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Biomedical subjects

Uwe Janssens

Publications and source records attributed to Uwe Janssens.

31 records · Page 2Linked to original sources
PubMed2004

Brain natriuretic peptide kinetics during dynamic exercise in patients with chronic heart failure.

BACKGROUND: The kinetics of brain natriuretic peptide (BNP) secretion in chronic heart failure (CHF) during dynamic exercise have been the subject of controversial debate. The present study was therefore aimed to further clarify whether marked changes in BNP levels occur during and directly after vigorous exercise in CHF patients. METHODS: We prospectively studied 37 patients with CHF (60+/-10 years, LVEF 26+/-6%) and 20 healthy controls (58+/-11 years, LVEF 60+/-3%). Standardized exercise testing was performed in all CHF patients and controls. Venous blood samples for measurement of BNP were obtained prior to symptom-limited exercise, at peak exercise and at 1 and 5 min of recovery time. RESULTS: BNP concentrations were significantly higher in CHF compared to controls at rest, peak exercise and at 1 and 5 min of recovery. BNP levels did not change significantly during exercise in the control group. In CHF patients, BNP levels showed no marked difference at rest (428+/-421 pg/ml), peak exercise (507+/-450 pg/ml, n.s.), 1 min (560+/-460 pg/ml, n.s.) and 5 min recovery (526+/-424 pg/ml, n.s.). Strikingly, 6 of 37 CHF patients (16%) showed a decrease in BNP at exercise compared to rest but none of the controls. CONCLUSIONS: BNP levels in CHF patients and healthy controls are not significantly altered by vigorous exercise. In contrast to controls, 16% of CHF patients showed a decrease in BNP levels at exercise. In CHF, BNP levels were inversely correlated with peak VO(2), VO(2)-AT and LVEF.

Aged↗
PubMed2004

Brain natriuretic peptide predicts right heart failure in patients with acute pulmonary embolism.

BACKGROUND: Plasma levels of brain natriuretic peptide (BNP) are increased in patients with left heart failure. In patients with severe pulmonary embolism (PE), primary right ventricular (RV) dysfunction is frequent. Little is known about BNP secretion in acute RV failure. METHODS: We prospectively studied 50 consecutive patients with confirmed PE (age range, 57 +/- 19 years; 36 men). PE was confirmed with pulmonary angiography, spiral computed tomography, or echocardiography and subsidiary analyses. On admission, echocardiography and BNP measurements were performed in all patients. RESULTS: Patients without RV dysfunction had significantly lower BNP levels than patients with RV dysfunction (55 +/- 69 pg/mL vs 340 +/- 362 pg/mL, P <.001). There was a significant correlation between RV end-diastolic diameter and BNP (r = 0.43, P <.05). BNP discriminated patients with or without RV dysfunction (area under the receiver operating characteristic curve, 0.78; 95% CI, 0.64-0.92). A BNP >90 pg/mL was associated with a risk ratio of 28.4 (95% CI, 3.22-251.12) for the diagnosis of RV dysfunction. All patients without LV systolic dysfunction who had syncope necessitating cardiopulmonary resuscitation had normal BNP levels. Patients with RV dysfunction had significantly more in-hospital complications (cardiogenic shock, inotropic therapy, mechanical ventilation). However, BNP levels were not predictive of mortality or in-hospital complications. CONCLUSIONS: BNP levels are frequently increased in patients with PE who have RV dysfunction, whereas patients without RV dysfunction show reference range BNP levels in the absence of left ventricular dysfunction. In acute PE, BNP elevation is highly predictive of RV dysfunction, but not of in-hospital complications and mortality.

Acute Disease↗
PubMed2003

[Brain natriuretic Peptide. Diagnostic and prognostic value in chronic heart failure].

