Crosstalk between Tryptophan Metabolism via Kynurenine Pathway and Carbohydrate Metabolism in the Context of Cardio-Metabolic Risk-Review.

Scientific interest in tryptophan metabolism via the kynurenine pathway (KP) has increased in the last decades. Describing its metabolites helped to increase their roles in many diseases and disturbances, many of a pro-inflammatory nature. It has become increasingly evident that KP can be considered an important part of emerging mediators of diabetes mellitus and metabolic syndrome (MS), mostly stemming from chronic systemic low-grade inflammation resulting in the aggravation of cardiovascular complications. An electronic literature search of PubMed and Embase up to March 2021 was performed for papers reporting the effects of tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), xanthurenic acid (XA), anthranilic acid (AA), and quinolinic acid (QA), focusing on their roles in carbohydrate metabolism and the cardiovascular system. In this review, we discussed the progress in tryptophan metabolism via KP research, focusing particular attention on the roles in carbohydrate metabolism and its complications in the cardiovascular system. We examined the association between KP and diabetes mellitus type 2 (T2D), diabetes mellitus type 1 (T1D), and cardiovascular diseases (CVD). We concluded that tryptophan metabolism via KP serves as a potential diagnostic tool in assessing cardiometabolic risk for patients with T2D.

Effectiveness of surgical closure of left atrial appendage during minimally invasive mitral valve surgery.

BACKGROUND: Left atrial appendage closure (LAAC) reduces the risk of stroke in patients with atrialfibrillation. It can be performed surgically from the inside of the left atrium or from the outside. Stapling or clipping devices can also be used from the outside. Despite providing an excellent interior view of the appendage, those techniques cannot be implemented during minimally invasive mitral valve surgery conducted through right­sided minithoracotomy. AIMS: This study aimed to assess the effectiveness of surgical closure of the left atrial appendage from the inside during minimally invasive mitral valve surgery. METHODS: A total of 50 patients with mitral valve disease and atrial fibrillation who underwent minimallyinvasive mitral valve surgery and LAACbetween 2012 and 2017 were included in this study. The appendagewas closed from the inside using a continuous suture. After a median follow­up of 1.6 years after surgery, 19 patients were examined by transthoracic and transesophageal echocardiography (TEE). Transesophageal echocardiography was performed to assess whether the appendage had been effectively closed. When any leakage was suspected, cardiac computed tomography was performed. RESULTS: In 19 patients, TEE was performed at 0.5 to 5 years after the surgery. A single patient did not tolerate TEE, and minimal leakage was suspected in 2 patients. All 3 individuals underwent computed tomography examination, which confirmed leakage in a single patient. CONCLUSIONS: Surgical LAACduring minimally invasive mitral valve surgery through right minithoracotomyis an effective technique that provides durable results.

The Gene and Protein Expression of the Main Components of the Lipolytic System in Human Myocardium and Heart Perivascular Adipose Tissue. Effect of Coronary Atherosclerosis.

The aim of our study was to examine the regulation of triacylglycerols (TG) metabolism in myocardium and heart perivascular adipose tissue in coronary atherosclerosis. Adipose triglyceride lipase (ATGL) is the major TG-hydrolase. The enzyme is activated by a protein called comparative gene identification 58 (CGI-58) and inhibited by a protein called G0/G1 switch protein 2 (G0S2). Samples of the right atrial appendage and perivascular adipose tissue were obtained from two groups of patients: 1-with multivessel coronary artery disease qualified for coronary artery bypass grafting (CAD), 2-patients with no atherosclerosis qualified for a valve replacement (NCAD). The mRNA and protein analysis of ATGL, HSL, CGI-58, G0S2, FABP4, FAT/CD36, LPL, ß-HAD, CS, COX4/1, FAS, SREBP-1c, GPAT1, COX-2, 15-LO, and NFκß were determined by using real-time PCR and Western Blot. The level of lipids (i.e., TG, diacylglycerol (DG), and FFA) was examined by GLC. We demonstrated that in myocardium coronary atherosclerosis increases only the transcript level of G0S2 and FABP4. Most importantly, ATGL, ß-HAD, and COX4/1 protein expression was reduced and it was accompanied by over double the elevation in TG content in the CAD group. The fatty acid synthesis and their cellular uptake were stable in the myocardium of patients with CAD. Additionally, the expression of proteins contributing to inflammation was increased in the myocardium of patients with coronary stenosis. Finally, in the perivascular adipose tissue, the mRNA of G0S2 was elevated, whereas the protein content of FABP-4 was increased and for COX4/1 diminished. These data suggest that a reduction in ATGL protein expression leads to myocardial steatosis in patients with CAD.

Is real time contrast echocardiography useful for assessment of the right ventricular morphology, function, and perfusion?

BACKGROUND: Contrast-enhanced echocardiography (CE) is recommended to assess left ventricular function and perfusion but is rarely used to assess the right ventricle (RV). We used CE to assess RV function and perfusion and evaluated whether RV perfusion defects varied in different patient groups with RV failure due to pressure overload. METHODS: We studied 17 patients with acute pulmonary embolism (PE), 19 patients with chronic pulmonary arterial hypertension (CPH), and 7 healthy volunteers. The examination included RV opacification (RVO) and myocardial CE. RV end-diastolic area (RVEDA), RV end-systolic area (RVESA), fractional area change (FAC), and wall-motion score index (WMSI) were assessed before and after contrast agent administration. Perfusion was evaluated qualitatively and quantitatively. RESULTS: RVEDA, RVESA, FAC, and regional contractility were comparable before and after contrast agent injection. Significant perfusion defects were seen in PE and CPH (18/39 segments and 37/51 segments, respectively, vs. 0/21 segments in healthy volunteers; P < 0.0001). Wall-perfusion score index (WPSI) was higher in PE and CPH compared to healthy volunteers (1.5 ± 0.3 and 1.8 ± 0.4 vs. 1.0 ± 0.0; P = 0.02 and P = 0.0003, respectively). Linear correlations were noted between WMSI, FAC and WPSI (r = 0.5, P = 0.014 and r = -0.55, P = 0.005, respectively). Quantitative perfusion assessment revealed perfusion defects in the apical segment in the PE group. The mean region of interest value was insignificantly reduced in PE and CPH groups. CONCLUSION: Contrast-enhanced echocardiography is feasible and may be useful for RVO and perfusion assessment in patients with RV dysfunction due to systolic overload. The SonoVue contrast agent was well tolerated by stable patients with PE and CPH.