should report on all clinically relevant end points and adverse events to evaluate benefit versus harm of therapy.

Therapeutics Targeting Drivers of Thoracic Aortic Aneurysms and Acute Aortic Dissections: Insights from Predisposing Genes and Mouse Models

Thoracic aortic diseases, including aneurysms and dissections of the thoracic aorta, are a major cause of morbidity and mortality. Risk factors for thoracic aortic disease include increased hemodynamic forces on the ascending aorta, typically due to poorly controlled hypertension, and heritable genetic variants. The altered genes predisposing to thoracic aortic disease either disrupt smooth muscle cell (SMC) contraction or adherence to an impaired extracellular matrix, or decrease canonical transforming growth factor beta (TGF-β) signaling. Paradoxically, TGF-β hyperactivity has been postulated to be the primary driver for the disease. More recently, it has been proposed that the response of aortic SMCs to the hemodynamic load on a structurally defective aorta is the primary driver of thoracic aortic disease, and that TGF-β overactivity in diseased aortas is a secondary, unproductive response to restore tissue function. The engineering of mouse models of inherited aortopathies has identified potential therapeutic agents to prevent thoracic aortic disease.

Reference values for echocardiographic assessment of the diameter of the aortic root and ascending aorta spanning all age categories

Thoracic aortic dilatation requires accurate and timely detection to prevent progression to thoracic aortic aneurysm and aortic dissection. The detection of thoracic aortic dilatation necessitates the availability of cut-off values for normal aortic diameters. Tools to evaluate aortic dimension above the root are scarce and inconsistent regarding age groups. The aim of this study was to provide reference values for aortic root and ascending aortic diameters on the basis of transthoracic echocardiographic measurements in a large cohort of children and adults. Diameters at the level of the sinuses of Valsalva (SoV) and ascending aorta (AA) were assessed with transthoracic echocardiography in 849 subjects (453 females, age range 1 to 85 years, mean 40.1 ± 21.3 years) and measured according to published guidelines. Linear regression analysis was applied to create nomograms, as well as equations for upper limits of normal and z-scores. SoV and AA diameters were strongly correlated with age, body surface area (BSA), and weight (r = 0.67 to 0.79, p <0.001 for all). Male subjects had significantly larger aortic dimensions at all levels in adulthood, even after BSA correction (p ≤0.004 for all age intervals). Gender-, age-, and BSA-specific upper limits of normal and z-score equations were developed from a multivariate regression model, which strongly predicts SoV and AA diameters (adjusted R(2) for SoV = 0.84 and 0.67 and for AA = 0.82 and 0.74, for male and female subjects, respectively). In conclusion, this study provides widely applicable reference values for thoracic aortic dilatation screening purposes. Age, BSA, and gender must be taken into account when assessing an individual patient.

[Familial thoracic aortic aneurysms and dissections can be divided into three different main categories]

Thoracic aortic aneurysms and dissections (TAAD) can be divided into three different main categories. 1. Inherited syndromes predisposing to TAAD such as Marfan syndrome, Ehlers-Danlos syndrome type IV and Loeys-Dietz syndrome (less than 5% of all TAAD). 2. Familial TAAD (FTAAD) with more than one affected family member (20 % of all TAAD). Inheritance shows an autosomal dominant pattern and there are no features of known syndromes. 3. Sporadic forms of TAAD with no family history or features of syndromic forms. FTAAD present earlier in life and dissections occur in smaller diameter than in sporadic cases. The underlying genetic cause can be found in about 20 % of the inherited cases. The pathogenesis seems to be an involvement of the transforming growth factor β (TGFβ) signaling pathway or a dysfunction of the smooth muscle cell contraction. The role of β-blockers for aneurysm prevention is uncertain and there are on-going studies comparing angiotensin receptor blockers and β-blockers.

