P11.35.B The clinical course of long-term survivors after the diagnosis of brain metastasis

Background

To asses demographic and clinical parameters, treatment, and course of disease in patients surviving longer ≥ 5 years after the diagnosis of brain metastasis (BM).

Material and Methods

We retrospectively identified patients who were treated for BM and survived ≥ 5 years after initial BM diagnosis. We analysed and described clinical and treatment related parameters with respect to histology, time to occurrence and systemic/ BM-specific treatment.

Results

We included 48 patients with a mean age of 55 years (range 33-81, SD 12) at diagnosis of primary tumor and 58 (range 41-84, SD 20) at initial BM diagnosis. Histology was non-small-cell lung cancer in 18 (37.5%), melanoma in 14 (29.2%), breast cancer in 11 (22.9%), renal carcinoma in 2 (4.2%), and small-cell lung cancer, cancer of unknown primary and gastrointestinal cancer in one case each (2.1%). Treatment for primary tumor included resection (83.3%), chemotherapy (43.8%), radiation (33.3%), interferon therapy (18.8%), and immuno-/targeted therapy (25%). Most patients received a combination of latter. The mean interval between primary tumor and BM diagnosis was 36 months (range -2 to 277; SD 57). At the time of BM diagnosis, 50% of patients presented with systemically stable disease, 66.7% showed BM related symptoms, 92% showed a KPS ≥70. Most patients had 1 BM (72.9%), while 20.9% had 2-3 and 6.3% >3. Initial treatment for BM comprised resection (60.4%), stereotactic radiosurgery (27.2%), whole-brain-radiation therapy (8.4%), and interstitial brachytherapy (4.2%). Approximately half of the patients (52.1%) suffered from ≥1 BM relapse at initial treatment site. At the time of the analysis, 13 (27.1%) patients had died; cause of death was mostly unknown, in two patients each, systemic/cerebral cause was confirmed. The mean overall survival (OS) was 131 months (range 64-344, SD 68) and 95 (range 60-246, SD 36) after diagnosis of primary tumor and BM, respectively. All patients suffering from melanoma who had received interferon therapy (n=8) survived. Neither systemic status at BM diagnosis nor the administration of novel treatment agents or chemotherapy after BM diagnosis showed an impact on OS (p=0.642, p=0.177 and p=0.628, respectively). Further survival analysis was omitted due to subgroup sizes.

Conclusion

Despite the usually fatal course after BM development, some patients show long-term survival. Whether specific genetic parameters have a particular impact in this subgroup of patients, warrants further investigation.

Impact of respiratory infectious epidemics on STEMI incidence and care

The effect of respiratory infectious diseases on STEMI incidence, but also STEMI care is not well understood. The Influenza 2017/2018 epidemic and the COVID-19 pandemic were chosen as observational periods to investigate the effect of respiratory virus diseases on these outcomes in a metropolitan area with an established STEMI network. We analyzed data on incidence and care during the COVID-19 pandemic, Influenza 2017/2018 epidemic and corresponding seasonal control periods. Three comparisons were performed: (1) COVID-19 pandemic group versus pandemic control group, (2) COVID-19 pandemic group versus Influenza 2017/2018 epidemic group and (3) Influenza 2017/2018 epidemic group versus epidemic control group. We used Student's t-test, Fisher's exact test and Chi square test for statistical analysis. 1455 patients were eligible. The daily STEMI incidence was 1.49 during the COVID-19 pandemic, 1.40 for the pandemic season control period, 1.22 during the Influenza 2017/2018 epidemic and 1.28 during the epidemic season control group. Median symptom-to-contact time was 180 min during the COVID-19 pandemic. In the pandemic season control group it was 90 min (p = 0.183), and in the Influenza 2017/2018 cohort it was 90 min, too (p = 0.216). Interval in the epidemic control group was 79 min (p = 0.733). The COVID-19 group had a door-to-balloon time of 49 min, corresponding intervals were 39 min for the pandemic season group (p = 0.038), 37 min for the Influenza 2017/2018 group (p = 0.421), and 38 min for the epidemic season control group (p = 0.429). In-hospital mortality was 6.1% for the COVID-19 group, 5.9% for the Influenza 2017/2018 group (p = 1.0), 11% and 11.2% for the season control groups. The respiratory virus diseases neither resulted in an overall treatment delay, nor did they cause an increase in STEMI mortality or incidence. The registry analysis demonstrated a prolonged door-to-balloon time during the COVID-19 pandemic.

P14.06 Radiomics for the non-invasive determination of the BRAF mutational status in patients with melanoma brain metastases

BACKGROUND

The BRAF V600E mutation is present in approximately 50% of patients with melanoma and is an important prerequisite for a response to targeted therapies such as BRAF inhibitors. In the majority of patients, the BRAF mutational status is based on the analysis of tissue samples from the extracranial primary tumor only. Since the extracranial and intracranial BRAF mutational status may be discrepant, the additional information on the BRAF mutational status of melanoma brain metastases would be of clinical value, e.g., for the prediction of response to targeted therapies. Here, we evaluated the potential of structural MRI radiomics for the determination of the intracranial BRAF mutational status in patients with melanoma brain metastases.

MATERIAL AND METHODS

Fifty-nine patients with melanoma brain metastases from two university hospitals (group 1, 45 patients; group 2, 14 patients) underwent surgery with subsequent genetic analysis of the brain metastases tissue to determine the BRAF mutational status. All patients underwent structural MRI preoperatively. Areas of contrast enhancement were manually segmented and analyzed. Group 1 was used for model training and validation, group 2 for model testing. After image preprocessing, 1,316 radiomics features were extracted using the open-source PyRadiomics package. A test-retest analysis was performed to identify robust features prior to feature selection. Finally, the best performing radiomics model was applied to the test data (group 2). Diagnostic performances were evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

Twenty-two patients (49%) in group 1, and 6 patients (43%) in group 2 had an intrametastatic BRAF V600E mutation. Using a six parameter radiomics signature, a linear support vector machine classifier yielded an average area under the ROC curve (AUC) of 0.87 (accuracy, 85%; sensitivity, 78%; specificity, 91%) for prediction of the BRAF mutational status in the training data (group 1). Finally, the classifier achieved an AUC of 0.85 (accuracy, 86%; sensitivity, 83%; specificity, 88%) in the test data (group 2).

