Beat A. Kaufmann

Predictors for efficacy of percutaneous mitral valve repair using the MitraClip system: the results of the MitraSwiss registry

Background Percutaneous mitral valve repair (MVR) using the MitraClip system has become a valid alternative for patients with severe mitral regurgitation (MR) and high operative risk. Objective To identify clinical and periprocedural factors that may have an impact on clinical outcome. Design Multi-centre longitudinal cohort study. Setting Tertiary referral centres. Patients Here we report on the first 100 consecutive patients treated with percutaneous MVR in Switzerland between March 2009 and April 2011. All of them had moderate–severe (3+) or severe (4+) MR, and 62% had functional MR. 82% of the patients were in New York Heart Association (NYHA) class III/IV, mean left ventricular ejection fraction was 48% and the median European System for Cardiac Operative Risk Evaluation was 16.9%. Interventions MitraClip implantation performed under echocardiographic and fluoroscopic guidance in general anaesthesia. Main outcome measures Clinical, echocardiographic and procedural data were prospectively collected. Results Acute procedural success (APS, defined as successful clip implantation with residual MR grade ≤2+) was achieved in 85% of patients. Overall survival at 6 and 12u2005months was 89.9% (95% CI 81.8 to 94.6) and 84.6% (95% CI 74.7 to 91.0), respectively. Univariate Cox regression analysis identified APS (p=0.0069) and discharge MR grade (p=0.03) as significant predictors of survival. Conclusions In our consecutive cohort of patients, APS was achieved in 85%. APS and residual discharge MR grade are important predictors of mid-term survival after percutaneous MVR.

Molecular Imaging of Inflammation and Platelet Adhesion in Advanced Atherosclerosis Effects of Antioxidant Therapy With NADPH Oxidase Inhibition

Background—In atherosclerosis, local generation of reactive oxygen species amplifies the inflammatory response and contributes to plaque vulnerability. We used molecular imaging to test whether inhibition of NADPH oxidase with apocynin would reduce endothelial inflammatory activation and endothelial–platelet interactions, thereby interrupting progression to high-risk plaque phenotype. Methods and Results—Mice deficient for both the low-density lipoprotein receptor and Apobec-1 were studied at 30 weeks of age and again after 10 weeks with or without apocynin treatment (10 or 50 mg/kg per day orally). In vivo molecular imaging of vascular cell adhesion molecule-1 (VCAM 1) P-selectin, and platelet glycoprotein-1b&agr; (GPIb&agr;) in the thoracic aorta was performed with targeted contrast-enhanced ultrasound molecular imaging. Arterial elastic modulus and pulse wave transit time were assessed using ultrahigh frequency ultrasound and invasive hemodynamic measurements. Plaque size and composition were assessed by histology. Molecular imaging in nontreated mice detected a 2-fold increase in P-selectin expression, VCAM-1 expression, and platelet adhesion between 30 and 40 weeks of age. Apocynin reduced all of these endothelial events in a dose-dependent fashion (25% and 50% reduction in signal at 40 weeks for low- and high-dose apocynin). Apocynin also decreased aortic elastic modulus and increased the pulse transit time. On histology, apocynin reduced total monocyte accumulation in a dose-dependent manner as well as platelet adhesion, although total plaque area was reduced in only the high-dose apocynin treatment group. Conclusions—Inhibition of NADPH oxidase in advanced atherosclerosis reduces endothelial activation and platelet adhesion, which are likely responsible for the arrest of plaque growth and improvement of vascular mechanical properties.

