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At least 1,027 records · Page 57Linked to original sources
PubMed2002

Stratification of mammographic computerized analysis by BI-RADS categories.

The Breast Imaging Reporting and Data System (BI-RADS) was implemented to standardize characterization of mammographic findings. The purpose of the present study was to evaluate in which BI-RADS categories the changes recommended by computerized mammographic analysis are most beneficial. Archival cases including, 170 masses (101 malignant, 69 benign) and 63 clusters of microcalcifications (MCs; 36 malignant, 27 benign), were evaluated retrospectively, using the BI-RADS categories, by several radiologists, blinded to the pathology results. A computerized system then automatically extracted from the digitized mammogram features characterizing mammographic lesions, which were used to classify the lesions. The results of the computerized classification scheme were compared, by receiver operating characteristics (ROC) analysis, to the conventional interpretation. In the "low probability of malignancy group" (excluding BI-RADS categories 4 and 5), computerized analysis improved the A(z )of the ROC curve significantly, from 0.57 to 0.89. In the "high probability of malignancy group" (mostly category 5) the computerized analysis yielded an ROC curve with an A(z )of 0.99. In the "intermediate probability of malignancy group" computerized analysis improved the A(z )significantly, from 0.66 for to 0.83. Pair-wise analysis showed that in the latter group the modifications resulting from computerized analysis were correct in 83% of cases. Computerized analysis has the ability to improve the performance of the radiologists exactly in the BI-RADS categories with the greatest difficulties in arriving at a correct diagnosis. It increased the performance significantly in the problematic group of "intermediate probability of malignancy" and pinpointed all the cases with missed cancers in the "low probability" group.

Biopsy↗
PubMed2004

Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia.

The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) ( P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event ( P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy.

Cardiotonic Agents↗
PubMed1998

[Duplex ultrasound risk stratification of percutaneous puncture of the brachial artery for diagnostic and interventional coronary angiography].

Diagnostic and interventional heart catheterization in peripheral vascular disease often requires due to iliacal disease additional methods of arterial approach besides the Judkin's technique. The percutaneous catheterization of the brachial artery finds widespread use. A major complication linked with this method is an increased rate of thrombotic occlusions at the puncture site. Thus, we investigated in a prospective set-up the ability of duplex ultrasound to identify predictive risk factors for vascular complications. Over a period of 20 months, 8000 patients referred to heart catheterization were studied. Routine catheterization via the femoral route was contraindicated in 34 out of 8000 mostly due to severe peripheral vascular disease with multiple vascular risk factors (diabetes, hypertension, and smoking). 53 patients who had a comparable low risk-profile served as the control group. The brachial artery was examined by ultrasound duplex for vessel anatomy and diameter at the puncture site before coronary angiography. Both groups (patient and control group) showed in 15% a variable anatomy with a premature division of the brachial artery in 6% proximal of the elbow and in 9% already distal to the axillary artery. Because of reduced diameters of these variable vessels no procedure was carried out at these arms. In all cases the opposite arm was successfully used instead, because the variants were always located only at one arm. The diameter of the brachial artery measured in average 5.0 +/- 0.8 mm and 4.8 +/- 0.7 mm in patients and controls, respectively. Women had a significantly smaller vessel diameter than men, measuring a difference of 0.4 and 0.6 mm, respectively (p < 0.05). For coronary angiography 6F and 7F arterial sheats were used equally, and in 32% of all cases a coronary intervention was performed. 31 (91%) procedures were carried out without complications; there was a false aneurysm in 1 patient (3%) and an occlusion of the brachial artery at the puncture site in 2 patients (6%). The occluded vessels of two diabetic women had a reduced diameter at the level of 10% of the standard distribution and an unfavorable ratio of sheat-to-vessel-diameter which lead initially to an obstruction of nearly 50% of the vessel lumen during catheterization. Screening of the brachial artery by ultrasound duplex before a percutaneous catheterization for coronary angiography and intervention showed reproducibly the variable anatomy and differences in vessel diameter, which can be risk factors for thrombotic occlusion. Important details for the location of the puncture site and the possible size of the arterial sheat can be obtained, so that coronary interventions with 7F catheter systems are still practicable. This technique is a simple and efficient method to estimate the relative risk of arterial occlusion prior to percutaneous puncture of the brachial artery, especially in a group of patients with severe atherosclerosis and elevated vascular risk-factors.

Adult↗
PubMed2000

Baroreflex sensitivity as a new marker for risk stratification.

