In patients with aortic stenosis increased flow-mediated dilation is independently associated with higher peak jet velocity and lower asymmetric dimethylarginine levels

BACKGROUND

Recently, it has been shown that endothelial dysfunction and aortic stenosis (AS) share several risk factors. Endothelial function represents a crucial factor for the regulation of vascular tonus and its malfunction influences the formation of thrombosis and inflammation. However, the role of endothelial dysfunction in AS remains unclear.

METHODS

Echocardiographic, clinical, and laboratory data of 34 patients (age 74.5 ± 7.9 years, 20 men) with at least moderate AS (peak jet velocity 3.8 ± 0.8 m/s) were collected. In all patients, endothelial function was determined by brachial artery flow-mediated dilation (FMD). Patients with rheumatic or endocarditic valve disease, bicuspid valves, a left ventricular ejection fraction of ≤40%, and coronary artery disease were excluded. Sixteen volunteers (age 69.3 ± 9.4 years, 10 men) without valve disease served as controls.

RESULTS

Patients with AS had a trend toward a lower FMD than controls with a comparable risk profile (5.4% ± 3.6% vs 7.4% ± 4.1%, P = .1). Univariate correlates of FMD in patients with AS were peak jet velocity, medication with angiotensin-converting enzyme inhibitor, diabetes, diastolic blood pressure, and asymmetric dimethylarginine. Backward elimination identified peak jet velocity (β = 0.51, P = .001), and asymmetric dimethylarginine (β = -0.45, P = .003) as independent predictors of FMD in multivariate analysis.

CONCLUSIONS

In patients with AS, we found a strong positive relation between the peak jet velocity and a higher FMD. This effect might be mediated by nitric oxide release due to turbulent poststenotic blood flow or the rising transvalvular gradient, and the increasing pulse pressure may be counteracted by a parallel increase in FMD.

Autonomic regulation during mild therapeutic hypothermia in cardiopulmonary resuscitated patients

OBJECTIVE

We investigated whether there are differences in autonomic cardiovascular regulation in resuscitated patients undergoing therapeutic hypothermia (TH) in relation to the clinical outcome.

METHOD

Between 2005 and 2007, 18 consecutive resuscitated patients were enrolled. ECG and blood pressure data were recorded for 48 h during hypothermia and warming up to a body core temperature of 36°C. Autonomic regulation was assessed by applying time, frequency, and non-linear dynamics domain methods from heart rate and blood pressure variability (HRV/BPV) analyses.

RESULTS

Nine patients survived with good neurological recovery, and nine patients died during the ICU stay. In both groups, we found a decreased HRV presented by standard deviation of R-R intervals (sdNN) below 50 ms(2) at each time of measurement. Immediately after recovery to a body core temperature of 36°C, a significant higher HRV was found in survivors compared to non-survivors by means of indices sdNN (40.2 ± 19.5 vs. 10.9 ± 4.1 ms(2), P = 0.01), R-R intervals distribution histogram [shannon] (3.7 ± 0.6 vs. 2.2 ± 0.4, P = 0.008), very low frequency band [VLF] (152.2 ± 99.3 vs. 3.4 ± 1.9, P = 0.001) and the variance of the time series of R-R intervals [Wsdvar] (1.16 ± 0.52 vs. 0.29 ± 0.25, P = 0.02) . A decreased spontaneous BPV was found only among survivors comparing blood pressure characteristics within stable hypothermia to the initial state before hypothermia.

CONCLUSION

Resuscitated patients show a significantly reduced HRV before, during and after TH. Compared to survivors, the non-survivors show a further and significantly decrease of HRV immediately after hypothermia.

Transesophageal left ventricular electrogram-recording and temporary pacing to improve patient selection for cardiac resynchronization

Cardiac resynchronization therapy (CRT) with biventricular pacing (BV) is an established therapy for heart failure (HF) patients with inter- and intraventricular conduction delay. The aim of this pilot study was to test the feasibility of both transesophageal measurement of left ventricular (LV) electrical delay and transesophageal LV pacing prior to implantation, to better select patients for CRT. Esophageal TO8 Osypka catheter was perorally applied in 30 HF patients in position of maximum LV deflection to measure LV electrical delay and to study arterial pulse pressure (PP) during transesophageal bipolar LV pacing. There were 15 responders with a PP increase of a mean 65 ± 24 mmHg to 79 ± 27 mmHg (P < 0.001) and a mean LV electrical delay of 86.8 ± 33 ms. The 15 non-responders with poor PP increase of a mean 63.5 ± 23.5 mmHg to 64.1 ± 23.9 mmHg (P = 0.065) had a significantly smaller LV electrical delay of 36 ± 21 ms (P < 0.001). During a 34 ± 26 month CRT follow-up, the responders New York Heart Association (NYHA) class improved from 3.1 ± 0.35 to 2.1 ± 0.35 (P < 0.001). Determination of left ventricular electrical delay by transesophageal electrogram recording and transesophageal left ventricular pacing may be additional useful techniques to improve patient selection for CRT.