CONCLUSION

The developed radiomics classifier allows a non-invasive prediction of the intracranial BRAF V600E mutational status in patients with melanoma brain metastases and may be of value for treatment decisions.

Combining NGN2 Programming with Developmental Patterning Generates Human Excitatory Neurons with NMDAR-Mediated Synaptic Transmission

Transcription factor programming of pluripotent stem cells (PSCs) has emerged as an approach to generate human neurons for disease modeling. However, programming schemes produce a variety of cell types, and those neurons that are made often retain an immature phenotype, which limits their utility in modeling neuronal processes, including synaptic transmission. We report that combining NGN2 programming with SMAD and WNT inhibition generates human patterned induced neurons (hpiNs). Single-cell analyses showed that hpiN cultures contained cells along a developmental continuum, ranging from poorly differentiated neuronal progenitors to well-differentiated, excitatory glutamatergic neurons. The most differentiated neurons could be identified using a CAMK2A::GFP reporter gene and exhibited greater functionality, including NMDAR-mediated synaptic transmission. We conclude that utilizing single-cell and reporter gene approaches for selecting successfully programmed cells for study will greatly enhance the utility of hpiNs and other programmed neuronal populations in the modeling of nervous system disorders.

Prediction model for obtaining spermatozoa with testicular sperm extraction in men with non-obstructive azoospermia

STUDY QUESTION

Can an externally validated model, based on biological variables, be developed to predict successful sperm retrieval with testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA) using a large nationwide cohort?

SUMMARY ANSWER

Our prediction model including six variables was able to make a good distinction between men with a good chance and men with a poor chance of obtaining spermatozoa with TESE.

WHAT IS KNOWN ALREADY

Using ICSI in combination with TESE even men suffering from NOA are able to father their own biological child. Only in approximately half of the patients with NOA can testicular sperm be retrieved successfully. The few models that have been developed to predict the chance of obtaining spermatozoa with TESE were based on small datasets and none of them have been validated externally.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective nationwide cohort study. Data from 1371 TESE procedures were collected between June 2007 and June 2015 in the two fertility centres.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All men with NOA undergoing their first TESE procedure as part of a fertility treatment were included. The primary end-point was the presence of one or more spermatozoa (regardless of their motility) in the testicular biopsies.We constructed a model for the prediction of successful sperm retrieval, using univariable and multivariable binary logistic regression analysis and the dataset from one centre. This model was then validated using the dataset from the other centre. The area under the receiver-operating characteristic curve (AUC) was calculated and model calibration was assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 599 (43.7%) successful sperm retrievals after a first TESE procedure. The prediction model, built after multivariable logistic regression analysis, demonstrated that higher male age, higher levels of serum testosterone and lower levels of FSH and LH were predictive for successful sperm retrieval. Diagnosis of idiopathic NOA and the presence of an azoospermia factor c gene deletion were predictive for unsuccessful sperm retrieval. The AUC was 0.69 (95% confidence interval (CI): 0.66-0.72). The difference between the mean observed chance and the mean predicted chance was <2.0% in all groups, indicating good calibration. In validation, the model had moderate discriminative capacity (AUC 0.65, 95% CI: 0.62-0.72) and moderate calibration: the predicted probability never differed by more than 9.2% of the mean observed probability.

LIMITATIONS, REASONS FOR CAUTION

The percentage of men with Klinefelter syndrome among men diagnosed with NOA is expected to be higher than in our study population, which is a potential selection bias. The ability of the sperm retrieved to fertilize an oocyte and produce a live birth was not tested.

WIDER IMPLICATIONS OF THE FINDINGS

This model can help in clinical decision-making in men with NOA by reliably predicting the chance of obtaining spermatozoa with TESE.

STUDY FUNDING/COMPETING INTEREST

This study was partly supported by an unconditional grant from Merck Serono (to D.D.M.B. and K.F.) and by the Department of Obstetrics and Gynaecology of Radboud University Medical Center, Nijmegen, The Netherlands, the Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Den Bosch, The Netherlands, and the Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. Merck Serono had no influence in concept, design nor elaboration of this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Prediction model for live birth in ICSI using testicular extracted sperm

STUDY QUESTION

Which parameters have a predictive value for live birth in couples undergoing ICSI after successful testicular sperm extraction (TESE-ICSI)?

SUMMARY ANSWER

Female age, a first or subsequent started TESE-ICSI cycle, male LH, male testosterone, motility of the spermatozoa during the ICSI procedure and the initial male diagnosis before performing TESE were identified as relevant and independent parameters for live birth after TESE-ICSI.

WHAT IS KNOWN ALREADY

In reproductive medicine prediction models are used frequently to predict treatment success, but no prediction model currently exists for live birth after TESE-ICSI.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study between 2007 and 2015 in two academic hospitals including 1559 TESE-ICSI cycles. The prediction model was developed using data from one centre and validation was performed with data from the second centre.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included couples undergoing ICSI treatment with surgically retrieved sperm from the testis for the first time. In the development set we included 526 couples undergoing 1006 TESE-ICSI cycles. In the validation set we included 289 couples undergoing 553 TESE-ICSI cycles. Multivariable logistic regression models were constructed in a stepwise fashion (P < 0.2 for entry). The external validation was based on discrimination and calibration.

MAIN RESULTS AND THE ROLE OF CHANCE

We included 224 couples (22.3%) with a live birth in the development set. The occurrence of a live birth was associated with lower female age, first TESE-ICSI cycle, lower male LH, higher male testosterone, the use of motile spermatozoa for ICSI and having obstructive azoospermia as an initial suspected diagnosis. The area under the receiver operating characteristic (ROC) curve was 0.62. From validation data, the model had moderate discriminative capacity (c-statistic 0.67, 95% confidence interval: 0.62-0.72) but calibrated well, with a range from 0.06 to 0.56 in calculated probabilities.

LIMITATIONS, REASONS FOR CAUTION

We had a lack of data about the motility of spermatozoa during TESE, therefore, we used motility of the spermatozoa used for ICSI after freeze-thawing, information which is only available during treatment. We had to exclude data on paternal BMI in the model because too many missing values in the validation data hindered testing. We did not include a histologic diagnosis, which would have made our data set less heterogeneous and, finally, our model may not be applicable in centres which have a different policy for the indication for performing sperm extraction. The prognostic value of the model is limited because of a low 'area under the curve'.

