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Gilles Chatellier

Publications and source records attributed to Gilles Chatellier.

At least 37 records · Page 2Linked to original sources
PubMed2005

Modulation of the renal response to ACE inhibition by ACE insertion/deletion polymorphism during hyperglycemia in normotensive, normoalbuminuric type 1 diabetic patients.

ACE inhibition protects kidney function, but ACE insertion/deletion (I/D) polymorphism affects renal prognosis in type 1 diabetic patients. ACE genotype may influence the renal benefits of ACE inhibition. We studied the impact of ACE I/D polymorphism on the renal hemodynamic changes induced by ACE inhibition in type 1 diabetes. We studied renal hemodynamics (glomerular filtration rate [GFR], effective renal plasma flow [ERPF], filtration fraction [GFR/ERPF], mean arterial pressure [MAP], and total renal resistances [MAP/ERPF]) repeatedly during normoglycemia and then hyperglycemia in 12 normotensive, normoalbuminuric type 1 diabetes and the II genotype (associated with nephroprotection) versus 22 age- and sex-matched subjects with the ACE D allele after three randomly allocated 2- to 6-week periods on placebo, 1.25 mg/day ramipril, and 5 mg/day ramipril in a double-blind, cross-over study. During normoglycemia, the hemodynamic changes induced by ramipril were similar in both genotypes. During hyperglycemia, the changes induced by ramipril were accentuated in the II genotype group and attenuated dose dependently in the D allele group (treatment-genotype interaction P values for ERPF, 0.018; MAP, 0.018; and total renal resistances, 0.055). These results provide a basis to different renal responses to ACE inhibition according to ACE genotype in type 1 diabetes.

Adult↗
PubMed2004

Personalized versus non-personalized computerized decision support system to increase therapeutic quality control of oral anticoagulant therapy: an alternating time series analysis.

BACKGROUND: The quality control of oral anticoagulant therapy (OAT) during the initiation and maintenance treatment is generally poor. Physicians' ordering of OAT (especially fluindione and warfarin) can be improved by dose adjustment algorithms, taking into account the results of International Normalized Ratio (INR). Reminders at the point of care, computerized or not, have been demonstrated to be effective in changing physicians prescription behavior.However, few studies have addressed the benefit of personalized reminders versus non personalized reminders, whereas the personalized reminders require more development to access patient record data and integrate with the computerized physician order entry system. The Hospital Information System of George Pompidou European Hospital integrates an electronic medical record, lab test and drugs order entry system. This system allows to evaluate such reminders and to consider their implementation for routine use as well as the continuous evaluation of their impact on medical practice quality indicators. The objective of this study is to evaluate the impact of two types of reminders on overtreatment by oral anticoagulant: a simple reminder of text formatted dose adjustment table and a personalized recommendation for oral anticoagulant dose and next date of INR control, adapted to patient data. Both types of reminders appear to the physician at the moment of drug ordering.

Administration, Oral↗
PubMed2004

Serial left ventricular adaptations in world-class professional cyclists: implications for disease screening and follow-up.

OBJECTIVES: The purpose of this research was to study long-term left ventricular (LV) adaptations in very-high-level endurance athletes. BACKGROUND: Knowledge of cardiac changes in athletes, who are at particularly high risk of sudden cardiac death, is mandatory to detect hypertrophic cardiomyopathy (HCM) or dilated (DCM) cardiomyopathy. METHODS: We carried out echocardiographic examinations on 286 cyclists (group A) and 52 matched sedentary volunteers (group C); 148 cyclists participated in the 1995 "Tour de France" race (group A1), 138 in the 1998 race (group A2), and 37 in both (group B). RESULTS: In groups A, A1, A2, and C, respectively, diastolic left ventricular diameter (LVID) was 60.1 +/- 3.9 mm, 59.2 +/- 3.8 mm, 61.0 +/- 3.9 mm, and 49.0 +/- 4.3 mm (A vs. C and A1 vs. A2, p < 0.0001), and maximal wall thickness (WT) was 11.1 +/- 1.3 mm, 11.6 +/- 1.3 mm, 10.6 +/- 1.1 mm, and 8.6 +/- 1.0 mm (A vs. C and A1 vs. A2, p < 0.0001). Among group A, 147 (51.4%) had LVID >60 mm; 17 of them had also a below normal (<52%) left ventricular ejection fraction (LVEF). Wall thickness exceeded 13 mm in 25 athletes (8.7%) (always <15 mm), 23 with LVID >55 mm. In group B, LVID increased (58.3 +/- 4.8 mm to 60.3 +/- 4.2 mm, p < 0.001) and WT decreased (11.8 +/- 1.2 mm to 10.8 +/- 1.2 mm, p < 0.001) with time. CONCLUSIONS: Over one-half of these athletes exhibited unusual LV dilation, along with a reduced LVEF in 11.6% (17 of 147), compatible with the diagnosis of DCM. Increased WT was less common (always <15 mm) and scarce without LV dilation (<1%), eliminating the diagnosis of HCM. Serial examinations showed evidence of further LV dilation along with wall thinning. These results might have important implications for screening in athletes.

