Improvement of endothelial dysfunction in experimental heart failure by chronic RAAS-blockade: ACE-inhibition or AT1-receptor blockade?

Chronic heart failure (CHF) is associated with endothelial dysfunction. Activation of the renin-angiotensin-aldosterone system (RAAS) is believed to be important in the deterioration of endothelial dysfunction in CHF through stimulation of oxidative stress. Whereas angiotensin-converting enzyme inhibitors (ACE-I) improve endothelial function in CHF, the effects of angiotensin II AT1-receptor blockers (ARB) are less well established. Therefore we compared the effects of the ACE-I lisinopril vs. the ARB candesartan on endothelial dysfunction in a rat model of CHF. CHF was induced by myocardial infarction (MI) after coronary ligation. Two weeks after MI, daily treatment with lisinopril (2 mg/kg) or candesartan cilexetil (1.5 mg/kg) was started. After 13 weeks, rats were sacrificed and endothelial function was determined by measuring acetylcholine (ACh)-induced vasodilation in aortic rings, with selective presence of the nitric oxide synthase (NOS)-inhibitor NG-monomethyl-L-arginine (L-NMMA) to determine the contribution of nitric oxide (NO). ACh-induced vasodilation was attenuated in untreated MI (-50%) compared with control rats. This was in part due to an impaired contribution of NO (-49%). Lisinopril and candesartan cilexetil fully normalised ACh-induced dilation, including the part mediated by NO. Chronic RAAS-blockade with lisinopril and candesartan cilexetil normalised endothelial function in CHF in a comparable way. The effect of both treatments included the increase of the NO-mediated dilation, further indicating the important role of oxidative stress in the relationship between the RAAS and endothelial dysfunction in CHF

Three cases of hepatocellular carcinoma in Fontan patients: Review of the literature and suggestions for hepatic screening

The Fontan procedure has been used since 1971 as a palliative treatment for various (functionally) univentricular hearts. The systemic venous blood flows passively to the pulmonary arteries, without passing through a functional ventricle. This results in chronic systemic venous congestion, which may lead to liver fibrosis, cirrhosis and hepatocellular carcinoma. This review discusses possible screening modalities for liver fibrosis and cirrhosis in the Fontan population and proposes a screening protocol. We suggest starting screening for progression of fibrosis and cirrhosis in collaboration with the hepatologist circa 10 years after Fontan completion. The screening programme will consist of a yearly evaluation of liver laboratory tests in conjunction with imaging of the liver with ultrasound or MRI every two years. In case of liver fibrosis or cirrhosis, (reversible) causes should be ruled out (e.g. obstruction in the Fontan circuit). In case of severe fibrosis or cirrhosis, other complications of portal hypertension should be evaluated and screening for hepatocellular carcinoma is required on a regular (6-12 months) basis. As regards hepatocellular carcinoma, treatment should be discussed in a multidisciplinary team, before deciding a treatment modality. (C) 2016 Elsevier Ireland Ltd. All rights reserved

Evidence of myocardial scarring and microvascular obstruction on cardiac magnetic resonance imaging in a series of patients presenting with myocardial infarction without obstructed coronary arteries

Patients with acute chest pain, electrocardiographic ST-elevation and significant elevation of cardiac troponin but without obstructive coronary artery disease represent a diagnostic and therapeutic dilemma. Cardiac magnetic resonance imaging (CMR) can elucidate underlying alternative causes of troponin elevation including detection of (minor) myocardial infarction (MI) by identifying myocardial scarring as delayed enhancement. Of 77 patients, who were admitted between March 2009 and December 2012 with electrocardiographic (ECG) and biochemical evidence of acute MI without obstructive coronary artery disease, 45 patients underwent CMR that showed in 11/77 (14 %) late gadolinium enhancement (LGE), compatible with myocardial scarring. We analyzed clinical, echocardiographic, and CMR data of these patients. Elevated troponin I levels were observed in all patients (median 1.3 ng/l, IQR 0.44–187) with median peak creatinine phosphokinase of 485 U/l (IQR 234–618). Echocardiographic wall motion abnormalities were detected in 8/11 (73 %) patients; in 75 % of these segments, ECG abnormalities were observed in corresponding leads. CMR detected LGE in the inferior (4/11), the inferolateral (5/11), the inferoseptal (2/11), the anterior (3/11), apical (3/11) and in the lateral segments (2/11). In addition, in all but two patients, these segments matched ECG abnormalities in corresponding leads. CMR identified microvascular obstruction in 4/11 (36 %) patients. Patients with clinical, ECG, and biochemical signs of acute MI but unobstructed coronary arteries may have CMR-detectable myocardial scars. Information on myocardial scarring may help to make the diagnosis and draw therapeutic consequences. This case series underlines the value of contrast-enhanced CMR for myocardial tissue characterizatio

Differential localisation of the renin-angiotensin system in de-novo lesions and in-stent restenotic lesions in in-vivo human coronary arteries

Objective: Different components of the renin-angiotensin system (RAS) have been demonstrated in atherosclerotic plaques. However, the involvement of the RAS in in-stent restenosis is not clear. We studied the differential immunolocalisation of angiotensin converting enzyme (ACE) and the angiotensin II type 1 (AT1) receptor in de-novo stenotic lesions and in-stent restenotic lesions in human coronary arteries. Methods: Using a pullback atherectomy catheter, biopsies from de-novo coronary lesions (n = 19) and in-stent restenotic lesions (n = 19) were obtained. The biopsies were immunostained for vascular smooth muscle cells (VSMCs), macrophages, ACE and the AT I receptor. Results: In biopsies from de-novo stenotic lesions ACE-positive macrophages were more numerous than in in-stent restenotic lesions (P=0.002). Moreover, in the latter lesions, ACE-positive macrophages decreased when the time interval of stent implantation was longer. On the other hand, in-stent restenotic lesions contained predominantly young VSMCs, which abundantly expressed AT1 receptors. Conclusions: Lesional ACE expression is not a prominent feature of in-stent restenotic lesions. In contrast, AT1 receptors are abundantly expressed on young VSMCs. In de-novo lesions ACE and AT1 receptors were found on macrophages and VSMCs. which were present in all specimens. (C) 2003 European Society of Cardiology. Published by Elsevier B.V. All rights reserve