Biomedical subjects

G Chatellier

Publications and source records attributed to G Chatellier.

At least 37 records · Page 2Linked to original sources

PubMed2001

Very long-term results (more than 20 years) of valve repair with carpentier's techniques in nonrheumatic mitral valve insufficiency.

BACKGROUND: Mitral valve repair is considered the gold standard in surgery of degenerative mitral valve insufficiency (MVI), but the long-term results (>20 years) are unknown. METHODS AND RESULTS: We reviewed the first 162 consecutive patients who underwent mitral valve repair between 1970 and 1984 for MVI due to nonrheumatic disease. The cause of MVI was degenerative in 146 patients (90%) and bacterial endocarditis in 16 patients (10%). MVI was isolated or, in 18 cases, associated with tricuspid insufficiency. The mean age of the 162 patients (104 men and 58 women) was 56+/-10 years (age range 22 to 77 years). New York Heart Association functional class was I, II, III, and IV in 2%, 39%, 52%, and 7% of patients, respectively. The mean cardiothoracic ratio was 0.58+/-0.07 (0.4 to 0.8), and 72 (45%) patients had atrial fibrillation. Valve analysis showed that the main mechanism of MVI was type II Carpentier's functional classification in 152 patients. The leaflet prolapse involved the posterior leaflet in 93 patients, the anterior leaflet in 28 patients, and both leaflets in 31 patients. Surgical technique included a Carpentier's ring annuloplasty in all cases, a valve resection in 126 patients, and shortening or transposition of chordae in 49 patients. During the first postoperative month, there were 3 deaths (1.9%) and 3 reoperations (2 valve replacements and 1 repeat repair [1.9%]). Six patients were lost to follow-up. The remaining 151 patients with mitral valve repair were followed during a median of 17 years (range 1 to 29 years; 2273 patient-years). The 20-year Kaplan-Meier survival rate was 48% (95% CI 40% to 57%), which is similar to the survival rate for a normal population with the same age structure. The 20-year rates were 19.3% (95% CI 11% to 27%) for cardiac death and 26% (95% CI 17% to 35%) for cardiac morbidity/mortality (including death from a cardiac cause, stroke, and reoperation). During the 20 years of follow-up, 7 patients were underwent surgery at 3, 7, 7, 8, 8, 10, or 12 years after the initial operation. Valve replacement was carried out in 5 patients, and repeat repair was carried out in 2 patients. At the end of the study, 65 patients remained alive (median follow-up 19 years). Their median age was 76 years (age range 41 to 95 years). All except 1 were in New York Heart Association functional class I/II. CONCLUSIONS: Mitral valve repair using Carpentier's technique in patients with nonrheumatic MVI provides excellent long-term results with a mortality rate similar to that of the general population and a very low incidence of reoperation.

Adult↗

PubMed2001

Blood pressure levels, risk factors and antihypertensive treatments: lessons from the SHEAF study.

