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PubMed2001

[Arrhythmia risk stratification in patients with heart failure: prognostic evaluation of arrhythmia risk].

Sudden cardiac death is one of the more frequent causes of death in patients with heart failure. Thus, identification of patients at risk is a major clinical problem not only for the unpredictability of the event but also for the continuous growth of patients' number. The most widely used parameter for risk stratification is ejection fraction. Unfortunately, its predictive accuracy is limited and often it is impossible to distinguish patients with an increased arrhythmic mortality from those with an increased mortality due to pump failure. Heart rate variability and baroreflex sensitivity analysis has been largely utilized to obtain information on autonomic modulation of sinus node as well as to identify patients at risk. However, at variance with results observed in post-myocardial infarction patients, lower values of both parameters have been reported in patients with either an increased total or arrhythmic mortality. More recently, T wave alternans analysis has been found effective in identifying patients with an increased arrhythmic risk. Ongoing studies will provide evidence to support the use of this non-invasive technique in patients with cardiac insufficiency. Finally, the role of programmed electrical stimulation in heart failure patients appears limited. Inducibility of monomorphic sustained ventricular tachycardia seems to correlate better with the presenting clinical arrhythmia than with patient outcome. In conclusion, our capability of identifying heart failure patients at risk for arrhythmic death is far from being satisfactory. It is possible that the combination of results of multiple non-invasive tests such as reduction in ejection fraction and positivity for T wave alternans may not only provide general prognostic information but also facilitate the appropriate identification of patients at risk who may benefit from antiarrhythmic therapy.

Arrhythmias, Cardiac↗
PubMed2002

Both TPA and SCC-Ag levels are prognostic even in high-risk stage Ib-IIa cervical carcinoma as determined by a stratification analysis.

OBJECTIVE: To determine the prognostic values of tissue polypeptide antigen (TPA), squamous cell carcinoma antigen (SCC-Ag), and carcinoembryonic antigen (CEA) in the sera of cervical carcinoma patients, especially in those with a poor prognosis. METHODS: In this retrospective study, the preoperative serum SCC-Ag, TPA, and CEA were analyzed in 779 patients with cervical squamous cell carcinoma of stage Ib-IIa who received radical hysterectomy and pelvic lymph node dissection (RAH-PLND) between 1984 and 1994. RESULTS: Due to poor predictive value and poor correlation between serum CEA and clinico-pathological factors, CEA was abandoned in this study. Elevated TPA and SCC-Ag levels, pelvic lymph node metastasis (PLNM), lymphvascular space involvement (LVSI) and deep stromal invasion (DSI) were associated with poor survival time by univariate analysis. The correlation study showed that elevated serum TPA was significantly related to PLNM, LVSI, and DSI (p = 0.004, 0.008, and 0.021, respectively), and SCC-Ag was related to PLNM and bulky tumor size (p = 0.001 and 0.02, respectively). In the multivariate analysis, only PLNM and LVSI remained independently significant indicating poor survival. Further stratification studies by PLNM and LVSI showed that elevated TPA levels could even indicate higher recurrence rates in patients with PLNM (p = 0.045), as well as SCC-Ag in patients with LVSI (p = 0.038). CONCLUSIONS: The results suggest that both elevated TPA and SCC-Ag levels depicting poor prognosis in stage Ib-IIa cervical SCC, especially indicates a group of high-risk patients who may need more aggressive therapy.

Adult↗
PubMed1975

[Stratification in the central nervous system].

Stratigenesis in the optic tectum of developing chick embryos was investigated between the 4th and the 11th day of incubation. Stratification is achieved by successive emigration of cell contigents from the proliferative layer. In the opinion of the authors the main factor which determines this very regular cell migration would be a gradient of oxygen and of metabolites. The gradient has to appear in the wall of tectum due to its typical vascular network. Experiences with induced hypoxia or with selective damage of the proliferative layer strengthen the hypotesis of an oxygen gradient playing the role of a generally active epigenetic factor in the stratigenesis of the central nervous system.

Animals↗
PubMed2002

Risk stratification in clinically localized prostate cancer.