WIDER IMPLICATIONS OF THE FINDINGS

This model enables the differentiation between couples with a low or high chance to reach a live birth using TESE-ICSI. As such it can aid in the counselling of patients and in clinical decision-making.

STUDY FUNDING/COMPETING INTERESTS

This study was partly supported by an unconditional grant from Merck Serono (to D.D.M.B. and K.F.) and by the Department of Obstetrics and Gynaecology of Radboud University Medical Center, Nijmegen, The Netherlands, the Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Den Bosch, The Netherlands, and the Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. Merck Serono had no influence in concept, design, nor elaboration of this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Couples with non-obstructive azoospermia are interested in future treatments with artificial gametes

STUDY QUESTION

Would couples diagnosed with non-obstructive azoospermia (NOA) consider two future treatments with artificial gametes (AGs) as alternatives for testicular sperm extraction followed by ICSI (TESE-ICSI)?

SUMMARY ANSWER

Most couples with NOA (89%) would opt for treatment with AGs before attempting TESE-ICSI and/or after failed TESE-ICSI.

WHAT IS KNOWN ALREADY

Couples with NOA who undergo TESE-ICSI have a 25% chance of conceiving a child. Two future treatments that are being developed are 'ICSI with artificial sperm formed from somatic cells' (ICSI with AGs) and 'natural conception after autotransplantation of in vitro proliferated spermatogonial stem cells' (natural conception with AGs). It is unknown what treatment preferences patients have.

STUDY DESIGN, SIZE, DURATION

A cross-sectional survey conducted in 2012-2013, addressing all 921 couples diagnosed with NOA and treated with TESE-ICSI in Dutch fertility clinics between 2007 and 2012. The coded questionnaires were sent by mail and followed up with two reminders.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We developed the questionnaire based on a literature review and previous qualitative interviews, and included treatment preference and the valuation of nine treatment characteristics. We assessed reliability of the questionnaires and calculated mean importance scores (MISs: 0-10) of each treatment characteristic. We assessed which patient and treatment characteristics were associated with a couple's hypothetical treatment preference using binominal regression.

MAIN RESULTS AND THE ROLE OF CHANCE

The vast majority (89%) of the 494 responding couples (response rate: 54%) would potentially opt for AGs as a first and/or a last resort treatment option. More specifically, as a first treatment couples were likely (67%) to prefer natural conception with AGs over TESE-ICSI and less likely to prefer ICSI with AGs over TESE-ICSI (34%). After failed TESE-ICSI, the majority of couples (75%) would want to attempt ICSI with AGs as a last resort option. The most important characteristics of treatment were safety for children (MIS: 8.2), pregnancy rates (MIS: 7.7) and curing infertility (MIS: 6.8). Costs, burden, naturalness and technological sophistication were of about equal importance (MIS: 3.1-4.0). The majority of patients rated conception at home and moral acceptability as not important (MIS: 1.7 and 0.8, respectively), but the importance attributed to these variables did still affect patients' likeliness to opt for AGs.

LIMITATIONS AND REASONS FOR CAUTION

Couples with NOA not opting for TESE-ICSI were not included and might have other perspectives. Couples' hypothetical choices for AGs might differ from their actual choices once data on the costs, safety and pregnancy rates become available from these new treatment options.

WIDER IMPLICATIONS OF THE FINDINGS

The interest of couples with NOA in potential future treatments with AGs encourages further pre-clinical research. Priority setting for research and future decision-making on clinical application of AGs should take all characteristics important to patients into account.

STUDY FUNDING/COMPETING INTERESTS

The authors report no financial or other conflict of interest relevant to the subject of this article.

[Comparison of Costs and Revenues in Conservative and Invasive Treatment in Cardiology: a Contribution Margin Analysis]

Aim of the study: Direct costing is a specialized form of cost analysis well suited for medical areas with DRG-orientated flat rate payments. By comparing case-related variable costs and payments, it is possible to compare the economic benefits of different medical treatments. This aim was pursued by developing a direct costing concept and by its application to invasively and non-invasively treated cardiac patients. Methods: The entire database comprised 7 330 cases of a tertiary cardiac center between 2007 and 2011. It was derived from databases of the hospital information system, the materials management department and the catheter laboratory. On the revenue side, DRG payments were included. Costs related to heart catheterization such as material, personnel and maintenance expenses were considered to be variable costs. Contribution margins and relative contribution margins were calculated by introducing the length of hospital stay as a time reference. Results: During the observation period, caseload and annual revenues increased by about 20 percent. Contribution margins were higher in invasively than in non-invasively treated patients (2 097±1 590 vs. 1 614±1 105 €; p<0,001). However, the relative relation of both patient groups was not altered during the observation period. A remarkable shortening of the duration of catheter laboratory examinations was observed between 2007 and 2011 (46,2±39,1 auf 36,7±33,5 min; p<0,001). In the same period, relative contribution margins increased from 461±306 to 530±335 € (p<0,001). Conclusions: Within existing supply structures, direct costing is a useful tool for economic comparison of different treatment services. Furthermore, temporal constraints of an economic bottleneck can be easily monitored and tackled with the help of time management tools.

[Prophylaxis and therapy for atrial fibrillation after general thoracic surgery]

Following thoracic surgery atrial fibrillation (AF) frequently occurs in 12 to 44 % of cases postoperatively and is related to an increased morbidity and mortality. In 2011, the Society of Thoracic Surgeons of the United States published guidelines for the prophylaxis and treatment of postoperative AF. High evidence levels are provided for continuing β-blocker treatment despite its known negative inotropic effects. Alternatively, the calcium channel blocker diltiazem, or amiodarone for patients without pneumonectomy are recommended for prophylactic therapy. For rate control of AF occurring post surgery, not only selective β1-blockers, calcium channel blockers, but also magnesium or digoxin are suitable in haemodynamically stable patients. Amiodarone, β1-blockers and flecainide are preferred for rhythm control in case of haemodynamic stability in regard to possible side effects and contraindications. In contrast, electrical cardioversion is indicated in those patients with haemodynamic instability. Persistent AF of > 48 hours is a target for anticoagulation treatment depending on the individual aspects of the patient and in accordance to the CHADS2 score. The present review article further discusses the evidence for the recommended medical therapy and treatment strategies.

