Low Adiponectin Level Causes Vascular Remodeling?: A Perspective through Intravascular Ultrasound

Epicardial Adipose Tissue Thickness is Higher in Right Ventricular Outflow Tract Tachycardia

Introduction: Idiopathic ventricular arrhythmias, which occur in the absence of structural heart disease, are commonly originating from the outflow tract, and 80% of the them arise from the right ventricle. Epicardial adipose tissue (EAT), which originates from the splanchnopleuric mesoderm, has been shown to be an important source of inflammatory mediators and plays an important role in cardiac autonomic function by epicardial ganglionated plexuses. EAT may potentially contribute to the pathophysiology of idiopathic right ventricular outflow tract (RVOT) tachycardia by different mechanisms. In this study, we aimed to investigate the relationship between EAT thickness and RVOT tachycardia. Methods: This study included 55 patients (32 male, 23 female) with RVOT tachycardia and 60 control subjects (38 male, 22 female). Patients who had more than three consecutive ventricular beats over 100 bpm with specific morphological features on the electrocardiogram (ECG) were diagnosed with RVOT tachycardia. EAT thickness was measured by transthoracic echocardiography. Results: EAT thickness was significantly higher in the RVOT tachycardia group (p <0.05). Ejection fraction (EF), and the thickness of the posterior wall of the left ventricle and of the interventricular septum were significantly lower, and left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left atrial diameter were significantly higher in patients who had RVOT tachycardia compared to normal subjects (p <0.05). Conclusion: Patients who were diagnosed with RVOT tachycardia had increased EAT thickness compared to normal subjects. The underlying mechanism of the condition could be mechanical, metabolic, infiltrative, or autonomic effects of the EAT.

Usefulness of adiponectin as a predictor of all cause mortality in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Substantial evidence points to a protective role of adiponectin against atherosclerosis and cardiovascular (CV) disease. However, in the setting of an acute myocardial infarction (AMI), the role of adiponectin has not previously been studied. Consequently, the aim of this study was to investigate the prognostic role of adiponectin after AMI in a large population of patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. A total of 735 consecutive patients with ST-segment elevation myocardial infarction admitted to a single high-volume invasive heart center and treated with primary percutaneous coronary intervention from September 2006 to December 2008 were included. Blood samples were drawn immediately before the invasive procedure. Plasma adiponectin was measured using a validated immunoassay. End points were all-cause mortality, CV mortality, and admission for new AMI or heart failure. The median follow-up time was 27 months (interquartile range 22 to 33). Patients with high adiponectin (quartile 4) had increased mortality compared to patients with low adiponectin (quartiles 1 to 3) (log-rank p <0.001). After adjustment for conventional risk factors (age, gender, smoking, hypertension, hypercholesterolemia, diabetes, body mass index, C-reactive protein, peak troponin I, creatinine, estimated glomerular filtration rate, previous AMI, multivessel disease, complex lesions, left anterior descending coronary artery lesion, and symptom-to-balloon time) by Cox regression analysis, high adiponectin remained an independent predictor of all-cause mortality (hazard ratio 2.1, 95% confidence interval 1.3 to 3.2, p = 0.001) and CV mortality (hazard ratio 2.6, 95% confidence interval 1.5 to 4.5, p = 0.001). In conclusion, increased plasma adiponectin independently predicts all-cause and CV mortality in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention.

Adiponectin and vulnerable atherosclerotic plaques

High-risk plaques that are vulnerable to rupture demonstrate distinct morphological characteristics. They are differentiated from the lesions responsible for stable coronary artery disease by their large necrotic cores, thin-inflamed fibrous caps, and positive remodeling. Adiponectin is an adipocytokine that is reduced in obesity and type 2 diabetes. Hypoadiponectinemia has been associated with an increased risk of coronary artery disease and acute coronary syndrome in several though not all studies. The involvement of adiponectin provides clues to the inflammatory and atherogenic mechanisms associated with pathological coronary disease progression.