Brain natriuretic peptide (BNP) has been established as a new and reliable laboratory marker for chronic heart failure (CHF). BNP is a neurohormone secreted by the cardiac ventricles in response to volume expansion and pressure overload. It is released as N-terminal pro-brain natriuretic peptide and then Korrelaenzymatically cleaved into the NT fragment and the immunoreactive BNP. BNP promotes vasodilatation, natriuresis, diuresis, and inhibits the renin-angiotensin- aldosterone system. BNP values depend on sex, age, renal function, and the assay used. BNP exhibits a high sensitivity and specificity for the diagnosis of CHF. BNP determination improves the differential diagnosis of acute dyspnea. Normal BNP levels are found, if dyspnea is caused by pulmonary disease, pathologic BNP values are typical of a cardiac disorder. In CHF, BNP levels can be used as a reliable independent predictor of cardiac death or deterioration of cardiac functional status at follow-up. As a general screening test for CHF, BNP is of limited value due to a substantial number of false positive test results, which lead to further cardiac diagnostic testing. BNP is helpful for the assessment of the success of CHF therapy in acute cardiac decompensation and outpatients. An individually tailored CHF therapy with serial determination of BNP opens up new perspectives for a more objective and effective treatment of CHF patients.

Biomarkers↗
PubMed2003

Chemokine receptor (CCR2) genotype is associated with myocardial infarction and heart failure in patients under 65 years of age.

Inflammation is associated with atherosclerosis of coronary arteries. Chemokines have an important role in inflammation. The CCR2 chemokine receptor mediates leukocyte chemoattraction, which is involved in the pathogenesis of coronary heart disease. We prospectively studied 1960 consecutive patients aged under 65 years and referred for a first-time left ventricular catheter. Left heart catheters were analyzed by two independent cardiologists for the presence of myocardial infarction (regional wall motion abnormality) and moderate or severely reduced left ventricular function on cineventriculography and presence of coronary atherosclerosis on angiography. Genotyping for CCR2 V64I polymorphism was performed. The presence of the rare allele of the CCR2 gene was significantly associated with a higher prevalence of myocardial infarction on cinventriculography (32.0% vs. 24.2%, moderately or severely reduced left ventricular function (14.0% vs. 9.5%) and NYHA class III or IV (16.7% vs. 12.2%). The association of the CCR2 genotype with heart failure was not independent of the presence of myocardial infarction in multivariate analysis. There was no association of the CCR2 genotype with coronary atherosclerosis. The CCR2 genotype seems to predispose patients for myocardial infarction before the age of 65 years. The higher prevalence of heart failure in gene carriers with the rare alle might be a consequence of myocardial infarction. If the CCR2 genotype is associated with higher mortality in the general population must be investigated in further studies.

Alleles↗
PubMed2003

[Cost analysis and outcome prediction with the Therapeutic Intervention Scoring System (TISS and TISS-28].

BACKGROUND AND PURPOSE: The "Therapeutic Intervention Scoring System" (TISS) and the simplified version TISS-28 obtain the therapeutic workload in the critically ill and may be used for outcome prediction. The feasibility and applicability regarding cost analysis and outcome prediction of TISS and TISS-28 have been assessed in 303 consecutive medical patients staying longer than 24 h in the intensive care unit (ICU). PATIENTS AND METHODS: The mean age of the enrolled patients was 62 +/- 12 years, 216 (71%) patients were male, length of ICU stay 3.7 +/- 4.7 days, and SAPS II (Simplified Acute Physiology Score) 26 +/- 13 points. The overall mortality was 44 patients (14.5%) with 25 patients (8.3%) dying while on the ICU. RESULTS: The data collection process for TISS took significantly longer than for TISS-28. On the day of admission, the correlation of TISS and TISS-28 was excellent (r(2) = 0.91; p < 0.001). The discriminatory power as assessed by the area under the receiver operating characteristic (ROC) curve was satisfactory for TISS (0.79 +/- 0.04), TISS-28 (0.76 +/- 0.04), and SAPS II (0.77 +/- 0.04) with regard to outcome prediction. Patient-specific costs per TISS-28 point amounted to 36 euros.--and were significantly higher than the 25 euros.--calculated per TISS point. Staff costs (42%) were the most prominent cost-generating factor, and patient-specific costs contributed two thirds to the total ICU costs. There was no association of severity of illness or number of organ failure and costs. Only the length of ICU stay correlated strongly with the costs of the individual patients during the ICU stay (r(2) = 0.79; p < 0.001). CONCLUSION: The faster data collection process as well as the uniformity of the system are strong clinical and scientific advantages of the TISS-28. In addition, TISS-28 is capable of calculating individual costs in an acceptable time frame. Therefore TISS-28 serves as a valuable tool for quality assurance and cost analysis purposes in the medical ICU.

