Age-Dependent D-dimer Cut-off to Avoid Unnecessary CT-Exams for Ruling-out Pulmonary Embolism.

PURPOSE: To evaluate the effect of an age-dependent D-Dimer cut-off in patients who underwent a computed tomography pulmonary angiogram (CTPA) for suspected pulmonary embolism (PE) Material and Methods: Retrospective application of an age-dependent D-dimer cut-off (age/100 in patients aged over 50) in 530 consecutive patients, both in- and outpatients, aged over 18, who underwent CTPA for suspected PE according to the guidelines. RESULTS: The application of an age-dependent D-dimer cut-off showed a now negative test-result in 17 of 530 patients (3.2%). The proportion was 4.1% (17 of 418) in patients aged over 50. None of these 17 cases was diagnosed with PE in CTPA, the false-negative rate was 0%. The effect could be seen in outpatients (14 of 377 [3.7%]) as well as in inpatients(3 of 153 [2.0%]) with no statistically significant difference (p > 0.05). CONCLUSION: The application of an age-dependent D-dimer cut-off as part of the guidline-based algorithm for suspected PE reduced the number of necessary CTPA in outpatients as well as in inpatients. KEY POINTS: The application of an age-dependent D-dimer cut-off reduces the number of CTPA as part of the diagnostic algorithm in patients suspected for PENo reduction in diagnostic safety was found. The age adjustement performed equally in outpatients and inpatients

Differences in zinc status and the leptin axis in anorexic and recovered adolescents and young adults: a pilot study.

BACKGROUND: Evidence from animal studies suggests that leptin metabolism is associated with zinc (Zn) status. However, research investigating this relationship in adolescents and young adults with anorexia nervosa (AN) is scarce; the present study aims to fill that gap. METHODS: Serum concentrations of leptin, the soluble leptin receptor (sOB-R) and the free leptin index (FLI) were obtained in healthy control subjects (n=19), acutely ill individuals (n=14) and recovered patients with AN (n=15). Serum Zn concentrations noted in previous research data were also incorporated for all groups. RESULTS: Leptin, FLI and Zn concentrations were higher in recovered subjects with AN when compared with acutely ill AN patients. Remitted patients showed higher sOB-R concentrations but no difference in FLI compared with the control group. Leptin and FLI were lower in the acutely ill patients compared with the control subjects, who showed no differences in Zn concentrations. Zn concentrations were not correlated with leptin, sOB-R or FLI concentrations in any of the three investigated subgroups. CONCLUSIONS: The present investigation does not entirely support an association between Zn, Leptin and FLI concentrations in subjects with AN, possibly due to limited statistical power. Further research and replication of the present findings related to the interaction between leptin and Zn is warranted. However, with respect to serum leptin levels the data of the present investigation indicate that acutely ill and remitted patients with AN differ as regards serum leptin concentrations and FLI, which is in line with previous research.

Long- and short-term in vitro D-dimer stability measured with INNOVANCE D-Dimer.

In vitro D-dimer stability in plasma is widely assumed, but has not yet been documented by systematic studies using samples covering a wide range of D-dimer. We investigated the short- and long-term stability of D-dimer in clinical citrated plasma samples with normal and pathological levels. The short-term stability was analysed by measuring D-dimer fresh, after storage of plasma for 4 hours at room temperature (RT) and after an additional 24 h storage at +2 to +8 degrees C (n=40). Long-term stability samples (n=40) were measured fresh and after storage for 19, 25 and 36 months at < or =-60 degrees C. The effect of repeated freezing was analysed by measuring samples (n=50) fresh and after four consecutive freeze-thaw cycles. D-dimer was measured on the BCS System using the INNOVANCE D-Dimer assay (Siemens Healthcare Diagnostics Products GmbH, Marburg, Germany). D-dimer values at baseline ranged from 0.23-22.2 mg/l FEU. The mean percentage change after storage for 4 hours at RT and additional 24 hours at +2 to +8 degrees C was +3.8% and +2.7%, respectively. The mean percentage change after frozen storage for 19, 25 and 36 months at < or =-60 degrees C was -11.7%, -4.8% and -9.3%, respectively. The small decrease of D-dimer values after frozen storage was not time-dependent. Repeated freezing did not significantly alter D-dimer values (mean change < or =5%). The data demonstrate stability of D-dimer in plasma prior to freezing for up to 4 hours at RT and for up to 24 hours at +2 to +8 degrees C as well as in plasma stored for up to three years at < or =-60 degrees C.

