Biomedical subjects

G Chatellier

Publications and source records attributed to G Chatellier.

At least 73 records · Page 4Linked to original sources

PubMed1999

Renal changes on hyperglycemia and angiotensin-converting enzyme in type 1 diabetes.

Hyperglycemia causes capillary vasodilation and high glomerular capillary hydraulic pressure, which lead to glomerulosclerosis and hypertension in type 1 diabetic subjects. The insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme (ACE) gene can modulate risk of nephropathy due to hyperglycemia, and the II genotype (producing low plasma ACE concentrations and probably reduced renal angiotensin II generation and kinin inactivation) may protect against diabetic nephropathy. We tested the possible interaction between ACE I/D polymorphism and uncontrolled type 1 diabetes by measuring glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) during normoglycemia ( approximately 5 mmol/L) and hyperglycemia ( approximately 15 mmol/L) in 9 normoalbuminuric, normotensive type 1 diabetic subjects with the II genotype and 18 matched controls with the ID or DD genotype. Baseline GFR (145+/-22 mL/min per 1.73 m2) and ERPF (636+/-69 mL/min per 1.73 m2) of II subjects declined by 8+/-10% and 10+/-9%, respectively, during hyperglycemia; whereas baseline GFR (138+/-16 mL/min per 1.73 m2) and ERPF (607+/-93 mL/min per 1.73 m2) increased by 4+/-7% and 6+/-11%, respectively, in ID and DD subjects (II versus ID or DD subjects: P=0.0007 and P=0.0005, for GFR and ERPF, respectively). The changes in renal hemodynamics of subjects carrying 1 or 2 D alleles were compatible, with a mainly preglomerular vasodilation induced by hyperglycemia, proportional to plasma ACE concentration (P=0.024); this was not observed in subjects with the II genotype. Thus, type 1 diabetic individuals with the II genotype are resistant to glomerular changes induced by hyperglycemia, providing a basis for their reduced risk of nephropathy.

Adult↗

PubMed1999

Intracerebral calcification in systemic sclerosis.

BACKGROUND AND PURPOSE: Advanced cerebrovascular wall calcification was recently observed at autopsy in 2 patients with systemic sclerosis. To further investigate this issue, we conducted a prospective CT study of scleroderma patients to detect intracerebral calcification. METHODS: Thirty-seven consecutive patients with systemic sclerosis underwent unenhanced brain CT. Images were blindly interpreted, together with those of 2 age-matched (+/-1 year) and sex-matched control subjects per patient. RESULTS: Intracerebral calcification was found in 12 patients (32.4%) and 7 controls (9.5%) (P=0.006). Among the patients, intracerebral calcification was associated with the duration of Raynaud's phenomenon (P=0.005) and not with age (P=0.086). CONCLUSIONS: Intracerebral calcification is closely associated with scleroderma, which suggests that scleroderma causes primary cerebrovascular changes.

Adult↗

PubMed1999

Interobserver variability in the interpretation of renal digital subtraction angiography.

OBJECTIVE: Our purpose was to analyze interobserver variability in the interpretation of renal digital subtraction angiography and to describe the main factors associated with observer discrepancies. MATERIALS AND METHODS: Forty-nine cases of unilateral atheromatous renal artery stenosis of more than 60% were quantified first by local investigators in a multicenter study and then by five other radiologists. Differences between radiologists for the minimum diameter (Dmin), the reference diameter (Dref), and the percentage of stenosis of the renal arteries were analyzed. Interpretations by the local investigators were then compared with the gold standard, defined as the mean for the five radiologists. RESULTS: The average SD for estimation of all renal artery stenoses by all radiologists was 7% for stenosis percentage, 0.5 mm for Dmin, and 0.7 mm for Dref. Main discrepancies occurred more frequently in cases of weakly opacified renal artery stenosis and poststenotic dilatation. The observations of local investigators disagreed by more than two SDs (14%) with the gold standard for 11 of 49 cases (22%). CONCLUSION: The accuracy of digital subtraction angiography in renal artery interpretations is poor because of variations in evaluating both Dmin and Dref. Precise and reproducible methods for quantification of renal artery stenosis are required.

Adult↗

PubMed1999

[Audit of the treatment of arterial hypertension in specialized consultation].

