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PubMed1982

The value of prognostic parameters for the stratification of advanced breast cancer patients.

One hundred seventy-five patients with metastatic breast cancer, treated with a combination chemotherapy (Cooper regimen), were analyzed retrospectively to identify the value of the traditional prognostic parameters (disease-free interval; menopausal status; dominant site of metastatic lesion) for the stratification of patients before randomization. Response rate and survival time were not significantly affected by the disease-free interval and menopausal status. A significant difference was detected among the three categories of dominant disease (locoregional; osseous; visceral). However, an estimate of total extent of disease (according to Swenerton) was found to be the most important factor for predicting response and survival time after combination cytotoxic treatment. The differences between the dominant size of metastatic disease are mainly influenced by different size of metastatic spread. Therefore, there is found a significant correlation between the different types of dominant lesions and total extent of disease. In conclusion, the particular sites of metastatic spread seem to be of less importance than overall extent of disease in predicting the outcome. A critical evaluation of the three traditional stratification parameters and introduction of a semiquantitative estimation of total tumor burden as a new stratification parameter seems to be necessary when planning and comparing future trials.

Adult↗

PubMed1994

Risk stratification after myocardial infarction: role of electrical instability, ischemia, and left ventricular function.

The problem of risk stratification after myocardial infarction is reviewed. There are three major complications: new ischemic events, congestive heart failure, and malignant arrhythmias and sudden death, related to the presence of residual ischemia, left ventricular dysfunction, and electrical instability. The bidirectional interactions among these three factors is analyzed. The risk is in the middle of a triangle, the three angles of which are the above-mentioned factors. All the "satellite" factors that appear from all three angles are presented. Furthermore, the most important parameters and techniques employed to detect risk, multifactorial approach of risk stratification, and changes of risk stratification in the thrombolytic era are briefly reviewed.

Arrhythmias, Cardiac↗

PubMed2006

[Risk stratification of patients with diabetes mellitus undergoing coronary artery bypass grafting--a comparison of statistical methods].

Among the coronary bypass patients from our Datamart database, we found a prevalence of 29.6% of diagnosed diabetics. 5.2% of the patients without a diagnosis of diabetes mellitus and a fasting plasma glucose level > 125 mg/dl were defined as undiagnosed diabetics. The objective of this paper was to compare univariate methods and techniques for risk stratification to determine, whether undiagnosed diabetes is per se a risk factor for increased ventilation time and length of ICU stay, and for increased prevalence of resuscitation, reintubation and 30-d mortality for diabetics in heart surgery. Univariate comparisons reveals that undiagnosed diabetics needed resuscitation significantly more often and had an increased ventilation time, while the length of ICU stay was significantly reduced. The significantly different distribution between the diabetics groups of 11 from 32 attributes examined, demands the use of methods for risk stratification. Both risk adjusted methods regression and matching confirm that undiagnosed diabetics had an increased ventilation time and an increased prevalence of resuscitation, while the length of ICU stay was not significantly reduced. A homogeneous distribution of the patient characteristics in the two diabetics groups could be achieved through a statistical matching method using the propensity score. In contrast to the regression analysis, a significantly increased prevalence of reintubation in undiagnosed diabetics was found. Based on an example of undiagnosed diabetics in heart surgery, the presented study reveals the necessity and the possibilities of techniques for risk stratification in retrospective analysis and shows how the potential of data collection from daily clinical practice can be used in an effective way.

Coronary Artery Bypass↗

PubMed1999

[Cardiac autonomic tone in risk stratification after myocardial infarct: results of a prospective long-term study of 411 consecutive patients].