Clinical outcomes in patients with localized prostate cancers are heterogeneous. In recent years, analyses of large datasets from multiple centres have yielded a better understanding of how to measure risk in localized prostate cancer. Regardless of whether patients are treated with prostatectomy, radiotherapy, brachytherapy, or expectant management, three factors appear correlated with clinical outcome: biopsy Gleason score, clinical T stage, and serum prostate-specific antigen (PSA). Partin Tables, derived from these parameters and recently updated and refined, may be used to estimate the risk of metastasis and to assess certain aspects of surgical management in clinically localized disease. Partin tables, however, are limited by the fact that pathologic stage does not always predict clinical outcome. Nomograms that employ serum PSA, biopsy Gleason score, and clinical T-stage have been developed with the aim of predicting clinical recurrence after radical prostatectomy or radiation therapy. Three risk categories for clinically localized prostate cancer have recently been developed by the Canadian Genito-Urinary Radiation Oncologists Consensus Conference, which group cases according to serum PSA, T-stage, and biopsy Gleason score. Additional factors have been assessed in the hopes of improving the prediction of outcome in clinically localized disease, but none of these has consistently been demonstrated to add independent value to the principal parameters of serum PSA, T-stage, and Gleason score. Virtually all predictive nomograms, algorithms, and tables incorporate a combination of these three parameters. While these tools may be useful in prognosticating an individual case, several limitations preclude their widespread use. The greatest benefit to date of risk stratification is its use in comparing outcomes of series of patients treated with various modalities, and in clinical trial design and analysis.

Humans↗
PubMedDate not supplied

[Management of essential arterial hypertension and cardiovascular risk levels. Observation in general medicine: national PHENOMEN study. Evaluation and stratification of cardiovascular risk based on the 2000 ANAES recommendations in a population of hypertensive patients].

OBJECTIVE: To define the prevalence of cardiovascular risk (CVR) levels in a population of hypertensive patients (whether treated or not) monitored by General Practitioners, using the stratification system proposed by the ANAES in 2000. METHODS: Between January and July 2001, a nation-wide survey was carried out based on a representative sample of 8,177 General Practitioners spread evenly throughout all of the 22 administrative regions in France. The evaluation of CVR levels took into account blood pressure readings as well as CVR factors and indicators. RESULTS: This survey covered 16,358 patients (53.2% men, 46% women; mean age = 62.5 +/- 11.9 years; BMI = 27.3 +/- 4.5 kg/m2) with a mean history of hypertension of 7 +/- 7 years. The most common CVR factors were dyslipidemia (59.5%), smoking (19%) and diabetes (16%). Concomitant target organ damage was recorded in 17% and heart disease in 21.8%. One patient in four had more than three CVR factors; respectively 56.5%, 30.9% and 12.5% of the patients had mild, moderate or severe hypertension. More than 50% of the patients were classified as being at "high" or "very high" CV risk. The distribution of risk levels was similar throughout the country with a North-South gradient of the high/very high levels. Only 17% of the patients being treated had completely normal blood pressure (< 140/190 mmHg), although 19% more count as normal if the limit values are included. CONCLUSION: The main objective of this large-scale, nation-wide epidemiological survey was to evaluate how well CVR is being managed in a representative sample of patients with high blood pressure. In general, none of the risk factors is adequately controlled, especially in populations considered as being at high CVR. Moreover, the notion of CVR has only been partially assimilated by General Practitioners.

Aged↗
PubMed2002

[Fibrinolysis and thrombosis of mechanical valvular prosthesis: risk stratification by transesophageal echocardiography].