The objective of the study was to estimate the control of elevated blood pressure (BP) among patients regularly followed-up and to analyse physicians attitudes in patients having uncontrolled BP. Two hundred and fifty-eight consecutive patients (mean age 56 years, 58% of males) with essential hypertension attending the outpatient department of a specialised hypertension clinic, having at least a 6-month follow-up at the clinic and at least 3 prior visits, were included in the study. Twelve different physicians were in charge of these patients. Data were collected [1] from the structured computerised record called ARTEMIS and [2] from a structured questionnaire filled up by the physician after each visit, where he/she explained the reasons for his/her decisions. BP was measured by a nurse using an automatic device (oscillometric method) and then by a physician using a mercury sphygmomanometer. During follow-up, mean physician's BP fell from 179/107 to 148/91 mmHg and mean nurse BP fell from 164/96 to 143/83 mmHg. Percentages of patients having a controlled hypertension (BP < 140/90 mmHg) were 27% (physician's BP) and 45% (nurse BP). Physicians did not modify treatment in 59% of patients among whom they measured a BP > or = 140/90 mmHg. The 3 main reasons given by physicians for not modifying treatment were: BP controlled when using other BP measurement methods (nurse, home or ambulatory BP), 44%; BP control considered as satisfactory, 29%; systolic hypertension in the elderly, 8%. The person (physician or nurse) who measures BP and the measurement method have dramatic consequences on BP control level. Reasons for not modifying treatment in uncontrolled patients (physician's BP > or = 140/90 mmHg) were based on opinions rather than evidence, for example when isolated systolic hypertension in the elderly is concerned.

Adult↗

PubMed1999

[Arterial hypertension and cerebrovascular accident: the need for improved prevention strategies].

It is well demonstrated that the antihypertensive treatment is effective, particularly for the primary prevention of stroke. However, benefits of treatment are rather small in certain groups of patients. The explicit assessment of absolute cardiovascular risks and likely treatment benefits in patients with hypertension can usefully guide treatment decisions and provide a more rational basis for initiating therapy than blood pressure levels alone. This approach highlights the generally greater cardiovascular risk and potential treatment benefits in older compared with younger hypertensive patients. Some specific questions remain still unanswered. Evidence is accumulating concerning protective effect of antihypertensive treatment against dementia. Trials are in progress to investigate the effect of treatment on stroke incidence in hypertensive patients over the age of 80 years. Finally, despite the worldwide use of calcium antagonists and converting enzyme inhibitors, solid evidence of their safety and efficacy compared with the references drugs (beta-blockers and diuretics) is still lacking.

Antihypertensive Agents↗

PubMed1999

[Angioplasty of atherosclerotic carotid stenoses].

Explore the source record for details and available documents.

Angioplasty, Balloon↗

PubMed1999

Decision aids for triage of patients with chest pain: a systematic review of field evaluation studies.

We performed an overview of published controlled trials to assess the overall effectiveness of decision aids directed at improving triage of patients with acute chest pain. Searches of the Medline database identified 11 randomized or quasi-randomized controlled trials testing various decision aids: risk stratification system (n = 6), practice guidelines (n = 3), and formalized protocols of care (n = 2). Sensitivity, specificity of the decision aid and length of stay (LOS) in the intensive care unit (ICU) were the main outcomes. Decision aids slightly modified sensitivity and specificity (available in 5 studies), but sensitivity was already high in reference groups. Among the 9 studies providing information on LOS, 7 showed a statistically significant difference favoring the decision aid. The level of evidence concerning the efficacy of decision aids in this domain is relatively low. Larger and appropriately designed clinical trials are required to show an impact on acute cardiac ischaemia complications and mortality.

Humans↗

PubMed1999

Decision aids for triage of patients with chest pain: a systematic review of field evaluation studies.

Chest Pain↗

PubMed1999

A critical appraisal of the use of Internet for calculating cardiovascular risk.