Adult↗
PubMed2004

A regression shrinkage method tailored to qualitative regressors and clustered data.

We propose a shrinkage method for estimation in linear regression models with qualitative regressors. Due to the nature of the shrinkage constraint, this method tends to give estimates that are exactly zero for some groups of coefficients belonging to the same regressor. The method hence results in concise models, since some of the regressors are entirely eliminated. In conjunction with this estimation method, a model with a fixed cluster effect turns out to be closely related to frailty models. We apply the method for modelling hospital readmissions.

Adolescent↗
PubMed2004

Cardiovascular prognosis of "masked hypertension" detected by blood pressure self-measurement in elderly treated hypertensive patients.

CONTEXT: Blood pressure (BP) measurement in clinicians' offices with a mercury sphygmomanometer has numerous drawbacks. In contrast, the use of home BP measurement improves measurement precision and reproducibility. However, data about its prognostic value are lacking. OBJECTIVE: To assess the prognostic value of home vs office BP measurement by general practitioners in a European population of elderly patients being treated for hypertension. DESIGN, SETTING, AND PARTICIPANTS: Office and home BP and cardiac risk factors were measured at baseline in a cohort of 4939 treated hypertensive patients (mean age, 70 [SD, 6.5] years; 48.9% men) who were recruited and followed up by their usual general practitioners without specific recommendations about their management. The cohort was then followed up for a mean of 3.2 (SD, 0.5) years. The thresholds defining uncontrolled hypertension were at least 140/90 mm Hg for office BP and 135/85 mm Hg for home BP. MAIN OUTCOME MEASURES: The primary end point was cardiovascular mortality. Secondary end points were total mortality and the combination of cardiovascular mortality, nonfatal myocardial infarction, nonfatal stroke, transient ischemic attack, hospitalization for angina or heart failure, percutaneous transluminal coronary angioplasty, or coronary artery bypass graft surgery. RESULTS: At the end of follow-up, clinical status was known for 99.9% of patients. At least 1 cardiovascular event had occurred in 324 (incidence, 22.2/1000 patient-years). For BP self-measurement at home, each 10-mm Hg increase in systolic BP increased the risk of a cardiovascular event by 17.2% (95% confidence interval [CI], 11.0%-23.8%) and each 5-mm Hg increase in diastolic BP increased that risk by 11.7% (95% CI, 5.7%-18.1%). Conversely, for the same increase in BP observed using office measurement, there was no significant increase in the risk of a cardiovascular event. In a multivariable model with patients having controlled hypertension (normal home and office BP) as the referent, the hazard ratio of cardiovascular events was 1.96 (95% CI, 1.27-3.02) in patients with uncontrolled hypertension (high BP with both measurement methods), 2.06 (95% CI, 1.22-3.47) in patients with normal office BP and elevated home BP, and 1.18 (95% CI, 0.67-2.10) in patients with elevated office BP and normal home BP. CONCLUSIONS: Our findings suggest that home BP measurement has a better prognostic accuracy than office BP measurement. Blood pressure should systematically be measured at home in patients receiving treatment for hypertension.

Aged↗
PubMed2004

Coccygectomy for instability of the coccyx.

Between 1993 and 2000, 61 patients with instability-related coccygodynia were operated on by a single surgeon using the same technique. There were 49 women and 12 men, mean age 45.3 (18-72) years. Twenty-seven patients had hypermobility of the coccyx and 33 subluxation. In all cases, the unstable portion was removed through a limited incision directly over the coccyx. The outcome was assessed using a detailed questionnaire. Follow-up was between 12 months and more than 30 months. The outcome was rated excellent or good in 53 patients, fair in one, and poor in seven. There were nine patients with infection requiring reoperation.

Adolescent↗
PubMed2004

Effects of low dose ramipril on cardiovascular and renal outcomes in patients with type 2 diabetes and raised excretion of urinary albumin: randomised, double blind, placebo controlled trial (the DIABHYCAR study).