Prognosis of patients surviving acute myocardial infarction has substantially improved over the last two decades. However, stratification of patients at risk for death due to arrhythmic events remains a clinical challenge. Due to the important role of the autonomic nervous system in the genesis of sudden death, autonomic markers such as heart rate variability and baroreflex sensitivity have recently gained attention as risk stratification parameters. The present study reports the results of noninvasive risk stratification in 411 consecutive postinfarction patients treated due to contemporary therapeutical guidelines with a high proportion of patients discharged with a patent infarct related artery. The diagnostic arsenal of risk parameters comprised heart rate variability, baroreflex sensitivity, and more traditional markers such as non-sustained ventricular tachycardia, left ventricular ejection fraction, and ventricular late potentials. Patients were followed for a mean of 33 +/- 21 months. Stepwise logistic regression analysis revealed that left ventricular function, both autonomic markers, and the patency of the infarct related artery were independent predictors of the prospectively defined primary study endpoint, i.e., all-cause mortality plus ventricular tachyarrhythmic events. With respect to the secondary endpoint (ventricular tachyarrhythmic events), left ventricular function, heart rate variability, and infarct vessel patency were independent predictors. Ventricular late potentials and nonsustained ventricular tachycardia had no predictive value with respect to ventricular tachyarrhythmic events. These findings from a large prospective long-term study demonstrate the value of markers of cardiac autonomic tone in identifying infarct survivors at risk for malignant ventricular tachyarrhythmias and sudden death.

Adult↗

PubMed2007

Delay in invasive risk stratification of women with acute coronary syndrome is associated with worse outcomes.

BACKGROUND: Invasive risk stratification in patients with acute coronary syndromes (ACS) has been shown to improve outcomes. There is paucity of data on women undergoing invasive risk stratification. We investigated whether the time to coronary angiography affects survival of female patients admitted with ACS. METHOD: Female patients admitted to the coronary intensive care unit with ACS between 1/1/97 and 12/31/00 and undergoing coronary angiography during same hospitalization were divided into three groups based on the time to angiography: same day, 1-2 days and >2 days. The baseline clinical features, angiography results and outcomes were compared between the angiography groups. RESULTS: Of the total 350 female patients who fulfilled the inclusion criteria, 63% underwent angiography within two days of presentation. Three year mortality rates in women undergoing angiography on the same day, 1-2 days and >2-days were 7%, 7% and 22% respectively (p = 0.001). Using multivariate analysis, angiography beyond 2 days was a significant predictor of mortality among women (OR 2.6, 95% CI 1.3-5.0, p = 0.006) after adjusting for confounding variables. CONCLUSION: Later invasive risk stratification after 2 days of presentation in women with ACS is associated with worse survivial. Gender should not be a reason to defer early coronary angiography in these patients.

Aged↗

PubMed2006

Current status of risk stratification methods in acute coronary syndromes.

Distinguishing which patients with chest pain are at high risk versus which are at low risk remains an important clinical problem despite modern risk stratification strategies. Current approaches often over-utilize hospital resources, yet still miss a significant number of true acute coronary syndromes (ACS). This review focuses on important developments in risk stratification in ACS from 2004 through 2005. Risk models have been developed that use readily available patient characteristics, and head to head comparisons of the various models have been performed to guide clinicians in selecting between the different options. The most powerful models now include measurement of renal function, which has emerged as an important marker of risk. In addition to cardiac troponins, B-type natriuretic peptide (BNP) clearly augments risk prediction, and in the past year serial BNP measurement after discharge has shown promise as a simple way to monitor patient risk following ACS. Newer biomarkers are on the horizon but have not yet established their clinical value. Finally, advances in coronary CT angiography and bedside echocardiography offer hope that noninvasive imaging may play a more important role in early risk stratification in the near future.

Albumins↗

PubMed1976

Limiting role of stratification in alveolar exchange of oxygen.

On the basis of a simple lung model the limiting effects of stratification on tidal/alveolar transfer of O2 are calculated using values for diffusive conductance of distal airways previously obtained from analysis of wash-out kinetics of He and SF6. In particular it is shown that the alveolar-capillary transfer of O2 (neglected in a previous study) plays an important role in giving rise to stratificational gradients of O2 in distal airways. For 10 kg dogs breathing hypoxic mixtures the stratificational component of the alveolar-arterial Po2 difference is estimated at about 0.8 torr for resting conditions and at about 3.5 torr for medium level exercise.

