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At least 937 records · Page 52Linked to original sources
PubMed1996

A comparison of three techniques for rapid model development: an application in patient risk-stratification.

Accurately risk-stratifying patients is a key component of health care outcomes assessment. And, many health care organizations increasingly are relying upon automated means for assistance in making patient risk-stratification decisions. Unfortunately, the process of outcome model development, as it is currently practiced, is both time consuming and difficult. We investigated the relative abilities of three modeling techniques (logistic regression, artificial neural network (ANN), and Bayesian) to rapidly develop models for risk-stratifying patients. Our results demonstrated that all three modeling techniques perform equally well in certain situations. However, the Bayesian model with conditional independence had the best overall performance. Unfortunately, none of the models were able to achieve the degree of accuracy which would be required in a medical setting.

APACHE↗
PubMed1996

Preoperative risk stratification identifies low-risk candidates for early extubation after aortocoronary bypass grafting.

Early tracheal extubation has been the focus of recent attempts to accelerate the care of patients after aortocoronary bypass. Following the 1994 validation of a preoperative mortality risk mode based on the Society of Thoracic Surgeons National Cardiac Surgery Database, we examined the records of 328 aortocoronary bypass patients from our institution and identified 133 patients with low preoperative mortality risk. Their records were then analyzed for duration of tracheal intubation. One low-risk patient who did not survive was excluded from the analysis. Of the remaining 132 patients, 108 experienced no postoperative complications; nevertheless, 50 of these were intubated longer than 10 hours despite freedom from complications. In a 2nd group of 153 consecutive low-risk patients, we prospectively implemented a patient care protocol that designated low-risk patients as eligible for accelerated weaning. Compared were the 1st group, these patients with low preoperative mortality risk were weaned from mechanical ventilation in 40% less time. Thus, we found that low preoperative mortality risk predicts success in early tracheal extubation. Risk stratification appears to be a simple and useful means of identifying patients least likely to encounter postoperative complications. Risk-based accelerated recovery was successfully implemented without requiring a change in anesthetic or surgical management.

Coronary Artery Bypass↗
PubMed1996

[Combined use of bicycle ergometry test and echo-dipyridamole in stratification of risk after thrombolysed myocardial infarct].

AIM: Verify the value of the combined use of Dipyridamole Stress Echocardiography (DSE) and Exercise Testing (ET) for predicting cardiac events after Thrombolysed Myocardial Infarction (TMI). STUDY DESIGN: Prospective, with a medium follow-up of 221 days (range 30-446). CLINICAL SETTINGS: Coronary Care Unit with Cardiology Service. PATIENTS: 32 consecutive patients, 24 men and 8 women, mean age 61 years (range 39-72) with acute myocardial infarction. INTERVENTIONS: Systemic thrombolysis with PTPA. DSE and ET in therapeutic wash out 12 +/- 3 days after admission to the Coronary Care Unit. RESULTS: 9 patients had positive ET, 18 patients had negative ET, 5 patients did not perform ET. 19 patients had positive DSE, 13 patients had negative DSE. Patients with positive DSE had in 6 cases (group 1) WMA remote from the infarction area (WMAR), in 13 cases (group 2) WMA appeared in the infarct related area. Cardiac events occurred in 15 patients: 1 cardiovascular death, 1 myocardial re-infarction, 13 cases of unstable angina. 2 patients with negative DSE had cardiac events. All patients in group 1 had events, 1 patient with a previous positive ET, 3 patients with previous negative ET. 2 patients in this group didn't perform ET. 7 patients in group 2 had cardiac events, in all cases with a previous positive ET. 1 single patient in this group with negative ET had events. CONCLUSIONS: 1) Patients without WMA at DSE are at low risk for cardiac events after thrombolysed myocardial infarction. 2) Presence of WMAR appears to be associated with a higher risk, whatever the result of ET may be. 3) Patients without WMAR can be further stratified by ET in therapeutic wash out. High risk patients seem to be those with positive DSE and positive ET. 4) Combined use of DSE and ET seem to allow optimal risk stratification after thrombolysed myocardial infarction.