As the arterial baroreflex importantly contributes to modulation of the autonomic influences on the heart and thereby arrhythmogenesis, baroreflex sensitivity has been used as a measure of the interaction between sympathetic and parasympathetic activities at the cardiac level. The most widely applied technique both in the experimental and clinical setting is the measurement of the heart rate slowing in response to a blood pressure rise induced by small intravenous boluses of phenylephrine. Baroreflex sensitivity is expressed as ms/mmHg and prevailing vagal reflexes are reflected by the wider R-R interval lengthening. The experimental evidence that the occurrence of ventricular fibrillation was inversely related to baroreflex sensitivity, opened the way to clinical studies. The ATRAMI (Autonomic Tone and Reflexes After Myocardial Infarction) trial has definitely demonstrated not only that a depressed baroreflex sensitivity (< 3 ms/mmHg) is a strong risk factor for cardiac death, but also that the information gained by the analysis of autonomic markers adds to the information obtained by better recognized measures of cardiovascular outcome such as left ventricular function and ventricular arrhythmias. The value of a depressed baroreflex sensitivity as a risk stratifier is meaningful in patients below age 65 in combination of a simultaneously depressed left ventricular ejection fraction. In these patients, the analysis of autonomic activity might be of value in the identification of patients who may need an implantable automatic defibrillator for primary prevention of sudden cardiac death.

Animals↗
PubMed2006

Stratification of medulloblastoma on the basis of histopathological grading.

Medulloblastoma (WHO grade IV) is an embryonal tumour of the cerebellum and the most common malignant central nervous system tumour in children. Despite significant advances in treatment, 5-year survival rates are still less than 70%, suggesting the presence of subgroups with different response to radio/chemotherapy. In the present study, we re-evaluated a series of 347 medulloblastomas from the SIOP II clinical trial of the International Society of Paediatric Oncology to identify features predictive of clinical outcome. Relapse free survival for medulloblastomas with severe anaplasia [5-year rate: S(60)=49.5%], was significantly shorter than for tumours with moderate or mild anaplasia S(60)=65.4%; P=0.001). The difference between both groups was even larger when the presence or absence of extensive apoptosis was included (46.5 vs. 66.7%; P=0.0216). Other histological features including nodularity, necrosis, vascular proliferation and the presence of beta-catenin mutations (7% of cases) were not predictive for relapse free survival. These findings indicate that degree of anaplasia is the most significant histologic feature predictive of the survival of medulloblastoma patients.

Adolescent↗
PubMed2003

Stratification by CARD15 variant genotype in a genome-wide search for inflammatory bowel disease susceptibility loci.

Previously we have conducted a genome-wide search for inflammatory bowel disease susceptibility loci in a large European cohort. Results from this study demonstrated suggestive evidence of linkage to loci at chromosomes 1q, 6p, and 10p and replicated linkages on chromosomes 12 and 16. Recently, NOD2/CARD15 on chromosome 16q12 has been found to be strongly associated with Crohn's disease. In order to determine if there are other loci in the genome that interact with the three associated functional variants in CARD15 (R702W, G908R, 1007fs), we have stratified our large inflammatory bowel disease genome scan cohort by dividing pedigrees into two groups stratified by CARD15 variant genotype. The two pedigree groups were analysed using non-parametric allele sharing methods. The group of pedigrees that contained one of the three CARD15 variants had two suggestive linkage results occurring in 6p (lod = 3.06 at D6S197, IBD phenotype) and 10p (lod=2.29 at D10S197, CD phenotype). In addition, at 16q12 where CARD15 is located, the original genome scan had a peak lod score of 2.18 at D16S415 (CD phenotype). The stratified pedigree cohort containing one of three CARD15 variants had a peak lod score of 0.90 at D16S415 (CD phenotype), accounting for approximately less than half of the genetic evidence for linkage at this locus. This result is in agreement with the existence of a substantial number of private variants at the NOD2/CARD15 locus. Interaction with NOD2/CARD15 needs to be considered in future gene identification efforts on chromosomes 6 and 10.

Apoptosis Regulatory Proteins↗
PubMed2002

Preoperative risk stratification using electron beam computed tomography in elective vascular surgery: relationship to clinical risk prediction and postoperative complications.

We studied the utility of electron beam computed tomography as a screening test for the cardiovascular risk of elective vascular surgery. In 45 patients undergoing principally carotid and aortic surgical procedures, coronary artery calcification was prevalent and severe, and related to the clinically predicted cardiovascular risk of the procedure. However, only the clinically predicted surgical risk, and not coronary artery calcification, was related to the incidence of perioperative cardiovascular complications.

