Activated factor X stimulates atrial endothelial cells and tissues to promote remodeling responses through AT1R/NADPH oxidases/SGLT1/2

AIMS

Atrial fibrillation (AF), the most common cardiac arrhythmia favoring ischemic stroke and heart failure involves left atrial remodeling, fibrosis and a complex interplay between cardiovascular risk factors. This study examined whether activated factor X (FXa) induces pro-remodeling and pro-fibrotic responses in atrial endothelial cells (AECs) and human atrial tissues and determined the underlying mechanisms.

METHODS AND RESULTS

AECs were from porcine hearts and human right atrial appendages (RAA) from patients undergoing heart surgery. Protein expression levels were assessed by Western blot and immunofluorescence staining, mRNA levels by RT-qPCR, formation of reactive oxygen species (ROS) and NO using fluorescent probes, thrombin and angiotensin II generation by specific assays, fibrosis by Sirius red staining and senescence by senescence-associated beta-galactosidase (SA-β-gal) activity.In AECs, FXa increased ROS formation, senescence (SA-β-gal activity, p53, p21), angiotensin II generation and the expression of pro-inflammatory (VCAM-1, MCP-1), pro-thrombotic (tissue factor), pro-fibrotic (TGF-β and collagen-1/3a) and pro-remodeling (MMP-2/9) markers whereas eNOS levels and NO formation were reduced. These effects were prevented by inhibitors of FXa but not thrombin, protease-activated receptors antagonists (PAR-1/2) and inhibitors of NADPH oxidases, ACE, AT1R, SGLT1/SGLT2. FXa also increased expression levels of ACE1, AT1R, SGLT1/2 proteins which was prevented by SGLT1/2 inhibitors. Human RAA showed tissue factor mRNA levels that correlated with markers of endothelial activation, pro-remodeling and pro-fibrotic responses and SGLT1/2 mRNA levels. They also showed protein expression levels of ACE1, AT1R, p22phox, SGLT1/2, and immunofluorescence signals of nitrotyrosine and SGLT1/2 colocalized with those of CD31. FXa increased oxidative stress levels which were prevented by inhibitors of the AT1R/NADPH oxidases/SGLT1/2 pathway.

CONCLUSIONS

FXa promotes oxidative stress triggering premature endothelial senescence and dysfunction associated with pro-thrombotic, pro-remodeling and pro-fibrotic responses in AECs and in human RAA involving the AT1R/NADPH oxidases/SGLT1/2 pro-oxidant pathway. Targeting this pathway may be of interest to prevent atrial remodeling and the progression of atrial fibrillation substrate.

COVID-19 promotes endothelial dysfunction and thrombogenicity: role of proinflammatory cytokines/SGLT2 prooxidant pathway

BACKGROUND

COVID-19 is associated with an increased risk of cardiovascular complications. Although cytokines have a predominant role in endothelium damage, the precise molecular mechanisms are far from being elucidated.

OBJECTIVES

The present study hypothesized that inflammation in patients with COVID-19 contributes to endothelial dysfunction through redox-sensitive SGLT2 overexpression and investigated the protective effect of SGLT2 inhibition by empagliflozin.

METHODS

Human plasma samples were collected from patients with acute, subacute, and long COVID-19 (n = 100), patients with non-COVID-19 and cardiovascular risk factors (n = 50), and healthy volunteers (n = 25). Porcine coronary artery endothelial cells (ECs) were incubated with plasma (10%). Protein expression levels were determined using Western blot analyses and immunofluorescence staining, mRNA expression by quantitative reverse transcription-polymerase chain reaction, and the level of oxidative stress by dihydroethidium staining. Platelet adhesion, aggregation, and thrombin generation were determined.

RESULTS

Increased plasma levels of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, monocyte chemoattractant protein-1, and soluble intercellular adhesion molecule-1 were observed in patients with COVID-19. Exposure of ECs to COVID-19 plasma with high cytokines levels induced redox-sensitive upregulation of SGLT2 expression via proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor-α which, in turn, fueled endothelial dysfunction, senescence, NF-κB activation, inflammation, platelet adhesion and aggregation, von Willebrand factor secretion, and thrombin generation. The stimulatory effect of COVID-19 plasma was blunted by neutralizing antibodies against proinflammatory cytokines and empagliflozin.

