Highlights of Acta Cardiologica.

peer reviewe

Focus issue on cardiomyopathies.

editorial reviewe

Effect of streptozotocin-induced diabetes on left ventricular function in adult rats: an in vivo Pinhole Gated SPECT study

<p>Abstract</p> <p>Background</p> <p>Recent studies have suggested that diabetes mellitus (DM) may cause left ventricular (LV) dysfunction directly resulting in increased susceptibility to heart failure. Using pinhole collimators and advances in data processing, gated SPECT was recently adapted to image the rat heart. The present study was aimed to assess this new imaging technique for quantifying LV function and remodeling from the Streptozotocin (STZ) rat model compared to controls.</p> <p>Methods</p> <p>Twenty one rats were randomly assigned to control or diabetic group. Six months after the induction of diabetes by STZ, Pinhole 99 m Tc-sestamibi gated SPECT was performed for determining rat LV volumes and function. Post-mortem histopathologic analysis was performed to evaluate the determinant of LV remodeling in this model.</p> <p>Results</p> <p>After six months, the normalized to body weight LV End-systolic volume was significantly different in diabetic rats compared to controls (0.46 ± 0.02 vs 0.33 ± 0.03 μL/g; p = 0.01). The normalized LV End-diastolic volume was also different in both groups (1.51 ± 0.03 vs 0.88 ± 0.05 μL/g; p = 0.001) and the normalized stroke volume was significantly higher in STZ-rats (1.05 ± 0.02 vs 0.54 ± 0.06 μL/g; p = 0.001). The muscular fibers were thinner at histology in the diabetic rats (0.44 ± 0.07 vs 0.32 ± 0.06 AU; p = 0.01).</p> <p>Conclusion</p> <p>Pinhole 99 m Tc-sestamibi gated SPECT can successfully be applied for the evaluation of cardiac function and remodeling in STZ-induced diabetic rats. In this model, LV volumes were significantly changed compared to a control population, leading to a LV dysfunction. These findings were consistent with the histopathological abnormalities. Finally, these data further suggest the presence of diabetes cardiomyopathy.</p

Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography

Targeting of vascular cell adhesion molecule-1 by18F-labelled nanobodies for PET/CT imaging of inflamed atherosclerotic plaques

Aims Positron emission tomography-computed tomography (PET-CT) is a highly sensitive clinical molecular imaging modality to study atherosclerotic plaque biology. Therefore, we sought to develop a new PET tracer, targeting vascular cell adhesion molecule (VCAM)-1 and validate it in a murine atherosclerotic model as a potential agent to detect atherosclerotic plaque inflammation. Methods and results The anti-VCAM-1 nanobody (Nb) (cAbVCAM-1-5) was radiolabelled with Fluorine-18 (F-18), with a radiochemical purity of >98%. In vitro cell-binding studies showed specific binding of the tracer to VCAM-1 expressing cells. In vivo PET/CT imaging of ApoE(-/-) mice fed aWestern diet or control mice was performed at 2h30 post-injection of [F-18]-FB-cAbVCAM-1-5 or F-18-control Nb. Additionally, plaque uptake in different aorta segments was evaluated ex vivo based on extent of atherosclerosis. Atherosclerotic lesions in the aortic arch of ApoE(-/-) mice, injected with [F-18]-FB-anti-VCAM-1 Nb, were successfully identified using PET/CT imaging, while background signal was observed in the control groups. These results were confirmed by ex vivo analyses where uptake of [F-18]-FB-cAbVCAM-1-5 in atherosclerotic lesions was significantly higher compared with control groups. Moreover, uptake increased with the increasing extent of atherosclerosis (Score 0: 0.68 +/- 0.10, Score 1: 1.18 +/- 0.36, Score 2: 1.49 +/- 0.37, Score 3: 1.48 +/- 0.38% ID/g, Spearman's r(2) = 0.675, P < 0.0001). High lesion-to-heart, lesion-to-blood, and lesion-to-control vessel ratios were obtained (12.4 +/- 0.4, 3.3 +/- 0.4, and 3.1 +/- 0.6, respectively). Conclusion The [F-18]-FB-anti-VCAM-1 Nb, cross-reactive for both mouse and human VCAM-1, allows non-invasive PET/CT imaging of VCAM-1 expression in atherosclerotic plaques in a murine model and may represent an attractive tool for imaging vulnerable atherosclerotic plaques in patients