OBJECTIVE: To investigate whether a low dose of the angiotensin converting enzyme (ACE) inhibitor ramipril lowers cardiovascular and renal events in patients with type 2 diabetes who have microalbuminuria or proteinuria. DESIGN: Randomised, double blind, parallel group trial comparing ramipril (1.25 mg/day) with placebo (on top of usual treatment) for cardiovascular and renal outcomes for at least three years. SETTING: Multicentre, primary care study conducted mostly by general practitioners in 16 European and north African countries. PARTICIPANTS: 4912 patients with type 2 diabetes aged >50 years who use oral antidiabetic drugs and have persistent microalbuminuria or proteinuria (urinary albumin excretion > or = 20 mg/l in two consecutive samples), and serum creatinine < or = 150 micromol/l. MAIN OUTCOME MEASURES: The primary outcome measure was the combined incidence of cardiovascular death, non-fatal myocardial infarction, stroke, heart failure leading to hospital admission, and end stage renal failure. RESULTS: Participants were followed for 3 to 6 (median 4) years. There were 362 primary events among the 2443 participants taking ramipril (37.8 per 1000 patient years) and 377 events among the 2469 participants taking placebo (38.8 per 1000 patient years; hazard ratio 1.03 (95% confidence interval 0.89 to 1.20, P = 0.65)). None of the components of the primary outcome was reduced. Ramipril lowered systolic and diastolic blood pressures (by 2.43 and 1.06 mm Hg respectively after two years) and favoured regression from microalbuminuria (20-200 mg/l) or proteinuria (> 200mg/l) to normal level (< 20 mg/l) or microalbuminuria (P < 0.07) in 1868 participants who completed the study. CONCLUSIONS: Low dose (1.25 mg) ramipril once daily has no effect on cardiovascular and renal outcomes of patients with type 2 diabetes and albuminuria, despite a slight decrease in blood pressure and urinary albumin. The cardiovascular benefits of a daily higher dose (10 mg) ramipril observed elsewhere are not found with an eightfold lower daily dose.

Aged↗
PubMed2004

Angiogenic growth factors and/or cellular therapy for myocardial regeneration: a comparative study.

BACKGROUND: Locally delivered angiogenic growth factors and cell implantation have been proposed for patients with myocardial infarcts without a possibility of percutaneous or surgical revascularization. The goal of this study was to compare the effects of these techniques in an experimental model of myocardial infarct. METHODS: Left ventricular myocardial infarction was created in 27 sheep by ligation of 2 coronary arteries. Three weeks after creation of the infarct, animals were randomized into 4 groups. In group 1, sheep received a culture medium injection to the infarct area (control group); group 2 underwent autologous myoblast implantation; group 3 received vascular endothelial growth factor; and group 4 received injection of both vascular endothelial growth factor and myoblasts. Evaluation included serum troponin IC levels, echocardiography (2-dimensional and color kinesis), and immunohistologic studies for quantitative analysis of capillaries (3 months after surgery). RESULTS: Four animals died of refractory ventricular fibrillation during myocardial infarction; 2 died after surgery because of stroke and 2 because of infections. Serum troponin increased to 45.6 +/- 4.7 ng/mL at postinfarction day 2. Echocardiography at 3 months showed a significant limitation of left ventricular dilation in the cell group (57 +/- 11.1 mL) and in the cell plus vascular endothelial growth factor group (58.6 +/- 6.6 mL: control group, 74.4 +/- 11.2 mL; vascular endothelial growth factor group, 68.1 +/- 3.4 mL). Color kinesis echography showed important improvements of regional fractional area change in the cell group (from 13.6% +/- 0.8% to 21.1% +/- 1.5%) and in the cell plus vascular endothelial growth factor group (from 12.8% +/- 0.9% to 18.7% +/- 2.3%). The number of capillaries increased in the peri-infarct region of the vascular endothelial growth factor group (1036 +/- 75: control group, 785 +/- 31; cell group, 830 +/- 75; cell plus vascular endothelial growth factor group, 831 +/- 83). CONCLUSIONS: In the cell therapy groups, regional ventricular contractility improved and heart dilatation was limited compared with either vascular endothelial growth factor or control; thus, postischemic remodeling was reduced. Angiogenesis was demonstrated in the vascular endothelial growth factor group, without improvement of ventricular function and remodeling. To improve local conditions for cell survival, further studies are warranted on prevascularization of myocardial scars with angiogenic therapy.

Animals↗
PubMed2004

Pulmonary nodules: preliminary experience with three-dimensional evaluation.