Ultrasound molecular imaging of atherosclerosis

Recent advances in our understanding of the pathophysiological mechanisms of atherosclerosis have created the need for better non-invasive imaging of vascular phenotype. Ultrasound is widely available, inexpensive, and well suited for high-throughput screening in populations that are at risk for atherosclerosis. Novel ultrasonic approaches for the diagnosis of vascular changes in atherosclerosis include (1) assessment of plaque composition by evaluation of the backscattering properties of tissue, (2) assessment of the changes in arterial wall biomechanics, (3) assessment of plaque neovascularization, and (4) molecular imaging of vascular phenotype changes on a subcellular level. It is thought that such new imaging methodologies will lead to earlier detection of atherosclerosis, and better assessment of the risk for aggressive disease progression. Novel therapies for atherosclerosis will undoubtedly become available within the next decades, and non-invasive imaging techniques will be needed for cost-efficient application of existing and new drugs.

Functional assessment of the left atrium by real-time three-dimensional echocardiography using a novel dedicated analysis tool: initial validation studies in comparison with computed tomography

AIMSnA novel real-time three-dimensional echocardiography (RT3DE) analysis tool specifically designed for evaluation of the left atrium enables comprehensive evaluation of left atrial (LA) size, global, and regional function using a dynamic 16-segment model. The aim of this study was the initial validation of this method using computed tomography (CT) as the method of reference.nnnMETHODS AND RESULTSnThe study population consisted of 34 prospectively enrolled patients with clinical indication for pulmonary vein isolation. A dynamic polyhedron model of the left atrium was generated using RT3DE. LA maximum and minimum volumes (LA(max)/LA(min)) and emptying fraction (LAEF) were determined and compared with the results obtained by CT. High correlations between RT3DE and CT were found for LA(max) (r = 0.92, P < 0.001), LA(min) (r = 0.95, P < 0.001), and LAEF (r = 0.82, P < 0.001). LA(max) and LA(min) were lower by RT3DE than by CT (95.0 ± 44.7 vs. 119.8 ± 50.5 mL, P < 0.001 and 58.1 ± 41.3 vs. 83.3 ± 52.6 mL, P < 0.001, respectively), whereas LAEF was measured higher by RT3DE (42.8 ± 15.2 vs. 34.2 ± 15.4%, P < 0.001, respectively). RT3DE measurements closely correlated in terms of intra-observer (intra-class correlation r = 0.99, r = 0.99, r = 0.96, respectively) and inter-observer variability (r = 0.97, r = 0.98, r = 0.88, respectively).nnnCONCLUSIONSnLA volumes and EF as assessed by RT3DE correlate highly with CT measurements, albeit there is some bias between the imaging modalities. Most importantly, RT3DE measurements using the novel dedicated LA analysis tool are robust in terms of observer variability and thus suitable for follow-up analyses.

Noninvasive Ultrasound Molecular Imaging of the Effect of Statins on Endothelial Inflammatory Phenotype in Early Atherosclerosis

Background/Objectives Inflammatory changes on the endothelium are responsible for leukocyte recruitment to plaques in atherosclerosis. Noninvasive assessment of treatment-effects on endothelial inflammation may be of use for managing medical therapy and developing novel therapies. We hypothesized that molecular imaging of vascular cell adhesion molecule-1 (VCAM-1) with contrast enhanced ultrasound (CEU) could assess treatment effects on endothelial phenotype in early atherosclerosis. Methods Mice with atherosclerosis produced by gene deletion of the LDL-receptor and Apobec-1-editing protein were studied. At 12 weeks of age, mice received 8 weeks of regular chow or atorvastatin-enriched chow (10 mg/kg/day). At 20 weeks, CEU molecular imaging for aortic endothelial VCAM-1 expression was performed with VCAM-1-targeted (MBVCAM) and control microbubbles (MBCtr). Aortic wall thickness was assessed with high frequency ultrasound. Histology, immunohistology and Western blot were used to assess plaque burden and VCAM-1 expression. Results Plaque burden was reduced on histology, and VCAM-1 was reduced on Western blot by atorvastatin, which corresponded to less endothelial expression of VCAM-1 on immunohistology. High frequency ultrasound did not detect differences in aortic wall thickness between groups. In contrast, CEU molecular imaging demonstrated selective signal enhancement for MBVCAM in non-treated animals (MBVCAM 2±0.3 vs MBCtr 0.7±0.2, p<0.01), but not in statin-treated animals (MBVCAM 0.8±0.2 vs MBCtr 1.0±0.2, pu200a=u200ans; p<0.01 for the effect of statin on MBVCAM signal). Conclusions Non-invasive CEU molecular imaging detects the effects of anti-inflammatory treatment on endothelial inflammation in early atherosclerosis. This easily accessible, low-cost technique may be useful in assessing treatment effects in preclinical research and in patients.