OBJECTIVES: The SHEAF study (Self measurement of blood pressure at Home in the Elderly: Assessment and Follow-up) is a 3-year prospective cohort study of French elderly (> or =60 years) hypertensive patients designed to assess whether home blood pressure (HBP) measurement provides additional prognostic information over office blood pressure (OBP) in terms of cardiovascular mortality and morbidity. The objective of the present work is to describe the baseline data of the population enrolled in the SHEAF study with special emphasis on blood pressure control in treated hypertensives. METHODS: During the 2-week initial inclusion phase, baseline demographics, cardiovascular risk factors, antihypertensive treatments as well as office and home blood pressure were recorded. Baseline OBP was assessed using a mercury sphygmomanometer (three consecutive measurements during two visits performed 2 weeks apart). HBP was performed over a 4-day period (three consecutive measurements in the morning and in the evening). RESULTS: A total of 4939 (95%) of the 5211 patients included in the SHEAF study were treated with at least one antihypertensive drug. Their ages ranged from 60 to 99 years (mean age 70 +/- 7 years); 49% were men, 12% had a previous history of coronary artery disease, 14% diabetes and 43% a treated dyslipidaemia. A total of 45% of the treated patients received a single antihypertensive drug, 34% two drugs, 21% three drugs or more. Overall 23% of treated hypertensives were normalised at the doctor's office (systolic BP <140 mm Hg and diastolic BP <90 mm Hg) and 27% at home (home systolic BP <135 mm Hg and home diastolic BP <85 mm Hg). Poor blood pressure control was associated with age, an increasing presence of diabetes and prescription of several antihypertensives. The proportion of subjects with controlled blood pressure decrease with age from 26% (60-69 years) to 21% (> or =80 years). Blood pressure control of diabetic patients was particularly poor as only 19% had an OBP <140/90 mm Hg and 6% a blood pressure <130/85 mm Hg. The percentage of patients with controlled OBP decreased from 26% when receiving a single antihypertensive drug to 11% when receiving four antihypertensives or more. CONCLUSION: In the SHEAF study, less than one-third of the patients had an OBP adequately controlled thus confirming previous studies performed in younger populations. Presence of associated cardiovascular risk factors including diabetes did not give rise to a better blood pressure control. When blood pressure control was assessed using HBP measurement similar results were found. As the beneficial effect of antihypertensive treatment has been particularly well established in the elderly, the data of this study underlines the need for a closer and more rigorous management of elderly hypertensives.

Age Factors↗

PubMed2001

Assessment of sexual activity in patients with back pain compared with patients with neck pain.

Recent research has shown significant adverse effects of chronic low back pain on sexual activity in 46% of patients. To establish whether and how chronic low back pain adversely affects sexual activity, a questionnaire-based study was conducted on a patient group (low back pain) and a comparison group (neck pain). Patients were administered a visual analog scale, a series of conventional questionnaires, and a specifically designed sexual activity questionnaire covering frequency of intercourse before and since onset of pain, discomfort during intercourse, satisfaction with sexual life, and comfortable and uncomfortable basic coital positions. Patients with low back pain reported more interference than did patients with neck pain, and women with low back pain were more affected than men. Compared with the other groups, women with low back pain had greater reduction in frequency of intercourse, more marked discomfort during intercourse, and more interference with their sexual lives. The most pain generating position was prone for both genders, and the most comfortable one was supine. Sexual impairment, more marked in women, seems to be related to the triggering of pain by intercourse and to psychologic factors.

Adult↗

PubMed2001

Determinants of right ventricular pressure in mild hypertension.

OBJECTIVE: Doppler echocardiography was used to define reference values and determinants of tricuspid regurgitation peak velocity (TRV) in hypertensive patients. A TRV value > 2.5 m/s is the threshold usually defining abnormal right ventricular systolic pressure. DESIGN AND PATIENTS: Doppler echocardiography was performed in 320 consecutive uncomplicated hypertensive patients, without overt pulmonary or heart disease. Doppler echocardiography included LV mass measurement, LV inflow and pulmonary venous flow analysis, LV systolic function and TRV measurements. RESULTS: Among 320 patients, 255 had normal TRV < 2.5 m/s and 65 had elevated TRV > or = 2.5 m/s. Compared with the normal TRV group, the elevated TRV group was older (60 versus 50 years, P < 0.0001), systolic blood pressure was higher (156 versus 151 mmHg, P = 0.02) and antihypertensive therapy was more frequent (68 versus 51%, P = 0.02); indexed LV mass was higher (45.4 versus 40.6 g/m2.7, P = 0.001), pulmonary D wave peak velocity was higher (42 versus 38 cm/s, P = 0.03). In univariate analysis, age was the most predictive variable of TRV (r = 0.36). In multivariate analysis, three variables were independently related to TRV: age, LV mass, pulmonary D wave (multiple r = 0.47). CONCLUSION: In mild hypertension, TRV is independently related to age, and to a lesser extent, to LV morphology and LV filling pressure. In clinical practice, age should be taken into account to interpret TRV.

Aging↗

PubMed2001

Prevalence and therapeutic control of hypertension in 30,000 subjects in the workplace.