[Anesthetic management of intraoperative aortic dissection during cardiovascular surgery]

Despite considerable advances in anesthesia technique, intraoperative aortic dissection remains a potentially lethal complication during on-pump cardiovascular surgery. Intraoperative dissection has been described worldwide, ranging between 0.06% and 0.24%. Here we present 8 patients who had intraoperative dissection during 10-year period with 6,266 on-pump cases (0.13%, 95% confidence interval 0.12% to 0.14%). In-hospital mortality rate of intraoperative dissection was 12.5% (1/8) at our institution, which was exceptionally lower than that reported previously (24% to 43%). Therefore, we also show our treatment strategy for intraoperative dissection with the related-literature review. The original surgical procedures were descending aortic replacement in 3 patients, valve replacement in 4 patients, and aortic-root replacement in 1 patient. Dissection occurred during aortic cannulation in 6 patients and during manipulation of aortic cross-clamping/de-clamping in 2 patients. Three patients had retrograde dissection extending and beyond the arch. Trans-esophageal echocardiography was useful to confirm dissection and ensure proper perfusion of the aortic-branches. Immediately after its diagnosis, all patients were managed with hypotensive strategy and subsequently underwent deep hypothermic circulatory arrest for prevention of dissection propagation. Among patients with intraoperative aortic dissection undergoing on-pump cardiovascular surgery, not only earlier diagnosis but proper anesthetic management may be crucial for the successful outcome.

[SHOULD PATIENTS WITH GIANT CELL ARTERITIS BE TESTED FOR AORTIC ANEURYSMS?]

Aortitis is one of the manifestations of giant cell arteritis (GCA) and is included in its definition. There is a significantly increased risk of aortic aneurysm formation in GCA patients. In some GCA patients aortic aneurysm dissection is diagnosed only in autopsy. Monitoring of these patients, especially in long lasting disease, requires a doctor's awareness of the possibility of aneurysm formation and aortic aneurysm dissection. Based on the available reports it cannot be confirmed whether intensification of aortitis treatment in GCA prevents the development of aneurysms. This article presents an overview of the available literature and our own experience on a rational diagnosis of inflammation and aneurysms of the aorta in GCA, as well as the prospects for its prevention.

[Clinical guideline 'Turner syndrome']

Turner syndrome occurs in women who are missing one X chromosome. The most obvious symptoms are small stature and ovarian failure. Turner patients have an increased risk of a large number of disorders, and should therefore have lifelong medical supervision. Recent insights into patient management have been incorporated into the guidelines. Patients are increasingly involved in their own treatment. In patients with 45,X karyotype, Y-chromosomal material is actively sought in a larger number of cells and/or other tissues, using FISH. Pubertal induction therapy, if required, is initiated at an appropriate age. Egg donation or vitrification are new therapeutic options for fertility treatment. Monitoring for cardiac and vascular disease using cardiac ultrasound and MRI is performed more often, partly in connection with the risk of aortal dissection. The coordination of care of patients with Turner syndrome is concentrated in specialized centres in the Netherlands and Belgium.

[ The new 2010 Ghent criteria for the indication to surgical treatment of patients affected by Marfan syndrome. Experience of a single cardiac surgery center]

BACKGROUND

The diagnosis and surgical treatment of patients with Marfan syndrome remain controversial. It is of utmost importance to identify patients at risk for acute aortic events to establish the correct surgical timing and the appropriate surgical treatment.

METHODS

From May 2008 to December 2012, 500 patients were screened at the Marfan Presidium of the Tor Vergata University Hospital of Rome (Italy). Patients were evaluated by a cardiac surgeon, including echocardiographic, orthopedic, ophthalmologic and dental examinations. All patients received genetic counseling, and genetic sampling was performed if appropriate.

RESULTS

The diagnosis of Marfan syndrome was confirmed in 146 patients (29.2%). Fifty-four patients (37%) underwent cardiac surgery on the aortic root, 4 patients had surgery on the mitral valve, 13 patients had combined surgery; 11 cases were emergent surgery for acute aortic dissection. Twenty-eight patients (52%) were operated on at our Division: 13 underwent valve-sparing aortic root replacement (David procedure), 1 underwent Yacoub remodeling procedure and 14 underwent Bentall procedure. Following the establishment of the Marfan Center, the David aortic valve-sparing operation was the most frequently performed procedure compared to the previous period of surgical activity (63 vs 22%, p<0.0001).