CONCLUSION

In patients with COVID-19, proinflammatory cytokines induced a redox-sensitive upregulation of SGLT2 expression in ECs, which in turn promoted endothelial injury, senescence, platelet adhesion, aggregation, and thrombin generation. SGLT2 inhibition with empagliflozin appeared as an attractive strategy to restore vascular homeostasis in COVID-19.

SGLT1/2 expression in the heart of transplanted patients is associated with inflammatory induction of oxidative stress: potential protective effect of SGLT2 inhibitors

Introduction

Heart transplantation is a life-saving surgical procedure for patients with end-stage cardiac dysfunction, however, such procedures are usually at risk of rejection due to acute inflammatory activation. While such inflammatory induction leaves the newly transplanted heart at risk of functional and structural remodeling subsequent to oxidative damage, current anti-inflammatory treatment options expose the patient to an elevated risk for adverse reactions in addition to absence of cardio-protective effects. Therefore, novel therapies with anti-inflammatory and cardio-protective dual effects are needed. Recently, our group has reported that low-grade inflammation is associated with upregulation of SGLT1/2 in arteries of human with cardiovascular diseases. Yet, the role and function of SGLT2 in human cardiac tissue remains poorly understood.

Aim

This study focuses on the expression pattern of SGLT1/2 in cardiac biopsies of heart transplanted patients and aim to identifying their functional impact.

Methods

Routine endomyocardial Biopsies (23) were performed for the detection of acute rejection heart transplanted patients (less than 2 years) at our University Hospital. Gene expression levels were assessed using RT-qPCR, the in situ tissue localization of proteins by immunofluorescence staining, and the level of oxidative stress by dihydroethidium staining.

Results

Gene expression analysis revealed strong inflammatory reaction in 5 samples indicated by at least 20-fold higher levels of mRNA of IL1B, IL6, TNFA and CD68 compared to the other 18 samples and concomitant with high expression levels of SLC5A1, SLC5A2, AT1R, CYBA, NCF1, ICAM1, VCAM1, MMP2, MMP9 and TGFB1 in contrast to low levels of NOS3. In addition, increased levels of oxidative stress were observed in the same biopsies, which were diminished by the antioxidant N-acetylcysteine (NAC), NADPH oxidase inhibitor (VAS-2870), TNF-α receptor neutralizing antibody (infliximab), ACE inhibitor (perindoprilat), AT1R antagonist (losartan), dual SGLT1/2 inhibitor (sotagliflozin) and selective SGLT2 inhibitor (empagliflozin) with inhibitory effects reaching up to 80%. Immunofluorescence staining indicated signals for nitro-tyrosine, TNF-alpha, SGLT1 and 2 in several samples.

Conclusion

These findings indicate that both isoforms SGLT1 and SGLT2 are expressed in the transplanted human heart and suggest a pattern of expression associated with pro-inflammatory response. They further indicate a potential protective effect of SGLT2 inhibitors in transplanted hearts through mitigating oxidative stress and hence providing a possible novel therapy for heart transplantation recipients to preserve the heart function.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim Pharma GmbH & Co. KG

GLP-1 receptor expression in human internal thoracic arteries is dependent on low-grade inflammation potentially explaining the cardiovascular protective effect of GLP1-R agonists

Background

Clinical research showed that glucagon-like peptide-1 receptor (GLP1R) agonists (GLP1RA) reduced the incidence of major cardiovascular events in diabetic patients. The protective effect was more noteworthy in patients with established cardiovascular disease, associated with chronic low-grade inflammation resulting in endothelial dysfunction and arterial remodeling and fibrosis. Despite the clinically proven cardiovascular benefit of GLP1RA, the expression pattern of GLP1R and its function in the human vasculature remain poorly studied.

