[Transcatheter aortic-valve implantation for aortic stenosis. An established procedure?]

Western countries are facing a huge increase of hemodynamically relevant cases of aortic stenosis in an aging population. In the past, about 33% of patients with symptomatic aortic stenosis were not referred for aortic valve replacement although the three years survival rate is only 25 percent after conservative treatment. In Germany transcatheter aortic-valve implantations (TAVI) procedures are reimbursed according to a DRG number. Its usage its not only regulated in a position paper of the German Society of Cardiology giving detailed recommendations for its application and indication. In Germany, approximately 4.000 TAVI procedures were performed in 2009 and even more are expected in 2010. According to the frequency of its usage, DRG reimbursement, and position papers, TAVI procedures seem to be established. However, according to health regulations a new treatment modality is only established if its safety and efficiency is proven, if there is a demand, and if the procedure has economic advantages. According to this definition TAVI is not established since its safety and efficiency compared to the surgical treatment was not been proven in randomised trials yet. Its economic burden in this context is unclear, too. However, there is a need for an alternative to surgical aortic valve replacement to increase the acceptance of valve implantation in an aging population.

Extra cellular matrix remodelling after heterotopic rat heart transplantation: gene expression profiling and involvement of ED-A+ fibronectin, alpha-smooth muscle actin and B+ tenascin-C in chronic cardiac allograft rejection

Chronic cardiac rejection is represented by cardiac allograft vasculopathy (CAV) and cardiac interstitial fibrosis (CIF) known to cause severe complications. These processes are accompanied by remarkable changes in the cardiac extra cellular matrix (cECM). The aim of our study was to analyse the cECM remodelling in chronic rejection and to elucidate a potential role of ED-A domain containing fibronectin (ED-A(+) Fn), alpha smooth muscle actin (ASMA) and B domain containing tenascin-C (B(+) Tn-C). A model of chronic rejection after heterotopic rat heart transplantation was used. Allografts, recipient and control hearts were subjected to histological assessment of rejection grade, to real-time PCR based analysis of 84 genes of ECM and adhesion molecules and to immunofluorescence labelling procedures, including ED-A(+) Fn, ASMA and B(+) Tn-C antibodies. Histological analysis revealed different grades of chronic rejection. By gene expression analysis, a relevant up-regulation of the majority of ECM genes in association with chronic rejection could be shown. For 8 genes, there was a relevant up-regulation in allografts as well as in the corresponding recipient hearts. Association of ASMA positive cells with the grade of chronic rejection could be proven. In CAV and also in CIF there were extensive co-depositions of ED-A(+) Fn, ASMA and B(+) Tn-C. In conclusion, chronic cardiac allograft rejection is associated with a cECM remodelling. ASMA protein deposition in CAV, and CIF is a valuable marker to detect chronic rejection. Interactions of VSMCs and Fibro-/Myofibroblasts with ED-A(+) Fn and B(+) Tn-C might functionally contribute to the development of chronic cardiac rejection.

Induced expression of lectin-like oxidized ldl receptor-1 in vascular smooth muscle cells following Chlamydia pneumoniae infection and its down-regulation by fluvastatin

Microorganisms such as Chlamydia pneumoniae have been shown to infect vascular cells and are believed to contribute to vascular inflammation and atherosclerotic plaque development. Plasma levels of oxidized low density lipoprotein (oxLDL) have received considerable attention as potential predictors of prognosis in atherosclerotic diseases. Lectin-like oxidized LDL receptor-1 (LOX-1) is one of the major receptors for oxidized LDL. It was investigated whether C. pneumoniae infection can stimulate expression of LOX-1 in vascular smooth muscle cells. Expression of LOX-1 in VSMC was measured by RT-PCR and immunoblotting following C. pneumoniae infection. To examine the pharmacological effect of a HMG-CoA reductase inhibitor on LOX-1 expression, cells were co-incubated with fluvastatin immediately after infection. A dose and time dependent expression of LOX-1mRNA and protein was found in C. pneumoniae infected SMC. After heat and UV light treatment of the chlamydial inoculum the level of LOX-1 was reduced to that of mock-infected cultures. Furthermore, treatment of infected cells with fluvastatin decreased LOX-1 expression to baseline levels. The up-regulation of LOX-1 induced by C. pneumoniae could lead to continued lipid accumulation in atherosclerotic lesions. Together with the widespread expression of LOX-1, this might contribute to the epidemiologic link between C. pneumoniae infection and atherosclerosis. The effect of lowering the LOX-1 expression by fluvastatin may provide a pharmacological option of limiting oxLDL uptake via its scavenger receptor.