Adult↗
PubMed1994

Risk stratification in patients with chest pain.

The evaluation of patients with chest pain and suspected coronary disease remains a challenge for primary care physicians. In this article, three major points are emphasized. First, making full use of the data collected during the initial encounter prior to performance of an exercise test is helpful in formulating assessments of both the likelihood of significant coronary disease and of the short-term risk of a major cardiac event. Second, exercise testing is helpful for intermediate-likelihood patients because positive tests in low-likelihood patients cannot "rule in" disease, and negative tests in high-likelihood patients cannot "rule out" disease. Finally, exercise testing in risk stratification of the patient with suspected coronary artery disease is valuable in identifying low-risk patients in whom further testing, including catheterization, may be safely deferred.

Chest Pain↗
PubMed1998

Sudden death in hypertrophic cardiomyopathy: risk stratification and prevention.

Hypertrophic cardiomyopathy is an important cause of sudden death in young and asymptomatic patients. Young athletes and patients with unexplained sudden death, including their relatives, should be screened for its presence. Risk stratification identifies a high-risk group, in which preventive measures should be taken to reduce the risk for sudden death: moderate to heavy physical activity has to be avoided and arrhythmias with haemodynamic impact should be rigorously prevented.

Adolescent↗
PubMed1998

Dipyridamole stress echocardiography and exercise testing for risk stratification after uncomplicated myocardial infarction.

BACKGROUND: Risk stratification for subsequent cardiac events after an acute infarction can be obtained by exercise testing or dipyridamole stress echocardiography. It remains to be determined whether these modalities are equivalent and provide incremental information on top of clinical evaluation. The aim of our study was to compare the prognostic information obtained early after an acute uncomplicated myocardial infarction of high dose dipyridamole coupled with echocardiography (stress echo) or maximal symptom-limited exercise testing. METHODS AND RESULTS: Ninety patients underwent dipyridamole stress echo and exercise testing at a mean +/- SD of 9 +/- 4 days after admission for acute uncomplicated first myocardial infarction. All patients were prospectively followed for 22 +/- 16 months. There were 9 hard events (3 cardiac deaths and 6 acute myocardial infarctions) and 12 soft events due to post MI angina (6 angioplasty and 6 bypass surgery procedures). Univariate predictor of hard events was rest-stress wall motion score index variation (p = 0.009); univariate predictors of all events (hard + soft) were: positive exercise testing (p = 0.001), positive stress echo (p = 0.001), rest-stress wall motion score index variation (p = 0.002), extent of ischemia at echo (p = 0.008). Multivariate analysis by Cox selected a non-Q wave infarction and rest-stress wall motion score index variation as predictors of death or reinfarction (overall chi-square for the model 12.2, p = 0.0022). CONCLUSIONS: Stress echo is superior to ergometric variables for predicting events after uncomplicated myocardial infarction.

Aged↗
PubMedDate not supplied

[Serotypical stratification of HIV-1 in populations of intravenous drug users in the south/southwestern Ukraine].

A total of 101 HIV-1 positive sera from intravenous drug users (IVDU) in Southern and South-Eastern Ukraine were serotyped using V3-mimicking peptides. Serotype B circulates in Nikolaev and type A/C in Odessa and Donetsk. Prevalence of A/C serotype in the population of IVDU is a characteristic feature of the epidemic situation in this region, in contrast to the USA and Western Europe, where subtype B circulates. Serotypical stratification indicates that routes of HIV-1 dissemination in the Ukraine differ from those in the USA and Western Europe, which should be borne in mind when planning the strategy of epidemic control.

Amino Acid Sequence↗
PubMed1997

Ambulatory system to aid in decision making and risk stratification in postinfarction patients.