Aged↗
PubMed2003

Health-related quality of life before, 1 month after, and 9 months after intensive care in medical cardiovascular and pulmonary patients.

OBJECTIVE: Assessment of health-related quality of life before, 1 month after, and 9 months after an intensive care unit stay using an established generic instrument, the Medical Outcome Survey Short Form-36 (SF-36). DESIGN: Prospective, observational study. SETTING: University hospital medical intensive care unit. PATIENTS: Two hundred forty-five patients with predominantly cardiovascular and pulmonary disorders. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographic data, Simplified Acute Physiology Score (SAPS) II, and Sepsis-Related Organ Failure Assessment (SOFA) were obtained. All adult survivors staying in the intensive care unit for >24 hrs were eligible. Pre-intensive care unit status was obtained for 245 patients (179 males, mean age 64 yrs, mean intensive care unit stay 3 days, SAPS II 26 +/- 10), and 153 patients completed all three questionnaires. In this cohort, none of the eight health dimensions of the SF-36 showed impaired functioning after 9 months compared with baseline values. Physical and emotional role deteriorated after 1 month but returned to baseline thereafter. Notably, the mental health summary scale did not change during the course of the study, whereas the physical health summary scale consistently improved over time. Patients older than the median of 66 yrs rated their physical functioning lower. No association with SAPS II or SOFA and SF-36 was found. CONCLUSION: Quality of life after intensive care unit is a dynamic process, with some functions improving shortly after intensive care unit discharge and others deteriorating but returning at least to baseline values later on. In this patient population, the SF-36 was independent from measures of severity of illness or morbidity. Health-related quality of life represents a feasible method to collect patients' individual views in contrast to surrogate measures of outcome.

Aged↗
PubMed2002

brain natriuretic peptide levels predict functional capacity in patients with chronic heart failure.

OBJECTIVES: The goal of this study was to determine if brain natriuretic peptide (BNP) levels are associated with exercise capacity in patients with chronic heart failure (HF). BACKGROUND: Plasma levels of BNP are increased subject to the degree of systolic and diastolic left ventricular dysfunction in patients with chronic HF. Exercise testing is useful to assess functional capacity and prognosis in chronic HF. METHODS: We prospectively studied 70 consecutive patients with chronic HF (60.3 +/- 10.4 years, 51 men) referred for cardiopulmonary exercise testing. Resting BNP was obtained after 10 min of supine rest before symptom-limited bicycle exercise testing. RESULTS: In patients with chronic HF, BNP levels correlated with oxygen uptake (VO(2)), both at anaerobic threshold (VO(2)AT: r = -0.54, p < 0.001) and peak exercise (peak VO(2): r = -0.56, p < 0.001). Impairment of ventilatory efficiency (EqCO(2): r = 0.43, p < 0.001) and maximum exercise level (W % predicted: r = -0.44, p < 0.05) correlated less well with BNP. There was a significant inverse correlation between left ventricular ejection fraction and BNP (r = -0.50, p < 0.05). Brain natriuretic peptide discriminated well chronic HF patients with a peak VO(2) <10 ml/min/kg (area under the receiver operating characteristic [ROC] 0.93) or <14 ml/min/kg (area under the ROC 0.72). A BNP >316 pg/ml was associated with a risk ratio of 6.8 (95% confidence interval, 2.3 to 19.8) for a reduced exercise capacity with a peak VO(2) <14 ml/min/kg. CONCLUSIONS: Brain natriuretic peptide is clearly associated with exercise capacity in chronic HF. Brain natriuretic peptide levels show a significant correlation with the impairment of VO(2) at peak exercise and anaerobic threshold. Brain natriuretic peptide is able to differentiate between chronic HF patients with moderately and severely impaired exercise capacity.