-To assess blood pressure (BP) control in a French working population through the use of a careful assessment of BP based on 2 different visits in 1 month, 17 359 men and 12 267 women were evaluated from January 1997 to April 1998. The initial phase was a cross-sectional analysis of a cohort study designed to assess the incidence of arterial hypertension in a French working population. Information was collected by the work-site physician during the annual examination. BP was measured with a validated automatic device. Among subjects with BP >/= mm Hg, patients not treated with antihypertensive drugs were invited to have an additional BP measurement taken 1 month later. The prevalence of hypertension (BP >/= mm Hg) based on 2 visits was 16.2% in men and 9.4% in women. When the diagnosis of hypertension was based on 2 visits, its prevalence was 41% lower in men and 36% lower in women compared with that of a diagnosis based on a single visit. Accordingly, the awareness of hypertension was 49% higher in men and 40% higher in women. Overall, 12.5% of hypertensive men and 33.2% of hypertensive women taking antihypertensive medication had their BP levels lowered to < mm Hg by treatment. Although the percentage of hypertensive men and women under current treatment who were aware of their hypertension increased with age, BP control among treated subjects decreased with age. Ineffective BP control with treatment accounted for 33% of BP levels >/= mm Hg in men and 40% of those observed in women. In this large French working population, estimates of hypertension therapeutic control depend heavily on the number of BP measurements. Despite these methodological precautions, insufficient awareness of BP and insufficient BP control through treatment remain 2 major public health problems.

Adolescent↗

PubMed2001

Factors associated with perioperative morbidity and mortality in patients with pheochromocytoma: analysis of 165 operations at a single center.

To identify preoperative factors associated with 30-day morbidity and mortality after pheochromocytoma surgery, we carried out an external review of the records of all patients undergoing pheochromocytoma surgery from 1975 to 1997 at a single center. One hundred and forty-seven patients, including 23 with malignant tumors at the time of the first operation, underwent 165 operations. Death, resection of a neighboring organ, further surgery, secondary transfer to an intensive care unit, and any events associated with a surgical stay exceeding 10 days were defined as complications. Mortality and morbidity were 4 of 165 (2.4%) and 38 of 161 (23.6%), respectively. Morbidity included 13 spleen resections and hematomas. Spleen complications were not related to tumor location, but were probably due to the operative strategy used, a transperitoneal complete abdominal exploration including both adrenal glands. Complications were independently associated with preoperative systolic blood pressure [odds ratio (OR), 1.14/cm Hg], urinary metanephrine excretion (OR, 1.18/10 micromol x day), and with the number of operations (repeat vs. first operation OR, 5.36). In conclusion, pheochromocytoma resection consistently involves a risk of complications. Spleen damage should be prevented by complete preoperative localization studies and an elective or laparoscopic surgical approach. Careful blood pressure control should help prevent complications. Patients with high secretion tumors and those undergoing repeat intervention are at high risk of complications and should be referred to centers familiar with pheochromocytoma management.

Adolescent↗

PubMed2001

[Prognosis and risk evaluation of postoperative coronary patients (PERISCOP). Methodology and study population characteristics].

The aim of the PERISCOP study was to evaluate the predictive value of cardiological investigations performed after recent coronary bypass surgery with regards to cardiac event and mortality at one year. The treatment of lipid abnormalities was also analysed. This first article describes the methodology and patient characteristics at inclusion. This prospective national multicenter trial included 2065 patients (86% men) with an average age of 63.1 +/- 9.9 years. The number of diseased vessels was 2.6 +/- 0.6. Preoperative left ventricular function was normal (ejection fraction 60 +/- 13%). Revascularisation was complete in 73% of cases (22% of arterial grafts). The cardiological investigations were performed at Day 20 +/- 10 after surgery. The duration of exercise on stress testing was 429 +/- 170 seconds. It was positive or doubtful in 9% of cases. Ventricular arrhythmias were observed in 6.5% of cases. The blood pressure response was abnormal in 6% of cases. Holter monitoring showed a median number of ventricular extrasystoles over 24 hours of 44. Three per cent of patients had one episode of ventricular tachycardia and 7% had ischaemic episodes. The echocardiographic index of segmental contractility was on average 1.75 (ejection fraction: 52.6%). The lipid analysis performed at one month, under lipid therapy in 34% of cases, showed a total cholesterol level at 1.91 +/- 0.10 g/l, an LDL-cholesterol of 1.27 +/- 0.08 g/l. The therapeutic target (LDL-cholesterol < 1 g/l) was attained in 46% of cases with treatment and in 18% of cases without treatment.