PURPOSE: To evaluate software designed to calculate pulmonary nodule volume in three dimensions. MATERIALS AND METHODS: Fifty-four solid noncalcified pulmonary nodules measuring 5-18 mm in diameter were studied with computed tomographic (CT) volumetric software. Baseline CT examinations were performed for various indications by using four-detector row multisection CT units, 1.25- or 2.50-mm sections, and a standard reconstruction algorithm. The percentage of successful nodule segmentations, as well as intraobserver variability, interreader agreement, and global repeatability of calculated volumes, was determined on the basis of consecutive measurements performed three times by three different radiologists by using the Bland and Altman method. The software was used to calculate the doubling time of 22 nodules for which a final diagnosis and comparable CT scans were available. RESULTS: Fifty-two (96%) of the 54 nodules were successfully segmented, allowing their volume to be calculated. Repeatability was high: There was no variation in the nine measurements of 35 (67%) of the 52 nodules. The coefficient of variation for the remaining 17 nodules (33%) was 2.26%. Bland and Altman 95% limits of acceptability, calculated on the basis of log-transformed data, yielded a maximum software measurement error of 6.38% of the previous volume measurement. Doubling time ranged from 4 to 188 years for the 13 benign nodules and from 37 to 216 days for the nine malignant nodules. CONCLUSION: Software volumetric analysis yielded repeatable estimates for 96% of the nodules examined. All software-calculated doubling times were in keeping with the benign or malignant nature of the nodules.

Adult↗
PubMed2004

Extra vertebrae in Ingres' La Grande Odalisque.

"La Grande Odalisque," a painting by Jean-Auguste Ingres (1780-1867), was throughout the 19th century notorious for its anatomical inaccuracy; in particular, the woman was said to have three lumbar vertebrae too many. This view was accepted by all art critics, but never tested and proven. We measured the length of the back and of the pelvis in human models, expressed the mean values in terms of head height, and transferred them to the painting. The deformation was found to be greater than originally assumed (five, rather than three, extra lumbar vertebrae), and to involve both the back and the pelvis. Ingres' paintings skilfully combine realism and symbolism. We suggest that the deformation may have been introduced for psychological reasons. By placing the harem woman's head further away from her pelvis the artist may have been marking the gulf between her thoughts (expressed by her aloof, resigned look) and her social role (symbolized by her deliberately lengthened pelvis).

Anthropometry↗
PubMed2004

Computerization of guidelines: a knowledge specification method to convert text to detailed decision tree for electronic implementation.

The initial step for the computerization of guidelines is the knowledge specification from the prose text of guidelines. We describe a method of knowledge specification based on a structured and systematic analysis of text allowing detailed specification of a decision tree. We use decision tables to validate the decision algorithm and decision trees to specify and represent this algorithm, along with elementary messages of recommendation. Edition tools are also necessary to facilitate the process of validation and workflow between expert physicians who will validate the specified knowledge and computer scientist who will encode the specified knowledge in a guide-line model. Applied to eleven different guidelines issued by an official agency, the method allows a quick and valid computerization and integration in a larger decision support system called EsPeR (Personalized Estimate of Risks). The quality of the text guidelines is however still to be developed further. The method used for computerization could help to define a framework usable at the initial step of guideline development in order to produce guidelines ready for electronic implementation.

Decision Making, Computer-Assisted↗
PubMed2004

Development of computerized guidelines for the management of chronic diseases allowing to position any patient within recommended therapeutic strategies.

Chronic diseases are complex to manage. One reason comes from the difficulty to synchronize a patient's therapeutic history with the guideline-based sequence of treatments. We propose to represent guideline knowledge as a two-level decision tree, a clinical level describing theoretical clinical situations and a therapeutic level formalizing the different steps of corresponding recommended therapeutic strategies. Guideline-based strategies are first represented as bidimensional matrices structured in lines of therapy and levels of therapeutic intention. A revised version introducing levels of therapeutic combination is then developed. The therapeutic level is operationalized for any patient therapeutic history to provide the next best step of treatment. Evaluated on actual patient records, our system proved to impact physicians' decisions in 78% of the cases and led to a significant improvement of their compliance with recommendations.

Chronic Disease↗
PubMed2003

A computer decision aid for medical prevention: a pilot qualitative study of the Personalized Estimate of Risks (EsPeR) system.