Alzheimer's disease: early alterations in brain DNA methylation at ANK1, BIN1, RHBDF2 and other loci

Here, we leverage a unique collection of 708 prospectively collected autopsied brains to assess the methylation state of the brain's DNA in relation to Alzheimer's disease (AD). We find that the level of methylation at 71 of the 415,848 interrogated CpGs is significantly associated with the burden of AD pathology, including CpGs in the ABCA7 and BIN1 regions, which harbor known AD susceptibility variants. We validate 11 of the differentially methylated regions in an independent set of 117 subjects. Further, we functionally validate these CpG associations and identify the nearby genes whose RNA expression is altered in AD: ANK1, CDH23, DIP2A, RHBDF2, RPL13, RNF34, SERPINF1 and SERPINF2. Our analyses suggest that these DNA methylation changes may have a role in the onset of AD since (1) they are seen in presymptomatic subjects and (2) six of the validated genes connect to a known AD susceptibility gene network.

Publication rates of abstracts presented at the 2007 and 2010 Canadian Association of Radiation Oncology meetings

BACKGROUND

We set out to determine the rate, time-trend, and defining factors associated with publication of abstracts presented at two annual scientific meetings of the Canadian Association of Radiation Oncology (caro).

METHODS

All abstracts accepted for oral presentation in 2007 and 2010 were obtained from the caro program archives and searched using the PubMed database. Variables in the dataset included the year of presentation at caro and of publication in a scientific journal, time to publication (in months), publishing journal, impact factor of publishing journal, abstract research type (clinical, technical, or basic science) and disease site, country of origin, and university of the first author.

RESULTS

Overall, 88 of 172 abstracts from the 2007 (n = 102) and 2010 (n = 70) caro meetings were published in peer-reviewed journals (publication rate: 51.2%). Mean time to publication was 18.5 months. Among research types, clinical research (62.5%) and, among disease sites, prostate cancer (40.4%) were most likely to be published. Of all the abstracts, 50.1% were contributed by only 2 universities, a proportion that resembles the overall abstract publication rate of 51.2%. The conversion rate for those 2 universities (51.1%) is very similar to that for all abstracts presented at the two meetings.

CONCLUSIONS

Half the abstracts presented at the 2007 and 2010 caro meetings were ultimately published in journals indexed in PubMed by about 1.5 years after presentation. Half the abstracts and publications came from just 2 universities; more must to be done to close the gap.

Perspectives of infertile men on future stem cell treatments for nonobstructive azoospermia

Concerns have been expressed about the rapid introduction of new fertility treatments into clinical practice. Patients' perspectives on new treatments and their introduction into clinical practice are unexplored. Two alternative treatments for testicular sperm extraction followed by intracytoplasmic sperm injection in men with nonobstructive azoospermia (NOA), the formation of artificial sperm and autotransplantation of in vitro proliferated spermatogonial stem cells, are in a preclinical phase of development. This study aimed to explore, prior to future clinical introduction, which treatment aspects are valued by NOA patients and would be taken into account in deciding to undergo these future treatment options. In-depth telephone interviews were conducted with 14 men with NOA. Interviews were transcribed, analysed with content analysis and data saturation was reached. Besides the obvious factors, success rates and safety, patients valued 'the intensity of the procedure', 'the treatments' resemblance to natural conception' and 'feeling cured'. Patients supported the development of these treatments and were eager to take part if such treatments would become available in the future. The patient's perspective on innovative treatments can (co)direct reproductive research. More research into the patients' perspectives on innovations and minimal thresholds to be met prior to their introduction into clinical practice is required.

Angular momentum sensitive two-center interference

In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

[Echocardiographic tissue Doppler imaging analysis of the systolic and early diastolic velocities of the mitral annulus motion in hypertrophic cardiomyopathy and in top-level athletes]

BACKGROUND AND OBJECTIVE

Echocardiographic Tissue Doppler Imaging (TDI) has been proposed for the differentiation of pathological left ventricular hypertrophy (e. g. hypertrophic cardiomyopathy, HCM) and physiologic left ventricular hypertrophy (athlete's heart). The aim of this study was the TDI analysis of the systolic (S') and early diastolic (E') velocities in patients (pts.) with non-obstructive hypertrophic cardiomyopathy (HCM) and in top-level athletes in consideration of the previously published cut-off values (S' < 9 cm/s, E' < 9 cm/s).

PATIENTS AND METHODS

Pulsed-wave TDI of the systolic and early-diastolic velocities was performed at the lateral and septal mitral annulus in the four-chamber view in 17 HCM pts (12 men; mean age 44 ± 16 years) and 80 consecutive athletes (80 men; mean age 26 ± 5 years).

RESULTS

Pts with HCM showed significantly decreased systolic velocities of the septal (S' septal: 5.1 ± 1.2 cm/s versus 9.5 ± 1.5 cm/s, p < 0.001) and lateral mitral annulus (S' lateral: 6.4 ± 2.0 cm/s vs. 10.5 ± 2.1 cm/s, p < 0.001). The early diastolic velocity of the mitral annulus E' was significantly decreased in HCM, too (E' septal: 5.9 ± 2.2 cm/s vs. 13.1 ± 2.9 cm/s, p < 0.001; E' lateral: 8.2 ± 3.0 cm/s vs. 16.5 ± 3.4 cm/s, p < 0.001).

CONCLUSION

Tissue Doppler Imaging of the systolic and early diastolic velocity of the mitral annulus might be helpful as a promising additional method for the echocardiographic differentiation between pathological and physiologic left ventricular hypertrophy.

[Stress-related alteration of urine compositions: idiopathic CaOx stone formers, patients with chronic inflammatory bowel disease (CIBD) and healthy controls]

BACKGROUND

Increased emotional stress in everyday life influences the way of living and metabolism of people living in developed countries. Contemporaneously, the incidence and prevalence of urolithiasis rises. Does a pathogenetically relevant relationship exist between chronic stress burden and permanently altered urinary composition?

PATIENTS AND METHODS

The influence of chronic stress burden on urine composition and risk of urinary calcium oxalate (CaOx) stone formation was, for the first time, comprehensively investigated in 29 healthy controls (CG), 29 idiopathic CaOx stone formers (SF) and 28 patients suffering from chronic inflammatory bowel disease (CIBD). After 4 days with standardized nutrition, 24-h urine was collected. Extensive urinalysis was performed and APCaOx index calculated. Evaluation of subjective stress level was carried out by using the standardized and well-established questionnaire Trierer Inventar zur Beurteilung von chronischem Stress (TICS). The concentration values of the urinary parameters as well as the APCaOx values were linearly correlated with the stress scores obtained from the different items of the TICS. A significance level p≤0.05 was considered to indicate statistical significance.