Animals↗

PubMed2006

Hazardous to your health: kinetic foundations of risk stratification and therapeutic triage.

BACKGROUND: Risk stratification is widely used in the prognostic assessment of patients with a variety of clinical disorders on the unquestioned assumption that the intensity of treatment should be proportionate to the threat of an adverse event over some finite period of time (risk). However, just as the physical trajectory of an object depends on its current magnitude of displacement (velocity) and the concurrent rate of change of that displacement (acceleration), the prognostic trajectory of a patient depends on the current magnitude of risk and the concurrent rate of change of that risk (hazard). Clinical risk stratification nevertheless relies only on the former. METHODS: We therefore integrated the quantitative assessment of risk and hazard by way of a kinetic model that characterizes the development of an adverse event as a series of exponential state-to-state transitions-from stable to unstable to event. This model serves to shift the clinical emphasis from prognosis (the assessment of risk) to treatment (the improvement in outcome). In this context, treatment is well advised (even in low-risk individuals) when the hazard is large (risk is rising), and is less well advised (even in high-risk individuals) when the hazard is small (risk is stable). RESULTS: The kinetic model outlined here thereby promises to supersede the superficial practice of risk stratification with a more sophisticated strategy of therapeutic triage that allows one to predict the incremental clinical benefit of alternative treatment strategies.

Humans↗

PubMed2005

Acute coronary syndromes: risk stratification and initial management.

For patients who have acute coronary syndromes (ACS), risk stratification is key to initiating appropriate treatment. For ST-segment elevation MI, immediate reperfusion therapy is needed, and thus rapid identification of ST elevation on the ECG is critical. Then, having a standardized protocol for rapid treatment- with either primary percutaneous coronary intervention or thrombolysis - is critical. For unstable angina/non-ST elevation ACS, after first identifying the patients who have a higher likelihood of actually having an ACS (as opposed to noncardiac chest pain) stratification to high versus lower risk is needed to choose appropriate therapies. Thus, it is important for risk stratification to be a central part of all management of patients who have ACS.

Acute Disease↗

PubMed2004

Post infarction risk stratification using the 3-D angle between QRS complex and T-wave vectors.

Present experience with prospective identification of patients who might benefit from prophylactic antiarrhythmic intervention is restricted to risk stratification using left ventricular ejection fraction (LVEF). The precision of LVEF-based identification of high risk patients is neither highly sensitive nor highly specific. This study investigated risk stratification of 466 survivors of acute myocardial infarction (86 women, mean age 57.5 years) for whom a 5-year follow-up was available. During the follow-up 67 patients died and 24 of these events were sudden arrhythmic deaths. In addition to LVEF, patients were stratified by mean heart rate, heart rate variability and the slope of heart rate turbulence, all derived from 24-hour Holter recording obtained before hospital discharge, and by the 3D angle between QRS complex and T wave vectors (total cosine R-to-T, TCRT) obtained from digital resting electrocardiogram before hospital discharge. Individual risk characteristics and their combinations were evaluated by calculating the areas under the receiver operator characteristics (ROC). The bootstrap technology was used to investigate these statistically. For the stratification of both all cause mortality and sudden arrhythmic death, TCRT was the strongest risk stratifier (area under ROC of 0.6857 +/- 0.0367, and 0.7275 +/- 0.0544, respectively) that compared very favourably to LVEF (area under the ROC of 0.6610 +/- 0.0362 and 0.6346 +/- 0.0595, for all cause and arrhythmic death prediction, both P < 10(-10) for the comparison with TCRT). TCRT was also stronger in combination with other stratifiers, eg, TCRT + LVEF (area under ROC of 0.7631 +/- 0.0325 and 0.8057 +/- 0.0473, for all cause and arrhythmic death prediction) was stronger than mean heart rate + LVEF (area under ROC of 0.7396 +/- 0.0298 and 0.7673 +/- 0.0445, respectively, both P < 10(-10) for comparison with TCRT + LVEF). Hence the 3D QRS-T angle is a very powerful risk stratifier especially suited for the prediction of sudden arrhythmic death. It should be prospectively investigated in future trials of prophylactic antiarrhythmic interventions.