[Haemostatic testing prior to elective surgery? Yes!]. / Laboranalytischer Ausschluss einer hämorrhagischen Diathese vor elektiven Eingriffen? Ja!

Haemorrhagic disorders must be excluded prior to any operation or other invasive procedure that has the potential to involve serious bleeding. When assessing the individual risk of bleeding, screening tests of hemostasis must be combined with the patient's clinical history and symptoms, and any history of bleeding must be explored under direct medical supervision using a standardized questionnaire. However, this bleeding history is neither very specific, nor is it particularly sensitive. Screening tests that have been found to be useful include platelet count, activated partial thrombo plastin time (aPTT), prothrombin time (PT) and clottable fibrinogen. No reliable, sensitive and specific screening test is however available today to screen for platelet dysfunction or von Willebrand disease. A specialized coagulation laboratory should be involved when the bleeding history or laboratory screening indicate a potential haemorrhagic disorder.

Prognostic value of plasma tissue factor and tissue factor pathway inhibitor for cardiovascular death in patients with coronary artery disease: the AtheroGene study.

BACKGROUND: Tissue factor (TF) and its specific inhibitor, tissue factor pathway inhibitor (TFPI), are important contributors to the initiation of the coagulation process. OBJECTIVES: To compare plasma levels of soluble TF (sTF) and free-TFPI (f-TFPI) between patients with stable angina pectoris (SAP) and acute coronary syndrome (ACS) and to assess the impact of the two variables on long-term prognosis. PATIENTS/METHODS: Patients with SAPs (n = 1146) and acute coronary syndrome (n = 523) from the AtheroGene study were included and followed for 2.3 years. Because of the strong impact of unfractionated heparin (UFH) on f-TFPI levels, but not on sTF levels, patients having received UFH before blood drawing were excluded from the analyses on f-TFPI (n = 226). RESULTS: On admission, no significant differences in sTF levels were observed between SAP and ACS patients. By comparison to patients with stable angina, f-TFPI levels significantly increased in patients with acute unstable angina and further increased in patients presenting with non-ST-elevation myocardial infarction and ST-elevation myocardial infarction (P < 10(-4)). Among the 1669 individuals with a coronary artery disease, 56 died from a cardiovascular cause. In prospective analyses, high sTF levels were independently associated with an increased risk of cardiovascular death in individuals with ACS (fully adjusted hazard ratio associated with one quartile increase = 2.06; 95% confidence interval 1.24-3.45; P = 0.006) but not in those with SAP (hazard ratio = 1.07; 95% confidence interval 0.78-1.46; P = 0.67). In SAP and ACS patients, high f-TFPI levels were not independently associated with an increased risk of cardiovascular death. CONCLUSIONS: Plasma sTF levels were predictive of cardiovascular mortality in individuals with ACS, whereas f-TFPI levels were associated with the severity of myocardial damage on admission but were not independently related to outcome.

Haemostatic factors and the risk of cardiovascular death in patients with coronary artery disease: the AtheroGene study.

OBJECTIVE: To get a better insight into the role of hemostasis in coronary artery disease (CAD), we assessed the impact of von Willebrand factor (vWF), fibrinogen, thrombin-antithrombin (TAT) complexes, D-dimers, and plasmin-antiplasmin (PAP) complexes on the risk of cardiovascular event in a prospective cohort of CAD patients. METHODS AND RESULTS: The prospective Atherogene cohort includes 1057 individuals with an angiographically proven coronary artery disease at baseline. After a median follow-up of 6.6 years, 135 individuals died from a cardiovascular cause and 97 had a nonfatal cardiovascular event. Higher levels of all 5 hemostatic markers at baseline were associated with an increased risk of cardiovascular death, but not of nonfatal event. Except for vWF, these associations remained significant after adjustment for conventional cardiovascular risk factors and C-reactive protein (CRP) levels (P for trend according to increasing tertiles=0.20, 0.011, 0.026, 0.019, and 0.01 for vWF, fibrinogen, TAT, D-Dimer, and PAP, respectively). When including the 5 hemostatic markers in a stepwise Cox regression analysis where conventional risk factors and CRP were forced into the model, fibrinogen and D-dimers remained independently associated with the risk of cardiovascular death. Adjusted hazard ratios (95% CI) associated with one SD increase of fibrinogen and D-dimers were 1.27 (1.04 to 1.55) and 1.29 (1.09 to 1.53), respectively. CONCLUSIONS: In patients with coronary artery disease, fibrinogen and D-dimer levels are independent predictors of subsequent cardiovascular death. Our data support a role of impaired coagulation/fibrinolysis process in the complications of coronary artery disease.