Aim

This study investigated the expression of GLP1R and its role in internal thoracic arteries (ITA) from patients with coronary artery disease.

Methods

Human ITA were collected from patients (N=30) undergoing coronary artery bypass surgery at the University Hospital of Strasbourg. Gene expression levels were assessed using RT-qPCR, protein levels by Western blot analysis, in situ tissue localization of proteins by immunofluorescence (IF) staining, and the level of oxidative stress using dihydroethidium.

Results

ITA showed a substantial difference in GLP1R mRNA levels reaching up to 7-fold among patients. GLP1R mRNA levels were positively correlated with those of SLC5A1, SLC5A2, F3, AT1R, IL1B, IL6, TNFα, VCAM1 and NCF1, and negatively with NOS3 mRNA levels. High GLP1R expressing ITA showed high levels of phosphorylated p65 NF-κB, cell adhesion molecule VCAM1, members of the angiotensin system (ACE1 and AT1R), remodeling and fibrotic markers (MMP9, MMP2, TGFβ) and a low level of eNOS, whereas the contrary was observed for low GLP1R expressing ITA. IF staining showed that GLP1R signals were predominantly observed in the endothelium of low GLP1R expressing ITA and in the vascular smooth muscle of high GLP1R expressing ITA. Prominent CD68 staining associated with the endothelium and the perivascular adipose tissue were observed in high but not low GLP1R expressing ITA. High GLP1R expressing ITA showed increased levels of oxidative stress, which were inhibited by the antioxidant N-acetylcysteine (NAC), NADPH oxidase inhibitor (VAS-2870), ACE inhibitor (perindoprilat), AT1R antagonist (losartan), TNF-α receptor neutralizing antibody (infliximab), selective SGLT2 inhibitor (empagliflozin), dual SGLT1/2 inhibitor (sotagliflozin) and by GLP1R agonists (liraglutide and semaglutide) with inhibitory effects amounting to about 50 to 75%.

Conclusion

These findings indicate that GLP1R expression levels in human ITA are dependent on low-grade inflammation and linked to endothelial dysfunction, pro-thrombotic, pro-remodeling and pro-fibrotic responses. Furthermore, they were associated with increased level of oxidative stress sensitive to inhibitors of either the local angiotensin system, SGLT2, TNFα and agonists of GLP1R. Thus, the cardiovascular beneficial effects of GLP1R agonists might be attributable to their ability to reduce the pro-oxidant stimulatory signal related to low-grade inflammation.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Frency Society of Vascular Medicine (SFMV)

Phosphorus Supplementation Mitigates Perivascular Adipose Inflammation-Induced Cardiovascular Consequences in Early Metabolic Impairment

Background

The complexity of the interaction between metabolic dysfunction and cardiovascular complications has long been recognized to extend beyond simple perturbations of blood glucose levels. Yet, structured interventions targeting the root pathologies are not forthcoming. Growing evidence implicates the inflammatory changes occurring in perivascular adipose tissue (PVAT) as early instigators of cardiovascular deterioration.

Methods and Results

We used a nonobese prediabetic rat model with localized PVAT inflammation induced by hypercaloric diet feeding, which dilutes inorganic phosphorus (Pi) to energy ratio by 50%, to investigate whether Pi supplementation ameliorates the early metabolic impairment. A 12‐week Pi supplementation at concentrations equivalent to and twice as much as that in the control diet was performed. The localized PVAT inflammation was reversed in a dose‐dependent manner. The increased expression of UCP1 (uncoupling protein1), HIF‐1α (hypoxia inducible factor‐1α), and IL‐1β (interleukin‐1β), representing the hallmark of PVAT inflammation in this rat model, were reversed, with normalization of PVAT macrophage polarization. Pi supplementation restored the metabolic efficiency consistent with its putative role as an UCP1 inhibitor. Alongside, parasympathetic autonomic and cerebrovascular dysfunction function observed in the prediabetic model was reversed, together with the mitigation of multiple molecular and histological cardiovascular damage markers. Significantly, a Pi‐deficient control diet neither induced PVAT inflammation nor cardiovascular dysfunction, whereas Pi reinstatement in the diet after a 10‐week exposure to a hypercaloric low‐Pi diet ameliorated the dysfunction.