The Occlutech Figulla PFO and ASD occluder: a new nitinol wire mesh device for closure of atrial septal defects

BACKGROUND

We investigated the safety, feasibility and efficacy of the Occlutech devices for patent foramen ovale (PFO) and atrial septal defect (ASD) closure in a prospective trial.

METHODS

The retention discs of the PFO device (23 x 25 mm, 27 x 30 mm) are connected by a 3 mm waist in the center with only one right atrial side central pin. The left atrial disc is produced either with a single or double flat layer, which allows a significant reduction of meshwork material. The ASD occluder (6-40 mm, 3 mm increments) has only one central pin on the right atrial side. Indications for closure included cryptogenic stroke with evidence of a PFO on transesophageal echocardiography (TEE) or an ASD II. The devices were implanted in 29 patients with PFO and in 12 patients with ASD II (fluoroscopy and TEE). An echocardiographic follow-up examination was performed after 1, 2 and 6 months.

RESULTS

The devices were successfully implanted in all 41 patients. There were no periprocedural complications. One patient with ASD II died of recurrent myocardial infarction without evidence of cardioembolic origin. TEE studies showed a residual shunt in 11.2% after 60 days in patients with PFO and a left-to-right shunt in 9.1% of the remaining patients with ASD II. After 180 days only 1 patient with PFO had a right-to-left shunt (3.7%). A residual shunt in the patients with ASD was not observed.

CONCLUSIONS

The novel Occlutech devices appear to be safe, feasible and effective for PFO and ASD closure, with a significant reduction of the meshwork and absence of left atrial central pin.

Serum levels of large tenascin-C variants, matrix metalloproteinase-9, and tissue inhibitors of matrix metalloproteinases in concentric versus eccentric left ventricular hypertrophy

AIMS

Chronic hypertension may cause left ventricular hypertrophy (LVH). The role of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), and tenascin-C (Tn-C) splice variants in concentric vs. eccentric left ventricular remodelling has not been investigated.

METHODS AND RESULTS

Serum levels of B or C domain containing Tn-C, MMP-9, TIMP-1, -2, and -4 were determined in concentric (left ventricular posterior wall thickness >13 mm and intraventricular septum >13 mm, n = 61) and eccentric (end-diastolic left ventricular diameter >55 mm or end-systolic left ventricular diameter >40 mm, n = 34) LVH by enzyme-linked immunoassays. Levels of B domain containing Tn-C were higher in patients with LVH than in normal volunteers (P = 0.020) and higher in eccentric LVH (EH) compared with concentric LVH (CH) (P = 0.003). A cut-off value of 900 ng/mL might discriminate between these different forms of LVH. Matrix metalloproteinase-9 was higher in patients with LVH than in normal volunteers (P = 0.042), and levels were decreased in EH compared with CH (P = 0.028). Patients with LVH had higher levels of TIMP-1 (P = 0.059), TIMP-2 (P = 0.043), and TIMP-4 (P = 0.163) than normal volunteers, but there were no differences between the LVH groups.

CONCLUSION

Our data suggest that myocardial remodelling in LVH is associated with changes in serum levels of MMP-9, TIMP-1, -2, -4, and Tn-C splice variants. In addition, B domain containing Tn-C discriminated EH from CH and might be suggested as a potential diagnostic marker.