RESULTS

The mean APCaOx indices amounted to 0.8±0.3 in CG, 1.2±0.7 in SF and 1.9±1.2 in CIBD. The increased APCaOx in SF mainly results from relatively increased Ca and oxalate excretions, whereas in CIBD this also results from reduced urinary excretions of citrate and Mg as well as reduced 24-h urinary volumes. The calculation of linear correlation coefficients between a TICS stress dimension and a concentration value of a urinary parameter or APCaOx results in r values not exceeding 0.600. However, some of these correlations are statistically highly significant. In SF only one combination with Ca was observed, while in CIBD in contrast a number of combinations, in particular including Na, was obtained. In CG direct statistical relationships between stress burden and citrate as well as Mg exist. In this group, increased stress burden is associated with increased inhibitory potential to prevent CaOx stone formation.

CONCLUSION

In the investigated study groups, differently complex relationships between amount of stress burden and risk of CaOx stone formation were observed, however, without obvious physicochemical principle(s). In some individuals, stress can be associated with a significantly stress-related alteration of urinary composition towards increased CaOx stone formation risk. The results obtained from the CIBD group allow for the first time a conclusive link between emotional stress and inflammatory activity on the one hand and inflammatory activity and metabolic risk constellation of CaOx stone formation on the other hand.

Effects of a small acute subdural hematoma following traumatic brain injury on neuromonitoring, brain swelling and histology in pigs

An acute subdural hematoma (ASDH) induces pathomechanisms which worsen outcome after traumatic brain injury, even after a small hemorrhage. Synergistic effects of a small ASDH on brain damage are poorly understood, and were studied here using neuromonitoring for 10 h in an injury model of controlled cortical impact (CCI) and ASDH. Pigs (n = 32) were assigned to 4 groups: sham, CCI (2.5 m/s), ASDH (2 ml) and CCI + ASDH. Intracranial pressure was significantly increased above sham levels by all injuries with no difference between groups. CCI and ASDH reduced ptiO(2) by a maximum of 36 ± 9 and 26 ± 11%, respectively. The combination caused a 31 ± 11% drop. ASDH alone and in combination with CCI caused a significant elevation in extracellular glutamate, which remained increased longer for CCI + ASDH. The same two groups had significantly higher peak lactate levels compared to sham. Somatosensory evoked potential (SSEP) amplitude was persistently reduced by combined injury. These effects translated into significantly elevated brain water content and histological damage in all injury groups. Thus, combined injury had stronger effects on glutamate and SSEP when compared to CCI and ASDH, but no clear-cut synergistic effects of 2 ml ASDH on trauma were observed. We speculate that this was partially due to the CCI injury severity.

G1 arrest and differentiation can occur independently of Rb family function

Repression of E2F target genes is required for cell cycle arrest in Rb family (Rb, p107, and p130)-deficient cells.

The ability of progenitor cells to exit the cell cycle is essential for proper embryonic development and homeostasis, but the mechanisms governing cell cycle exit are still not fully understood. Here, we tested the requirement for the retinoblastoma (Rb) protein and its family members p107 and p130 in G0/G1 arrest and differentiation in mammalian cells. We found that Rb family triple knockout (TKO) mouse embryos survive until days 9–11 of gestation. Strikingly, some TKO cells, including in epithelial and neural lineages, are able to exit the cell cycle in G0/G1 and differentiate in teratomas and in culture. This ability of TKO cells to arrest in G0/G1 is associated with the repression of key E2F target genes. Thus, G1 arrest is not always dependent on Rb family members, which illustrates the robustness of cell cycle regulatory networks during differentiation and allows for the identification of candidate pathways to inhibit the expansion of cancer cells with mutations in the Rb pathway.

[Urinary tract infections and Urolithiasis]

The classic "infection stone" struvite is formed as a result of metabolic activity of urease-positive bacteria from alkaline urine with pH-values above 7.5. Due to improved infection diagnostics and antibiotic therapy, the occurrence of infection-related urinary stones in the western industrialized world decreases, despite the generally increasing prevalence rates of urolithiasis in these societies. Struvite is often associated with other mineral phases. These accessory mineral phases could indicate other, non-infection-related causes of urinary stone formation. Thus, mineral analysis is always recommended. Struvite stones as well as struvite encrustations on urinary tract implants are characterized by rapid growth. The rapid growth-related embedding of urease-positive bacteria in the crystalline material makes the urinary stone a persistent source of recurrent urinary tract infections. According to the German Society of Urology guidelines on urolithiasis, a patient with the diagnosis "infection stone" should be assigned to the "high-risk" patient group. Complete stone and debris removal, as well as a special metaphylaxis strategy are required to initiate successful stone therapy.

The value of the ECG for decision-making at first medical contact in the patient with acute chest pain

Background/Objectives. Rapid risk stratification of the patient with acute chest pain is essential to select the best management. We investigated the value of the ECG at first medical contact to determine size of the ischaemic myocardial area and thereby severity of risk.Methods. In 386 patients with acute chest pain, ECG findings were correlated with the coronary angiogram. Using ST-segment deviation patterns the location of the coronary culprit lesion was predicted and thereby size of the area at risk. Four groups of patients were present. Those with a narrow QRS and a total 12-lead ST-segment deviation score of >/=5 mm (group 1) or /=120 ms (group 3), and patients with previous coronary bypass grafting (CABG) or percutaneous coronary intervention (PCI) (group 4).Results. Correct coronary culprit lesion localisation was possible in 84% of the 185 patients in group 1, 40% of the total cohort. Accurate prediction was not possible in most patients in groups 2, 3 and 4, in spite of extensive coronary artery disease in group 3 and 4. Conclusions. Using the 12-lead ECG the size of the myocardial area at risk can be accurately predicted when the total ST-segment deviation score is >/=5 mm, allowing identification of those in need of a PCI. In most patients with bundle branch block, previous CABG or PCI, the ECG can not localise the culprit lesion. This approach simplifies and accelerates decision-making at first medical contact. (Neth Heart J 2010;18:301-6.).