BACKGROUND: Many preventable diseases such as ischemic heart diseases and breast cancer prevail at a large scale in the general population. Computerized decision support systems are one of the solutions for improving the quality of prevention strategies. METHODS: The system called EsPeR (Personalized Estimate of Risks) combines calculation of several risks with computerisation of guidelines (cardiovascular prevention, screening for breast cancer, colorectal cancer, uterine cervix cancer, and prostate cancer, diagnosis of depression and suicide risk). We present a qualitative evaluation of its ergonomics, as well as it's understanding and acceptance by a group of general practitioners. We organised four focus groups each including 6-11 general practitioners. Physicians worked on several structured clinical scenarios with the help of EsPeR, and three senior investigators leaded structured discussion sessions. RESULTS: The initial sessions identified several ergonomic flaws of the system that were easily corrected. Both clinical scenarios and discussion sessions identified several problems related to the insufficient comprehension (expression of risks, definition of familial history of disease), and difficulty for the physicians to accept some of the recommendations. CONCLUSION: Educational, socio-professional and organisational components (i.e. time constraints for training and use of the EsPeR system during consultation) as well as acceptance of evidence-based decision-making should be taken into account before launching computerised decision support systems, or their application in randomised trials.

Attitude to Computers↗
PubMed2003

Pain immediately upon sitting down and relieved by standing up is often associated with radiologic lumbar instability or marked anterior loss of disc space.

STUDY DESIGN: Comparison of functional radiographs in consecutive patients with low back pain with or without pain on sitting down and relieved by standing up. OBJECTIVES: To detect radiologic signs possibly associated with a clinical symptom. SUMMARY OF BACKGROUND DATA: No link has been established between increased vertebral mobility and a specific pain pattern or a clinical symptom. METHODS: Forty-two patients seen consecutively with low back pain occurring immediately on sitting down and relieved on standing up were compared with 32 controls whose low back pain did not show this pattern. Dynamic radiographs were taken in extension, erect, flexion, and sitting in the painful position. The segments thought to be responsible for the pain were identified by comparing clinical, radiographic, and magnetic resonance data. Endplate angles, rotation, and translation were measured. The radiographs were read twice each by two independent observers. RESULTS: Eighty-six percent (95% confidence interval, 72-99%) of the patients with the symptom were female. The segments identified as the source of pain were as follows: L4-L5 in 20 cases and L1-L2 to L3-L4 in 22 cases. Mean rotation of these segments was 13.9 +/- 4.5 degrees in the patient group versus 7.5 +/- 4.3 degrees in the control group (P < 0.001). In 14% of the patients (vs. 3% of controls), it exceeded 20 degrees (P = 0.13). Anterior or posterior translation >10% was seen in 31% of the patients (vs. 0% of controls; P < 0.001). In flexion, the endplate angle was -5.2 +/- 3.6 degrees (patients) versus 1.2 +/- 5.7 degrees (controls) (P < 0.01) and <-5 degrees in 55% of patients versus 12.5% of controls (P < 0.001). This value of <-5 degrees was associated with marked anterior loss of disc space. CONCLUSION: Low back pain occurring immediately on sitting down and relieved on standing up was statistically associated with instability (specificity 100%, sensitivity 31%) or marked anterior loss of disc space in flexion (specificity 87%, sensitivity 55%).

Female↗
PubMed2003

Use of non-invasive cardiac investigations to predict clinical endpoints after coronary bypass graft surgery in coronary artery disease patients: results from the prognosis and evaluation of risk in the coronary operated patient (PERISCOP) study.

AIMS: Little is known about which patients who have undergone coronary bypass surgery are at risk of future clinical cardiovascular events and may benefit from further medical treatment. We sought to determine if routine non-invasive cardiac investigations performed early after surgery were able to stratify the risk of cardiovascular events in this population. METHODS: Two thousand and sixty-five consecutive patients were enrolled in a prospective multicenter study (PERISCOP). Exercise testing, echocardiography, and 24-h ambulatory ECG monitoring were performed at day 20+/-10 after coronary bypass surgery. Follow-up was performed 1 year after coronary bypass surgery. Causes of all hospitalisation and death occurring within 1 year were documented and classified by an End-point Committee. The principal endpoint was the combination of all-cause deaths and cardiovascular events requiring hospitalisation (myocardial infarction, unstable or severe angina, stroke, congestive heart failure). RESULTS: The 1-year frequency of first events was 155 (8%). In multivariate analysis, exercise duration <420s (RR=1.68; 95% CI: 1.13-2.49), exercise induced ST segment depression >1mm (RR=1.90; 95% CI: 1.18-3.05), and left ventricular (LV) dysfunction (wall motion index <1.15) (RR=1.97; 95% CI: 1.10-3.51) were independent predictors of cardiovascular events and deaths. Ambulatory ECG monitoring had no predictive value. CONCLUSIONS: Exercise testing and echocardiography performed early after coronary bypass surgery are able to identify high-risk patients who may benefit from intensive secondary prevention.

Cohort Studies↗