Transvenous closure of patent foramen ovale: preliminary results with a new self-expanding nitinol wire mesh in a Swine model

Objectives. The transvascular closure of patent foramen ovale (PFO) with self-expanding devices carries the risk of left atrial thrombus formation related to material protruding into the left atrium. Thus, we developed a novel device with flat left atrial disc geometry. We evaluated feasibility, handling, and biocompatibility in a porcine animal model. Methods. Implantation of an Occlutech Figulla PFO device was performed in 10 mini pigs using fluoroscopy and intra-cardiac ultrasound after transseptal puncture of the interatrial septum. Angiographic follow-up was performed after six and twelve weeks. Results. Implantation was successful in 100%. There were no further implant related complications. One procedure related death occurred, as one animal died of ventricular tachycardia due to mispunture of the interatrial septum. Angiographic studies showed no residual shunt during follow-up. Histopathological evaluation could demonstrate partial neoendothelialization after 6 weeks with completion after 12 weeks. The devices were incorporated into connective tissue containing fibro muscular cells. An only mild inflammatory reaction was detected locally related to the polyester fibers. Conclusion. In terms of feasibility and handling, the new device does not seem to be inferior to other presently used implantation systems. Good biocompatibility was demonstrated with rapid and complete neoendothelialization.

Differential number of CD34+, CD133+ and CD34+/CD133+ cells in peripheral blood of patients with congestive heart failure

BACKGROUND

Endothelial progenitor cells (EPC) which are characterised by the simulateous expression of CD34, CD133 and vascular endothelial growth receptor 2 (VEGF 2) are involved in the pathophysiology of congestive heart failure (CHF) and their number and function is reduced in CHF. But so far our knowledge about the number of circulating hematopoietic stem/ progenitor cells (CPC) expressing the early hematopoietic marker CD133 and CD34 in CHF is spares and therefore we determined their number and correlated them with New York Heart Association (NYHA) functional class.

METHODS

CD34 and CD133 surface expression was quantified by flow cytometry in the peripheral venous blood of 41 healthy adults and 101 patients with various degrees of CHF.

RESULTS

CD34+, CD133+ and CD34+/CD133+ cells correlated inversely with age. Both the number of CD34+ and of CD34+/CD133+ cells inversely correlated with NYHA functional class. The number of CD133+ cells was not affected by NYHA class. Furthermore the number of CD133+ cells did not differ between control and CHF patients.

CONCLUSION

In CHF the release of CD34+, CD133+ and CD34+/CD133+ cells from the bone marrow seems to be regulated differently. Modulating the releasing process in CHF may be a tool in CHF treatment.

[Therapy of cardiogenic shock after myocardial infarction]

The therapy of infarct related cardiogenic shock should primarily focus on fastest possible revascularization. In addition, rapid restoration of sufficient organ perfusion pressure is recommended for the prevention of a multi-organ dysfunction syndrome (MODS). This can be achieved by mechanical circulatory assist devices as well as individual catecholamine therapy. Since assist devices require specially trained physicians, their use is limited to specialized cardiac care centers. However, future technologies such as portable heart-lung-machines may help to further improve transfer to specialized centers and therapy of shock patients.

[AV Shunt: a rare cause of cardiac decompensation]

HISTORY AND PHYSICAL EXAMINATION

A 66-year-old man presented with signs of heart failure for the first time. Apart from a history of arterial hypertension for several years, no relevant disease was known so far. The initial physical examination revealed symptoms of right heart failure and an elevated systolic blood pressure.

INVESTIGATIONS

X-ray of the chest showed an enlarged heart shadow and no definite signs of pulmonary congestion. Echocardiography revealed a dilated left ventricle (left ventricular end-diastolic diameter 59 mm) with moderately reduced contractility (ejection fraction 35%). Laboratory parameters were normal. An invasive investigation of the reduced contractility was prepared.

DIAGNOSIS, THERAPY, AND COURSE

While measuring blood pressure, a murmur and a little scar in the left elbow flexure were discovered. The suspicion of a traumatic arteriovenous fistula after a mirror glass injury 8 years ago was confirmed by sono- and angiography. The shunt volume was calculated by oxymetry as 6.2 l/min. The fistula was surgically dissected and ligated. At follow-up 1 year later, the patient reported no complaints and showed good exercise capacity. Echocardiography revealed normal parameters.