CONCLUSIONS

Regular follow-up twice a year may allow to identify patients at risk for acute aortic syndromes. Early surgical treatment is recommended in these patients to achieve optimal results of valve-sparing procedures and life-saving management, especially for patients who live far away from a cardiac surgery center.

[Hypertensive crisis: pathogenesis, clinic, treatment]

Contemporary data on mechanisms of development, types, and clinical picture of hypertensive crisis (HC) are presented. Algorithms of rational therapy of uncomplicated and complicated HC are considered. Appropriateness of the use in HC of antihypertensive drugs with multifactorial action is stressed. These drugs include urapidil - an antihypertensive agent with complex mechanism of action. Blocking mainly the postsynaptic 1-adrenoreceptors urapidil attenuates vasoconstrictor effect of catecholamines and decreases total peripheral resistance. Stimulation of 5HT1-receptors of medullary vasculomotor center promotes lowering of elevated vascular tone and prevents development of reflex tachycardia.

Ovarian function and in vitro fertilization (IVF) in Turner syndrome

Normal numbers of oocytes and ovarian follicles develop to the ovaries during the first half of the fetal life. The oocytes then start gradually disappearing. Abnormal meiotic division due to the lack of a paring X-chromosome has been suggested as the causative factor. A large proportion, 40-50% of Turner girls have at least some pubertal development, and about 10% may undergo menarche. Ovarian follicles have been found in some 40% of teenagers with Turner syndrome. Serum concentrations of antimullerian hormone (AMH) and follicle stimulation hormone (FSH), karyotype with mosaicism or structural chromosomal abnormalities, and spontaneous onset of pubertal development are positive prognostic signs for the presence of oocytes and ovarian function. Spontaneous pregnancies occur in some 2-10% of Turner women, a higher number than estimated earlier. This is probably due to failed identification of the syndrome among Turner women with ovarian function. Premature ovarian failure (POF) at some age can be expected in most of Turner women. FSH-stimulated oocyte retrieval and IVF can be carried out before predicted POF. Counseling not to postpone childbearing unnecessarily is advisable. Collected oocytes can be cryopreserved using vitrification, and stored until a pregnancy is desired. Large number of primordial oocytes within ovarian follicles can be stored in within superficial biopsied pieces of ovarian cortical tissue, for transplantation back to the ovary later on. Oocyte donation is an effective infertility treatment for Turner women who have undergone POF. Adequate hormonal replacement therapy (HRT) before IVF is necessary. Only one embryo at a time should be transferred particularly to these women in order to avoid pregnancy complications. Pregnancies in Turner syndrome women have high risks. Comprehensive health control including MRI of the aorta is recommended already before a planned pregnancy, and aorta has to be followed up by echography at least twice during the pregnancy to evaluate the risk of aortic dissection. Some 30% of Turner women develop hypertension during pregnancy, but this is also common among all oocyte donation pregnancies.

Effect of celiprolol on prevention of cardiovascular events in vascular Ehlers-Danlos syndrome: a prospective randomised, open, blinded-endpoints trial

BACKGROUND

Vascular Ehlers-Danlos syndrome is a rare severe disease that causes arterial dissections and ruptures that can lead to early death. No preventive treatment has yet been validated. Our aim was to assess the ability of celiprolol, a β(1)-adrenoceptor antagonist with a β(2)-adrenoceptor agonist action, to prevent arterial dissections and ruptures in vascular Ehlers-Danlos syndrome.

METHODS

Our study was a multicentre, randomised, open trial with blinded assessment of clinical events in eight centres in France and one in Belgium. Patients with clinical vascular Ehlers-Danlos syndrome were randomly assigned to 5 years of treatment with celiprolol or to no treatment. Randomisation was done from a centralised, previously established list of sealed envelopes with stratification by patients' age (≤32 years or >32 years). 33 patients were positive for mutation of collagen 3A1 (COL3A1). Celiprolol was administered twice daily and uptritrated by 100 mg steps every 6 months to a maximum of 400 mg per day. [DOSAGE ERROR CORRECTED]. The primary endpoints were arterial events (rupture or dissection, fatal or not). This study is registered with ClinicalTrials.gov, number NCT00190411.