[Brain-natriuretic-peptide (BNP) for improvement of the diagnostic determination in a conserving emergency room]. / Brain-natriuretic-peptide (BNP) zur Verbesserung der Diagnosefindung in einer konservativen Notaufnahme.

BACKGROUND: Dyspnea is one of the most common symptoms for presentation in an emergency department. Evaluation of this very unspecific symptom can be very time-consuming and costly. Thus, we investigated the value of a rapid bedside-test for BNP in discriminating dyspnea due to "cardiac" reasons from "non-cardiac" dyspnea in the emergency room. METHODS AND RESULTS: We studied 100 patients who presented to the emergency department with "severe dyspnoea" as the leading symptom. In all patients BNP was determined from blood samples drawn on admission. All patients had to complete a dyspnea score for severity of dyspnea. The treating physician was blinded to the results of BNP measurements. After discharge patients were divided into "cardiac" and "non-cardiac" dyspnea on the basis of all findings gathered during the hospital stay by a panel of 3 physicians blinded to the results of BNP measurements. The 2 groups were compared for difference in BNP levels and for differences in the dyspnea score. While the dyspnea score showed no significant difference, there was a significant difference in BNP measurements (p < 0.0001). CONCLUSIONS: With the TRIAGE BNP test a rapid discrimination between dyspnea due to ventricular failure and "non-cardiac" dyspnea can be obtained within 20 minutes after first presentation. This test can save time and resources in this critical group of patients.

[Influence of impaired fasting glucose on the incidence and prognosis of atherosclerosis in various vascular regions]. / Einfluss eines gestörten Glukosestoffwechsels auf Manifestationen und Prognose der Atherosklerose in verschiedenen Gefässregionen.

UNLABELLED: Patients with cardiovascular disease have a poorer diagnosis if they are diabetic. The risk for cardiovascular events is already increased in individuals with impaired fasting glucose (IFG). The aim of this study was to evaluate the impact of diabetes mellitus (DM) and IFG on the incidence of atherosclerotic manifestations and on the long-term prognosis of patients with atherosclerosis in various vascular regions. METHODS: In a prospective study we included 906 patients (72.5% men, mean age 62 +/- 9 years) preceding heart catheterization. All patients were evaluated for the presence of peripheral stenosis by carotid duplex sonography (pathologic: stenosis >50%) and evaluation of the ankle-brachial index (pathologic <0.9). Blood samples were drawn from each subject after an overnight fasting period and serum glucose was evaluated. RESULTS: Patients were compared with regard to the presence of DM (known DMor fasting glucose > or =126 mg/dL, N = 283, 31.2%) or IFG (fasting glucose >110 and <126 mg/dL, N = 89, 9.8%). Patients with IFG and DM had a higher prevalence of atherosclerotic manifestations in the coronary, carotid and peripheral vessels. Diabetics had the highest prevalence of atherosclerotic manifestations in multiple vascular regions (=advanced atherosclerosis). Cardiovascular events (death, myocardial infarction and stroke) after a median follow-up of 4.1 years were evaluated in 901 patients (99.4%). Presence of IFG and DM significantly increased the incidence of cardiovascular events (event rate: no DM 10.9%, IFG 13.6%, DM 23.4%, P < 0.0001). Moreover, patients with advanced atherosclerosis suffered significantly more often from cardiovascular events (event rate: no stenosis 4.1%, coronary artery disease without peripheral stenosis 9.7%, advanced atherosclerosis 23.9%). Prognosis was worst in patients with DM and advanced atherosclerosis with an event rate of 35%.Patients with cardiovascular disease have a poorer prognosis if they are diabetic. The risk for cardiovascular events is already increased in individuals with impaired fasting glucose (IFG). The aim of this study was to evaluate the impact of diabetes mellitus (DM) and IFG on the incidence of atherosclerotic manifestations and on the long-term prognosis of patients with atherosclerosis in various vascular regions.