This paper aims to retrieve and evaluate the quality of the Internet sites providing information on cardiovascular risk. We searched web pages related to risk prediction using six search engines. Sites proposing a cardiovascular risk prediction were selected for evaluation. The quality of each site was checked against criteria testing the validity, type and potential usefulness of information for physicians or patients. Search engines retrieved about 50 10(6) web pages. Eight sites were included. Only 2 of them provided calculation of cardiovascular risk based on Framingham equation. The others proposed algorithms, guidelines, or general information on cardiovascular health. Most sites lacked details to ensure quality of information. Present search engines are inefficient to retrieve precise and valid information. Facing the inflation of medical information, a systematic approach to validate the quality of a site is mandatory. Application of Evidence Based Medicine concepts gives a solution for evaluation of internet-based medical information.

Cardiovascular Diseases↗

PubMed1998

Value of quantitative radionuclide bone scanning in the diagnosis of sacroiliac joint syndrome in 32 patients with low back pain.

A prospective study was performed to compare the results of quantitative radionuclide bone scanning with those of sacroiliac joint anesthetic block in patients with unilateral low back pain. Thirty-four subjects, forming the control group, underwent quantitative radionuclide bone scanning of the sacroiliac joints. The normal values in sacroiliac uptake difference were taken to be between -1.7% and +6.2%. Thirty-two patients with chronic unilateral low back pain underwent sacroiliac bone scanning and sacroiliac joint block. Six of the seven patients with increased uptake > 6.2% on the painful side had at least 75% pain reduction in response to the block. The sensitivity, specificity, and positive and negative predictive values of the quantitative bone scanning in the unilateral mechanical sacroiliac joint syndrome were 46.1%, 89.5%, 85.7%, and 72%, respectively.

Adolescent↗

PubMed1998

Vascular and cardiac remodeling in world class professional cyclists.

BACKGROUND: Numerous studies have demonstrated that left ventricular (LV) hypertrophy is often associated with conditioning. METHODS AND RESULTS: The aim of the study was to evaluate cardiac and carotid artery changes induced by professional cycling. We collected M-mode left ventricle and B-mode right common carotid artery data from 149 male professional cyclists before the 1995 "Tour de France" race and 52 male control subjects. LV mass indexed to body surface area in cyclists was double that in control subjects, with no overlap of 95% confidence intervals (cyclists 100.9 to 187 g/m2 and control subjects 51.8 to 96.3 g/m2). Both mean arterial diameter and mean arterial diastolic intima-media thickness (IMT) were 13% higher in cyclists than in control subjects, with overlap of 95% confidence intervals (for arterial IMT 0.45 to 0.65 mm in cyclists and 0.38 to 0.60 mm in control subjects). CONCLUSIONS: Our results suggest that intense cycling has an effect on the cardiovascular system, more pronounced on the left ventricle and less pronounced on large arteries. Nevertheless, athletic training should be considered as a potential determinant of carotid modification.

Adult↗

PubMed1998

Short-term effects of withdrawing angiotensin converting enzyme inhibitor therapy on home self-measured blood pressure in hypertensive patients.

The aim of this study was to compare blood pressure rise after interruption of two angiotensin converting enzyme (ACE) inhibitors in hypertensive patients. After a 2-week placebo run-in period, hypertensive patients were treated with either trandolapril 2 mg once daily or perindopril 4 mg once daily for 4 weeks in a double-blind design. A placebo was then administered for 1 week. Three periods of 1-week home self-measured blood pressure (SMBP) were programmed: end of placebo run-in period, end of treatment period, and final withdrawal placebo period. Every day, three consecutive measurements were requested both in the evening and in the morning. Individual reversion to baseline BP level was studied in the subgroup of patients responding to therapy (evening diastolic SMBP decrease > or =6 mm Hg). The ratio (R) of mean post-drug DBP lowering (residual effect) over evening on-drug DBP lowering (full effect) was used to study reversion to baseline. Patients exhibiting a lower value than the median of this ratio were called Reverters, whereas others were called Nonreverters. One hundred-nineteen patients entered the analysis. During the treatment period, mean SMBP decreased significantly, from 150 +/- 14/97 +/- 7 mm Hg to 139 +/- 15/91 +/- 9 mm Hg (all P < .001). The on-drug BP level was similar in the evening in the two treatment groups. However, both systolic and diastolic morning SMBP levels were significantly lower in the trandolapril group. After drug discontinuation, the mean BP level significantly rose to 144 +/- 14/94 +/- 9 mm Hg (all P = .01) but remained lower than the baseline BP values (P = .003 for SBP and P = .002 for DBP). The post-drug BP level was significantly lower in the trandolapril group than in the perindopril group. Seventy-four patients were responders to therapy. In this subgroup, the median of the R ratio used to analyze reversion to baseline after drug discontinuation was 44%. Nonreverters were characterized by a sustained on-drug BP decrease, compared to Reverters. We therefore conclude that ACE inhibitor treatment withdrawal is accompanied by a rapid rise in BP (within 48 h), followed by a 5-day BP plateau that is lower than the initial level. Reverters to baseline after drug discontinuation were more likely to be insufficiently controlled during therapy, particularly in the morning. The longer duration of action of trandolapril was associated with a lower BP level during both the morning during the active treatment phase and the 1-week posttreatment phase.