Unbiased reconstruction of a mammalian transcriptional network mediating pathogen responses

Models of mammalian regulatory networks controlling gene expression have been inferred from genomic data but have largely not been validated. We present an unbiased strategy to systematically perturb candidate regulators and monitor cellular transcriptional responses. We applied this approach to derive regulatory networks that control the transcriptional response of mouse primary dendritic cells to pathogens. Our approach revealed the regulatory functions of 125 transcription factors, chromatin modifiers, and RNA binding proteins, which enabled the construction of a network model consisting of 24 core regulators and 76 fine-tuners that help to explain how pathogen-sensing pathways achieve specificity. This study establishes a broadly applicable, comprehensive, and unbiased approach to reveal the wiring and functions of a regulatory network controlling a major transcriptional response in primary mammalian cells.

Mitral valve disease as well as uncommon extensive epipericardial and intramyocardial calcification secondary to massive mitral annular calcification

A 71-year-old woman with a history of childhood pulmonary tuberculosis was admitted to our hospital for exertional dyspnoea (NYHA functional class II). Transthoracic and transoesophageal echocardiography demonstrated moderate to severe mixed mitral valve disease due to massive mitral annular calcification (MAC) and extensive infiltrative calcification of the atrioventricular groove. In addition, a very uncommon intramyocardial calcification of the ventricular septum and the lateral free wall was diagnosed. This case demonstrates a rare combination of mitral valve disease secondary to MAC, and a small hypertrophied left ventricle, as well as epipericardial and myocardial calcification likely due either to the massive MAC with myocardial extension or to former tuberculous perimyocarditis. The multidimensional imaging approach, which has been used in this particularly case, provided an excellent visualization and clinical evaluation of this rare finding.

Inotropic therapy for cardiac low output syndrome: comparison of hemodynamic effects of dopamine/dobutamine versus dopamine/dopexamine

OBJECTIVE

To examine the effects of a therapy with dopexamine/dopamine in comparison with a regimen of dobutamine/dopamine on the outcome of patients with profound cardiogenic shock.

MATERIAL AND METHODS

Twenty patients presenting with an acute cardiogenic shock assisted with mechanical ventilation, being refractory to a therapy with dopamine alone were analyzed. After persistence of low cardiac output syndrome (cardiac index <2.5 l/min/m2) was confirmed, patients were treated either with receiving dopexamine (2 microg/kg/min) (group 1) or dobutamine (6 microg/kg/min) (group 2) in combination with dopamine (6 microg/kg/min) for 24 hrs. Hemodynamic parameters, urine production and clinical outcome were measured at intervals throughout the study. The groups were similar with respect to demographics and risk factors and there were no significant differences in the supportive treatment and hemodynamics at baseline.

RESULTS

The dopexamine treated patients had lower myocardial oxygen consumption (9310+/-2243 mmHg O2/sec vs. 10621+/-2552 mmHg O2/sec) and lower mean arterial pressure (66+/-11 mmHg vs. 71+/-10 mmHg) after the 24 hrs treatment interval, but no one of the changes reached statistical significance. No differences were found between the two groups for other variables and the overall clinical outcome.

CONCLUSION

The present study revealed that neither substance is superior in the treatment of cardiogenic shock, even if the effect on myocardial consumption and the reported beneficial effects on renal and splanchnic functions might favour the use of dopexamine under certain circumstances.

[Coating with plasma-deposited functionalized diamond-like carbon to decrease encrustations on urological implants]

The double-J stents used today for palliative artificial urinary diversion very often show extreme formation of encrustations, even a short time after implantation. Despite increased scientific material development, the complication rate has not really been strongly influenced. Grant-aided by the German Federal Ministry of Education and Research, we chose a new interdisciplinary and translational approach by coating standard stent materials with plasma-deposited amorphous diamond-like carbon. These stents show clearly reduced rates of encrustation in vitro. Ongoing clinical trials demonstrate a further enhancement of this effect in vivo. The underlying mechanisms are being investigated by extending the established in vitro model, thereby pushing research in this field to a new level.

Targeted deletion reveals essential and overlapping functions of the miR-17 through 92 family of miRNA clusters

miR-17 approximately 92, miR-106b approximately 25, and miR-106a approximately 363 belong to a family of highly conserved miRNA clusters. Amplification and overexpression of miR-1792 is observed in human cancers, and its oncogenic properties have been confirmed in a mouse model of B cell lymphoma. Here we show that mice deficient for miR-17 approximately 92 die shortly after birth with lung hypoplasia and a ventricular septal defect. The miR-17 approximately 92 cluster is also essential for B cell development. Absence of miR-17 approximately 92 leads to increased levels of the proapoptotic protein Bim and inhibits B cell development at the pro-B to pre-B transition. Furthermore, while ablation of miR-106b approximately 25 or miR-106a approximately 363 has no obvious phenotypic consequences, compound mutant embryos lacking both miR-106b approximately 25 and miR-17 approximately 92 die at midgestation. These results provide key insights into the physiologic functions of this family of microRNAs and suggest a link between the oncogenic properties of miR-17 approximately 92 and its functions during B lymphopoiesis and lung development.

Dnmt3b promotes tumorigenesis in vivo by gene-specific de novo methylation and transcriptional silencing

Increased methylation of CpG islands and silencing of affected target genes is frequently found in human cancer; however, in vivo the question of causality has only been addressed by loss-of-function studies. To directly evaluate the role and mechanism of de novo methylation in tumor development, we overexpressed the de novo DNA methyltransferases Dnmt3a1 and Dnmt3b1 in Apc Min/+ mice. We found that Dnmt3b1 enhanced the number of colon tumors in Apc Min/+ mice approximately twofold and increased the average size of colonic microadenomas, whereas Dnmt3a1 had no effect. The overexpression of Dnmt3b1 caused loss of imprinting and increased expression of Igf2 as well as methylation and transcriptional silencing of the tumor suppressor genes Sfrp2, Sfrp4, and Sfrp5. Importantly, we found that Dnmt3b1 but not Dnmt3a1 efficiently methylates the same set of genes in tumors and in nontumor tissues, demonstrating that de novo methyltransferases can initiate methylation and silencing of specific genes in phenotypically normal cells. This suggests that DNA methylation patterns in cancer are the result of specific targeting of at least some tumor suppressor genes rather than of random, stochastic methylation followed by clonal selection due to a proliferative advantage caused by tumor suppressor gene silencing.

Inotropic therapy for cardiac low output syndrome: comparison of hemodynamic effects of dopamine/dobutamine versus dopamine/dopexamine

OBJECTIVE

To examine the effects of a therapy with dopexamine/dopamine in comparison with a regimen of dobutamine/dopamine on the outcome of patients with profound cardiogenic shock.