[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.

Better outcome after cardiopulmonary resuscitation using percutaneous emergency circulatory support in non-coronary patients compared to those with myocardial infarction

BACKGROUND & OBJECTIVES

Mobile heart-lung-machines applied by percutaneous cannulation are mostly used in patients suffering from acute myocardial infarction (AMI). Whether patients with non-coronary reasons for circulatory arrest benefit of percutaneous emergency circulatory support (PECS) in the same way is still unclear.

METHODS

We included 22 consecutive patients who were treated by PECS during a registry period of two years. Primary study endpoint was 30-day mortality rate.

RESULTS

Circulatory arrest was caused by AMI in 14 patients (64%). The remaining 8 patients suffered from cardiomyopathy/myocarditis, 4; pulmonary embolism, 2; acute pulmonary failure, 1; and tumor lysis syndrome, 1. Revascularization rate was 93% in the AMI group under PECS support. Overall survival rate was 36.4% at one month: it reached 62.5% among non-coronary patients, but only 21.4% in the AMI group (P = 0.02). Weaning was possible by direct heart transplantation in two patients. Additional two patients required implantation of a left ventricular assist device. Pumpless extracorporeal lung assist was used in one case.

CONCLUSION

In this small retrospective study percutaneous emergency circulatory support provided sufficient hemodynamic stabilization in emergency situations. One fifth of AMI patients were saved by immediate restoration of circulation and causal treatment when other means of resuscitation failed. Higher survival rates were noted in non-coronary patients.

Heterotopic transcatheter tricuspid valve implantation: first-in-man application of a novel approach to tricuspid regurgitation

AIMS

Transcatheter treatment of heart valve disease is well established today. However, for the treatment of tricuspid regurgitation (TR), no effective catheter-based approach is available. Herein, we report the first human case description of transcatheter treatment of severe TR in a 79-year-old patient with venous congestion and associated non-cardiac diseases. In this patient, surgical treatment had been declined and pharmacological therapy had been ineffective. After ex vivo and animal studies, the treatment of TR was performed by percutaneous caval valve implantation.

METHODS AND RESULTS

In a transcatheter approach through the right femoral vein, a custom-made self-expanding heart valve was implanted into the inferior vena cava (IVC). The device was anchored in the IVC at the cavoatrial junction with the level of the valve aligned immediately above the hepatic inflow and protruding into the right atrium. After deployment, excellent valve function was observed resulting in a marked reduction in caval pressure and an abolition of the ventricular wave in the IVC. Sequential echocardiographic exams over a follow-up period of 8 weeks confirmed continuous device function without paravalvular leakage or remaining venous regurgitation. The patient experienced improved physical capacity and was able to resume off-bed activities. There was no recurrence of right heart failure during follow-up and a partial reduction of ascites. The patient was discharged from hospital into a rehabilitation programme.

CONCLUSION

Transcatheter treatment of severe TR by caval valve implantation is feasible resulting in an immediate abolition of IVC regurgitation and mid-term clinical improvement. Thus, in selected non-surgical patients, caval valve implantation may become a therapeutic option to treat venous regurgitation and improve associated non-cardiac diseases. Further confirmatory experience with longer follow-up is required to evaluate the long-term clinical benefit of the procedure as well as potential deleterious effects.

Expression of extra domain A containing fibronectin in chronic cardiac allograft rejection

BACKGROUND

Cardiac allograft vasculopathy (CAV) and fibrosis are important in chronic cardiac allograft rejection. The aim of our study was to analyze the up-regulation of extra domain A (ED-A) containing fibronectin (ED-A(+) Fn) in cardiac allografts after heterotopic rat heart transplantation using a human recombinant antibody applicable for targeted drug delivery.

METHODS

Cardiac allografts were subjected to immunofluorescence double labelling procedures combining a human recombinant small immunoprotein (SIP) format antibody recognizing ED-A(+) Fn (F8) with antibodies recognizing CD31, ASMA or CD45. Protein expression levels of ED-A(+) Fn were measured by quantitative confocal laser scanning microscopy and messenger RNA expression levels by real-time reverse-transcription polymerase chain reaction.

RESULTS

A distinct re-expression of ED-A(+) Fn was detectable with the F8 antibody, especially in vessel structures exhibiting CAV and in fibrotic areas. ED-A(+) Fn protein deposition but not messenger RNA expression levels increased with rising rejection grade (p ≤ 0.001). There were clear co-localizations of ED-A(+) Fn and α-smooth muscle actin in vessels and in fibrotic areas.

CONCLUSIONS

We could show first that ED-A(+) Fn is expressed in rat cardiac allografts in association with CAV and cardiac fibrosis. The protein is detectable with the human recombinant antibody F8 usable for targeted drug delivery to the side of disease. Second, protein expression levels increase with rising rejection grade. Thus, ED-A(+) Fn might be usable to monitor and target CAV as well as fibrosis after heart transplantation.

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.