Molecular Imaging Reveals Rapid Reduction of Endothelial Activation in Early Atherosclerosis With Apocynin Independent of Antioxidative Properties

Objective—Antioxidative drugs continue to be developed for the treatment of atherosclerosis. Apocynin is an nicotinamide adenine dinucleotide phosphate oxidase inhibitor with anti-inflammatory properties. We used contrast-enhanced ultrasound molecular imaging to assess whether short-term apocynin therapy in atherosclerosis reduces vascular oxidative stress and endothelial activation Approach and Results—Genetically modified mice with early atherosclerosis were studied at baseline and after 7 days of therapy with apocynin (4 mg/kg per day IP) or saline. Contrast-enhanced ultrasound molecular imaging of the aorta was performed with microbubbles targeted to vascular cell adhesion molecule 1 (VCAM-1; MBV), to platelet glycoprotein Ib&agr; (MBPl), and control microbubbles (MBCtr). Aortic vascular cell adhesion molecule 1 was measured using Western blot. Aortic reactive oxygen species generation was measured using a lucigenin assay. Hydroethidine oxidation was used to assess aortic superoxide generation. Baseline signal for MBV (1.3±0.3 AU) and MBPl (1.5±0.5 AU) was higher than for MBCtr (0.5±0.2 AU; P<0.01). In saline-treated animals, signal did not significantly change for any microbubble agent, whereas short-term apocynin significantly (P<0.05) reduced vascular cell adhesion molecule 1 and platelet signal (MBV: 0.3±0.1; MBPl: 0.4±0.1; MBCtr: 0.3±0.2 AU; P=0.6 between agents). Apocynin reduced aortic vascular cell adhesion molecule 1 expression by 50% (P<0.05). However, apocynin therapy did not reduce reactive oxygen species content, superoxide generation, or macrophage content. Conclusions—Short-term treatment with apocynin in atherosclerosis reduces endothelial cell adhesion molecule expression. This change in endothelial phenotype can be detected by molecular imaging before any measurable decrease in macrophage content and is not associated with a detectable change in oxidative burden.

Cardiovascular Management of Cancer Patients With Chemotherapy-Associated Left Ventricular Systolic Dysfunction in Real-World Clinical Practice

BACKGROUNDnChemotherapy-induced left ventricular systolic dysfunction (LVSD) may limit survival in cancer patients and therefore should be treated timely with appropriate heart failure medication. This study aimed to evaluate quality of cardiac care in cancer patients with documented chemotherapy-induced LVSD in real-world clinical practice.nnnMETHODSnUsing an institutional echo database, we screened 1,520 cancer patients for first documentation of chemotherapy-associated LVSD, defined as left ventricular ejection fraction (LVEF) ≤45%. Hospital charts of all 63 patients meeting inclusion criteria were reviewed regarding patient characteristics and frequency of heart failure medication prescription.nnnRESULTSnPatients were 61 (interquartile range [IQR], 50-70) years old, mostly symptomatic, and had an average LVEF of 34 ± 8%. Most patients received anthracyclines (73%) and/or alkylating agents (73%) as part of their chemotherapeutic regimen. Median time from cancer diagnosis to first documentation of LVSD was 2.2 (0.7-5.2) years. Fewer than two-thirds of patients received guideline-recommended heart failure medication, and only one-half of patients received cardiology consult. Cardiology consultation was associated with a significantly higher frequency of heart failure medication prescription (100% vs. 52% for angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (P < .0001); 94% vs. 41% for beta-blocker (P < .0001) and better survival (71% vs. 41%; P < .05).nnnCONCLUSIONSnChemotherapy-associated LVSD is insufficiently treated in cancer patients. Cardiology consultation improves rates of heart failure medication and therefore should be advocated in all patients with chemotherapy-induced LVSD.