FINDINGS

53 patients were randomly assigned to celiprolol (25 patients) or control groups (28). Mean duration of follow-up was 47 (SD 5) months, with the trial stopped early for treatment benefit. The primary endpoints were reached by five (20%) in the celiprolol group and by 14 (50%) controls (hazard ratio [HR] 0·36; 95% CI 0·15-0·88; p=0·040). Adverse events were severe fatigue in one patient after starting 100 mg celiprolol and mild fatigue in two patients related to dose uptitration.

INTERPRETATION

We suggest that celiprolol might be the treatment of choice for physicians aiming to prevent major complications in patients with vascular Ehlers-Danlos syndrome. Whether patients with similar clinical presentations and no mutation are also protected remains to be established.

FUNDING

French Ministry of Health, Programme Hospitalier de Recherche Clinique 2001.

Managing dissections of the thoracic aorta

Thoracic aortic dissection is associated with substantial morbidity and mortality, and it requires timely and accurate diagnosis and treatment. Long-term antihypertensive therapy remains critical for the treatment of this disease. Surgical intervention, although still a formidable undertaking, has evolved to better address both acute and chronic dissection, and the results have improved. Basic and clinical research, as well as technological advances, have increased our understanding of this challenging disease state.

NOX1 Deficiency Protects From Aortic Dissection in Response to Angiotensin II

Oxidative stress leads to vascular damage and participates in the pathomechanisms of aortic dissection and aneurysm formation. Here we study aortic dissection in mice deficient in the superoxide-generating reduced nicotinamide-adenine dinucleotide phosphate oxidase NOX1. Seven days of treatment with the hypertensive agent angiotensin II (3 mg/kg per day) led to aortic dissection in 23% of wild-type C57BL/6J mice but in only 4% of NOX1-deficient mice (P=0.05). In contrast, treatment of wild-type C57BL/6J mice with the hypertensive agent norepinephrine (12 mg/kg per day), did not lead to aortic dissection or sudden death, suggesting that hypertension is not sufficient to cause aortic dissection. Interestingly, norepinephrine-dependent blood pressure elevations were conserved in NOX1-deficient mice, demonstrating that, different from angiotensin II, it acts through NOX1-independent hypertensive mechanisms. The resistance of NOX1-deficient mice to angiotensin II-induced aortic dissection suggests a role for NOX1-dependent alterations of the vascular wall. We, therefore, studied gene expression and protease/inhibitor equilibrium. cDNA array analysis demonstrated differential effects of angiotensin II on gene expression in wild-type and NOX1-deficient mice. Tissue inhibitor of metalloproteinase 1 was increased both on the mRNA and the protein level in aortas from NOX1-deficient mice. Thus, our results demonstrate that NOX1 is involved in the mechanisms of angiotensin II-dependent aortic dissection. As one underlying mechanism, we have identified NOX1-dependent suppression of tissue inhibitor of metalloproteinase 1 expression, which could lead to tissue damage through an altered protease/inhibitor balance.

How to protect a patient with aortic aneurysm

Learn how to recognize and respond to the danger signs and act immediately to help save his life. Trouble is looming when the largest artery in the body develops a bulge. According to the Society for Vascular Surgery, each year approximately 200,000 people in the United States are diagnosed with aortic aneurysm - a bulge or ballooning in the artery that leads from the heart. About 15,000 of these aneurysms are severe enough to rupture, creating an urgent situation with a high risk of death. Read on to learn how to protect a patient with a suspected or known aortic aneurysm.