Adult↗

PubMed2023

International Liver Cancer Association (ILCA) white paper on hepatocellular carcinoma risk stratification and surveillance.

Major research efforts in liver cancer have been devoted to increasing the efficacy and effectiveness of surveillance for hepatocellular carcinoma (HCC). As with other cancers, surveillance programmes aim to detect tumours at an early stage, facilitate curative-intent treatment, and reduce cancer-related mortality. HCC surveillance is supported by a large randomised-controlled trial in patients with chronic HBV infection and several cohort studies in cirrhosis; however, effectiveness in clinical practice is limited by several barriers, including inadequate risk stratification, underuse of surveillance, and suboptimal accuracy of screening tests. There are several proposed strategies to address these limitations, including risk stratification algorithms and biomarkers to better identity at-risk individuals, interventions to increase surveillance, and emerging imaging- and blood-based surveillance tests with improved sensitivity and specificity for early HCC detection. Beyond clinical validation, data are needed to establish clinical utility, i.e. increased early tumour detection and reduced HCC-related mortality. If successful, these data could facilitate a precision screening paradigm in which surveillance strategies are tailored to individual HCC risk to maximise overall surveillance value. However, practical and logistical considerations must be considered when designing and implementing these validation efforts. To address these issues, ILCA (the International Liver Cancer Association) adjourned a single topic workshop on HCC risk stratification and surveillance in June 2022. Herein, we present a white paper on these topics, including the status of the field, ongoing research efforts, and barriers to the translation of emerging strategies.

Humans↗

PubMed2006

The bio-optical properties of CDOM as descriptor of lake stratification.

Multivariate statistical techniques are used to demonstrate the fundamental role of CDOM optical properties in the description of water masses during the summer stratification of a deep lake. PC1 was linked with dissolved species and PC2 with suspended particles. In the first principal component that the role of CDOM bio-optical properties give a better description of the stratification of the Salto Lake with respect to temperature. The proposed multivariate approach can be used for the analysis of different stratified aquatic ecosystems in relation to interaction between bio-optical properties and stratification of the water body.

Ecosystem↗

PubMed2005

Correlation of plasma von Willebrand factor levels, an index of endothelial damage/dysfunction, with two point-based stroke risk stratification scores in atrial fibrillation.

To test the hypothesis that the new CHADS2 and Framingham point-based risk stratification scores could be related to plasma vWf (a plasma index of endothelial damage/dysfunction) and soluble E-selectin (an index of endothelial activation) levels in a large cohort of AF patients, we studied 200 consecutive patients (101 male; 72+/-9 years) attending our anti-coagulation clinic for the initiation of anticoagulation treatment with acenocoumarol. AF patients had a median CHADS2 score of 2 (1-2) and a median Framingham point-based risk score of 14 (9-21). Results of research indices in our AF patients were as follows: vWf 142.8+/-41.8 IU/dL and sE-sel 44 (31-62) ng/mL. There were significant correlations between plasma vWf levels and both risk CHADS2 and Framingham risk scores (vWf-CHADS2 risk score: Spearman, r=0.249, p<0.001; vWf-Framingham risk score: r=0.294, p<0.001). sE-sel did not show any significant correlation with both risk scores (sE-sel-CHADS2 risk score: r=-0.054, p=0.460; sE-sel-Framingham risk score: r=0.062, p=0.460). There were no statistically significant correlations between vWf and sE-sel (r=-0.127, p=0.081). Both CHADS2 and Framingham risk scores were significantly correlated with each other, r=0.627, p<0.001. In conclusion, in a wide cohort of non-selected and consecutive AF patients, endothelial damage/dysfunction (assessed by plasma vWf levels) but not endothelial activation (sE-sel) correlated with two new risk stratification scores for stroke in AF. Further prospective studies are needed to assess the prognostic role of prothrombotic indices in AF in relation to stroke and thromboembolic events, and their role in complementing clinical risk stratification schemas.