Velocity ratio predicts outcomes in patients with low gradient severe aortic stenosis and preserved EF

Objective To evaluate the usefulness of velocity ratio (VR) in patients with low gradient severe aortic stenosis (LGSAS) and preserved EF. Background LGSAS despite preserved EF represents a clinically challenging entity. Reliance on mean pressure gradient (MPG) may underestimate stenosis severity as has been reported in the context of paradoxical low flow, LGSAS. On the other hand, grading of stenosis severity by aortic valve area (AVA) may overrate stenosis severity due to erroneous underestimation of LV outflow tract (LVOT) diameter, small body size or inconsistencies in cut-off values for severe stenosis. We hypothesised that VR may have conceptual advantages over MPG and AVA, predict clinical outcomes and thereby be useful in the management of patients with LGSAS. Methods Patients from the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study with an AVA<1.0u2005cm2, MPG≤40u2005mmu2005Hg and EF≥55% and asymptomatic at baseline were stratified according to VR with a cut-off value of 0.25. Outcomes were evaluated according to aortic valve-related events and cardiovascular death. Results Of 435 patients with LGSAS, 197 (45%) had VR<0.25 suggesting severe and 238 (55%) had VR≥0.25 suggesting non-severe stenosis. Aortic valve-related events (mean follow-up 42±14u2005months) were more frequent in patients with VR<0.25 (57% vs 41%; p<0.001) as was cardiovascular death within the first 24u2005months (p<0.05). In multivariable Cox regression analysis, MPG was the strongest independent predictor of aortic valve events (p<0.001) followed by VR (p<0.02). Adjusting AVA by VR increased predictive accuracy for aortic valve events (area under the receiver operating curve 0.62 (95% CI 0.57 to 0.67) vs 0.56 (95% CI 0.51 to 0.61) for AVA, p=0.02) with net reclassification improvement calculated at 0.36 (95% CI 0.17 to 0.54, p<0.001). VR did not improve the prediction of clinical events by MPG. Conclusions In the difficult setting of LGSAS, VR shows a strong association with valve-related events and—although not outperforming MPG—may be particularly useful in guiding clinical management. Trial registration number NCT00092677.

Ultrasound Imaging for Risk Assessment in Atherosclerosis

Atherosclerosis and its consequences like acute myocardial infarction or stroke are highly prevalent in western countries, and the incidence of atherosclerosis is rapidly rising in developing countries. Atherosclerosis is a disease that progresses silently over several decades before it results in the aforementioned clinical consequences. Therefore, there is a clinical need for imaging methods to detect the early stages of atherosclerosis and to better risk stratify patients. In this review, we will discuss how ultrasound imaging can contribute to the detection and risk stratification of atherosclerosis by (a) detecting advanced and early plaques; (b) evaluating the biomechanical consequences of atherosclerosis in the vessel wall; (c) assessing plaque neovascularization and (d) imaging the expression of disease-relevant molecules using molecular imaging.

Closure of apical access site after transapical, transcatheter paravalvular leak closure

The safety of percutaneous transapical mitral paravalvular leak (PVL) closure could potentially be enhanced by device closure of the ventricular access site. Percutaneous transapical PVL closure was performed. The 9F delivery sheath was pulled back, and a 6-mm Amplatzer muscular ventricular septal defect occluder was deployed at the apical puncture site. Immediate hemostasis was achieved. Total hospitalization was 9 days. New York Heart Association functional class was improved, hemoglobin and haptoglobin rose, while lactate dehydrogenase fell. Follow-up fluoroscopy and transthoracic echocardiography revealed a good functional result. Closure of the apical access site by means of an Amplatzer muscular ventricular septal defect occluder is feasible.