Adult↗

PubMed1998

An overview of the effect of computer-assisted management of anticoagulant therapy on the quality of anticoagulation.

Risks and benefits of anticoagulant therapy depend directly of the quality of anticoagulation. We carried out a meta-analysis of published randomized trials to assess the overall effectiveness of computer-assisted prescription systems on the quality of anticoagulation. Randomized controlled trials were identified through electronic searches of the Medline database (1966-1997) and systematic analyses of the references of articles. Two investigators selected relevant papers and summarized data from the studies. The outcome variable was the proportion of days within the target range of anticoagulation. A pooled estimate of the common odds ratio of being in the target range and its confidence interval was obtained by the Mantel-Haenszel method. Nine trials having included 1336 patients were identified. Computer systems were based on a pharmacokinetic-pharmacodynamic model and a bayesian prediction method. Most of them concerned the oral anticoagulant warfarin. The global odds ratio of being in the target range was 1.29 [95% CI: 1.17-1.49], thus meaning that the use of a computer for anticoagulation optimization increased by 29% the proportion of visits where patients were appropriately treated. The proportion of clinical events was too low for allowing a summary analysis, but major hemorrhages tended to be less frequent among patients of the computer groups than among patients of the control groups (2.0 versus 3.9%). Evidence from randomized controlled trials supports the effectiveness of computer-aided anticoagulant prescription. Widespread use of these systems in ambulatory care could increase the benefit/risk ratio of anticoagulant treatment at a low cost.

Anticoagulants↗

PubMed1998

Blood pressure outcome of angioplasty in atherosclerotic renal artery stenosis: a randomized trial. Essai Multicentrique Medicaments vs Angioplastie (EMMA) Study Group.

Data for the effects on blood pressure of renal artery balloon angioplasty are mostly from uncontrolled studies. The aim of this study was to document the efficacy and safety of angioplasty for lowering blood pressure in patients with atherosclerotic renal artery stenosis. Patients were randomly assigned antihypertensive drug treatment (control group, n = 26) or angioplasty (n = 23). Twenty-four-hour ambulatory blood pressure, the primary end point, was measured at baseline and at termination. Termination took place 6 months after randomization or earlier in patients who developed refractory hypertension. In those allocated angioplasty, antihypertensive treatment was discontinued after the procedure but was subsequently resumed if hypertension persisted. Secondary end points were the treatment score and the incidence of complications. Two patients in the control group and 6 in the angioplasty group suffered procedural complications (relative risk, 3.4; 95% confidence interval, 0.8 to 15.1). Early termination was required for refractory hypertension in 7 patients in the control group. Antihypertensive treatment was resumed in 17 patients in the angioplasty group. Mean ambulatory blood pressure at termination did not differ between control (141+/-15/84+/-11 mm Hg) and angioplasty (140+/-15/81+/-9 mm Hg) groups. Angioplasty reduced by 60% the probability of having a treatment score of 2 or more at termination (relative risk, 0.4; 95% confidence interval, 0.2 to 0.7). There was 1 case of dissection with segmental renal infarction and 3 of restenosis in the angioplasty group. No patient suffered renal artery thrombosis. In unilateral atherosclerotic renal artery stenosis, angioplasty is a drug-sparing procedure that involves some morbidity. Previous uncontrolled and unblinded assessments of angioplasty overestimated its potential for lowering blood pressure.