[Prevention of thromboembolism in trauma surgery by dose adjustment of low molecular weight heparin depending on levels of TAT and D-dimer]. / Prävention thromboembolischer Komplikationen in der Unfallchirurgie durch Dosisanpassung von niedermolekularem Heparin anhand TAT- und D-Dimer-Werten.

Deep vein thrombosis (DVT) is reported in up to 40% of trauma patients. The individual risk is nearly unpredictable. A daily single dose of a low molecular weight heparin (LMWH) was administered as prophylaxis to 518 trauma patients who were examined preoperatively and up to 10 days postoperatively in a prospective study. They were divided into two groups: group I comprised surgery of the hip and femur as well as total knee replacement and group II knee and lower leg surgery. Thrombin-antithrombin complex and D-dimer were analyzed. A second daily dose of LMWH was added if D-dimer exceeded the cutoff. If ultrasound was suspicious for DVT venography was added. Deep vein thrombosis was seen in five cases (group I=4, group II=1), without pulmonary embolism. TAT and D-dimer were significantly higher in group I than in group II ( p<0.005). One hundred patients, 79 of them belonging to group I, were treated with a second dose of LMWH. The daily cutoff had the highest sensitivity and specificity for day 4. Due to individual monitoring of coagulation markers, the risk for thromboembolism compared to actual data in the literature seems to be reduced.

Effects of combined therapy of clopidogrel and aspirin in preventing thrombus formation on mechanical heart valves in an ex vivo rabbit model.

BACKGROUND: The aim of our study was to investigate the efficacy of the combination of clopidogrel and aspirin in the prevention of thrombus formation on artificial heart valves in an experimental rabbit model as compared to anticoagulation with warfarin. METHODS: Studies were performed after oral administration of clopidogrel and aspirin in group I (n=9) for 5 days, after 5+/-2 days treatment with warfarin in group II (n=9) and without medication in group III (n=9). Leaflets from Sulzer Carbomedics bileaflet valves were placed in a flow chamber. The flow chamber was filled with blood in a continuous circulation between the carotid artery and the jugular vein. RESULTS: In group III, the flow chamber was clotted after a median of 15 min of circulation. Weight analysis before and after 1 h of perfusion showed that the median thrombus weight was 9.1 mg in group I, 14.4 mg in group II and 33.7 mg in group III. Further analysis by electron microscopy showed fewer platelets and erythrocytes on leaflets in group I than on leaflet surfaces in group II. CONCLUSION: Clopidogrel and aspirin were more effective than warfarin in preventing thrombus formation on artificial heart valve leaflets in our investigation. This rabbit model with a high dosage of clopidogrel and aspirin, and a short-time exposure of the heart valve leaflets to rabbit blood under laminar flow, should be further evaluated with respect to whether it can give information about antithrombotic regimens in patients after mechanical heart valve replacement.

[Coronary revascularization: off-pump versus on-pump--a comparison of behavior of biochemical cardiac ischemia markers]. / Koronarrevaskularisation: Off-pump versus On-pump--Verhalten der biochemischen kardialen Ischämiemarker im Vergleich.