Aged↗

PubMed2001

Identification of patients at high cardiovascular risk: a critical appraisal of applicability of statistical risk prediction models.

Assessment of cardiovascular risk is widely proposed as a basis for taking management decisions about patients presenting with hypertension or hypercholesterolemia. Our aim was to critically assess the use of risk equations derived from epidemiological studies for the purpose of identifying high-risk patients. Risk equations were retrieved from the MEDLINE database and then applied to a data set of 118 patients. This data set was an evaluation study of the clinical value of the World Health Organization 1993 hypertension guidelines for the decision to treat mild hypertensive patients. We calculated agreement: 1) between equations and 2) between equations and the decision to treat taken by the physician. Most models were not applicable to our population, mainly because the original population had a narrow age range or comprised only males. Between-model agreement was better for the lower and upper risk quintiles than for the three other risk quintiles (0.58, 0.33, 0.34, 0.45, 0.70, from the lower to the upper risk quintile). When using an arbitrary threshold for defining high-risk patients (i.e. > 2% per year), we observed a huge variation of the proportion of patients classified at high risk (from 0 to 17%). There was a poor agreement between risk models and the decision to treat taken by the physician. These results suggest that risk-based guidelines should be validated before their diffusion.

Antihypertensive Agents↗

PubMed2001

Expression and meaning of medical language: building an epistemological framework for the study of semantic distance.

The use of language for communication purposes introduces a semantic gap in data processing. We have developed a new tool called semantic distance to overcome this gap. A previous presentation of our tool was based on an empirical approach. Here, we examine the properties and theoretical foundation of semantic distance from a rationalistic perspective. We present an epistemological framework to explain the meaning of semantic distance. As a tool, the purpose of semantic distance is the exchange of data or knowledge based on linguistic expressions between software components. We propose a review of the relationship between language and its representation for data processing based on the underlying philosophical assumptions. Description logic is a new paradigm in the medical informatics community to express relations between terms in "is-a" hierarchies. The utility of semantic distance is compared to description logic for communication purposes in different use cases.

Knowledge↗

PubMed2001

Computerization of guidelines: towards a "guideline markup language".

Medical decision making is one of the most difficult daily tasks for physicians. Guidelines have been designed to reduce variance between physicians in daily practice, to improve patient outcomes and to control costs. In fact, few physicians use guidelines in daily practice. A way to ease the use of guidelines is to implement computerised guidelines (computer reminders). We present in this paper a method of computerising guidelines. Our objectives were: 1) to propose a generic model that can be instantiated for any specific guidelines; 2) to use eXtensible Markup Language (XML) as a guideline representation language to instantiate the generic model for a specific guideline. Our model is an object representation of a clinical algorithm, it has been validated by running two different guidelines issued by a French official Agency. In spite of some limitations, we found that this model is expressive enough to represent complex guidelines devoted to diabetes and hypertension management. We conclude that XML can be used as a description format to structure guidelines and as an interface between paper-based guidelines and computer applications.

Decision Making, Computer-Assisted↗

PubMed2001

From paper-based to electronic guidelines: application to French guidelines.

In order to develop an internet-based decision support system, making available for French general practitioners several prevention guidelines is was necessary to implement paper based guideline. We propose a framework allowing to transform paper based practice guideline into their electronic form. Three different problems were identified: computability (e.g. determinism of the eCPG), logic (e.g. ambiguities when combining Booleans operators) and external validity (i.e. stability of decision for variations around thresholds and proportion of subjects classified in the various terminal nodes). The last problem concerned documentation of evidence: the level of evidence was associated only with the terminal decision node and not with the pathway through the decision tree. We concluded that computerisation of guidelines is not possible without expertise or authors advice. To improve computability it is necessary to provide authors with a framework that checks ambiguities, and logical errors.

