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At least 1,225 records · Page 68Linked to original sources
PubMed1997

Risk stratification of patients with syncope.

STUDY OBJECTIVE: To develop and validate a risk classification system for patients presenting to emergency departments with syncope. METHODS: Two prospective studies were carried out at a large urban teaching hospital ED. One cohort of 252 patients with syncope who reported to the ED was used to develop the risk classification system; a second cohort of 374 patients with syncope was used to validate the system. Data from the patient's history, physical examination and ED ECG were used to identify predictors of arrhythmias or mortality within the first year. Arrhythmias were detected by cardiac monitoring or electrophysiologic studies. Logistic regression and Cox proportional hazards models were used to identify the important risk factors for the classification system. Performance of the system was measured by comparing the proportion of patients with arrhythmias or death at various levels of the risk and receiver operating characteristic curves. RESULTS: Multivariate predictors of arrhythmia or 1-year mortality were an abnormal ED ECG (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.6 to 6.4); history of ventricular arrhythmia (OR, 4.8; 95% CI, 1.7 to 13.9); history of congestive heart failure (OR, 3.2; 95% Cl, 1.3 to 8.1). Arrhythmias or death within 1 year occurred in 7.3% (derivation cohort) to 4.4% (validation cohort) of patients without any risk factors and in 80.4% (derivation) to 57.6% (validation) of patients with three or four risk factors. CONCLUSION: Historical and ECG factors available at the time of presentation can be used to stratify risk of arrhythmias or mortality within 1 year in ED patients presenting with syncope.

Adolescent↗
PubMedDate not supplied

[Application of artificial neural networks for risk stratification of hospital mortality].

OBJECTIVE: To compare the ability of an artificial neural network (ANN) to predict hospital mortality with that of the Acute Physiology and Chronic Health Evaluation II (APACHE II) system and multiple logistic regression (LR). A secondary objective was to compare the allocation of individual probability among the models. METHOD: The variables required for calculating the APACHE II were prospectively collected. A total of 1146 patients were divided (randomly 70% and 30%) into the Development (800) and the Validation (346) sets. With the same variables an LR model and an ANN were carried out (a 3-layer perceptron trained by algorithm backpropagation with bootstrap resampling and with 9 nodes in the hidden layer) in the Development set. The models developed were contrasted with the Validation set and their discrimination properties were evaluated using the area under the ROC curve (AUC [95% CI]) and calibration with the Hosmer-Lemeshow C (HLC) test. Differences between the probabilities were evaluated using the Bland-Altman test. RESULTS: The Validation set showed an APACHE II with an AUC = 0.79 (0.75-0.84) and HLC = 11 (p = 0.329); LR model AUC = 0.81 (0.76-0.85) and HLC = 29 (p = 0.0001) and an ANN AUC = 0.82 (0.77-0.86) and HLC = 10 (p = 0.404). The patients with the most important differences in the allocation of probability between LR and ANN (8% of the total) were neurological. The worst results were found in trauma patients with an AUC of not greater than 0.75 in all the models. In respiratory patients, the ANN achieved the best AUC = 0.87 (0.78-0.91). CONCLUSIONS: The ANN was able to stratify hospital mortality risk by using the APACHE II system variables. The ANN tended to achieve better results than LR, since, in order to work, it does not require lineal restrictions or independent variables. Allocation of individual probability differed in each model.

Female↗
PubMed1999

Acute renal failure in the intensive care unit. Therapy overview, patient risk stratification, complications of renal replacement, and special circumstances.

This article provides a basic definition of severity scoring among patients with acute renal failure and extends the definition into the types of dialysis support that are generally used in intensive care unit acute renal failure. Acute dialysis dosing and the problems that create a difference between chronic renal failure and acute renal failure support are described, the dialytic techniques and side effects and complications of each are compared, and nonrenal-based special situations in which extracorporeal therapy has been found to be helpful are defined.

Acute Kidney Injury↗
PubMed2003

[Risk stratification after acute myocardial infarction].

In recent years, the characteristics of patients who suffer acute myocardial infarction without complications during hospitalization have changed. In addition, the range of non-invasive studies available for evaluating left ventricular systolic function, residual myocardial ischemia, and myocardial viability in these patients has improved. Left ventricular systolic function and residual ischemia should be evaluated in all patients before release. The non-invasive technique used (exercise test, echocardiography, nuclear cardiology, magnetic resonance imaging) depends on availability, experience, and results at each institution. Coronary arteriography should be performed in patients with significant ischemia or severe left ventricular systolic dysfunction in non-invasive studies. In these cases coronary angiography must be performed to determine if coronary arteries are suitable for revascularization before performing a test of myocardial viability.