Adult↗

PubMed1998

Superiority of home blood pressure measurements over office measurements for testing antihypertensive drugs.

OBJECTIVE: To compare the effects on office blood pressure and home blood pressure of placebo and active drug administration. DESIGN: After a 2-week wash-out period, patients with mild-to-moderate hypertension entered a 2-week single-blind placebo period and then a 4-week double-blind period. Patients were randomly assigned to be administered either 2 mg trandolapril once daily or its placebo in a 2:1 proportion. Office blood pressure was measured by a physician at the end of each period, using a mercury sphygmomanometer (mean of three consecutive measurements). Home blood pressure was measured during the last week of each period according to standard procedure carefully taught to each patient by the physician. Compliance was checked by using electronic pill boxes. RESULTS: Data for 34 of the 44 patients who entered the study were eligible for analysis. Baseline systolic blood pressure/diastolic blood pressure were significantly (P = 0.0001/P = 0.0001) higher for office blood pressure (161/101 mmHg) than they were for home blood pressure (145/93 mmHg). There was no statistically significant difference between the placebo and active-treatment groups at baseline. During the single-blind period, blood pressures measured at the office and at home did not change significantly. Office blood pressure decreased by 2.7 +/- 10 mmHg for systolic blood pressure and by 0.5 +/- 4 mmHg for diastolic blood pressure whereas home blood pressure increased by 0.8 +/- 6 mmHg for systolic blood pressure and by 0.7 +/- 4 mmHg for diastolic blood pressure. During the double-blind period, office blood pressure fell significantly with trandolapril treatment (systolic by 10.2 +/- 12 mmHg, diastolic by 8.3 +/- 6 mmHg; P = 0.0005/0.0001, versus single-blind placebo period) but this decrease was not significantly different (P = 0.45/0.92) from the fall in members of the placebo group (systolic by 6.9 +/- 9 mmHg, diastolic by 8.0 +/-6 mmHg; P = 0.04/0.002, versus single-blind placebo period). Thus, no antihypertensive effect of trandolapril was demonstrated. The fall lin home blood pressure with trandolapril treatment was significant (systolic by 10.7 +/- 8 mmHg, diastolic by 5.8 +/- 5 mmHg; both P = 0.0001, versus single-blind placebo period) and was significantly greater (P = 0.0004/0.004) than the minimal change observed with placebo (systolic fell by 0.2 +/- 5mmHg, diastolic fell by 0.6 +/- 4 mmHg; P = 0.90/0.62, respectively, versus single-blind placebo period). The evening decrease in home blood pressure was similar to the morning decrease in home blood pressure in members of the trandolapril-treated group. The resulting morning:evening decrease in blood pressure ratio was 0.83 for diastolic blood pressure and 0.95 for systolic blood pressure. For the subgroup of responders, mean of individual ratios was 0.77 +/- 0.43 for diastolic blood pressure and 0.70 +/- 0.39 for systolic blood pressure. CONCLUSION: The placebo effect observed with office blood pressure measurements does not occur with home blood pressure measurements. Expected treatment effect can alter a physician's blood pressure readings. The precision of measurements is greater with home blood pressure (there is a lower SD). Use of home blood pressure measurements increases the power of comparative trials, allowing one either to study fewer subjects or to detect a smaller difference in blood pressure.

Journal Article↗

PubMed1998

Computer-adjusted dosage of anticoagulant therapy improves the quality of anticoagulation.

OBJECTIVE: Risks and benefits of anticoagulant therapy depend directly of the quality of anticoagulation. We performed a meta-analysis of published randomized trials to assess the overall effectiveness of computer-based prescription systems on the quality of anticoagulation. DESIGN: Randomized controlled trials were identified through electronic searches of the Medline database (1966-1997) and systematic analyses of the references of articles. Two investigators selected relevant papers and summarized data from the studies. METHODS: The outcome variable was the proportion of days within the target range of anticoagulation. A pooled estimate of the common odds ratio of being in the target range and its confidence interval was obtained by the Mantel-Haenszel method. RESULTS: Seven trials having included 1217 patients were identified. Computer systems were based on a pharmacokinetic-pharmacodynamic model and a bayesian prediction method. Most of them concerned the oral anticoagulant warfarin. The global odds ratio of being in the target range was 1.58 [95% CI: 1.34-1.86], thus meaning that the use of a computer for anticoagulation optimization increased by 58% the proportion of visits where patients were appropriately treated. The proportion of clinical events was too low for allowing a summary analysis. CONCLUSION: Evidence from randomized controlled trials supports the effectiveness of computer-aided anticoagulant prescription. Diffusion of these systems in ambulatory care could increase the benefit/risk ratio of anticoagulant treatment at a low cost.