Algorithms↗

PubMed2001

Logistic regression model: an assessment of variability of predictions.

Risk prediction models available for cardiovascular prevention are statistical or based on machine learning methods. This paper investigates whether the logistic regression method can be considered as reference for validation of other methods. In order to test the stability of the predictions using this method, we performed two types of analyses on 50 random training and test samples drawn from the same database. In first analyses three models were obtained by forced entry of different sets of four variables. In second analyses, models were built with increasing number of predictive variables. The predictive performance was assessed by the area under the ROC curve. Although across-samples variability is low for a given model, it is large enough to lead to wrong conclusions when comparing different prediction methods. We also suggest that a low events-per-variable ratio alters the stability of a model's coefficients but does not affect the variability of prediction performance.

Area Under Curve↗

PubMed2001

Modeling uncertainty in computerized guidelines using fuzzy logic.

Computerized Clinical Practice Guidelines (CPGs) improve quality of care by assisting physicians in their decision making. A number of problems emerges since patients with close characteristics are given contradictory recommendations. In this article, we propose to use fuzzy logic to model uncertainty due to the use of thresholds in CPGs. A fuzzy classification procedure has been developed that provides for each message of the CPG, a strength of recommendation that rates the appropriateness of the recommendation for the patient under consideration. This work is done in the context of a CPG for the diagnosis and the management of hypertension, published in 1997 by the French agency ANAES. A population of 82 patients with mild to moderate hypertension was selected and the results of the classification system were compared to whose given by a classical decision tree. Observed agreement is 86.6% and the variability of recommendations for patients with close characteristics is reduced.

Decision Making, Computer-Assisted↗

PubMed2000

Causes and mechanisms of common coccydynia: role of body mass index and coccygeal trauma.

STUDY DESIGN: A total of 208 consecutive coccydynia patients were examined with the same clinical and radiologic protocol. OBJECTIVES: To study radiographic coccygeal lesions in the sitting position, to elucidate the influence of body mass index on the different lesions, and to establish the effect of coccygeal trauma. SUMMARY OF BACKGROUND DATA: A protocol comparing standing radiographs and radiographs subsequently taken in the painful sitting position in coccydynia patients and in controls has shown two culprit lesions: posterior luxation and hypermobility. Obesity and a history of trauma have been identified as risk factors for luxation. METHODS: Dynamic radiographs were obtained. The body mass index was compared with the coccygeal angle of incidence, sagittal rotation of the pelvis when sitting down, and the presence and time of previous trauma. The patients with the newly described lesions were examined after an anesthetic block under fluoroscopic guidance. RESULTS: Two new coccygeal lesions are described (anterior luxation and spicules). Obesity was found to be a risk factor. The body mass index determines the way a subject sits down, and lesion patterns were different in obese, normal-weight, and thin patients (posterior luxation: 51%, 15.2%, 3.7%; hypermobility: 26.5%, 30.3%, 14.8%; spicules: 2%, 15.9%, 29.6%; normal: 16.3%, 32.6%, 48.1%, respectively; P < 0.0001). Trauma affected the type of lesion only if it was recent (<1 month before the onset of coccydynia), in which case the instability rate increased from 55.6% to 77.1%. Backward-moving coccyges were at greatest risk of trauma. CONCLUSIONS: This protocol allows identification of the culprit lesion in 69.2% of cases. The body mass index determines the causative lesion, as does trauma sustained within the month preceding the onset of the pain.

Adult↗

PubMed2000

[Description of long-term stays, based on PMSI data, in hospital specializing in short-term stays].