Aged↗

PubMed2006

Risk stratification in penile carcinoma: 25-year experience with surgical inguinal lymph node staging.

OBJECTIVES: In penile carcinoma, the most reliable staging method for lymph node involvement remains radical dissection with its associated high morbidity. However, the patient's prognosis is closely associated with lymph node status, and radical dissection is potentially curative. We report our experience with surgical lymph node staging and evaluate which group of patients could be assigned to a wait-and-see strategy or dynamic sentinel node biopsy and which group should undergo groin dissection. METHODS: From 1979 to 2004, 56 consecutive patients with penile cancer underwent surgical inguinal lymph node staging. On the basis of the histopathologic results, we defined risk stratification into low, high, and intermediate-risk groups according to the clinical examination findings, stage, and grade. RESULTS: Tumor stage (P = 0.019) and tumor grade (P <0.001) correlated significantly with lymph node status. Stratification into low (pT1G1, pT1G2), high (all G3 tumors), and intermediate-risk (all others) groups found 7.7% of low-risk patients with metastases. In the intermediate and high-risk groups, 28.6% and 75.0% had nodal metastases, respectively. Correlation with nodal involvement according to risk group was R2 = 0.608 (P <0.001). CONCLUSIONS: Risk stratification might enable a modified staging strategy for lymph node status according to stage, grade, and clinical examination findings. Highly motivated low-risk patients could be included in a surveillance program; however, high-risk patients should undergo bilateral inguinal dissection. Dynamic sentinel lymph node biopsy might be encouraged for intermediate-risk patients in the future.

Adult↗

PubMed2003

QRS duration and prediction of mortality in patients undergoing risk stratification for ventricular arrhythmias.

This study tested the hypothesis that prolonged QRS duration independently predicts long-term mortality in patients who underwent risk stratification and treatment for ventricular arrhythmias. Patients who underwent risk stratification by electrophysiologic study were identified. Electrophysiologic study results were defined as positive if sustained monomorphic ventricular tachycardia was induced. Mortality was the primary end point. Of 915 patients studied, mean left ventricular (LV) ejection fraction (EF) was 35.3 +/- 15.7%, 608 (66.4%) had coronary artery disease, 233 (25.5%) had positive electrophysiologic study findings, 298 (32.6%) received implantable cardioverter-defibrillators, and 174 (19%) died (mean follow-up 35.0 +/- 15.0 months). Cox regression analysis identified older age, coronary artery disease, digoxin use, absence of beta blockers, lower LVEF, and prolonged QRS duration to be independent predictors of mortality. QRS duration > or =130 ms, present in 33.6% of patients, was associated with a twofold increase in mortality (hazard ratio 2.1, 95% confidence interval 1.5 to 2.8; p <0.0001). For every 10 ms increase in QRS duration, mortality rate increased 10%. In a subgroup of patients with coronary artery disease and LVEF < or =30%, prolonged QRS duration remained an independent predictor of mortality (hazard ratio 2.6, 95% confidence interval 1.6 to 4.2; p <0.0001). Thus, prolonged QRS duration is a strong independent marker of long-term mortality in patients who undergo risk stratification for ventricular arrhythmias. Whether QRS duration represents only a marker for mortality or if modification of this factor using resynchronization therapies will impact mortality merits further study.

Aged↗

PubMed1997

Usefulness of the Killip classification for early risk stratification of patients with acute myocardial infarction in the 1990s compared with those treated in the 1980s. Israeli Thrombolytic Survey Group and the Secondary Prevention Reinfarction Israeli Nifedipine Trial (SPRINT) Study Group.