Conclusions

Our present results propose Pi supplementation as a simple intervention to reverse PVAT inflammation and its early cardiovascular consequences, possibly through the interference with hypercaloric‐induced increase in UCP1 expression/activity.

Sodium-glucose co-transporter 1 and 2 expression in the mammary artery of patients with bypass surgery: role of the pro-inflammatory response and contribution to oxidative stress

Background

Selective sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown cardiovascular protection independently of glycemic control. Angiotensin II (Ang II) and H2O2 induced the expression of SGLT1 and 2 in cultured endothelial cells and isolated arteries to promote oxidative stress and endothelial dysfunction. However, the expression level and role of SGLT1 and 2 in human arteries remain poorly studied.

Purpose

This study examined the expression level of SGLT1 and 2 in the human internal mammary artery (IMA) obtained from bypass surgery patients, and, if so, determined the underlying mechanism and function.

Methods

IMAs were obtained from 40 bypass surgery patients (age 45 to 82). The expression level of target factors was assessed by Western blot analysis, immunofluorescence staining and RT-PCR, and the level of oxidative stress using dihydroethidium staining. Human kidney was used as a control tissue known to express SGLT1 and 2. Porcine coronary artery endothelial cells (CAEC) were cultured and studied at passage 1.

Results

Western blot analysis of 40 IMA samples indicated a high level of both SGLT1 and 2 in 16 and 17 IMAs, an intermediate level in 8 and 6 IMAs, and a low one in 16 and 17 IMAs, respectively. Immunofluorescence staining of IMA sections indicated that SGLT1 and 2 immunofluorescence signals were observed predominantly in the intima thickening and the media. The expression levels of SGLT1 and 2 were associated with p-p65 NF-kB signals but not angiotensin-converting enzyme (ACE), AT1R, MCP-1, VCAM-1. IMAs with a high expression level of SGLT1 and 2 had a high level of ROS throughout the arterial wall including the intima thickening and endothelium, which was inhibited by the antioxidant N-acetylcysteine, the ACE inhibitor perindoprilat, the AT1R antagonist losartan, and also by the dual SGLT1 and 2 inhibitor sotagliflozin and the selective SGLT2 inhibitor empagliflozin. Pro-inflammatory cytokines mRNA levels of IL-1β, TNF-α and IL-6 were detected in IMAs. Exposure of CAEC to either TNF-α, IL-1β or IL-6 caused a concentration-dependent upregulation of SGLT1 and 2.

Conclusion

The present findings indicate that SGLT1 and 2 expression is observed in some but not all IMAs of bypass surgery patients predominantly in the media, the intima thickening and the endothelium. High expression levels of SGLT1 and 2 are associated with NF-kB activation and oxidative stress that is prevented by a selective SGLT2 inhibitor and by a dual SGLT1/2 inhibitor. Since pro-inflammatory cytokines triggered SGLT1 and 2 expression in endothelial cells, the inflammatory burden of patients appears to be an important trigger regulating SGLT1/2 expression and the subsequent pro-oxidant response prompting pro-inflammatory and pro-thrombotic responses.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This work was supported by an unrestricted research grant from Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany.

Worsening baroreflex sensitivity on progression to type 2 diabetes: localized vs. systemic inflammation and role of antidiabetic therapy