The place of fibrinolysis in the treatment of mechanical valvular prostheses is still much discussed. The aim of this work is to define the role of transoesophageal echocardiography in risk stratification. This monocentric study draws on 49 cases of thrombolysis preceded by transoesophageal echocardiography (average age 62.1 years, 37 mitral, 11 aortic, 1 tricuspid, 1 mitro-tricuspid). There were 41 obstructive thromboses (OT) and 8 non-obstructive thromboses (NOT). Clinical events and the effectiveness of fibrinolysis were studied as a function of the obstructive or non-obstructive character of the thrombosis and the size of the thrombus < 10 mm (n = 33) or > or = 10 mm (n = 16). Complete success was observed in 34 patients (69.4%). Follow up revealed 2 early cerebral haemorrhages (4.1%) of which one was in the NOT group, and six systemic emboli (12.2%) of which one was in the NOT group. There was a relationship between the size of the thrombus and embolus at the limit of significance in favour of an increased risk of embolus for a voluminous thrombus. Furthermore, the mobility of the thrombi went in hand with an increased rate of systemic emboli (p < 0.01). The rate of failure of fibrinolysis and/or complications correlated with the size of thrombus (complete success in 88% of the < 10 mm thrombus group, versus 35% in the > or = 10 mm; p < 0.01). This work underlines the significance of trans-oesophageal echocardiography in the therapeutic choice for valvular prosthesis thrombosis and suggests that the existence of a voluminous thrombus especially if mobile is a contra-indication for fibrinolysis.

Adult↗
PubMed2002

[Stratification of patients with hypertension and selection of antihypertensive therapy].

Patients with hypertension (78 men, 113 women aged 20-73 years) were stratified according to risk of development of cardiovascular complications. In low and moderate risk patients (n=31) with borderline hypertension, dyslipidemia and pronounced obesity mainly non-drug measures were employed directed at lowering of excess body mass. Medium risk patients (n=25) with isolated hypertension group were treated with angiotensin converting enzyme inhibitors and phenylalkylamine calcium antagonists. High risk patients (n=55) with metabolic syndrome received same antihypertensive drugs as medium risk patients. In very high risk patients (n=79) with diabetes, excessive body mass, dyslipidemia and proteinuria complex therapy consisting of antihypertensive and hypoglycemic drugs and non-drug interventions was used. This risk stratification based management of patients with hypertension on turned out to be highly effective and resulted not only in normalization of blood pressure but also in improvement of carbohydrate and lipid metabolism, lowering of resistance to insulin and excessive body mass, and improvement of renal function.

Adult↗
PubMed1975

Health services system in Hong Kong: professional stratification in a modernizing society.

A characteristic of modernizing societies is the coexistence of modern and traditional professions that claim to perform the same functions for the society. As a result of differential support by the dominant classes and their social values, and by the academic and the political authorities, the modern profession occupies a higher stratificational ranking than the traditional profession. In order to struggle for survival and to compete for more social-political and economic resources, the traditional profession advocates a rational revival, i.e. a rationalization of its social organization and technical contentmin this paper, I have illustrated these generalized statements by analyzing and comparing the profession of modern medicine with that of Chinese medicine in the modernizing society of Hong Kong, These two types of professional services are coexisting in the pluralistic health context of Hong Kong, but the former enjoys greater power, higher prestige and more economic resources. The state of modern medical dominance may be due to its connection with the dominant social value of science and to its support by the "higher" classes and the university and the government in Hong Kong. In recent years; however, there has emerged a revivalistic movement in the realm of Chinese medical care. In significant part, this may be influenced by developments in the People's Republic of China.

Acupuncture Therapy↗
PubMed2003

T wave alternans for ventricular arrhythmia risk stratification.

Sudden cardiac death remains one of the leading causes of death in Europe and the United States. Accordingly, the ability to identify patients at high risk of sudden cardiac death is important so that appropriate treatments can be used efficiently. Recently, T wave alternans (TWA) has emerged as a promising new test for such risk stratification. TWA is a heart rate dependent measure of arrhythmia vulnerability, with maximal predictive accuracy at sustained, regular heart rates of 100-120 bpm. In the clinical setting these conditions may be achieved by either exercise or atrial pacing. TWA has been shown to predict inducibility of ventricular tachycardia with programmed stimulation and also spontaneous arrhythmic events. TWA has been successfully applied to diverse populations, including patients with coronary artery disease, nonischemic cardiomyopathy, congestive heart failure and those with implantable defibrillators. Despite these encouraging results, the role of TWA to guide clinical therapy still needs to be better elucidated.