Cardiac Catheterization↗
PubMed2003

[Risk stratification using combined ECG, clinical, and biochemical assessment in patients with chest pain without ST-segment elevation. How long should we wait? ].

INTRODUCTION: We use clinical, ECG, and biochemical data to stratify risk in patients with chest pain without ST segment elevation. However, the prognostic performance of these studies in relation to time from onset of symptoms is unknown. PATIENTS AND METHOD: In a single-center, prospective study, 321 consecutive patients who had been admitted in the emergency room with a suspected acute coronary syndrome without ST segment elevation were included in the study. Blood samples were collected for CK, CK-MB mass, myoglobin, and cardiac troponin T analysis 6, 12 and 18 hours after the onset of pain and other clinical and ECG data were recorded. Univariate and multivariate analysis was used to identify independent prognostic predictors 6 and 12 hours after the onset of chest pain. RESULTS: Five variables were independent predictors of the recurrence of ischemia. The model correctly classified 82% of the patients. Age, history of coronary artery disease, prolonged chest pain at rest in the preceding 15 days, pain, ST-segment changes with pain, and cardiac troponin T in excess of 0.1 ng/m 12 hours after the onset of chest pain were identified by logistic regression. A similar model was analyzed at 6 hours, after changing the cutoff point for cardiac troponin T. Cardiac troponin T was considered positive with values of 0.04 ng/ml 6 hours after the onset of chest pain. CONCLUSIONS: More than 80% of the patients admitted to the emergency room with chest pain without ST segment elevation can be correctly classified for new ischemic recurrences using clinical, ECG, and biochemical parameters 6 hours after the onset of pain.

Aged↗
PubMed2001

Retrospective stratification of a consecutive cohort of prostate cancer patients treated with a combined regimen of external-beam radiotherapy and brachytherapy.

PURPOSE: The evaluation of clinical variables that influence biochemical relapse-free survival in a cohort of patients treated by combined radiotherapy over a fixed interval. METHODS AND MATERIALS: Three hundred forty-eight patients diagnosed with clinical Stage T1--T3a prostate cancer were treated with a course of (103)Pd or (125)I brachytherapy followed by a limited course of external beam radiation formed the basis for study. All censored patients had a minimum 2-year follow-up. Biochemical relapse-free survival (BRFS) was estimated using a modified American Society for Therapeutic Radiology and Oncology consensus definition. Discrete "risk groups" were developed based on BRFS as influenced by pretreatment parameters. RESULTS: Significant risk factors contributing to biochemical failure were serum prostate-specific antigen (PSA) greater than 20 ng/mL, Gleason sum of 7 or greater, or clinical stage T2c or greater. Five-year biochemical control for those exhibiting no risk factor was 88%; one risk factor, 75%; two or more risk factors, 51%. The differences in BRFS among all three risk groups were statistically significant. Outcomes for patients presenting with PSA 10 to 20 ng/mL, but otherwise low-risk disease, fared no differently from those low risk patients presenting with PSA less than 10 ng/mL. CONCLUSIONS: Combined radiotherapy with (103)Pd or (125)I followed by external beam radiotherapy achieves a high rate of biochemical and clinical control in patients with low- to intermediate-risk clinically organ confined disease.

Analysis of Variance↗
PubMed2000

Kdap, a novel gene associated with the stratification of the epithelium.

The skin develops and differentiates during embryogenesis, which is concertedly regulated by a variety of genes. The present study isolated from the rat embryonic skin a novel differentiation-associated gene named Kdap (keratinocyte differentiation-associated protein) by suppression subtractive hybridization between the skin of 14day postcoitus (dpc) embryo (the prehair-germ stage) and that of 17dpc embryo (the hair-germ stage). Its mRNA contained four spliced forms in these tissues. The gene encoded a protein of total 98 amino acids with a calculated molecular mass of 11kDa and an isoelectric point of 6.1 as an unspliced form. The two splicing zones were well conserved among rat, mouse, and human. This protein had a high hydrophobic N-terminal region, a possible signal sequence, and contained two putative N-myristoylation sites and two casein kinase II phosphorylation sites. In situ hybridization experiments detected Kdap transcripts exclusively in the suprabasal cell layers of the embryonic epidermis. Intense expression was also seen in suprabasal cells in regions of infundibulum of the hair follicle. These results indicated that Kdap provides a new insight into the mechanism of differentiation and the maintenance of stratified epithelia.

Amino Acid Sequence↗
PubMed1998

Epigenetic stratification: the role of individual change in the biological aging process.