Effect of mechanical ventilation on microvascular perfusion in critical care patients

PURPOSE

Microvascular perfusion, pivotal for adequate tissue oxygenation is potentially linked to outcome in critical care therapy. Mechanical ventilation (MV) and positive end-expiratory pressure (PEEP) as standard concepts of respiratory management are known to have deleterious effects on regional organ perfusion especially in the splanchnic area. As these effects have been attributed to different physiologic mechanisms, the purpose of this study was to investigate the effect of positive pressure ventilation on extra-abdominal tissue perfusion in non-surgical intensive care patients.

METHODS

Sublingual microcirculation was evaluated in 46 severely ill patients (group 1: n=26 requiring MV and PEEP; group 2: n=20 spontaneous breathing) admitted to the intensive care unit using sidestream darkfield intravitalmicroscopy. According to current guidelines, sublingual vessels were categorized by means of size and flow in semi-quantitative categories determining microvascular flow index (MFI). Total microvascular flow index (TMFI) was calculated for each patient as mean value of flow in all vessel categories.

RESULTS

No significant difference was observed between both groups in microvascular flow index in each vessel category and in total microvascular flow index. Patients requiring mechanical ventilation presented with more comorbidities and higher acuity of illness scores resulting in a higher ICU mortality, which however was not accompanied by microcirculatory differences at the time of measurement.

CONCLUSION

Mechanical ventilation and PEEP have no general deleterious effects on microvascular perfusion of the sublingual mucosa. However, further clinical studies are required to investigate potential effects of higher levels of ventilation pressure or PEEP on microvascular perfusion.

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.

Anthropometric indices as predictors of the metabolic syndrome and its components in adolescents

BACKGROUND

Overweight and related health problems are becoming increasingly recognized, especially in children and adolescents. For early screening, different anthropometrical measurements of obesity have been proposed to identify individuals at risk. We compared body mass index (BMI), BMI standard deviation score, waist circumference, waist-to-hip ratio (WHR), and waist/height ratio with respect to their power to predict the metabolic syndrome, its components and low-grade inflammation.

METHODS

A total of 79 male Caucasian German adolescents (13-17 years) were studied. All anthropometrical measurements of obesity were recorded and blood samples drawn. Predictive power was estimated using receiver operating characteristic curves, by comparing the area under the curve (AUC).

RESULTS

Except for WHR, all tested anthropometrical measurements of obesity showed comparably good AUC values for correct prediction, with the highest AUC for BMI (P < 0.001, AUC = 0.885 +/- 0.039). Superior prediction power was not observed for BMI standard deviation score, waist circumference, WHR or waist/height ratio. Furthermore, BMI was the best predictor of elevated C-reactive protein levels as a marker for low-grade inflammation (P < 0.001, AUC = 0.786 +/- 0.064).

CONCLUSIONS

In this cross-sectional study the well-established parameter BMI was shown to have the best predictive power to identify metabolic syndrome, its components and markers for low-grade inflammation. Newly developed parameters did not provide superior values. Future longitudinal studies are needed to compare these anthropometrical markers in larger cohorts, incorporating different age groups and ethnic backgrounds.

Churg-strauss syndrome presenting with cardiac mass and right ventricular obstruction

A 57-year-old woman presenting with asthma, hypereosinophilia, and generalized unspecific symptoms was diagnosed with Churg-Strauss syndrome. Echocardiography revealed a cardiac mass obliterating the right ventricle and severely impaired left ventricular function, which were caused by endomyocardial fibrosis. Cortisone and cyclophosphamide therapy resulted in amelioration of left ventricular function and significant size reduction of the right ventricular mass.

Changes in extra cellular matrix remodelling and re-expression of fibronectin and tenascin-C splicing variants in human myocardial tissue of the right atrial auricle: implications for a targeted therapy of cardiovascular diseases using human SIP format antibodies

Cardiovascular diseases are accompanied by changes in the extracellular matrix (ECM) including the re-expression of fibronectin and tenascin-C splicing variants. Using human recombinant small immunoprotein (SIP) format antibodies, a molecular targeting of these proteins is of therapeutic interest. Tissue samples of the right atrial auricle from patients with coronary artery disease and valvular heart disease were analysed by PCR based ECM gene expression profiling. Moreover, the re-expression of fibronectin and tenascin-C splicing variants was investigated by immunofluoerescence labelling. We demonstrated changes in ECM gene expression depending on histological damage or underlying cardiac disease. An increased expression of fibronectin and tenascin-C mRNA in association to histological damage and in valvular heart disease compared to coronary artery disease could be shown. There was a distinct re-expression of ED-A containing fibronectin and A1 domain containing tenascin-C detectable with human recombinant SIP format antibodies in diseased myocardium. ED-A containing fibronectin showed a clear vessel positivity. For A1 domain containing tenascin-C, there was a particular positivity in areas of interstitial and perivascular fibrosis. Right atrial myocardial tissue is a valuable model to investigate cardiac ECM remodelling. Human recombinant SIP format antibodies usable for an antibody-mediated targeted delivery of drugs might offer completely new therapeutic options in cardiac diseases.