Aged↗
PubMed2002

New biomarkers in the risk stratification of patients with suspected acute myocardial infarction.

The acute coronary syndromes (ACS) remain a diagnostic and prognostic challenge for today's physician. Over the past decade, studies have identified several serologic biomarkers to aid the clinician in assessing risk and predicting outcomes in ACS. Still others are being identified that show promise for increasing the accuracy with which this risk is assessed. However, further research remains necessary to identify the perfect cardiac biomarker or combination of markers and to define their roles in clinical management of ACS patients.

Biomarkers↗
PubMed2003

T-wave alternans for risk stratification and prevention of sudden cardiac death.

Despite considerable progress in the management of ischemic heart disease, a substantial proportion of patients continue to experience life-threatening arrhythmic events. The Multicenter Automatic Defibrillator Implantation Trial 2 has recently shown the superiority of implantable cardioverter defibrillators (ICDs) over conventional strategies to prevent sudden death in patients with reduced ejection fraction, but at the expense of potentially unnecessary ICD implantation in a large percentage of patients. T-wave alternans (TWA), which reflects alternation of cellular repolarization, results in a substantial increase in dispersion of repolarization, a prerequisite for reentrant arrhythmias. Recent trials, cumulating close to 3000 patients, have established TWA analysis as a powerful tool for arrhythmia prevention. Based on the most recent estimates, at least one third of post-myocardial infarction patients are expected to be tested negative. With a negative predictive value greater than 90%, TWA might allow for targeting of patients most likely to benefit from ICD therapy. Accurate identification of high-risk patients by noninvasive TWA may allow for improved widespread screening for sudden death prevention in the general population.

Arrhythmias, Cardiac↗
PubMed2006

Right heart catheterization and risk stratification in advanced heart failure.

Right heart catheterization (RHC) has remained the gold standard in diagnosing elevated cardiac filling pressures. Despite advances in medical therapy, patients with persistent volume overload and heart failure (HF) have a poor prognosis. The diagnosis of volume overload can be difficult in advanced HF with clinical symptoms and signs often lacking sensitivity and specificity. Hemodynamic measurements at rest, especially pulmonary capillary wedge pressure and change in pulmonary capillary wedge pressure, have been closely linked to prognosis. However, RHC is invasive with attendant risks of complications. Noninvasive models without using catheterization-derived values have been shown to be equally predictive of survival. In selected clinical situations, especially the cardiorenal syndrome, RHC continues to play an important role. Newer invasive and noninvasive techniques to assess volume status are available, but large prospective trials are lacking. The advantage with continuous hemodynamic monitoring could be the development of an early warning system prior to the onset of symptomatic decompensation.

Adult↗
PubMed1986

Clinical course and risk stratification of myocardial infarct survivors with three-vessel disease.

Prevalence of three-vessel disease was prospectively analyzed in a series of 462 consecutive infarct survivors aged 60 years or less. Eighty-seven percent (403) of the patients were catheterized within one month of the acute event, and were followed for a mean of 43 months (range 21 to 69). Three-vessel disease was present in 96 cases (24%) and these patients form the study population. The primary goals of this study were to determine the prevalence of three-vessel disease and to identify predictors of survival and new coronary events among this subset of infarct survivors. During follow-up, 15 patients died, 17 had a recurrent nonfatal infarction, and 54 developed angina (4-year probability of each cardiac event being 0.20, 0.22, and 0.59, respectively). Cox's stepwise multivariate analysis identified the ejection fraction (EF) as the only predictor of survival (p less than 0.001). No predictors for nonfatal ischemic events were found among the independent variables considered. Patients were stratified in risk categories according to the EF. Four-year probability of survival was 1.0 in participants with EF = greater than 50% (n = 23), 0.77 for those with EF = 21% to 49% (n = 66), and 0.22 in patients with more severe left ventricular dysfunction, EF = less than 20% (n = 7). Probability of occurrence of nonfatal reinfarction or angina was similar in the three risk categories. Thus, our results indicate that a normal ejection fraction is found in 25% of infarct survivors with three-vessel disease, and that this subset of patients has a low incidence of early and intermediate range coronary events.

Angina Pectoris↗
PubMed1987

Risk stratification after acute myocardial infarction by means of exercise two-dimensional echocardiography.