Chronic Disease↗
PubMed2002

Analysis of resource use and cost-generating factors in a German medical intensive care unit employing the Therapeutic Intervention Scoring System (TISS-28).

OBJECTIVE: Evaluation of resource use and costs of a medical intensive care unit (ICU) utilising the simplified Therapeutic Intervention Scoring System (TISS-28). DESIGN: Prospective observational study. SETTING: : Medical ICU of a tertiary care centre. PATIENTS: Consecutive patients with an ICU length of stay (LOS) more than 24 h. INTERVENTIONS: Over a 3 month period SAPS II, TISS-28 and SOFA were determined daily. Patients were retrospectively classified as receiving active (AT) or non-active (NAT) treatment according to TISS-28 variables, with AT representing a therapeutic intervention that could not be performed outside the ICU. Individual expenditure for all patients was calculated using a modified 'top-down' method. MEASUREMENTS AND RESULTS: Out of 303 consecutive patients, 241 (79.5%), including all non-survivors, were categorised AT. The hospital mortality was 14.5%. TISS-28 and ICU LOS were higher in patients receiving AT ( p<0.001). Patient-specific costs accounted for 36 EUR per TISS-point and daily treatment costs 1336 EUR for all patients. Daily costs of care were 68 EUR higher for AT, compared to NAT, patients ( p<0.001). There was no association between ICU costs and measures of severity of illness (SAPS II, SOFA). CONCLUSIONS: TISS-28 is a fast, reliable and readily applicable tool to identify patients receiving AT. Although total and daily costs of care were significantly higher in patients receiving AT, the difference of the daily costs was, albeit statistically significant, economically negligible. The main difference in ICU costs was attributable to ICU LOS. Therefore cost-saving strategies must aim at reducing ICU LOS, without compromising quality of care.

APACHE↗
PubMed2002

Analysis of several hundred genetic polymorphisms may improve assessment of the individual genetic burden for coronary artery disease.

BACKGROUND: Single polymorphisms of different genes have been associated with coronary artery disease (CAD). The aim of this study was to evaluate the benefit of analyzing multiple genetic polymorphisms as a compound unit to assess the individual genetic burden for CAD. METHODS AND RESULTS: The study population consisted of 100 case patients with, and 100 control patients without, angiographically proven CAD. The patients were matched for age, sex, and numbers of standard cardiac risk factors. Sixteen different genetic polymorphisms were analyzed using polymerase chain reaction-based technologies. None of these polymorphisms showed a significant difference in the allele frequency between case and control patients. Eight genes with a higher allele frequency in the case group (delta allele frequency >0.05) were defined as risk alleles (RA) and subsequently tested as a compound unit. A risk stratification for 64.5% of all patients was possible when eight genes with their 16 RA were included in the analysis. With more than eight RA per individual, the odds ratio for developing CAD was 3.21 (95% CI 1.77-5.82, P<0.001). However, there was still an overlap in the number of RA in case and control patients. A computer simulation estimated that more than 200 polymorphisms were needed for a reasonable genetic discrimination for patients at risk for CAD. CONCLUSIONS: An increasing number of risk alleles are associated with an elevated risk for CAD. An analysis of multiple polymorphisms, some several hundred, each with a small impact, may allow improved assessment of the individual genetic burden for CAD. Larger studies are needed to prove this hypothesis.

Journal Article↗
PubMed1998

Clinical Determinations of Volumes of Normal and Aneurysmatic Left Ventricles by Three-Dimensional Transesophageal Echocardiography.