CONCLUSION

This case demonstrates the reversibility of high-output heart failure after treatment of the underlying cause. It stresses the importance of careful interrogation and examination of the patient. Apparently obvious causal connections must be thoroughly worked up and critically questionned.

Spontaneous heart rate turbulence in patients with dilated cardiomyopathy

Parameters of heart rate turbulence (HRT) and blood pressure turbulence (BPT) reflect the baroreflex mediated transient acceleration-deceleration response of the sinus node triggered by a premature ventricular complex (PVC) and are known to be useful risk markers in different cardiac diseases. However, the analyses of HRT and BPT are based on the prevalence of PVC. In this study the spontaneous HRT and BPT after most premature normal beats (MPNB) was investigated in comparison to HRT and BPT after PVC. ECG and blood pressure were recorded from 91 patients with dilated cardiomyopathy (DCM) and 45 healthy subjects (REF). In 69% of DCM and 33% of REF data sets PVCs were present. HRT and BPT were determined for all patients with PVC as well as in all patients triggered by MPNB. Univariate statistical analysis of the comparison between DCM and REF revealed similar results for HRT/BPT after PVC and MPNB. In conclusion, HRT and BPT triggered by PVC might be substituted by spontaneous HRT and BPT after MPNB. In contrast to the HRT and BPT after PVC, an increased number of data sets can be included in the analysis and may lead to an enhancement in risk stratification in different cardiac diseases.

Toxic myocarditis due to oral ingestion of hydrofluoric acid

We report the case of a 32-year-old man, admitted to cardiac care unit with congestive heart failure, caused by a reduced global cardiac function four months after oral hydrofluoric acid ingestion while attempting suicide. Biopsy results of left ventricular myocardium confirmed toxic myocarditis due to ingestion of hydrofluoric acid. This case represents an uncommon example of toxic myocarditis as a long-term complication of oral hydrofluoric acid ingestion. We recommend cardiological follow-up consultations in patients with hydrofluoric acid intoxication for early detection of cardiac deterioration.

Impact on adenosine stress cardiac magnetic resonance for recanalisation and follow up of chronic total coronary occlusions

OBJECTIVE

To evaluate the impact on cardiac magnetic resonance imaging (CMRI) with adenosine stress and delayed enhancement for indication and follow up after interventional recanalisation of chronic total coronary occlusions (CTOs).

MATERIAL AND METHODS

Twenty consecutive patients (15 males; 5 females; mean age 65 years) with CTO verified by cardiac catheterisation referred to CMRI. Sixteen of them got CMRI before and after coronary recanalisation. Wall motion abnormalities (WMAs), first pass perfusion with adenosine and viability were assessed using a 1.5 T MR scanner (Sonata; Siemens). CMRI results were compared with clinical classifications, the results of cardiac catheterisation and follow up angiography.

RESULTS

Sixteen patients had a successful recanalisation, 15 of the occluded coronary artery and one of collateral donor artery stenosis. After recanalisation all stress-induced progressive or new wall motion abnormalities (WMAs) of the corresponding segments and in the collateral donor territory (5 patients) and all adenosine induced perfusion defects (PD) or delay (12 patients) were regredient. 13/16 patients showed no transmural and one patient transmural delayed enhancement (DE) indicating myocardial scar. In 10/16 patients CSS grading of angina improved after recanalisation.

CONCLUSION

After successful recanalisation of CTOs, patients with preinterventional stress-induced PDs and WMAs in viable myocardium did not display any signs of stress-induced ischemia postinterventionally. A comprehensive CMRI approach, including assessment of rest and stress WMAs, first pass perfusion and myocardial viability represents an important tool for the pre-interventional decision to recanalise CTOs and follow up.

Apoptosis in patients with dilated cardiomyopathy and diabetes: a feature of diabetic cardiomyopathy?