Arrhythmias, Cardiac↗
PubMed2002

[Risk stratification in unstable angina pectoris and non-Q myocardial infarct: anamnesis, physical examination, electrocardiography, specific cardiac markers].

Patients with unstable angina pectoris or non Q-infarction of the myocardium are a very heterogeneous group. It comprises patients with angina pectoris which developed for the first time in their life and had only an episodic character, as well as patients with a severe clinical course and prognostically serious coronary finding. In this connection risk stratification of patients is useful as a provision from which the further diagnostic and therapeutic procedure develops. Based on an analysis of anamnestic data, physical examination, electrocardiogram and examination of cardiospecific, biochemical markers we can divide the patients into groups with a high, medium and low risk. In patients with a high risk the authors use in addition to standard medicamentous treatment also an early invasive examination with possible revascularization. Coronary angiography without the necessity of immediate implementation is also indicated in the majority of patients with medium risk. Conversely low risk patients do not require hospital admission in some cases, or they may be discharged soon.

Angina, Unstable↗
PubMed2003

[Clinical aspects and risk stratification of acute coronary syndromes without ST-segment elevation].

The clinical classification of acute coronary syndromes without ST-segment elevation has long been a topic of debate. Braunwald's classification, however, is now widely adopted and permits to recognize the most severe forms of acute coronary syndromes. Risk stratification is essential and is based upon clinical and biological markers. Among them, recent and repeated anginal attacks, ST-segment modifications on admission electrocardiogram, and increased markers of myonecrosis (particularly increased troponine levels) are strong predictors of untoward outcome. These variables can be used to construct risk scores, among which the Timi risk score is the most widely used.

Acute Disease↗
PubMed2003

Risk stratification after acute myocardial infarction: role of neurohormones, inflammatory markers and albumin excretion rate.

Activation of several neurohormonal systems occurs during acute myocardial infarction (AMI) and is associated with short- and long-term outcomes. In the last few years, many circulating factors have received close attention but it is not clear which are the best prognostic indicators of mortality. Renin and natriuretic cardiac peptides appeared to be strong predictors of outcome in patients with AMI, and could represent helpful markers of risk in these patients. Though the role of acute inflammatory markers has been investigated only recently, mounting evidence indicates that C-reactive protein is also associated with an adverse outcome after AMI. Recent research from our laboratory indicates that the albumin excretion rate (AER) is a powerful predictor of the in-hospital and 3-year mortality in patients with AMI and that its prognostic power is stronger than that shown by other humoral markers of risk or by clinical and echocardiographic signs of congestive heart failure. The reason why AER is so closely associated with an adverse prognosis is not completely understood, but the available data support the hypothesis that it reflects both the hemodynamic as well as the inflammatory changes which accompany AMI. The determination of the brain natriuretic peptide and of C-reactive protein appears to be a valuable tool in the risk stratification of subjects with AMI. Even though available evidence is still limited, the evaluation of AER could be useful for the identification of those patients at higher risk for whom additional preventive and therapeutic measures would be advisable.

Biomarkers↗
PubMed2003

Risk stratification, management and outcomes of patients with non-ST elevation acute coronary syndrome: a Canadian teaching hospital perspective.