OBJECTIVE: In a context of organization of care where the budget of hospitals is a function of the number and of the severity of the in-patients and not of the duration of stay, stays of long duration (SLD) in short-stay hospitals represent a problem of both medical and administrative management. To identify the characteristics of long-duration stays. METHODS: The data used in this retrospective study were drawn from the Standardized Discharge Summaries of the year 1997 of a University Hospital of the Paris area (France). A stay of long duration (SLD) was defined in an arbitrary way as a stay exceeding 30 days. The stays of long duration (> 30 days) were subdivided in "long stays" (from 31 to 60 days) and "very long stays" (more than 60 days). RESULTS: The SLDs represent 3.7% of the discharge summaries of our hospital, among them, 40% are medical DRGs and 60% surgical DRGs. The patients in SLD more often come from other structures of care than the patients having a short duration stay of (SDS) coming mainly from their residence and were also hospitalised in several different units during their stay. Patients having a long stay were more often classified in DRGs outside the principal activity of this hospital (i.e. cardiovascular diseases). CONCLUSION: This first approach suggests that a set of simple descriptive variables (pre-existing and acquired co-morbidity, admission in surgical ward, multi-unit stay...) makes it possible to identify the patients likely to have a long duration stay. Simple variables added to the current hospital minimum medical record would make it possible to consider a predictive approach.

Diagnosis-Related Groups↗

PubMed2000

The use of the personalized estimate of death probabilities for medical decision making.

Data coming from the French national statistics on the cause of deaths are used to calculate the probabilities of death from pathologies. These probabilities are calculated according to age, sex, and place of residence of the patient to "personalize" the estimate. This individual prediction of the risk of death is proposed for pathologies for which the feasibility and the utility of prevention measures had been demonstrated. Relative risks of death according to the socioprofessional category, which are coming from the scientific literature, are used to adjust the probabilities of death as a function of the patient socioprofessional category. The aim of this work is to guide a scientist toward a prevention strategy according to the age and characteristics of patient. The use of computers by the scientists will make possible the diffusion of such tool of prediction to improve a personalized prevention.

Cause of Death↗

PubMed2000

Influence of coronary artery and contralateral carotid artery status on long-term results of carotid artery surgery.

The main cause of death and long-term disability of patients undergoing carotid artery surgery is coronary artery disease. To identify the prognostic value of the status of the contralateral artery, we studied the course of 224 consecutive patients in whom one or both carotid arteries were operated on at our institution between 1985 and 1995. The 224 patients were divided into three groups: group I (n = 56) had an occluded contralateral carotid artery, in group II (n = 56) both carotids were operated on, and group III (n = 112) had a normal contralateral carotid artery. The clinical status of all patients except one was ascertained by one of us. We found that the status of the contralateral artery does not influence the long-term prognosis of patients undergoing carotid artery surgery. A periodic cardiological and vascular follow-up of these patients seems warranted to improve their survival.

Actuarial Analysis↗

PubMed2000

The non-insulin-dependent diabetes, hypertension, microalbuminuria or proteinuria, cardiovascular events, and ramipril (DIABHYCAR) study: design, organization, and patient recruitment. DIABHYCAR Study Group.

The non-insulin-dependent DIABetes, HYpertension, microalbuminuria or proteinuria, CARdiovascular events, and Ramipril (DIABHYCAR) study is a randomized, prospective, double-blind, placebo-controlled, multicenter international trial of the ACE inhibitor ramipril (1.25 mg/day) in patients with type II diabetes and micro- or macroalbuminuria. The main outcome of the study is the time to first occurrence of either death from a cardiovascular origin, including sudden death, nonfatal myocardial infarction, stroke, or congestive heart failure, or requirement of hemodialysis or renal transplantation. The study was launched in France in early 1995 with the participation of general practitioners only, but had to be extended to 15 other countries in 1997 due to difficulties in recruitment. Since 2.5 years after the beginning of the trial the observed event rate was much less than anticipated, it was decided to increase recruitment and follow-up duration and to include congestive heart failure in the definition of the main outcome to keep the study power at a satisfactory level. Recruitment ended on April 1, 1998 with 4937 randomized patients. Following the early discontinuation for efficacy of another study of ramipril in high cardiovascular risk patients, the Heart Outcomes Prevention Evaluation study (HOPE), the second interim analysis of DIABHYCAR was performed early (when 406 instead of 500 patients presented a main outcome) and the Data Safety and Monitoring Board recommended that the study continue. Follow-up is planned to end on March 31, 2001.

Aged↗