BACKGROUND

Dilated cardiomyopathy (DCM) has been suggested to be a consequence of a prior viral infection leading to a chronic inflammatory and immunological reaction that leads to a structural and functional deterioration of the heart. Nevertheless, the results of present studies are conflicting, regarding the natural course of heart diseases associated with detection of viral genome and inflammation. On the other hand, diabetes mellitus (DM) is the leading endocrine disorder worldwide and sufficient to induce a cardiomyopathy. It is not known whether DM contributes to the clinical picture of cardiomyopathy associated with the presence of viral genome or inflammatory cells in the myocardium. Therefore, the present study was undertaken to compare histological, immunohistochemical, biochemical, and functional data as well as the outcome of patients presenting with DCM and positive for DM with patients negative for DM to evaluate for a diabetic contribution in the course of the disease.

METHODS

A total of 216 patients were biopsied between January 1998 and April 2003. From 197 patients diagnosed as having DCM, we were able to complete data set regarding the presence of DM in 108 patients, 20 patients with and 88 patients without DM.

RESULTS

There was no significant difference regarding age, gender, body mass index, presence of viral genome and inflammatory cells in the myocardium, left ventricular function and diameter, and the degree of heart insufficiency. There was a significant difference of apoptotic cells in the myocardium of patients with DCM and DM compared to patients with DCM alone (1.7+/-1.9 vs. 0.2+/-0.4, p=0.028). During the follow-up of 16 months, left ventricular function improved in both groups significantly, but not between the groups. Death or transplantation-free survival was not significantly different.

CONCLUSION

The different findings regarding the presence of apoptotic cells suggest a contribution of pathobiological pathways in the patients with DM to the underlying heart disease.

Stress testing in coronary artery disease by Magnetic Field Imaging: a 3D current distribution model

OBJECTIVE

Magnetic field imaging (MFI) combines depolarization and repolarization registration of the cardiac electromagnetic field with a 3D current distribution model. An interesting application for MFI is the possibility to detect myocardial ischemia under stress.

METHODS

Using a new reconstruction technique, it is possible to generate a pseudo-current distribution on the epicardial surface: the comparison of the time evolution of such current distributions at rest and under stress shows difference in coronary artery disease (CAD). The model works with a realistic epicardial surface generate on the basis of computerised tomography or magnetic resonance tomography data or with a standardized ellipsoidal model. To take into account the vectorial character of the epicardial current distribution, the current flow in the epicardial surface element is represented in the graphic display by a cone. Thus indicating the direction of current flow the height of the cone represents the current intensity.

RESULTS

As an example of the method, data of pharmacological stress MFI on a CAD patient will be presented. The newly developed algorithm operates in different segments of the electromagnetic heart beat. The indicated myocardial area strongly correlated to invasive coronary angiography results. In such a situation the advantage provided by the "friendly" ellipsoidal surface on the numerical solution of the inverse problem seems to overcome the advantage of a realistic heart model.

CONCLUSION

We conclude MFI is a promising procedure for a non-invasive stress testing as well as screening method as for localization of myocardial ischemia.

Comparison of nonlinear methods symbolic dynamics, detrended fluctuation, and Poincare plot analysis in risk stratification in patients with dilated cardiomyopathy

Dilated cardiomyopathy (DCM) has an incidence of about 20100 000 new cases per annum and accounts for nearly 10 000 deaths per year in the United States. Approximately 36% of patients with dilated cardiomyopathy (DCM) suffer from cardiac death within five years after diagnosis. Currently applied methods for an early risk prediction in DCM patients are rather insufficient. The objective of this study was to investigate the suitability of short-term nonlinear methods symbolic dynamics (STSD), detrended fluctuation (DFA), and Poincare plot analysis (PPA) for risk stratification in these patients. From 91 DCM patients and 30 healthy subjects (REF), heart rate and blood pressure variability (HRV, BPV), STSD, DFA, and PPA were analyzed. Measures from BPV analysis, DFA, and PPA revealed highly significant differences (p<0.0011) discriminating REF and DCM. For risk stratification in DCM patients, four parameters from BPV analysis, STSD, and PPA revealed significant differences between low and high risk (maximum sensitivity: 90%, specificity: 90%). These results suggest that STSD and PPA are useful nonlinear methods for enhanced risk stratification in DCM patients.