BACKGROUND: Current guidelines for non-ST elevation acute coronary syndromes (NSTACS) recommend tailoring the intensity of therapeutic management according to the baseline risk of the patient. Although the clinical characteristics, risk stratification and therapeutic management of contemporary patients with NSTACS have been reported for other geographical regions, this information has not been documented from a Canadian perspective. OBJECTIVES: To describe the baseline clinical characteristics, therapeutic management and clinical outcomes of contemporary patients with NSTACS at a Canadian, tertiary care, teaching hospital, and to retrospectively risk stratify the patients with NSTACS according to the American College of Cardiology (ACC)/American Heart Association (AHA) and Thrombolysis in Myocardial Infarction (TIMI) risk guidelines to characterize management and outcomes according to the various risk classifications. METHODS: Baseline demographics, procedural variables and clinical outcome data were retrospectively collected in 380 patients with a diagnosis of NSTACS from July 1999 to July 2000. Patients were retrospectively categorized into high, intermediate and low risk categories using two classification schemes. RESULTS: According to the ACC/AHA guidelines, 10.3% and 89.7% of patients were intermediate and high risk, respectively. Applying the TIMI risk score, 20.0%, 52.4% and 27.6% of patients were low, intermediate and high risk, respectively. The use of antithrombotic, acetylsalicylic acid and beta-blocker therapy was very high both in hospital and at discharge. Glycoprotein IIb/IIIa inhibitors, angiotensin-converting enzyme inhibitors and lipid lowering agents were all underutilized. The use of pharmacological therapies and cardiovascular interventions did not appear to correlate with the level of risk of the patient, at least within these classification schemes. Adverse clinical events in hospital and length of hospital stay increased as the risk level of the patients increased. CONCLUSIONS: According to the ACC/AHA guidelines, patients with a discharge diagnosis of NSTACS in a nontrial setting are a high risk population, requiring prompt recognition and aggressive management. This study serves as an integral part of clinical practice to continually evaluate the quality of medical care.

Aged↗
PubMedDate not supplied

[Prognostic stratification of the patient with ischemic cardiopathy].

The mean goal in the evaluation of a patient with coronary artery disease is the identification of patients at high risk to develop major cardiac events, including mortality. Ischemic patients can be stratified using non-invasive and invasive methods. Invasive procedures have some disadvantages, especially in follow-up studies. Nuclear Cardiology procedures, such as perfusion studies performed with thallium or 99mTc labeled agents (sestamibi, tetrofosmin), radioventriculography for right and left ventricle function evaluation and Gated SPECT are considered the best non-invasive procedures not only for the diagnosis of myocardial ischemia but for risk stratification. These techniques can identify the group of patients at high risk to develop major cardiovascular events, constituted by patients with perfusion abnormalities, specially during stress and systolic left ventricle dysfunction.

Humans↗
PubMed1992

[Application of Bayes discriminatory analysis to malaria stratification in Hainan province].

The present study was conducted to explore a new method for stratification of malaria endemicity. Several socioeconomic and geographic factors deemed appropriate to be employed in association with malaria epidemic potential were deal with Bayes discriminatory analysis.55 local villages in 12 counties of Hainan province were selected for socioeconomic survey, among which 33 villages were taken as the modelling sample and 22 villages were the non-modelling sample. The questionnaire contained a total of 12 relevant items. After socioeconomic inquiry was performed, the data were analysed through Bayes discriminatory theorem. Six important factors ware selected, i.e. topography (X1), proportion of labour forces (X4), income per person (X5), house structure (X8), knowledge of malaria control (X10), frequency of over-night stay in mountain forest (X12). Three discriminatory function formulas referring respectively to hyper-, meso-, and hypo-endemicity were set up. These 3 discriminatory function formulas were further applied to fit the endemicity of 33 model-sampling villages and 22 non-model-sampling villages. The agreement rate were 91.0% and 77.3% respectively.

Bayes Theorem↗
PubMed2003

The role of exercise ventilation in clinical evaluation and risk stratification in patients with chronic heart failure.

