Junji Kawagoe

Osteoprotegerin is Secreted Into the Coronary Circulation: A Possible Association with the Renin-Angiotensin System and Cardiac Hypertrophy

The circulating osteoprotegerin (OPG) level reflects a series of cardiovascular diseases; however, the source(s) of circulating OPG remain(s) to be determined. This study explored whether OPG is released in the coronary circulation and whether it is associated with cardiac structure and function. Fifty-six patients (67±10 years old, male 57%, hypertension 73%, coronary artery disease 50%) were enrolled, and blood samples were collected simultaneously from the orifice of the left coronary artery (CA) and the coronary sinus (CS) after angiography. The concentration of OPG was higher in the CS than in the CA (7.7±4.1 vs. 6.7±3.6 pmol/l, p<0.001). The trans-cardiac OPG concentration was significantly (p=0.019) decreased in patients who have been prescribed either an angiotensin converting enzyme inhibitor or an angiotensin II type 1 receptor blocker (ACEI/ARB). In patients subgroup who did not take an ACEI/ARB (n=27), the trans-cardiac OPG level was positively correlated with age (r=0.396, p=0.041) and relative wall thickness of left ventricle (r=0.534, p=0.004). In multivariate linear regression analysis, relative wall thickness remained to be the independent variable for the trans-cardiac OPG level (p=0.004). Moreover, trans-cardiac OPG was significantly (p=0.021) increased in patients with relative wall thickness greater than 0.45 but it did not differ if the left ventricular mass index was increased (≥116 for males, or ≥ 104 for females, g/m(2)) or not (p=0.627). This study suggests that OPG is secreted into the coronary circulation and is associated with concentric remodeling/hypertrophy of LV, possibly in interactions with the renin-angiotensin system.

Reciprocal Production of Adiponectin and C-reactive Protein in Coronary Circulation of Patients with and without Coronary Artery Disease

Introduction & The adipocyte-specifi c plasma protein adi ponectin was originally isolated from human adipose tissues. Adiponectin has anti-atherosclerotic properties such as the suppression of adhesion molecule expression on endothelial cells, the proliferation of vascular smooth muscle cells, and the transformation of macrophages to foam cells. Systemic clinical hypoadiponectinemia is closely associated with obesity, type 2 diabetes, and coronary artery disease (CAD) [1] . These data suggest that adiponectin contributes to suppressing the initiation and progression of atherosclerosis. We already reported that adiponectin is locally produced in the coronary circulation and might participate in modulating the coronary circulation [2] . Iacobellis et al. recently showed that epicardial adipose tissue expresses adiponectin protein and that the level is signifi cantly lower in patients with, than in those without, CAD [3] . Locally produced adiponectin might exert local anti-atherosclerotic action on the adjacent coronary artery [3] . These fi ndings together indicate that the locally produced adiponectin in the coronary circulation might be at least partly attributable to its production and secretion from epicardial adipose tissue and affect coronary atherosclerosis. However, whether the plasma level of adiponectin in the coronary circulation varies with the presence of CAD remains unknown. We therefore investigated the relationship between the presence of CAD and the amount of adiponectin production in the coronary circulation and compared with the amount of C-reactive protein (CRP) in the coronary circulation of patients with and without CAD.

SIGNIFICANCE OF CARDIAC TROPONIN T LEVELS IN SUPRAVENTRICULAR TACHYCARDIA

Background: Cardiac troponin T is sensitive and specific markers of myocardial injury and is used routinely for the diagnosis of acute coronary syndrome. Recently, the magunitude of troponin T levels in heart failure patients has been reported to correlate with severity of the disease and with adverse outcomes. They may suggest ongoing myocardial damage. In supraventricular tachycardia, common atrial flutter (AFL) and atrial tachycardia (AT) often produce changes in cardiac function and structure, but atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) do not. To our knowledge, there are no reports about the relationship between the levels of troponin T and the types of supraventricular tachycardia. We examined the clinical usefulness of previously unmeasurable levels of troponin T (hs-TnT) by using highly sensitive assay for the differential diagnosis of supraventricular tachycardia.

[Ventricular fibrillation in a patient with Wolff-Parkinson-White syndrome].

症例は30歳,男性.動悸,気分不良が初めて出現し,近医を受診.待合室で意識消失し,心室細動を認めたため,電気的除細動を施行された.心電図でデルタ波を認め,電気生理学検査で副伝導路の順行性有効不応期は250msecと短かったためカテーテルアブレーションを施行した.無症候性WPW症候群は予後良好といわれているが,本症例は初発の頻拍発作が心室細動に至っており,注意を要すると思われた.