BACKGROUND: Recently, coronary artery bypass grafting (CABG) on the beating heart with avoidance of extracorporeal circulation (off-pump CABG technique) has been gaining increasing importance in modern cardiac surgery. The object of this prospective study was to compare postoperative kinetic and patterns of cardiac troponin I (cTnI), T (cTnT), and creatine kinase MB (CKMB) activities after off-pump CABG versus conventional on-pump CABG. METHODS: We studied 106 patients who underwent first-time elective on-pump (group I, n = 69, 56 male, 13 female, mean age: 64.3 +/- 9.9 years, mean ejection fraction: 56 +/- 15%) or off-pump (group II, n = 37, 24 male, 13 female, mean age: 68.4 +/- 9.1 years, mean ejection fraction: 57 +/- 13%) CABG surgery via median sternotomy. CTn I and cTnT levels, total creatine kinase (CK) and CK-MB activities in the serum were measured before operation, up on arrival at the ICU and 6, 12, 24, 48 and 120 hours later. Serial 12-lead ECGs were recorded preoperatively and on days 1, 2 and 5. RESULTS: Serum concentrations of cardiac troponins in all patients were preoperatively either not detectable or in the normal range and significantly increased after surgery. In group I, one patient developed a Q wave myocardial infarction, one patient a non-Q wave infarction and two patients a new left bundle branch block on the ECG. One patient of group II developed a new Q-wave myocardial infarction and another patient permanent atrial fibrillation associated with a continuous arrhythmia. All patients with a myocardial infarction in the ECG showed significant elevation of concentrations or activities of these biochemical markers. The median postoperative peak values for cTnI were measured at 24 h in both groups (2.7 micrograms/l, 95%-CI: [2.2, 3.2] in group I and 1.1 micrograms/l, 95%-CI: [0.5, 1.3] in group II). CTnT postoperatively presented an earlier median peak of 0.128 microgram/l at 12 h in group II (95%-CI: [0.041, 0.146]) than in group I at 48 h (0.298 microgram/l, 95%-CI: [0.254, 0.335]). CONCLUSIONS: All patients undergoing CABG surgery with or without extracorporeal circulation postoperatively showed an increase of cardiac troponin levels. After uncomplicated coronary revascularization, patients with the off-pump CABG technique continuously presented lower serum cardiac troponin concentrations than those with the on-pump CABG technique. CTnI showed the same patterns of release in both groups with different median postoperative peak values at 24 h. The patterns off cTnT release following CABC surgery with or without extracorporal circulation were different: CTnT reaches its postoperative peak value in patients with the off-pump CABG technique earlier than those with the on-pump CABG technique (12 h postoperatively versus 48 h).

Postoperative reduction of fibrinolysis as a prognostic factor of fatal outcome.

For the resection of an esophagus carcinoma a mortality rate of 2 to 30% was described. It is still unclear whether an abdominothoracic or transhiatal intervention is superior regarding the outcome. To investigate the prognostic value of fibrinolytic markers, plasmin-alpha2-antiplasmin (PAP) and D-dimer (DD) values were determined daily in the early postoperative period for 11 days. In addition, the course of PAP and DD concentrations was compared with the method of esophagectomy. Of the 28 patients enclosed in the study, 5 died between day 10 and day 34 owing to adult respiratory distress syndrome and septicemia. The PAP and DD concentrations increased in survivors after surgery until day 5 and day 7, respectively. The concentrations were twofold and 10-fold higher than the upper reference level. In contrast, four of five nonsurvivors showed an inadequate increase in PAP concentrations within the reference range, whereas the course of DD was inconspicuous. The sensitivity and specificity of PAP and DD in respect to a fatal outcome was calculated by receiver operating characteristic analysis based on all results: sensitivity 76% (PAP-cut off value 760 microg/L) and 49% (DD 6 mg/L), specificity 77% and 72%, respectively. The biochemical markers showed no significant differences between the abdominothoracic and transhiatal esophagectomy. In the abdominothoracic intervention, lower PAP and higher DD concentrations were observed. The results showed that the PAP concentrations could detect a fatal outcome within the first 5 days after surgery.

Circulating cell adhesion molecules and death in patients with coronary artery disease.

BACKGROUND: Vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, and E-selectin mediate adhesion and transmigration of leukocytes to the vascular endothelial wall and may promote plaque growth and instability. In a prospective study, we evaluated the effect of soluble adhesion molecules on the risk of future cardiovascular events among patients with angiographically documented coronary artery disease (CAD). Methods and Results- -We obtained baseline samples from a prospective cohort of 1246 patients with CAD. Besides various markers of inflammation, soluble VCAM-1 (sVCAM-1), sICAM-1, and sE-selectin were determined. Follow-up information on cardiovascular events was obtained (mean, 2.7; maximum, 4.1 years). Independently higher levels of sVCAM-1 (1932 versus 1128 ng/mL; P<0.0001), sICAM-1 (353 versus 287 ng/mL; P=0.015), and sE-selectin (81 versus 63 ng/mL; P=0.003) were observed in patients with future death from cardiovascular causes. In a multivariate model, fatal risk was 2.1-fold (1.1 to 4.0) higher in patients within the top quartile of baseline sVCAM-1 concentrations compared with lower quartiles. This association was present independent of general inflammatory response as reflected by low or high C-reactive protein (hs-CRP) levels. In a model that simultaneously controlled for all inflammatory and soluble adhesion markers determined, only sVCAM-1 remained independently significant for future fatal cardiovascular events, with a 2.8-fold increase in risk (P=0.003). CONCLUSIONS: Soluble adhesion molecules sVCAM-1, sICAM-1, and sE-selectin were significantly related to future death from cardiovascular causes among patients with documented CAD. Especially sVCAM-1 added to the predictive value of classic risk factors and hs-CRP in determining the risk of future cardiovascular death.