Newly mapped gene for thoracic aortic aneurysm and dissection

Thoracic aortic aneurysm and dissection (TAAD) is associated with high mortality and medical expense. These poor outcomes are preventable by surgical repair; however, identifying at-risk individuals is difficult. Researchers are actively surveying the human genome (the repository of human genes) to characterize the genetic determinants of TAAD by identifying chromosomal regions likely to harbor such predisposing genes. In previous studies, investigators identified genetic markers shared by a subset of families who were ascertained to have the disease, which clustered into 2 chromosomal regions: 5q13-q15 (TAAD1) and 11q23.2-q24 (familial aortic aneurysm [FAA1]). In a subsequent study, a third chromosomal region at 3p24-25 (TAAD2) was found to contribute to TAAD in a 4-generation, 52-member family that displayed little evidence of sharing either the TAAD1 or FAA1 regions. Although additional regions of the genome may contribute to TAAD, investigators are focusing their efforts on identifying the actual genes and the specific mutations that participate in the disease process. The goal of these endeavors is to develop screening tests to identify individuals at risk for familial TAAD. This genetic discovery has significant clinical implications because high-risk individuals and families can be closely monitored and can benefit from preventative surgical repairs.

Negative fluid displacement: an alternative method to assess patency of arterial line cannulation

Optimal flow rate with minimal pressure gradient is the goal of arterial cannulation for cardiopulmonary bypass (CPB). Misplacement of the arterial cannula or vascular pathology can lead to hemolysis or intimal damage with subsequent aortic dissection. The risk of dissection with aortic cannulation is low, 0.04-0.2% for ascending aortic cannulation and 0.2-3% for femoral cannulation. However, dissection-related mortality is significant. Common methods for assessing adequacy of arterial cannulation include minimal pressure when injecting 100-mL boluses and the presence of pulsation in the cannula. Using these techniques, misplacement of the cannula can be masked due to the small amount of volume that is transfused during the assessment. Displacement of fluid into a cannula that is in a false lumen or close to the intimal surface may not indicate a misplaced arterial cannula. Negative fluid displacement is an alternative method of evaluating the integrity of arterial cannulation. During retrograde arterial priming (RAP), fluid is drained from the arterial cannula into a collection bag. Absence of fluid return or a flow < 500 mL/minute is indicative of either arterial line occlusion or cannula misplacement. At this point, the arterial cannula can be repositioned prior to instituting CPB. Since using this technique in over 13000 bypass procedures, we have had only one dissection. This one event occurred during partial occlusion clamping of the ascending aorta. With increased use of femoral cannulation for minimally invasive cardiac surgical procedures, this RAP technique can enhance the perfusionist's and the surgeon's ability to safely perform bypass in the presence of higher dissection risk.

An angiotensin-converting enzyme inhibitor, not an angiotensin II type-1 receptor blocker, prevents beta-aminopropionitrile monofumarate-induced aortic dissection in rats

OBJECTIVE

Cystic medial degeneration (CMD) is a histologic abnormality that is common in aortic diseases such as aortic dilation, aneurysm, or dissection. Although little is known about the mechanism underlying CMD, we have previously demonstrated that angiotensin II signaling via angiotensin II type 2 receptor (AT2R) plays a central role in apoptosis of vascular smooth muscle cells (VSMCs) occurring in CMD associated with Marfan syndrome. The aim of this study is to elucidate the role of angiotensin II signaling in THE pathogenesis of aortic diseases associated with CMD.

METHOD

We investigated the effects of angiotensin-converting enzyme inhibitor (ACEI), temocapril (n = 15), angiotensin II receptor type-1 (AT1R) blocker, CS-866 (n = 15), and vehicle control (n = 17) on 0.25% beta-aminopropionitrile monofumarate (BAPN)-induced aortic dissection and histopathologic findings in a rat model.

RESULTS

Temocapril significantly prevented aortic dissection (P <.05), CMD (P <.01), and VSMC apoptosis (P <.01) compared with vehicle control in BAPN-fed rats. However, CS-866 did not show any preventive effect. Reversed transcriptase-polymerase chain reaction demonstrated that expression of both AT1R and AT2R was detected in control rat aortas, and that AT2R expression was significantly upregulated in the aortas of BAPN-fed rats (P <.01). Blood pressure was significantly and equally lowered in both temocapril and CS-866 groups compared with control.