Treatment with granulocyte-colony stimulating factor in patients with acute myocardial infarction. Evidence for a stimulation of neovascularization and improvement of myocardial perfusion

BACKGROUND

Stem cell therapy has been suggested to be beneficial in patients after acute myocardial infarction (AMI). Strategies of treatment are either a local application of mononuclear bone marrow cells (BMCs) into the infarct-related artery or a systemic therapy with the granulocyte-stimulating factor (G-CSF) to mobilize BMCs. Nevertheless, the mechanisms responsible for improvement of cardiac function and perfusion are speculative at present. This study has been performed to investigate the effect of G-CSF on systemic levels of vascular growth factors and chemokines responsible for neovascularization, that might help to understand the positive effects of a G-CSF therapy after AMI.

METHODS AND RESULTS

Five patients in the treatment group and 5 patients in the control group were enrolled in this study. The patients in the treatment group received 10 microg/kg bodyweight/day of G-CSF subcutaneously for a mean treatment duration of 6.6 +/- 1.1 days. In both groups, levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and monocyte chemotactic protein-1 (MCP-1) were measured on day 2 to 3 and day 5 after AMI. The regional wall perfusion and the ejection fraction (EF) were evaluated before discharge and after 3 months with ECG-gated MIBI-SPECT and radionuclide ventriculography, respectively. Significant higher levels of VEGF (p < 0.01), bFGF (p < 0.05) and MCP-1 (p < 0.05) were found in the treatment group compared to the control group. Levels of VEGF and bFGF remained on a plateau during the G-CSF treatment and decreased significantly in the control group. The wall perfusion improved significantly within the treatment group and between the groups (p < 0.05), respectively. The EF improved significantly within the treatment group (p < 0.05), but the change of the EF between the groups was not significant.

CONCLUSION

In patients with AMI, the treatment with G-CSF modulates the formation of vascular growth factors that might improve neovascularization and result in an improved myocardial perfusion and function.

Chemotactic activity of serum obtained from patients with idiopathic dilated cardiomyopathy

Elevated circulating levels of alpha- and beta-chemokines in heart failure have been reported. The objective of this study was to investigate the interrelation of chemotactic activity of serum and circulating chemokine levels in patients suffering from idiopathic dilated cardiomyopathy (IDCM). Chemokine serum levels (MCP-1, MIP1-alpha, RANTES, IL-8 and TNF-alpha) were determined in patients with IDCM (n = 10), patients with coronary artery disease with normal (CAD-1; n = 10) or depressed (CAD-2; n = 10) left ventricular function and healthy controls (n = 10). The chemotactic effect of sera obtained from these groups was measured using an in vitro chemotaxis assay. Sera obtained from IDCM (5475 +/- 681 cells) showed the highest chemotactic activity when compared to controls (1850 +/- 215 cells), CAD-1 (3325 +/- 275 cells) and CAD-2 (2800 +/- 275 cells, P < 0.05) associated with significantly higher circulating MCP-1 levels. Sera obtained from IDCM patients show a high chemotactic activity associated with significantly elevated circulating MCP-1.

Expression of androgen-binding protein (ABP) in human cardiac myocytes

Cardiomyocytes are known to be androgen targets. Changing systemic steroid levels are thought to be linked to various cardiac ailments, including dilated cardiomyopathy (DCM). The mode of action of gonadal steroid hormones on the human heart is unknown to date. In the present study, we used high-resolution immunocytochemistry on semithin sections (1 microm thick), IN SITU hybridization, and mass spectrometry to investigate the expression of androgen-binding protein (ABP) in human myocardial biopsies taken from male patients with DCM. We observed distinct cytoplasmic ABP immunoreactivity in a fraction of the myocytes. IN SITU hybridization with synthetic oligonucleotide probes revealed specific hybridization signals in these cells. A portion of the ABP-positive cells contained immunostaining for androgen receptor. With SELDI TOF mass spectrometry of affinity purified tissue extracts of human myocardium, we confirmed the presence of a 50 kDa protein similar to ABP. Our observations provide evidence of an intrinsic expression of ABP in human heart. ABP may be secreted from myocytes in a paracrine manner perhaps to influence the bioavailabity of gonadal steroids in myocardium.