The classification introduced in 1967 by Killip et al has proved to be a useful method for early risk stratification of patients with acute myocardial infarction (AMI). Over the past 3 decades the overall mortality due to AMI has decreased significantly. The present study evaluates the usefulness of the Killip classification as a method for early risk stratification of patients with AMI in the 1990s. One thousand eight hundred seventy-three consecutive AMI patients were hospitalized in 25 coronary care units operating in Israel, and were followed for 1 year. Higher Killip class was found to be associated with increased in-hospital and 1-year mortality, in thrombolysis- and nonthrombolysis-treated patients (30-day mortality for all patients was 5%, 21%, 35%, and 67% in Killip classes I to IV, respectively). The overall mortality among AMI patients in the 1990s was found to be lower for each Killip class compared with a comparable patient population with AMI, hospitalized in Israel in the 1980s. Thus, the Killip classification is a useful method for early risk stratification of AMI patients in the 1990s.

Aged↗

PubMed1998

Clinical impact of echocardiography in prognostic stratification after acute myocardial infarction.

Risk stratification is mandatory in the management of the postinfarction period. The identification of high-risk patients, on the basis of clinical data (recurrent angina, overt heart failure, etc.), is quite easy, whereas stratification of uncomplicated subjects needs an accurate noninvasive strategy. In the last 20 years, echocardiography has been gaining an increasing role, allowing increasingly precise evaluation of infarct size. This detection of the extent of infarct size has a definite prognostic value. Since 1980, we have observed that a dysfunctioning left ventricular myocardium >40% marked patients with a poor prognosis. These observations are most important in asymptomatic infarct patients, in whom clinical features may not reflect the amount of left ventricular dysfunction. Our recent results on a large series of patients with acute myocardial infarction (MI) without overt heart failure have shown that the extension of wall motion abnormalities at 2-dimensional (2D) echocardiography was highly predictive of cardiac death or new coronary events in a 3-year follow-up (univariate analysis; p <0.0005). Echocardiography also plays an important role in detecting postinfarct ischemia, as seen by its wide use during stress tests. In our experience, the response to exercise echocardiographic testing has a high prognostic value. In fact, in our series, univariate analysis (Kaplan-Meier) showed that the best predictors of coronary events were the number of markers of ischemia during exercise (p <0.00001), the work load (p <0.00001), a positive exercise echo (p <0.0005), and the echo score at rest (p <0.0005). Multivariate analysis (Cox) confirmed these data: number of markers of ischemia: odds ratio (OR) 4.45, 95% confidence interval (CI) 1.5-13.1; work load: OR 2.46, CI 1.3-4.5; positive exercise echo OR 1.88, CI 1.1-3.2. Thus, serial echocardiography together with predischarge stress echocardiography is recommended for risk stratification after acute MI. In particular, in thrombolytic-treated patients, echo examinations allow the detection of functional recovery of viable reperfused myocardium whereas stress echo may show exercise-induced worsening in the region supplied by the infarct-related vessel, a predictor of a higher rate of coronary events.

Echocardiography, Doppler↗

PubMed2001

Stratification of welding fumes and grinding particles in a large factory hall equipped with displacement ventilation.

The purpose of the study was to investigate the performance of displacement ventilation in a large factory hall where large components of stainless steel for paper, pulp and chemical industries were manufactured. The performance of displacement ventilation was evaluated in terms of concentration distributions of welding fumes and grinding particles, flow field of the supply air and temperature distributions. Large differences in vertical stratification patterns between hexavalent chromium (Cr(VI)) and other particulate contaminants were observed. The concentration of Cr(VI) was notably lower in the zone of occupancy than in the upper part of the factory hall, whereas the concentrations of total airborne particles and trivalent chromium (Cr(III)) were higher in the occupied zone than in the upper zone. The stratification of Cr(VI) had the same tendency as the air temperature stratification caused by the displacement flow field.

Air Pollution, Indoor↗