CONCLUSIONS

Differential expression of angiotensin II receptors and AT2R signaling are involved in the pathogenesis of CMD and aortic dissection in BAPN-fed rats. ACEIs might be of clinical value for the prevention and treatment of aortic diseases related to CMD.

Proximal aortic dissection late after aortic valve surgery: 119 cases of a distinct clinical entity

BACKGROUND

Besides systemic hypertension and Marfan syndrome, only previous aortic valve replacement (AVR) is independently associated with proximal (type A) aortic dissection. Little, however, is known to date about the characteristic features of this clinical entity.

METHODS

Clinical, prognostic and predisposing profiles in 119 cases of dissection and/or aneurysm occuring 1 month to 16 years after routine AVR were analyzed comprising 62 cases from our database and 57 reported cases.

RESULTS

Dissection after AVR has been observed in 0.6% of all routine AVR procedures in the past four decades. With clinical signs, symptoms and anatomical features different from classic aortic dissection post-AVR dissection is a distinct clinical entity with a high intraoperative mortality of 44% and a 30-day and 5-year survival of 62% and 43%, respectively. Aortic regurgitation and a thin and/or fragile aortic wall at AVR, however, predict late dissection. Using a prediction model, the risk of late dissection can be stratified based on information obtained during AVR surgery.

CONCLUSIONS

Aortic dissection following AVR is likely to represent a distinct clinical entity which can be predicted and possibly prevented at AVR.

Penetrating atherosclerotic ulcer of the aorta: imaging features and disease concept

Penetrating atherosclerotic ulcer is an ulcerating atherosclerotic lesion that penetrates the elastic lamina and is associated with hematoma formation within the media of the aortic wall. This pathologic condition is distinct from classic aortic dissection and aortic rupture; however, care should be taken in making the diagnosis, particularly if the disease is discovered incidentally. At computed tomography (CT), penetrating atherosclerotic ulcer manifests as focal involvement with adjacent subintimal hematoma and is often associated with aortic wall thickening or enhancement. Magnetic resonance imaging is superior to conventional CT in differentiating acute intramural hematoma from atherosclerotic plaque and chronic intraluminal thrombus and allows unenhanced multiplanar imaging. Spiral CT involves shorter examination times and allows high-quality two- and three-dimensional image reconstruction. CT angiography can demonstrate complex spatial relationships, mural abnormalities, and extraluminal pathologic conditions. Transesophageal echocardiography has been reported to be highly sensitive and specific in the differentiation of aortic disease, and intravascular ultrasonography may also be useful in this setting. Although rupture or other life-threatening complications are rare, patients with penetrating atherosclerotic ulcer must be followed up, particularly during the 1st month after onset. Surgical treatment may become necessary in cases involving evidence of intramural hematoma expansion, signs of impending rupture, inability to control pain, or blood pressure changes.

Comparison of slow oscillating versus fast balloon inflation strategies for coronary angioplasty

Previous studies suggest that slow and/or oscillating balloon inflation during coronary angioplasty may decrease the incidence of coronary dissection and improve clinical outcomes. To compare the effect of slow oscillating versus conventional fast inflation techniques on the incidence of severe coronary dissection during angioplasty, 622 patients were randomized to slow oscillating inflation versus fast inflation. Angiographic outcomes of the procedures and in-hospital clinical events were recorded. The primary end point of severe (type C, D, E, F) dissection occurred in 7.7% of patients undergoing slow oscillation and 6.6% of patients undergoing fast inflation (p = 0.87). Major complications (death, urgent coronary artery bypass graft surgery, stroke, abrupt closure, or Q-wave myocardial infarction) occurred in 4.7% of patients undergoing slow oscillation and 3.5% of patients undergoing fast inflation (p = 0.45). The 2 inflation strategies did not differ in the pressure at which the balloon achieved full expansion, angiographic success rate, residual stenosis, and incidence of all minor and/or major complications. We conclude that there is no benefit of slow oscillating inflation over routine fast inflation in angioplasty. Slow oscillating inflation did not dilate lesions at lower pressures, decrease the incidence of dissection or severe dissection, or reduce the incidence of adverse clinical outcomes.