Aging is a complex process. It consists of a diverse assortment of seemingly random manifestations that occur in the individual, the mutual relationship and impact on mortality of which is frequently obscure. We derive a simple equation to model the aging process based on scale invariant and increasing change. The solution to this equation indicates that this change itself, irrespective of its quality, is the cause and not simply the effect of aging. This model establishes loss of homeostasis as a fundamental feature of aging. The model is deterministic, but it supports the stochastic nature of age changes. Paradoxically, this model states that a sufficient augmentation of aging processes results in a lack of aging. Experimental evidence in support of this model is presented that spans the levels of population mortality rates, cellular spatial organization, and gene dysregulation.

Aging↗
PubMed1998

Evaluation and risk stratification of patients with chest pain in the emergency department. Predictors of life-threatening events.

While assessing chest pain in the emergency department, physicians must first estimate the probability of acute ischemic states in the patient. This first estimate is based on the patient's history, physical examination, and electrocardiogram. Patients who meet the threshold for acute cardiac ischemia are further evaluated to confirm or exclude this diagnosis, while other life-threatening factors are excluded.

Algorithms↗
PubMed2000

Cardiac troponin I for stratification of early outcomes and the efficacy of enoxaparin in unstable angina: a TIMI-11B substudy.

OBJECTIVES: We sought to evaluate cardiac troponin I (cTnI) for predicting early clinical outcomes and the efficacy of enoxaparin among patients with non-ST segment elevation acute coronary syndrome (ACS) and negative creatine kinase, MB fraction (CK-MB) levels. BACKGROUND: Cardiac TnI identifies patients with unstable angina who are at higher risk of death or myocardial infarction (MI) by 30 days. The utility of cTnI for predicting very early clinical events, including recurrent ischemia, and the efficacy of enoxaparin are not yet established. METHODS: At baseline and 12 h to 24 h after enrollment in the Thrombolysis in Myocardial Infarction (TIMI)-11B trial, samples were collected for cTnI determination. RESULTS: Among 359 patients with negative serial CK-MB values, 50.1% had a cTnI result > or =0.1 ng/ml within the first 24 h. Patients with elevated cTnI were at higher risk of death or MI at 48 h (3.9 vs. 0%, p = 0.01) and 14 days (13.9 vs. 2.2%, p<0.0001). Elevated cTnI also correlated with higher risk of recurrent ischemia requiring urgent revascularization by 48 h (10.0 vs. 1.7%, p = 0.001) and 14 days (20.6 vs. 5.6%, p< or =0.0001). Enoxaparin had a greater benefit among patients with elevated vs. normal cTnI (p = 0.03), achieving a 47% reduction in the risk of death, MI or urgent revascularization by 14 days in cTnI-positive patients (p = 0.007). CONCLUSIONS: Elevation of cTnI among patients with non-ST segment elevation ACS and negative levels of CK-MB identifies those at higher risk for very early adverse outcomes, including severe recurrent ischemia. Treatment with enoxaparin reduces the risk associated with elevated cTnI.

Aged↗
PubMed2000

Validated risk stratification model accurately predicts low risk in patients with unstable angina.

BACKGROUND: In the mid 1990s, two unstable angina risk prediction models were proposed but neither has been validated on separate population or compared. OBJECTIVES: The purpose of this study was to compare patient outcome among high, medium and low risk unstable angina patients defined by the Agency for Health Care Policy and Research (AHCPR) guideline to similar risk groups defined by a validated model from our institution (RUSH). METHODS: Four hundred sixteen patients consecutively admitted to the hospital with unstable angina between January 1, 1995, and December 31, 1997, were prospectively evaluated for risk factors. The presence of major adverse events such as myocardial infarction (MI), death and heart failure was assessed for each patient by chart review. RESULTS: The composite end point of heart failure, MI or death occurred in 3% and 5% of the RUSH and AHCPR low risk categories, respectively, and in 8% and 10% of AHCPR and RUSH high risk categories, respectively. Recurrent ischemic events were best predicted by the RUSH model (high: 24% vs. medium: 12% and low: 10%, p = 0.029), but not by the AHCPR model (high: 14% vs. medium: 13% and low: 9%, p = 0.876). The RUSH model identified five times more low risk patients than the AHCPR model. CONCLUSIONS: Both models identify patients with low and high event rates of MI, death or heart failure. However, the RUSH model allowed for five times more patients to be candidates for outpatient evaluation (low risk) with a similar observed event rate to the AHCPR model; also, the RUSH model more successfully predicted ischemic complications. We conclude that the RUSH model can be used clinically to identify patients for early noninvasive evaluation, thereby improving cost effectiveness of care.

Aged↗