Knowledge of the clinical and electrophysiological features of certain cardiovascular risk groups, the adaptation and specialization of clinical protocols, the availability of tools to make determinations for use in patient follow-up and to assess the efficacy of the treatments applied, and the proper processing of different parameters can aid in decision making, leading to the application of a given therapeutic approach, and can facilitate the performance of group and multicenter studies. To address these needs, a simple, low-cost, portable ECG processing system has been designed that complements the current techniques for managing patients with ischemic heart disease and nonmalignant ventricular arrhythmias. This system, consisting of an electrocardiograph and a laptop PC, determines the following parameters on the basis of the ECG: incidence of arrhythmia, heart rate variability, QT dispersion, ECG criteria for ventricular hypertrophy and late potentials. Left ventricular ejection fraction and diastolic function (according to Doppler ultrasound) and other basic epidemiological parameters are typed in. Moreover, the system integrates these parameters, which have usually been considered separately, to arrive at second-level indicators with a greater predictive capacity during the long-term follow-up of patients with ischemic heart disease and ventricular arrhythmias, thus providing an idea of the risk of mortality and the onset of arrhythmic events and allowing risk stratification in this patient population. Finally, the system includes a database of all the patients analyzed, with tools that make it possible to follow the course of their disease and to assess the efficacy of the treatments applied.

Arrhythmias, Cardiac↗
PubMed1998

[The stratification and prevention of the arrhythmia risk in nonischemic dilated cardiomyopathy].

The challenge of preventing arrhythmic sudden death is one of the major issues in today's treatment of heart failure. To achieve this ambitious goal, an accurate selection of the candidates for sudden death is needed on the one hand, while on the other hand, the assessment of the real cost/benefit ratio of the implantable cardioverter-defibrillator in selected patients, as compared to ACE inhibitors, beta-blockers and antiarrhythmic drug therapy, should no longer be delayed. As is well known, the incidence of sudden death is higher in ischemic dilated cardiomyopathy than it is in non-ischemic dilated cardiomyopathy. Moreover, tachyarrhythmic sudden death is prevalent in NYHA classes I and II (80%), whereas its incidence is lower (50%) in NYHA classes III and IV, since bradyarrhythmia, electromechanical dissociation and thromboembolic events characterize the other 50% of sudden deaths in patients in the latter NYHA class. The stratification of arrhythmic risk in non-ischemic dilated cardiomyopathy is questionable from any point of view, considering the poor predictive power of invasive and non-invasive indexes. However, some subgroups of high-risk patients should be selected, such as patients waiting for heart transplant or those with a severe disease but without an extreme degree of ventricular dysfunction, in whom the prognosis in terms of pump failure events is better and life expectancy is longer if the risk of arrhythmia is properly assessed and sudden death prevented. Consequently, the ICD implant may be effective in order to pursue the aim of reducing the tachyarrhythmic and bradyarrhythmic mortality in patients with a more severe disease and of minimizing the tachyarrhythmic risk in those with a less severe disease. Further studies will be developed to identify the ideal candidates for ICD implants.

Arrhythmias, Cardiac↗
PubMed2026

Catecholaminergic polymorphic ventricular tachycardia mediated by ryanodine receptor 2: a validated risk stratification.

BACKGROUND AND AIMS: Patients with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for potentially life-threatening arrhythmic events (AEs) even while treated with β-blockers. The aim was to develop a model for individualized prediction of AEs in patients with RYR2-mediated CPVT on β-blocker monotherapy. METHODS: The derivation and independent validation cohorts included 743 and 129 patients, respectively. AEs were defined as arrhythmic syncope, appropriate implantable cardioverter-defibrillator shock, sudden cardiac arrest (SCA), and sudden cardiac death. Near-fatal or fatal AEs (nf/fAEs) included all AEs except for arrhythmic syncope. Prediction models using Cox regression were developed and internally and externally validated. RESULTS: A total of 102 (13.7%) patients in the derivation cohort and 24 (18.6%) patients in the validation cohort experienced ≥1 AE over a median follow-up of 5.1 [interquartile range (IQR), 7.7] and 2.4 (IQR, 4.4) years, respectively. Predictors of AE were arrhythmic syncope or SCA prior to diagnosis and age at β-blocker initiation. In the derivation and validation cohorts, the optimism-corrected C-indices of the models for AE were 0.67 [95% confidence interval (CI) 0.62-0.72] and 0.59 (95% CI 0.48-0.71), respectively. For nf/fAEs, ventricular arrhythmia severity before β-blocker initiation was a fourth independent predictor, and C-indices of the models in the derivation and validation cohorts were 0.74 (95% CI 0.68-0.80) and 0.60 (95% CI 0.47-0.72), respectively. In the derivation cohort, calibration slopes were 1.00 (95% CI 0.59-1.41) for AE and 1.00 (95% CI 0.69-1.32) for nf/fAE. CONCLUSIONS: These externally validated risk prediction models using clinical parameters accurately distinguished CPVT patients on β-blocker monotherapy at low and high risk for future AEs while treated with β-blockers. These models provide guidance for implementation of clinical management therapies to prevent AEs in patients with CPVT.