Giant aneurysms of the middle cerebral artery trifurcation treated with extracranial-intracranial arterial bypass and endovascular occlusion. Report of two cases

Giant middle cerebral artery (MCA) trifurcation aneurysms that cannot be excluded directly can be treated by flow inversion achieved by creation of an extracranial-intracranial bypass distal to the aneurysm, followed by occlusion of the parent vessel proximal to the aneurysm. As opposed to surgical occlusion, endovascular occlusion avoids dissection of the aneurysm area, and the site of occlusion can be chosen according to the flow distribution demonstrated on angiography performed during test occlusions. Two patients with giant aneurysms of the MCA trifurcation benefited from flow inversion treatment. Forty-eight hours after an MCA-superficial temporal artery bypass had been created, the M1 segment was occluded by inserting a coil in the first patient and the internal carotid artery was occluded with balloons in the second patient (there was no communicating artery in the latter case). Both occlusions were performed immediately after a clinical test of occlusion tolerance. The patients were clinically intact during the postoperative course. Follow-up angiography performed 11 and 4 months, respectively, after vessel occlusion showed that the aneurysm occlusion was stable.

Internal carotid stent implantation with angioscopic control

Stent implantation is a method, which is being used more and more often, mainly in the field of peripheral arteries, but coronary stent implantation is also well-known. The authors apply this procedure for patients, who besides the carotid bifurcation stenosis also suffer from the internal carotid stenosis in a longer section of the artery. The indication are as follows: 1 in the case of internal carotid stenosis in a longer section we assure the flow with the help of carotid thrombendarterectomy and slove the run-off with balloon catheter dilatation and stent implantation. 2. in the case of a stenosis in a short section we use stent implantation to avoid dissection of the intima. With each intervention we perform the carotid bifurcation thrombendarterectomy. The authors made the first intervention 15 months ago, since then we have performed 17 stent implantations. One of the 17 patients developed a temporary stroke (TIA). This is a new method, further cases are needed for long-term experiences. Intervention under eye-control can be carried out with more confidence. As regards to the post-operative medicinal treatment, the administration of thrombocyte aggregation-blockers or heparinoid preparation (e.g.: PPS-SP 54) after the stent implantation has become a routine therapy. Summarized the foregoing, these cases constitute about 10-15% of all carotid operations, therefore the authors would like to make it clear, that this is not a routine method, but a possibility, strictly respecting the above-mentioned indications.

Marfan syndrome--current medical and genetic knowledge: how to treat and when

Marfan syndrome (MFS), first described 100 years ago, remains a clinical diagnosis. Two out of 3 major systems (ocular, cardiac, skeletal) must be classically affected, to avoid overdiagnosis. Diagnosis may be confirmed by linkage to the dominantly inherited gene MFS-1 on 15q21, or by discovering the family mutation. Either technique may be used for prenatal diagnosis. Modern medical and surgical management is prolonging life, by on average, 13 years, with postoperative 20 year survival rate 65%. Beta-blocker therapy slows aortic root dilatation, and elective surgery is offered at ascending aorta diameter > or = 5 cm. Known associations with early death include new mutation, family history of dissection < 5 cm, male sex, and emergency surgery where the death rate is 5 times higher than in elective surgery. Pregnancy bears a 1% risk of fatal complication, and this risk rises with increasing aortic root diameter. Caesarean section at 38 weeks gestation should be offered if aortic root diameter is greater than 4.5 cm. Gene mapping reveals almost every mutation to be unique, interfering with multimerization of fibrillin monomers, or interactions with other connective tissue elements. Neonatal MFS is caused by mutations in exons 24-32, in calcium-binding EGF-like sequences. Mutations affecting cysteines or amino acids critical for calcium binding in other EGF-like domains, or deletions of complete EGF-like domains, generally lead to classical MFS phenotypes, as do mutations in TGF receptor-like domains. Heterogeneity has been reported with a second locus (MFS-2) on chromosome 3 in one French pedigree.