Biplane methods of determining left ventricular volumes are inaccurate in the presence of aneurysmal distortions. Multiplane transesophageal echocardiography, which provides multiple, unobstructed cross-sectional views of the heart from a single, stable position, has the potential for more accurate determinations of volumes of irregular cavity forms than the biplane methods. The aim of the study was to determine the feasibility of three-dimensional measurements of ventricular volumes in patients with normal and aneurysmatic left ventricles by using multiplane transesophageal echocardiography. With the echotransducer in the mid-esophageal (transesophageal) position, nine echo cross-sectional images of the left ventricle in approximately 20 degrees angular increments were obtained from each of 29 patients with coronary artery disease who had undergone biplane ventriculography during diagnostic cardiac catheterization. In 17 of these 29 patients, echo cross-sectional images of the left ventricle with the echotransducer in transgastric position were also obtained. End-diastolic volume, end-systolic volume, and ejection fraction were determined from multiplane transesophageal echocardiographic images and biplane ventriculographic images by the disc-summation method and compared with each other. In another ten patients with indwelling pulmonary artery catheters, stroke volumes calculated from multiplane transesophageal echocardiographic images were compared with those derived from thermodilution cardiac output measurements. Correlations between biplane ventriculographic and multiplane transesophageal echocardiographic measurements were higher in the ten patients with normal ventricular shape [for end-diastolic volumes, r = 0.91, SEE = 19 ml; for end-systolic volumes, r = 0.98, SEE = 9.3 ml; for ejection fractions (EFs), r = 0.91, SEE = 5.4%] than in the 19 patients with ventricular aneurysms (for end-diastolic volumes, r = 0.61, SEE = 31.5 ml; for end-systolic volumes, r = 0.66, SEE = 32.5 ml; for EFs, r = 0.79, SEE = 8%). Correlations between echocardiographic volumes from the transesophageal and transgastric transducer positions were high independent of left ventricular geometry (for end-diastolic volumes, r = 0.84, SEE = 13.1 ml; for end-systolic volumes, r = 0.98, SEE = 9.6 ml; for EFs, r = 0.97, SEE = 3.4%). In 12 observations (4 normal and 8 aneurysmal) from the ten patients with indwelling pulmonary artery catheters, correlation between stroke volumes determined from thermodilution cardiac output measurements and those derived from multiplane transesophageal echocardiographic images was high (r = 0.91, SEE = 6 ml). The results indicate that three-dimensional measurements of volumes of irregular and distorted left ventricles are feasible with multiplane transesophageal echocardiography. This method may be more accurate than biplane methods, especially in the presence of left ventricular aneurysms.

Journal Article↗
PubMedDate not supplied

Mechanisms of myocardial hypoperfusion during rotational atherectomy of de novo coronary artery lesions and stenosed coronary stents: insights from serial myocardial scintigraphy.

BACKGROUND: Rotational atherectomy (rotablation) frequently results in transient myocardial hypoperfusion due to peripheral vessel obstruction. This study compares the incidence, extent, and severity of perfusion defects induced by rotablation of de novo coronary lesions with rotablation of in-stent restenosis. METHODS AND RESULTS: Twenty-five patients undergoing rotablation for restenosed stents (group A) were studied by technetium 99m sestamibi single photon emission computed scintigraphy at rest before rotablation, during rotablation, and 2 days after the procedure. For semiquantitative analysis, perfusion in 24 left ventricular regions was expressed as percentage of maximal sestamibi uptake. The results were compared with those of 25 patients treated for de novo coronary lesions (group B). Transient perfusion defects were observed in 22 (88%) of 25 patients in group A and, similarly, in 23 (92%) of 25 in group B. Perfusion was significantly reduced during rotablation in 3.1 +/- 2.6 (mean +/- SD) regions in group A and in 3.3 +/- 2.5 regions in group B. Perfusion in the region with maximal reduction during rotablation in groups A and B was 77% +/- 13% and 76% +/- 15% at baseline. Technetium uptake decreased to 59% +/- 19% and 54% +/- 14% during rotablation (P <.001 vs baseline, P = not significant for A vs B) and returned to 76% +/- 16% and 76% +/- 15% after rotablation. Intravascular ultrasonography indicated no correlation between the volume of ablated plaque and the extent and severity of perfusion defects in in-stent restenosis. CONCLUSIONS: Incidence, extent, and severity of rotablation-related transient hypoperfusion are influenced by neither the type nor the quantity of ablated plaque material. Thus embolization of ablated plaque may be less important compared with other factors such as microcavitation or platelet aggregation.

Atherectomy, Coronary↗