EuroEcho-Imaging 2016:highlights

International audienceThe annual meeting of the European Association of Cardiovascular Imaging, EuroEcho-Imaging, was held in Leipzig, Germany, in December 2016. In the present paper, we present a summary of the 'Highlights' session

Impact of the initial clinical presentation on the outcome of patients with infective endocarditis

Background: Infective endocarditis (IE) is a life-threatening disease. Despite advancements in diagnostic methods, the initial clinical presentation of IE remains a valuable asset. Therefore, the impact of clinical presentation on outcomes and its association with microorganisms and IE localization were assessed herein. Methods: This retrospective study included 183 patients (age 68.9 ± 14.2 years old, 68.9% men) with definite IE at two tertiary care hospitals in Belgium. Demographic data, medical history, clinical presentation, blood cultures, imaging data and outcomes were recorded. Results: In-hospital mortality rate was 22.4%. Sixty (32.8%) of the patients developed embolism, 42 (23%) shock, and 103 (56.3%) underwent surgery during hospitalization. Shock at admission predicted embolism during hospitalization (odds ratio [OR] 2.631, 95% confidence interval [CI] 1.119–6.184, p = 0.027). A new cardiac murmur at admission predicted cardiac surgery (OR 1.949, 95% CI 1.007–3.774, p = 0.048). Methicillin resistant Staphylococcus aureus predicted in-hospital mortality and shock (p = 0.005, OR 6.945, 95% CI 1.774–27.192 and p = 0.015, OR 4.691, 95% CI 1.348–16.322, respectively). Mitral valve and aortic valve IE respectively predicted in-hospital death (p = 0.039, OR 2.258, 95% CI 1.043–4.888) and embolism (p = 0.017, OR 2.328, 95% CI 1.163–4.659).  Conclusions: In this retrospective study, shock at admission independently predicted embolism during hospitalization in IE patients. Moreover, a new cardiac murmur at admission predicted the need for cardiac surgery. This emphasizes the importance of a comprehensive initial clinical evaluation in combination with imaging and microbiological data, in order to identify high-risk IE patients early

Impact of baseline left ventricular volume on left ventricular reverse remodeling after cardiac resynchronization therapy

Background: Left ventricular (LV) dilatation may limit LV reverse remodeling after cardiac resynchronization therapy (CRT).Objective: The purpose of this study was to evaluate the impact of baseline LV volumes on LV reverse remodeling after CRT and whether this is associated with improved survival.Methods: Patients were stratified into quintiles according to baseline LV end-diastolic volume indexed for body surface area (LVEDVi). LV reverse remodeling was defined as ≥15% reduction in LV end-systolic volume at 6-month follow-up after CRT. Independent associates of LV remodeling were assessed and long-term mortality rates were compared between patients with and without LV reverse remodeling (across LVEDVi quintiles).Results: A total of 864 patients were included (mean age 66 ± 10 years; 657 patients (76%) were male), of whom 101 (12%) were in quintile 1 (2), 272 (32%) in quintile 2 (65-95 mL/m2), 247 (29%) in quintile 3 (95-125 mL/m2), 151 (18%) in quintile 4 (125-155 mL/m2), and 93 (11%) in quintile 5 (>155 mL/m2). Patients with larger baseline LVEDVi had worse survival after CRT (log-rank, P = .019). The cumulative 10-year survival was significantly better in patients with vs without LV reverse remodeling (48.7% vs 33.9%; P Conclusion: Many patients with larger baseline LV volumes still show significant LV reverse remodeling after CRT and had superior survival (regardless of baseline LV volumes) than did patients without LV reverse remodeling. Therefore, CRT should not be denied on the basis of severe LV dilatation.</p