MATERIAL AND METHODS

Twenty patients presenting with an acute cardiogenic shock assisted with mechanical ventilation, being refractory to a therapy with dopamine alone were analyzed. After persistence of low cardiac output syndrome (cardiac index <2.5 l/min/m2) was confirmed, patients were treated either with receiving dopexamine (2 microg/kg/min) (group 1) or dobutamine (6 microg/kg/min) (group 2) in combination with dopamine (6 microg/kg/min) for 24 hrs. Hemodynamic parameters, urine production and clinical outcome were measured at intervals throughout the study. The groups were similar with respect to demographics and risk factors and there were no significant differences in the supportive treatment and hemodynamics at baseline.

RESULTS

The dopexamine treated patients had lower myocardial oxygen consumption (9310 +/- 2243 mmHg O2/sec vs. 10621 +/- 2552 mmHg O2/sec) and lower mean arterial pressure (66 +/- 11 mmHg vs. 71 +/- 10 mmHg) after the 24 hrs treatment interval, but no one of the changes reached statistical significance. No differences were found between the two groups for other variables and the overall clinical outcome.

CONCLUSION

The present study revealed that neither substance is superior in the treatment of cardiogenic shock, even if the effect on myocardial consumption and the reported beneficial effects on renal and splanchnic functions might favour the use of dopexamine under certain circumstances.

Non-determinable defibrillation threshold and inefficacy of implantable cardioverter/defibrillator shocks due to defective connections of the defibrillator lead terminals in the device header port

Inefficacy of implantable cardioverter/defibrillator (ICD) shocks or inappropriate shocks in ICD patients may occur due to mechanical or technical failure of the device. In our unusual case of ICD defibrillation failure, faulty insertion and configuration of the defibrillation lead in the header port resulted in ineffective shock therapies and a non-determinable defibrillation threshold. In cases of successless defibrillations during or after ICD implantation, this problem should be considered.

[Acute cardiogenic shock with inferior myocardial infarction associated with an abnormal origin of the coronary arteries]

HISTORY

A 45-year-old previously healthy man was admitted as an emergency having suddenly gone into cardiogenic shock. He had not been on any medications. The only known risk factor for cardiovascular disease was heavy smoking.

INVESTIGATION AND DIAGNOSIS

The patient was awake and responsive on admission but showed early signs of cardiogenic shock with hypotension (systolic blood pressure 70 mmHg) and a peripheral pulse rate of 25 beats/min, cold sweat, peripheral cyanosis, nausea and retching. A 12-lead electrocardiogram revealed a bradycardic idioventricular rhythm with a wide QRS and monophasic ST segment elevation in the inferior and posterolateral leads.

TREATMENT AND COURSE

The patient required resuscitation immediately after admission because of ventricular fibrillation and was intubated. Cardiopulmonary measures of resuscitation had to be continued while an emergency coronary angiography was performed. This demonstrated an anomalous origin of both coronary arteries from the right sinus of Valsalva and proximal occlusion of a dominant right coronary artery (RCA). Several episodes of ventricular fibrillation required repeated DC cardioversion until a regular rhythm was maintained. Closed-chest cardiac compression had to be continued until percutaneous coronary angioplasty had re-established flow in the artery and a long stent had been inserted, with subsequent hemodynamic stabilization and restitution of a normal cardiac rhythm. The patient was extubated 3 days after admission.

CONCLUSION

Sudden onset of cardiogenic shock and extensive monophasic ST elevations in the ECG without clear-cut localization of coronary supply to the infarcted area should bring to mind an atypical coronary supply pattern or possible coronary artery anomaly.

[Plasma-deposited carbon coating on urological indwelling catheters: Preventing formation of encrustations and consecutive complications]

BACKGROUND

Any material placed in the urinary tract is susceptible to the formation of encrustations of crystalline bacterial biofilms. These biofilms cause severe complications in some cases. The strategies used so far for reduction of these complications by surface modifications of the implant material failed to show the expected results.

PATIENTS AND METHODS

In this study, we investigated amorphous carbon coatings (a-C:H) for their ability to effectively reduce or to repress the progressive formation of infection-enhancing crystalline biofilms as new functional surface coatings. In nine patients suffering for several years from stenting, a-C:H-coated ureteral stents were tested in treatment attempts. The current replacement intervals amounted to a mean of 77 days; the principle cause for early replacement was massive stent encrustations associated with symptomatic urinary tract infections.

RESULTS

In total, 20 coated ureteral stents were tested spanning indwelling times between 3 and 4 months. No stent-related complications occurred. In all cases extraordinarily facile handling, less pain during replacement, and markedly increased tolerance were observed. Symptomatic urinary tract infections were reduced by more than 50%. The stents remained virtually free of encrustations.

CONCLUSION

a-C:H coatings are a novel strategy leading to an enhancement of long-term applicability of ureteral stents and catheters and to improved patient comfort.

[Extended metabolic diagnosis of urolithiasis]

PURPOSE

In Germany, urolithiasis, with a frequency of 5 % and a continuously increasing incidence, must be considered as a widespread disease. Ever growing socio-economic expenses have become the focus of attention. The present treatment strategies provide only limited support for the practitioner in evaluating the often complex causes of urolithiasis and in assessing the chosen treatment. A successful treatment with minimal effort requires a general improvement of existing options in prophylaxis as well as metaphylaxis of urolithiasis. For this purpose, detailed examination and interpretation of a stone-former's urinary composition are essential.

MATERIAL AND METHODS

The following two novel and significant methods with rapid and uncomplicated application procedures are presented: 1) The easy-to-perform and accurate determination of the calcium oxalate crystallisation risk from a urine sample using the BONN risk index (BRI) for the most frequently occurring stone type (75 %). 2) Consideration of the chemical depletion of lithogenic components in a urine sample due to in-vivo growing uroliths. This phenomenon, the so-called depletion effect, can be of considerable clinical relevance due to possible determination of false normal urinary parameters.

RESULTS

This review article explains the theoretical background of these methods and the many applications of the novel methods in practice.

CONCLUSIONS

New strategies in stone prevention can help to reduce the extent of urolithiasis in a patient. The BRI enables the practitioner to optimise patient treatment without major effort. Consideration of the stone growth-related alteration of composition improves the interpretation of urine analysis.