Anticoagulants↗

PubMed1998

Importance of the FcgammaRIIa-Arg/His-131 polymorphism in heparin-induced thrombocytopenia diagnosis.

Heparin-induced thrombocytopenia (HIT) involves heparin-dependent antibodies which induce platelet activation. In the present study, we searched for a relationship between the polymorphism of the Fc receptor (FcgammaRIIa) and the development of HIT. In this purpose, all the donors were genotyped for their FcgammaRIIA and HIT patients were selected on the basis of at least one positive answer by 14C-serotonin release assay (SRA). The frequency distribution of the FcgammaRIIa polymorphism in the HIT patient group was similar to that observed in the healthy control group. Moreover, a statistical analysis taking into account our results and those of 3 previously published studies, suggested at most only a weak association between HIT and the FcgammaRIIa-131 polymorphism. Laboratory tests used to diagnose HIT rely on the activation of normal donor platelets but fail to detect every HIT positive patient. We determined the role of FcgammaRIIa-131 polymorphism on the reactivity of control platelets to HIT plasmas. When control platelet FcgammaRIIa-131 was of Arg/Arg form, only 47% of the HIT plasmas were positive by SRA, compared to 81% and 74% for His/His or His/Arg forms, respectively. We also compared the level of anti PF4/heparin antibodies in the HIT plasmas with the response obtained by SRA. The mean anti PF4/heparin antibodies level in HIT plasma was significantly lower in negative SRA than in positive tests when using control platelets from FcgammaRIIa-Arg/Arg 131 and heterozygous donors. Thus, the variability of control platelets to respond to HIT plasmas in the SRA test is related to both the FcgammaRIIa-131 polymorphism, and to the amount of anti PF4/heparin antibodies.

Adult↗

PubMed1998

[Can echocardiography identify mildly hypertensive patients at high risk, left untreated, based on current guidelines?].

OBJECTIVE: To determine if the decision to treat uncomplicated mild hypertension with drugs, in accordance with the WHO/ISH guidelines based on a series of blood pressure (BP) measurements over six months, resulted in the treatment of patients at high risk, on the basis of echocardiography. BACKGROUND: The value of echocardiography in mild hypertension management remains is unclear. METHODS: One hundred and eighteen patients with mild hypertension (90 to 105 mmHg diastolic BP and/or 140 to 180 mmHg systolic BP) were examined by echocardiography at inclusion and followed up for 6 months by a single physician unaware of the echographic results. RESULTS: Drug treatment was given to 48 patients, and 70 remained untreated. Treated patients had higher echographic indices than untreated patients (all p < 0.05): LV mass/body surface area (82.8 +/- 15.9 vs 74.7 +/- 15.0 g/m2), interventricular septal thickness (9.7 +/- 1.7 vs 8.5 +/- 1.3 mm). LV posterior wall thickness (8.4 +/- 1.1 vs 7.8 +/- 1.1 mm), relative wall thickness (0.37 +/- 0.06 vs 0.34 +/- 0.06). Left ventricular (LV) geometry was normal in 98 patients, and 20 had LV concentric remodeling. The 10-year coronary disease risk (Framingham equation) was higher in treated patients than in untreated patients (10.0% vs 6.3%; p < 0.002), and in the 20 patients with concentric remodeling than in those with normal LV geometry (10.4%) vs 4.2%; p < 0.005). Nine of these 20 patients were still untreated at the end of the six-month follow-up period. CONCLUSION: Rigorous application of the WHO-ISH clinical guidelines in a group of mild hypertensive patients, led to the treatment of patients with slightly higher LV mass and more concentric LV geometry than were found in those not treated. However, a high-risk subgroup, with concentric remodeling, was not identified and left untreated.

Adult↗