Comparison of diagnostic performance of cardiac troponin I on the IMMULITE system with other automated troponin I assays in minor myocardial damage.

An analytical and clinical evaluation of cardiac troponin I (cTnI) on the IMMULITE system is presented. The assay results were compared with those of the Stratus II and the Dimension RxL-HM. A between-run imprecision CV < 20% was found at a cTnI concentration of 0.23 microg/L (functional limit of detection). On the basis of a reference study including 215 patients without ischemic heart disease (97.5th percentile: 0.294 microg/L) and 36 patients clinically classified as having stable angina pectoris (<0.22 microg/L) a preliminary cutoff level of 0.3 microg/L was defined. Assay linearity, sample stability, influence of sample material and method comparison studies were performed. In patients with Duchenne's disease, chronic hemodialysis treatment, pulmonary embolism, coronary artery bypass surgery and minimally cardiac surgery the cTnI results of the IMMULITE agreed better with the Dimension RxL-HM than with the Stratus II data. Of 142 samples from patients with unstable angina 67 samples were classified as cTnI positive with the IMMULITE, 76 with the Dimension RxL-HM, and 62 with the Stratus II. In conclusion, the new assay is sensitive for the determination of cTnI and easy to perform within 45 min.

Evaluation of the new ImmuliteTurbo cTnI assay and the original immulite cTnI assay.

OBJECTIVES: An analytical and clinical evaluation of cTnI on the ImmuliteTurbo system with 15 min assay time compared to 45 min with the original Immulite assay is presented. METHODS AND DESIGN: Detection limit, functional sensitivity, AMI decision limit, assay linearity, influence of sample material (serum, heparin, citrate and EDTA plasma), interference, analytical and clinical method comparison studies were performed. RESULTS: Functional sensitivity (at CV 20%) was 0.35 compared to 0.23 microg/L for the original assay. AMI decision limit (99th percentile of a reference control group) was 0.48 microg/L for both assays. In patients with acute coronary syndromes, chronic renal failure or pulmonary embolism the assays showed concordant results in 87.2-96.5%. Differing results were only found around the cut-off level and were attributed to assay imprecision. CONCLUSION: The new assay is sensitive for the determination of cTnI, shows comparable results to the original assay version and is easy to perform within 15 min.

Troponin I concentrations of shed blood might influence monitoring of myocardial injury after coronary operations.

In a prospective study we evaluated the concentration of cardiac troponin I (cTnI) and creatine kinase activities (CK) in shed mediastinal blood in the early postoperative period after coronary artery bypass grafting (CABG). Forty seven patients who underwent first time elective CABG were studied. CTnI levels and CK activities in arterial blood and shed mediastinal blood were measured after admission to the intensive care unit (ICU) and 6 h after unclamping the aorta. Mediastinal shed blood samples were drawn from 23 patients (group A) before the filter of the cardiotomy reservoir and from 24 patients (group B) behind. Additionally, both markers were measured in blood samples collected from the cell-saver. There were no significant differences between both groups (A and B) with regard to perioperative parameters. Mean loss of mediastinal shed blood in all patients was 207 +/- 127 ml within the first 6 h after operation. There was a positive correlation between CK activities and cTnI concentrations in serum and mediastinal shed blood, but shed blood contained significantly higher concentrations of cTnI as well as CK activities than the circulating blood after admission to the ICU and 6 h after unclamping the aorta. At both time points the cTnI-concentrations and CK activities in shed blood in group B were lower than those in group A but much higher than in serum. The effects of the use of a blood filter diminishes with time. Mediastinal shed blood contains extremely high cTnI concentrations and CK activities. Retransfusion of higher quantities of shed blood might lead to false-positive diagnosis of perioperative myocardial infarction.