Cardiac autonomic neuropathy (CAN) is an early cardiovascular manifestation of type 2 diabetes (T2D) that constitutes an independent risk factor for cardiovascular mortality and morbidity. Nevertheless, its underlying pathophysiology remains poorly understood. We recently showed that localized perivascular adipose tissue (PVAT) inflammation underlies the incidence of parasympathetic CAN in prediabetes. Here, we extend our investigation to provide a mechanistic framework for the evolution of autonomic impairment as the metabolic insult worsens. Early metabolic dysfunction was induced in rats fed a mild hypercaloric diet. Two low-dose streptozotocin injections were used to evoke a state of late decompensated T2D. Cardiac autonomic function was assessed by invasive measurement of baroreflex sensitivity using the vasoactive method. Progression into T2D was associated with aggravation of CAN to include both sympathetic and parasympathetic arms. Unlike prediabetic rats, T2D rats showed markers of brainstem neuronal injury and inflammation as well as increased serum levels of IL-1β. Experiments on PC12 cells differentiated into sympathetic-like neurons demonstrated that brainstem injury observed in T2D rats resulted from exposure to possible proinflammatory mediators in rat serum rather than a direct effect of the altered metabolic profile. CAN and the associated cardiovascular damage in T2D only responded to combined treatment with insulin to manage hyperglycemia in addition to a nonhypoglycemic dose of metformin or pioglitazone providing an anti-inflammatory effect, coincident with the effect of these combinations on serum IL-1β. Our present results indicate that CAN worsening upon progression to T2D involves brainstem inflammatory changes likely triggered by systemic inflammation.

[Mitral prolapse and sudden death. A case report]

The association between the mitral valve prolapse and the sudden Cardiac Death remains controversial, the high prevalence of this valvulopathy contrasting with the low incidence of sudden death in this population. We report the case of a 54-year-old woman admitted for a sudden cardiac death, revealing a bi-prolapse with low-grade leakage, leading to the implantation of a subcutaneous automatic defibrillator. Combined echocardiography and cardiac MRI can identify the mitral annular disjunction, the rolling motion of the posterior face of the mitral annulus towards the myocardium, and the myocardial fibrosis of the inferolateral wall induced by streching forces of the sub valvular apparatus, that may lead to ventricular arrhythmias. More than the conventional clinical parameters (young woman, ventricular premature beats with a right bundle branch block morphology, mitral bi-prolapse), mitral annular disjunction and myocardial fibrosis are to be considered as powerful markers of the rhythmic risk of mitral prolapse and must be systematically sought and integrated into the prognostic evaluation of these patients. In the absence of randomised trials, therapeutic management is difficult especially in primary prevention, and needs Heart Team advice.

Sex-based differences in myocardial infarction-induced kidney damage following cigarette smoking exposure: more renal protection in premenopausal female mice

The impact of cigarette smoking (CS) on kidney homeostasis in the presence of myocardial infarction (MI) in both males and females remains poorly elucidated. C57BL6/J mice were exposed to 2 weeks of CS prior to MI induction followed by 1 week of CS exposure in order to investigate the impact of CS on kidney damage in the presence of MI. Cardiac hemodynamic analysis revealed a significant decrease in ejection fraction (EF) in CS-exposed MI male mice when compared with the relative female subjects, whereas cardiac output (CO) comparably decreased in CS-exposed MI mice of both sexes. Kidney structural alterations, including glomerular retraction, proximal convoluted tubule (PCT) cross-sectional area, and total renal fibrosis were more pronounced in CS-exposed MI male mice when compared with the relative female group. Although renal reactive oxygen species (ROS) generation and glomerular DNA fragmentation significantly increased to the same extent in CS-exposed MI mice of both sexes, alpha-smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF) significantly increased in CS-exposed MI male mice, only. Metabolically, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide riboside-1 (NMRK-1) substantially increased in CS-exposed MI female mice only, whereas sirtuin (SIRT)-1 and SIRT-3 substantially decreased in CS-exposed MI male mice compared with their relative female group. Additionally, renal NAD levels significantly decreased only in CS-exposed MI male mice. In conclusion, MI female mice exhibited pronounced renal protection following CS when compared with the relative male groups.