BACKGROUND: Patients with chronic heart failure (CHF) are characterised by an increased ventilatory response to exercise. The role of exercise ventilation in the risk stratification and evaluation of patients with CHF has not yet been established. AIM: To examine the relationship between exercise ventilation indices and clinical parameters of CHF and to assess the prognostic value of the ventilatory response to exercise. METHODS: The study group consisted of 87 patients with CHF (72 males, mean age 58 years) with a mean left ventricular ejection fraction of 32%. Ten patients were in NYHA class I, 38 - in NYHA class II, 34 - in NYHA class III, and 5 - in NYHA class IV. The control group consisted of 20 patients without CHF (13 males, mean age 58 years, mean LVEF - 61%). All studied subjects underwent maximal exercise test with gas-exchange measurement. The following parameters were analysed: peak exercise oxygen consumption [peak VO(2) (ml/kg/min)], VE-VCO(2) index [a coefficient of linear regression analysis depicting an association between ventilation (VE) and carbon dioxide production (VCO(2)) during exercise] and VE/VCO(2) ratio at peak exercise to VE/VCO(2) ratio while at rest (VE/VCO(2 peak/rest)). RESULTS: Ventilatory response indices were significantly higher in patients with CHF compared with controls: VE-VCO(2) - 37.9+/-11.1 vs 27.1+/-4.1; VE-VCO(2 peak/rest) - 0.89+/-0.14 vs 0.75+/-0.10 (p<0.001). In CHF patients a significant positive correlation between ventilatory response parameters and NYHA class (VE-VCO(2) - r=0.52; VE/VCO(2 peak/rest) - r=0.47) and a negative correlation with peak VO(2) (VE-VCO(2) - r=-0.52; VE/VCO(2 peak/rest) - r=-0.49) were noted (p<0.0001 for all correlations). No correlation was found between ventilatory parameters and echocardiographic variables or CHF aetiology. During the follow-up period lasting at least 12 months, 17 (22%) patients died. In the univariate Cox model, NYHA class III-IV, decreased peak VO(2) and increased VE-VCO(2) and VE/VCO(2 peak/rest) values were significantly associated with the risk of death. The multivariate analysis revealed that VE/VCO(2 peak/rest) > or =1.0 was the adverse prognostic factor, independent of peak VO(2) (p=0.02) and NYHA class (p=0.01). The Kaplan-Meier analysis showed that prognosis during the 18-month follow-up period in patients with enhanced exercise ventilation was worse than in the remaining patients (59% survival in patients with VE/VCO(2 peak/rest) > or =1.0 59% vs 91% survival in patients with VE/VCO(2 peak/rest) <1.0, p=0.001). CONCLUSIONS: In patients with stable CHF simple exercise ventilation parameters may provide important clinical and prognostic information.

Adult↗
PubMed1992

Antiemetic study design: desirable objectives, stratifications and analyses.

Once the optimal dose and safety of an antiemetic has been established a randomised double blind parallel subjects design is recommended for phase III studies. Randomisation distributes the unknown prognostic variables so that their effects can be allowed for in tests for statistical significance. Stratification can equally distribute the known prognostic factors e.g. prior exposure to chemotherapy, strength of the emetic stimulus, age, sex and prior alcohol consumption. A cross-over design is often proposed because less patients would be required to achieve the same power as a parallel subjects study. The major problem with this design is in being able to estimate and allow for carry over effects or treatment period interactions which can interact with each other and the direct treatment effect. The study must be large enough to detect a statistically significant difference of clinical importance. Interim analyses should be preplanned and early termination should require a difference between the arms with a more significant P value than 0.05. Simple evaluation of efficacy could include quantitation of objective parameters and use of simple ordinal scales to record more subjective phenomena. In a parallel subjects design patients must assess their overall tolerance of therapy which balances the antiemetic's efficacy and toxicity.

Antiemetics↗
PubMed2003

Role of myocardial perfusion imaging in risk stratification.

This review paper is based on a topic invited for review presented by the first author at the Annual Meeting of Society of Nuclear Medicine of Serbia and Montenegro, September 2003. The optimal management of patients affected by coronary artery disease requires safe and cost-effective techniques for assessing the risk of subsequent cardiac events or the need for surgery. The ideal test should distinguish between high risk patients who will benefit from aggressive management and low risk patients who can be managed conservatively. Stress testing alone is believed to be inadequate for the assessment of risk. Nuclear Medicine techniques have routinely been used in the identification of patients with ischaemic heart disease and those with viable myocardium post myocardial infarction. While the essential methodology for the techniques remains same, the reporting and interpretation criteria for determining future risk are different. For instance, a fixed perfusion defect on stress myocardial perfusion imaging in a patient presenting cardiactype chest pain to the cardiologists for the first time, has a different value from a similar patient being presented to the noncardiologist for major vascular surgery. A review of the literature concerning the current usage of nuclear cardiology techniques in risk stratification is presented.

Coronary Artery Disease↗