Humans↗
PubMed2026

Genome-resolved analysis of colonization factor repertoires reveals ecological stratification in cervid gut microbiomes.

INTRODUCTION: Colonization factors (CFs) are important microbial traits associated with persistence and host adaptation in the gut, yet their large-scale organization in cervid gut microbiomes remains unclear. METHODS: A total of 3,311 non-redundant high-quality metagenome-assembled genomes (MAGs), derived from 688 cervid gut metagenomic samples across 15 publicly available projects and one in-house dataset, were analyzed. CF-associated genes were identified by comparison against the GHA CF database, and CF repertoires were characterized at genome, host-species, and gastrointestinal-segment levels. RESULTS: A total of 138,729 CF-associated genes spanning 71 CF families were identified. MAGs from Cervinae contained richer CF repertoires than those from Caprinae, and CF47 (Peptidase_C69), CF24_29 (QueH), and CF18 (Glycos_transf_2) were among the most prevalent families. CF repertoires were strongly structured by taxonomy, showed a moderate association with bacterial phylogenetic distance, and formed two recurrent genome-level configurations with distinct KEGG functional profiles. Integration of sample metadata further revealed differentiation of CF repertoires across host species and gastrointestinal segments, representing the major ecological dimensions examined in this study. Segment-associated CF variation was accompanied by redistribution of broader functional profiles, including enrichment of carbohydrate and lipid metabolism in the jejunum, membrane transport in the ileum, xenobiotics biodegradation in the cecum, and environmental adaptation in the rumen. DISCUSSION: These findings provide a genome-resolved view of CF repertoire organization in cervid gut microbiomes and demonstrate that colonization-associated functions are structured across microbial lineages and ecological contexts. This study highlights the importance of considering microbial taxonomy and host-associated environments when interpreting the distribution of CF repertoires in mammalian gut ecosystems.

Cervidae↗
PubMed1984

A proposed classification of intra-abdominal infections. Stratification of etiology and risk for future therapeutic trials.

Serious studies of ultra-abdominal infections have yielded a mortality that ranges from 3.5% (a composite of antibiotic studies evaluating 1,275 patients) to more than 60% in studies of multiple-organ failure. In reviewing these studies, it is apparent that under the umbrella of "serious intra-abdominal infection," different diseases, processes, and patients are being studied. We define a binomial classification incorporating both an anatomic and a functional approach to intra-abdominal infection. There are ten etiologic classifications of intra-abdominal infections combined with an acute physiologic score (APS), measuring severity of illness, in three gradations. In the patient with undifferentiated intra-abdominal sepsis, the patient will be in class I, II, III, or IV, with a score, A, B, or C, added. Each of the groups V-X, defining a specific infectious category, can also use the APS, which has been verified in patients in intensive care and in those with intra-abdominal infection. It is anticipated that using this approach will provide a technique to evaluate patient groups uniformly in which drug or technical approaches to the management of intra-abdominal infections are being studied. The patients being studied will be more clearly defined, and studies will be comparable from one center to another.

Bacterial Infections↗