Amelioration of perivascular adipose inflammation reverses vascular dysfunction in a model of nonobese prediabetic metabolic challenge: potential role of antidiabetic drugs

The onset of vascular impairment precedes that of diagnostic hyperglycemia in diabetic patients suggesting a vascular insult early in the course of metabolic dysfunction without a well-defined mechanism. Mounting evidence implicates adipose inflammation in the pathogenesis of insulin resistance and diabetes. It is not certain whether amelioration of adipose inflammation is sufficient to preclude vascular dysfunction in early stages of metabolic disease. Recent findings suggest that antidiabetic drugs, metformin, and pioglitazone, improve vascular function in prediabetic patients, without an indication if this protective effect is mediated by reduction of adipose inflammation. Here, we used a prediabetic rat model with delayed development of hyperglycemia to study the effect of metformin or pioglitazone on adipose inflammation and vascular function. At the end of the metabolic challenge, these rats were neither obese, hypertensive, nor hyperglycemic. However, they showed increased pressor responses to phenylephrine and augmented aortic and mesenteric contraction. Vascular tissues from prediabetic rats showed increased Rho-associated kinase activity causing enhanced calcium sensitization. An elevated level of reactive oxygen species was seen in aortic tissues together with increased Transforming growth factor β1 and Interleukin-1β expression. Although, no signs of systemic inflammation were detected, perivascular adipose inflammation was observed. Adipocyte hypertrophy, increased macrophage infiltration, and elevated Transforming growth factor β1 and Interleukin-1β mRNA levels were seen. Two-week treatment with metformin or pioglitazone or switching to normal chow ameliorated adipose inflammation and vascular dysfunction. Localized perivascular adipose inflammation is sufficient to trigger vascular dysfunction early in the course of diabetes. Interfering with this inflammatory process reverses this early abnormality.

Impaired Endothelium-Dependent Hyperpolarization Underlies Endothelial Dysfunction during Early Metabolic Challenge: Increased ROS Generation and Possible Interference with NO Function

Endothelial dysfunction is a hallmark of diabetic vasculopathies. Although hyperglycemia is believed to be the culprit causing endothelial damage, the mechanism underlying early endothelial insult in prediabetes remains obscure. We used a nonobese high-calorie (HC)-fed rat model with hyperinsulinemia, hypercholesterolemia, and delayed development of hyperglycemia to unravel this mechanism. Compared with aortic rings from control rats, HC-fed rat rings displayed attenuated acetylcholine-mediated relaxation. While sensitive to nitric oxide synthase (NOS) inhibition, aortic relaxation in HC-rat tissues was not affected by blocking the inward-rectifier potassium (Kir) channels using BaCl₂ Although Kir channel expression was reduced in HC-rat aorta, Kir expression, endothelium-dependent relaxation, and the BaCl₂-sensitive component improved in HC rats treated with atorvastatin to reduce serum cholesterol. Remarkably, HC tissues demonstrated increased reactive species (ROS) in smooth muscle cells, which was reversed in rats receiving atorvastatin. In vitro ROS reduction, with superoxide dismutase, improved endothelium-dependent relaxation in HC-rat tissues. Significantly, connexin-43 expression increased in HC aortic tissues, possibly allowing ROS movement into the endothelium and reduction of eNOS activity. In this context, gap junction blockade with 18-β-glycyrrhetinic acid reduced vascular tone in HC rat tissues but not in controls. This reduction was sensitive to NOS inhibition and SOD treatment, possibly as an outcome of reduced ROS influence, and emerged in BaCl₂-treated control tissues. In conclusion, our results suggest that early metabolic challenge leads to reduced Kir-mediated endothelium-dependent hyperpolarization, increased vascular ROS potentially impairing NO synthesis and highlight these channels as a possible target for early intervention with vascular dysfunction in metabolic disease. SIGNIFICANCE STATEMENT: The present study examines early endothelial dysfunction in metabolic disease. Our results suggest that reduced inward-rectifier potassium channel function underlies a defective endothelium-mediated relaxation possibly through alteration of nitric oxide synthase activity. This study provides a possible mechanism for the augmentation of relatively small changes in one endothelium-mediated relaxation pathway to affect overall endothelial response and highlights the potential role of inward-rectifier potassium channel function as a therapeutic target to treat vascular dysfunction early in the course of metabolic disease.