Analytical and clinical evaluation of troponin I determination on dimension RXL-HM.

The evaluation of cardiac troponin I (cTnI) on the Dimension RxL-HM analyzer is presented. The one-step enzyme immunoassay is based on two cTnI specific monoclonal antibodies. Performed on a separate module of the analyzer, assay-time is 17 minutes. Using as criterion a between-run impression CV <20% the functional limit of detection was set at 0.1 microg/l. Cutoff level for minor myocardial damage of 0.1 microg/l was found. In Duchenne's dystrophy, patients showed increased cardiac Troponin T (cTnT) but no increased cTnI. In patients with a history of coronary heart disease undergoing chronic hemodialysis, cTnT and cTnI were increased. In different patients with submassive pulmonary embolism, increased cTnI was determined. In coronary artery bypass surgery without perioperative myocardial infarction, patients with extracorporeal circulation showed significantly higher cTnI at 24 h after surgery than those with minimal cardiac surgery. In patients with unstable angina, increased cTnI was found more often than on Stratus analyzer. In conclusion, the new assay is a very sensitive cTnI assay, fast and easy to perform in parallel to enzyme and substrate assays.

Dose-adjusted thrombosis prophylaxis in trauma surgery according to levels of D-Dimer.

In 234 trauma surgery patients, thrombosis prophylaxis with Nadroparin-Calcium low-molecular-weight heparin (LMWH) was adjusted according to levels of D-Dimer. Basic prophylaxis was 2,850 IU per day. If D-Dimer concentrations rose above 2 mg/L after the fourth postoperative (p.o.) day, LMWH was administered twice a day. Color Doppler ultrasound was performed between the fifth and seventh p.o. days. Patients were divided into a high-risk (group 1: hip, femur, or knee replacement surgery, n=102) and a moderate-risk group (group 2: other surgery of the knee, tibia, fibula, or foot, n=132). Group 1 showed significantly higher D-Dimer levels than group 2 (p<0.001). Measurement of D-Dimer on days 2 and 4 p.o. showed a sensitivity of 100% and a specificity of 72.8% in identifying patients at risk (i.e., D-Dimer>2 mg/L after day 4 p.o.). The overall deep vein thrombosis (DVT) rate in group 1 was 3.9%, and the rate of proximal DVT was 1.96%. In group 2, one distal DVT (0.8%) occurred. The results show that D-Dimer is a useful marker to monitor p.o. coagulation activation and to manage LMWH prophylaxis in trauma surgery patients.

Retinal vascular occlusion and deficiencies in the protein C pathway.

PURPOSE: To report abnormalities in the protein C pathway and other vascular occlusion risk factors in patients with retinal vascular occlusion. METHODS: In a study, we investigated 76 consecutive patients who had in-patient evaluation of venous or arterial retinal vascular occlusion. All patients underwent comprehensive tests for coagulation disorders including determinations of protein C, protein S, lupus anticoagulants, and resistance to activated protein C and were screened for vascular disease risk factors. Resistance to activated protein C was confirmed by a polymerase chain reaction method to detect the specific factor V R506Q mutation. For comparative purposes, we also screened 209 consecutive inpatients with deep vein thrombosis from the same geographic region for resistance to activated protein C as well as protein C and protein S deficiencies. RESULTS: Ten (29%) of 35 patients with central retinal vein occlusion (CRVO) had factor V R506Q mutation. The factor V R506Q mutation was detected in four (19%) of 21 patients with branch retinal vein occlusion. The higher frequency in factor V R506Q mutation compared with the expected 9% mutation prevalence in a white population was highly significant for the central retinal vein occlusion group but not for the branch retinal vein occlusion group. In all patients with resistance to activated protein C, the factor V R506Q mutation was detected; 16 were heterozygous, one homozygous. No cases of lupus anticoagulants, protein C, or protein S deficiencies were detected. Forty (19%) of 209 patients with deep vein thrombosis were carriers of the factor V R506Q mutation. CONCLUSIONS: The prevalence of the factor V R506Q mutation is similar in patients with central retinal vein occlusion and patients with deep vein thrombosis and represents a relevant risk factor. Screening for this mutation is therefore recommended in all patients with central retinal vein occlusion.