Segmented Poincaré Plot Analysis for Risk Stratification in Patients with Dilated Cardiomyopathy

Background: The prognostic value of heart rate variability in patients with dilated cardiomyopathy (DCM) is limited and does not contribute to risk stratification although the dynamics of ventricular repolarization differs considerably between DCM patients and healthy subjects. Neither linear nor nonlinear methods of heart rate variability analysis could discriminate between patients at high and low risk for sudden cardiac death.

Objective: The aim of this study was to analyze the suitability of the new developed segmented Poincaré plot analysis (SPPA) to enhance risk stratification in DCM.

Methods: In contrast to the usual applied Poincaré plot analysis the SPPA retains nonlinear features from investigated beat-to-beat interval time series. Main features of SPPA are the rotation of cloud of points and their succeeded variability depended segmentation.

Results: Significant row and column probabilities were calculated from the segments and led to discrimination (up to p < 0.005) between low and high risk in DCM patients.

Conclusion: For the first time an index from Poincaré plot analysis of heart rate variability was able to contribute to risk stratification in patients suffering from DCM.

[Interventional therapy of heart valve diseases: future perspectives]

Transcatheter procedures have been adopted as novel treatment strategy for patients with valvular heart disease, particularly for those who are inoperable or at high risk for surgical valve procedures. Significant technological advances have resulted in an improvement of devices for transcatheter aortic valve replacement (TAVI) with downsizing of crossing profiles, reduction in the rate of paravalvular leakage and conduction abnormalities as well as a lower short- and mid-term mortality and a higher patient acceptance. In the near future, TAVI may potentially develop as first-line treatment for the majority of patients with aortic valve disease. For patients with mitral and pulmonary stenosis, balloon valvuloplasty is effective and well established and should be preferred over valve replacement, last but not least also for economic reasons. For treatment of mitral regurgitation, several transcatheter devices aiming to restore or replace mitral valve function are currently under investigation. This review summarizes the current state of interventional treatment of valvular heart disease along with implications for the future.

QT variability improves risk stratification in patients with dilated cardiomyopathy

Recently it could be demonstrated that systolic and diastolic blood pressure variability (BPV) as well as segmented Poincare plot analysis (SPPA) contribute to risk stratification in patients suffering from dilated cardiomyopathy (DCM). The aim of this study was to improve the risk stratification applying a multivariate technique including QT variability (QTV). We enrolled and significantly separated 56 low risk and 13 high risk DCM patients by nearly all applied BPV and QTV methods, but not with traditional heart rate variability analysis. The optimum set of two indices calculating the multivariate discriminate analysis (DA) included one BPV index calculated by symbolic dynamics method (DBP(Shannon)) and one index calculated from QTV (QTV(log)) achieving an area under the receiver operating characteristics curve (AUC) of 92%, sensitivity of 92.3% and specificity of 89.3%. Performing only electrocardiogram analysis, the optimum multivariate approach including indices from segmented Poincaré plot analysis and QTV still achieved a remarkable AUC of 88.3%. Increasing the number of indices for multivariate DA up to three, we achieved an AUC of 95.7%, sensitivity of 100% and specificity of 85.7% including one clinical, one BPV and one QTV index. Summarizing, we identified DCM patients with an increased risk of sudden cardiac death applying QTV analysis in a multivariate approach.

Altered red blood cell distribution width in overweight adolescents and its association with markers of inflammation

BACKGROUND

Obesity and the metabolic syndrome are dramatically increasing problems. Red blood cell distribution width (RDW), the variability in size of circulating red blood cells, has been demonstrated to be altered in different clinical settings. This analysis aimed to investigate the relationship between RDW and obesity in adolescents and in an animal model of diet-induced obesity (DIO).

METHODS

Seventy-nine male adolescents (aged 13-17 years) were studied. Thirty-seven of them were overweight (body mass index ≥ 90th percentile). RDW, markers of inflammation and stem cell factor (SCF) were determined. In an animal study, mice were fed with different diets for 15 weeks. RDW was determined using an animal blood count machine.

RESULTS

RDW differed significantly between normal-weight adolescents (13.07 ± 0.09) and overweight adolescents (13.39 ± 0.10, P = 0.015), whereas erythrocyte counts and haematocrit did not differ. RDW correlated to markers of inflammation and inversely to SCF. In the mice animal model, nutritional changes increased RDW, whereas overweight per se did not change RDW.

CONCLUSIONS

RDW is elevated in overweight and reflects the inflammatory state. RDW potentially represents an additional and cost-effective tool to indicate inflammation. Future studies are needed to understand the differential influences of nutrition and overweight on RDW.

Smelling heart failure from human skin odor with an electronic nose

The human body odor contains different volatile organic compounds which can be used as biomarkers for various diseases. The early detection of heart failure (HF) through periodical screening provides an early treatment application. Therefore we have developed a completely new non-invasive method to identify HF applying an "electronic nose" (e-nose) which provides a "smelling" of the disease based on the analysis of sweat volatile gases from the skin surface. For this e-nose a special applicator carrying the sensor chip was developed which can be applied directly on the skin surface. 27 patients with decompensated HF (DHF), 25 patients with compensated HF (CHF, mean age 70.72 ± 12.02) and 28 controls (CON) were enrolled in this first pilot study.

[Evaluation of microcirculatory disorders in shock patients]

The microcirculatory status depicts an indicator of organ perfusion in hemodynamic shock. Distribution pattern of microcirculatory disturbances reflects the underlying cause of shock: In septic shock, organ perfusion is severely impaired via arteriolo-venous shunting with shutting up small vessel perfusion; however, cardiogenic shock is characterized by a global impairment of microcirculation, involving all vascular beds. Hence, a differentiated evaluation of microcirculatory disturbances not only supports an early diagnosis of an imminent multiorgan dysfunction syndrome (MODS), but also allows a more accurate evaluation of severity of hemodynamic compromise in critical care medicine. Bedside sidestream darkfield (SDF) technique offers the opportunity to describe the microcirculatory status quo semiquantitatively and to evaluate the effect of novel therapeutic approaches on microcirculation. Further technical improvements of this technique may open new fields of diagnostic and therapeutic applications in intensive care medicine by supporting an early diagnosing of MODS, evaluating prognosis, and optimizing therapeutic measures .

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.

[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.

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.

In Vivo Evaluation of Tissue Microflow under Combined Therapy with Extracorporeal Life Support and Intra-aortic Balloon Counterpulsation

Treatment with, percutaneous extracorporeal mechanical assist devices provides the ultimate therapeutic option to improve the macrocirculation in patients suffering from refractory cardiac arrest, severe cardiogenic shock or during high-risk interventions. However, the flow in the smallest vessels in these critical periods is poorly understood but prognostically of high importance. Using sidestream darkfield intravitalmicroscopy, we visualised the sublingual microflow in a patient suffering from severe cardiogenic shock supported by extracorporeal membrane oxygenation and intra-aortic balloon pump. Our results show that intra-aortic balloon counterpulsation applied in addition to extracorporeal membrane oxygenation further improves the microflow. This in vivo finding supports pilot studies favouring the application of devices supporting cardiac output (extracorporeal membrane oxygenation) together with devices aimed at pulsatility (intra-aortic balloon pump).

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.

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.

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.

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.