Stress-induced Worsening of Left Ventricular Diastolic Function as a Marker of Myocardial Ischemia

Background:

Echocardiography has been the subject of interest in diagnosing diastolic dysfunction and estimating left ventricular filling pressures (LVFPs). The present study is set to estimate the correlation between the worsening of diastolic parameters and the evidence of inducible ischemia during an exercise stress echocardiography (SE) in comparison with the results of coronary computed tomographic angiogram (CCTA).

Methods:

A total of 191 consecutive patients from the executive screening program who underwent exercise SE followed by CCTA were evaluated. Baseline demographics, heart rate, and blood pressure measurements were extracted for analysis. Standard two-dimensional and tissue Doppler imaging parameters were analyzed. Diastolic function was graded at rest and peak exercise.

Results:

Patients who had worsening of diastolic function by at least one grade had had 2–3-fold higher odds of having abnormal SE. In addition, patients with worsening of diastolic function had higher stress LVFPs (E/e’ = 11.7 ± 2.7 vs. E/e’ 8.0 ± 2.0; P < 0.0001), more E/e’ change >25% (48% vs. 22%, P = 0.012), and were more likely to have obstructive coronary artery disease (CAD) on CCTA (23.8% vs. 9.2%; P = 0.045). A change in E/e’ >25% (stress-rest) was highly associated with a positive stress test and abnormal CCTA result. Patients with no change or improvement in diastolic function with stress had a 92% negative predictive value of having normal SE and 91% of normal/nonobstructive CCTA.

Conclusion:

A worsening of diastolic function and a change in E/e’ >25% (stress-rest) were associated with abnormal SE, positive stress test, and obstructive CAD when compared to CCTA results.

Maternal mortality in the American University of Beirut Medical Center (AUBMC) 1971-1982

Maternal deaths were reviewed at the American University of Beirut Medical Center (AUBMC) during an 11-year period, 1971-1982. There were 35,058 live births and 45 deaths making a maternal mortality rate of 128 per 100,000 live births. Hemorrhage, sepsis and toxemia were the main direct obstetric causes of death. The most important indirect causes were cerebrovascular accidents and heart disease. In this review, an analytic discussion of the direct and indirect causes of maternal death in Lebanon are presented and preventive measures are discussed.

Partial hypopituitarism in a patient with a pituitary stone

A case of sexual infantilism was found to have calcification within the sella turcica. Endocrine evaluation revealed partial hypopituitarism involving gonadotrophin and growth hormone secretion.

Ovarian biopsy in the evaluation of amenorrhea

Endoscopic ovarian biopsies were performed on 78 amenorrheic patients in an attempt to determine the etiology of their amenorrhea and predict its prognosis, correlating the histologic examination with physical findings, endocrine patterns and cytogenetic studies. Ovarian follicles were present while gonadotropins were high in 14 cases (6 primary, 8 secondary) and there were no follicles in 4 cases (3 primary, 1 secondary) whose gonadotropins were low. Secondary sex characteristics were well developed without prior estrogen stimulation in 5 cases of primary amenorrhea who had no follicles and whose gonadotropins were either low, 3, or high, 2. The mere presence of ovarian follicles was not enough to make them responsive to gonadotropin stimulation whether endogenous or exogenous; a phenomenon that had to do with the quality and quantity of germinal follicles available. The histologic examination of ovarian tissue for the evaluation of amenorrhea has been made feasible and relatively safe through recent advances in endoscopic techniques.

Varicocele and infertility in men

Varicocele is an important cause of infertility in men. The exact mechanism by which varicocele depresses spermatogenesis is unknown but probably the retrograde flow of blood rich in catecholamines into the testes plays a major role. Because subfertile semen qualities are present in a large percentage of men with varicocele and because the response to surgical procedures is very good, high ligation of the left internal spermatic vein is recommended in men with varicocele and infertility.

Abnormality in metabolism of 15N-labeled nitrate in toxemia

The urinary excretion of 15N-labeled ammonium nitrate was studied during the last few weeks in patients with normal pregnancy and in those with toxemia. Marked diminution of the 15N label was found consistently in patients with toxemia in the urinary fraction consisting of nitrogenous compounds other than urea and ammonia. The possible significance of this finding is discussed.