Occasional urinary tract infections and urinary depletion effect mask RTA and carbonate-apatite formation in a strong urinary stone former

We report on a female patient with severe bilateral urolithiasis. A once-off stone analysis performed in the past revealed Mg-phosphate. Occasional UTIs were considered to be the sole cause of stone formation. To date, this assumption had not been checked thoroughly, while stone formation in the patient steadily increased. An inpatient metabolic and analytical work up was performed and stone-growth related urinary alteration was taken into account in urinalysis interpretation. No UTI. NH4Cl-loading test indicated RTA. CT revealed calculi in both kidneys. Carbonate-apatite (CAP) dominates stone composition. Computed urinary composition proximal to stones indicates hypercalciuria. In this patient, occasional UTIs (pH) masked the causes of urolithiasis. Lack of updated stone analysis (CAP), metabolic work up (RTA) and improved urinalysis interpretation (hypercalciuria) concealed the true causes of stone formation.

A bivalent chromatin structure marks key developmental genes in embryonic stem cells

The most highly conserved noncoding elements (HCNEs) in mammalian genomes cluster within regions enriched for genes encoding developmentally important transcription factors (TFs). This suggests that HCNE-rich regions may contain key regulatory controls involved in development. We explored this by examining histone methylation in mouse embryonic stem (ES) cells across 56 large HCNE-rich loci. We identified a specific modification pattern, termed "bivalent domains," consisting of large regions of H3 lysine 27 methylation harboring smaller regions of H3 lysine 4 methylation. Bivalent domains tend to coincide with TF genes expressed at low levels. We propose that bivalent domains silence developmental genes in ES cells while keeping them poised for activation. We also found striking correspondences between genome sequence and histone methylation in ES cells, which become notably weaker in differentiated cells. These results highlight the importance of DNA sequence in defining the initial epigenetic landscape and suggest a novel chromatin-based mechanism for maintaining pluripotency.

MR-Techniken zur nicht-invasiven Diagnostik des Prostatakarzinoms

The diagnosis of prostate cancer is suggested on the basis of an elevated PSA level, abnormal digital exam, and abnormal transrectal ultrasound. US-guided biopsy is used to confirm the diagnosis, but up to 30% of prostate cancer may be missed with this approach. Meanwhile MR imaging and proton MR spectroscopy have emerged as the most sensitive additional tools for the noninvasive evaluation of prostate cancer. This article reviews the clinical indications for MRI of the prostate and summarizes new techniques such as high field strength (3 tesla) and dynamic contrast-enhanced MRI.

Reprogramming efficiency following somatic cell nuclear transfer is influenced by the differentiation and methylation state of the donor nucleus

Reprogramming of a differentiated cell nucleus by somatic cell nuclear transplantation is an inefficient process. Following nuclear transfer, the donor nucleus often fails to express early embryonic genes and establish a normal embryonic pattern of chromatin modifications. These defects correlate with the low number of cloned embryos able to produce embryonic stem cells or develop into adult animals. Here, we show that the differentiation and methylation state of the donor cell influence the efficiency of genomic reprogramming. First, neural stem cells, when used as donors for nuclear transplantation, produce embryonic stem cells at a higher efficiency than blastocysts derived from terminally differentiated neuronal donor cells, demonstrating a correlation between the state of differentiation and cloning efficiency. Second, using a hypomorphic allele of DNA methyltransferase-1, we found that global hypomethylation of a differentiated cell genome improved cloning efficiency. Our results provide functional evidence that the differentiation and epigenetic state of the donor nucleus influences reprogramming efficiency.

Reduced serine–16 and threonine–17 phospholamban phosphorylation in stunning of conscious dogs

OBJECTIVE

Cardiac stunning is the consequence of a brief cardiac ischemia. The underlying mechanism is not completely understood.

METHODS

Here we induced cardiac transient ischemia in conscious instrumented dogs by means of an occluder in the left anterior descending coronary artery (LAD). Contractile performance, monitored by ultrasound crystals, was reduced during and after ischemia in the LAD area. For control in the same animals cardiac performance was measured in the area of left circumflex coronary artery (Ramus circumflexus, RCx). In the RCx area, no decline in contractility was noted. Tissue was obtained from stunned LAD area and from control areas (RCx).

RESULTS

Phospholamban phosphorylation on both serine-16 and threonine-17 was reduced in LAD areas compared to RCx areas. Reduced phosphorylation of PLB is known to inhibit cardiac contractility. While phosphorylation of PLB was reduced, the activity of the appropriate protein phosphatases and protein kinases was not different between tissue obtained from LAD or RCx areas.

CONCLUSION

Reduced formation of cAMP might underlie the contractile dysfunction in myocardial stunning.

Comparison of electrical velocimetry and transoesophageal Doppler echocardiography for measuring stroke volume and cardiac output † †Declaration of interest. This study was supported by Osypka Medical GmbH, Berlin, Germany

BACKGROUND

Impedance cardiography (ICG) has been used extensively to estimate stroke volume (SV) and cardiac output (CO) from changes of thoracic electrical bioimpedance (TEB). However, studies comparing ICG with reference methods have questioned the reliability of this approach. Electrical velocimetry (EV) provides a new algorithm to calculate CO from variations in TEB. As the transoesophageal Doppler echocardiographic quantification of CO (TOE-CO) has emerged as a reliable method, the purpose of this study was to determine the limits of agreement between CO estimations using EV (EV-CO) and TOE-CO.

METHODS

Standard ECG electrodes were used for non-invasive EV-CO measurements. These were placed on 37 patients scheduled for coronary artery surgery necessitating transoesophageal echocardiography monitoring. Simultaneous EV-CO and TOE-CO measurements were recorded after induction of anaesthesia. EV-CO was calculated using the Bernstein-Osypka equation. TOE-CO was measured across the aortic valve using continuous-wave Doppler echocardiography and a triangular orifice model.

RESULTS

A significant high correlation was found between the TOE-CO and the EV-CO measurements (r2=0.86). Data were related linearly. The slope of the line (1.10 (se 0.07)) was not significantly different from unity, and the point at which it intersected the ordinate (-0.46 (0.32) litre min(-1)) was not significantly different from zero. Bland-Altman analysis revealed a bias of 0.18 litre min(-1) with narrow limits of agreement (-0.99 to 1.36 litre min(-1)).

CONCLUSIONS

The agreement between EV-CO and TOE-CO is clinically acceptable, and these two techniques can be used interchangeably.