To determine whether exercise two-dimensional echocardiography contributes to the prognostic information provided by exercise testing in patients recovering from acute myocardial infarction, 40 patients were prospectively studied by means of pre- and postexercise echocardiography 10 to 21 days after myocardial infarction. Patients were followed for 6 to 10 months or until one of the following clinical end points occurred: death, recurrent myocardial infarction, unstable angina, or coronary artery bypass grafting. Results of treadmill exercise tests were negative in 13 of 20 patients with good clinical outcome (65% specificity) and positive in 11 of 20 patients with poor clinical outcome (55% sensitivity). The resting echocardiogram was abnormal in 37 of 40 patients. The exercise echocardiogram was negative in 19 of 20 patients with good clinical outcome (95% specificity) and positive in 16 of 20 patients with poor clinical outcome (80% sensitivity). We conclude that exercise echocardiography is more sensitive and specific than treadmill exercise testing for predicting the occurrence of subsequent cardiac events after acute myocardial infarction.

Adult↗
PubMed1995

Long-term risk stratification with dipyridamole imaging.

This study was undertaken to assess the reliability of clinical parameters and dipyridamole-thallium 201 images for predicting the occurrence of future cardiac events (nonfatal myocardial infarction or cardiac death). Dipyridamole myocardial perfusion imaging is routinely performed in patients who have possible or known coronary disease and a low exercise tolerance. A total of 753 patients underwent clinical assessment and semiquantitative dipyridamole-201TI imaging and were followed up as outpatients. Patients who underwent coronary revascularization during the follow-up period were excluded from the study because the decision to intervene would have been based at least in part on the test itself. There were 82 cardiac events and 54 noncardiac deaths, and 11 patients were lost to follow-up after a mean follow-up of 15 months. With use of a quantitative index reflecting the amount of jeopardized myocardium, patients could be stratified by dipyridamole imaging into subsets with coronary morbidity and mortality rates ranging from 1% to 89%, (p = 0.0001). When clinical and scintigraphic variables were subjected to backward stepwise logistic regression analysis, the significant predictors of cardiac events were the jeopardized myocardium index by scintigraphy (p < 0.0001), left ventricular hypertrophy on the electrocardiogram (p = 0.0009), and transient dipyridamole-induced left ventricular cavitary dilatation (p = 0.0073). Quantitative dipyridamole-201TI imaging appears to be a powerful predictor of future cardiac events in patients with coronary disease and a low exercise tolerance and is a potentially useful contributor to risk-profile assessment and to the treatment of these patients.

Aged↗
PubMed1995

Stratification of the risk of thrombosis after intracoronary stenting for threatened or acute closure complicating coronary balloon angioplasty: a Cook registry study.

This study was carried out to stratify the risk of stent thrombosis by using three predictors: stent size, poststenting residual dissection, and residual filling defect. In the multicenter clinical trial, 1318 patients had successful deployment of Gianturco-Roubin coronary stent for threatened and acute closure. The 714 (54.2%) patients having none of these risk factors were designated a low-risk group; 484 (36.6%) had one factor and were designated an intermediate-risk group; 120 (9.1%) had two or all three factors and were designated a high-risk group. The incidence of stent thrombosis was 5.6%, 9.4%, and 16.7% in the low-, intermediate-, and high-risk groups; the difference among the three groups was highly significant (p < 0.0001). With these three predictors, the risk of stent thrombosis can be stratified. Avoiding the use of small stents (< 3.0 mm) and achieving optimal angiographic results after stenting for acute or threatened closure are useful strategies in reducing stent thrombosis.

Acute Disease↗
PubMed1978

Risk stratification after acute myocardial infarction.

One hundred patients admitted to the hospital with acute myocardial infarction who lived 10 days and agreed to enroll were studied. Data from the history, hospital course and a 24 hour Holter electrocardiographic recording were related to cardiac mortality in the 6 months after enrollment. Fifteen cardiac deaths occurred during this period; 12 of these were sudden. The univariates with the strongest association with mortality were (in descending order): blood urea nitrogen level, serum creatinine level, serum uric acid level, enlarged heart 2 weeks after infarction, ventricular tachycardia 2 weeks after infarction, peak creatine kinase level and left ventricular failure in the coronary care unit. The odds of dying if one of these factors was present rather than absent ranged from 3.6 to 11.5. Groups with two or these univariates had up to 20 times the odds of dying in 6 months. A period of greately enhanced risk for cardiac death persists for about 6 months after acute myocardial infarction. Relatively simple clinical variables can identify the groups at highest and lowest risk. This information is useful for designing management strategies.

Acute Disease↗