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Biomedical subjects

M Cucherat

Publications and source records attributed to M Cucherat.

At least 19 recordsLinked to original sources
PubMed2001

[Antihypertensive therapy and improved life expectancy without cerebrovascular accident or coronary artery disease].

The absolute benefit from antihypertensive therapy increases with the baseline risk. However, age is a major determinant of cardiovascular risk, so it is important to express therapeutic efficacy with indices for which age is not a confounder. With this aim we explored the expected gain in life expectancy without cardiovascular events according to age at the initiation of the treatment. The treatment effect estimated from the INDANA meta-analysis, was applied to the cardiovascular risk of a French hypertensive population, simulated from national vital statistics. The gain in life expectancy was estimated from the area between survival curves without events. The treatment effect varied according three different hypotheses: increasing, decreasing or constant effect. When assuming a constant treatment effect, our results show a 29 month gain without stroke for a man who began his treatment at 40 years, and 15 months if hypertension is screened and treatment initiated at 75 years. The gains without coronary heart disease are respectively of 11 and 6 months. The variation of treatment effect over time could have a major impact on the treatment benefit. The gain in life expectancy without events is a relevant decision tool, completing usefully the absolute benefit, since it takes into account the influence of age.

Adult↗
PubMed2000

[Clinical benefits of cholesterol lowering treatments. Meta-analysis of randomized therapeutic trials].

PRIMARY PREVENTION: A meta-analysis of the 7 available randomized cholesterol lowering trials (2 on statins, 2 on fibrates, 2 on resins and 1 on diet) demonstrates a significant 24% relative reduction in the frequency of fatal and non-fatal coronary events, leading to a significant 14% relative reduction in coronary disease related mortality. For total mortality, the statin trials were not comparable with other treatments where there was a trend to overmortality. With the 2 statin trials, there was a nonsignificant 13% reduction in total mortality. SECONDARY PREVENTION: A meta-analysis of the 13 available randomized trials (3 with clofribrate, 1 with gemfibrozil, 2 with nicotinic acid, and 4 with diet) showed a significant 21% reduction in the frequency of fatal and non-fatal coronary events, coronary mortality and total mortality. For total mortality, only the result of the 2 statin trials was significant (-20%). BENEFICIAL EFFECT OF STATINS, ABSOLUTE VALUES: Measured as the number of patients to treat for 5 years in order to avoid 1 event (NNT), there is a clinically pertinent benefit of secondary prevention (NNT = 15 for events, NNT = 30 for coronary mortality). The absolute value is weaker when patients with minimally elevated cholesterol levels are included. For primary prevention, the absolute value is low with NNT = 44 for events and NNT = 300 for coronary mortality. In addition, as these results were obtained in trials including populations with a much higher risk than the general French population, the absolute beneficial effect may not be pertinent in France except in high-risk patients who present, in addition to a high cholesterol level, other cardiovascular risk factors.

Anticholesteremic Agents↗
PubMed2000

[The results of a single clinical trial-is it sufficient information?].

Meta-analysis is a systematic and quantified synthesis of all clinical trials studying the same question. It is systematic because it implies an exhaustive search for all trials of the studied treatment, favourable or not, published and unpublished. It is quantified because it is based on statistical calculations leading to an estimation of the degree of the effect of the treatment. The use of statistical techniques allows to take into account the fact that different results can be obtained in different studies only by chance. Meta-analysis can be used to assess the efficacy of a treatment or to study the factors that modify this efficacy.

Clinical Trials as Topic↗
PubMed2000

Primary angioplasty versus intravenous thrombolysis for acute myocardial infarction.

BACKGROUND: Intravenous thrombolytic therapy is the standard care for patients with acute myocardial infarction, based upon its widespread availability and ability to reduce patient mortality well demonstrated in randomised trials. Despite its proven efficacy, thrombolytic therapy has limitations. Many patients are ineligible for treatment with thrombolytics. Of those given thrombolytic therapy, 10 to 15 percent have persistent occlusion or reocclusion of the infarct-related artery. Consequently, primary angioplasty (primary PTCA) has been advocated as a better treatment of myocardial infarction. OBJECTIVES: To determine whether primary coronary angioplasty is superior to thrombolytic therapy for the treatment of patients with acute myocardial infarction. SEARCH STRATEGY: Electronic search of The Cochrane Library (1998; Issue 2). MEDLINE (to January 1998); references from reviews, trials and previously published meta-analyses; and experts. Date of most recent searches January 1998. SELECTION CRITERIA: All unconfounded, randomised controlled trials comparing primary angioplasty against intravenous thrombolysis in patients with acute myocardial infarction DATA COLLECTION AND ANALYSIS: At least two independent reviewers abstracted data on morbidity and mortality and trial characteristics. The following outcomes were assessed: total mortality at the end of the study, reinfarction, stroke of any type, composite endpoint of death and reinfarction, recurrent ischemia, severe bleeding and coronary artery bypass grafting. MAIN RESULTS: Ten trials including 2573 subjects were identified. Compared to thrombolytic therapy, primary angioplasty was associated with a significant reduction in short-term mortality at the end of the studies (relative reduction in risk RRR = 32% 95%CI = 5%;50%). Similar reductions were observed for the rate of reinfarction (RRR = 52%, 95%CI = 30%;67%), recurrent ischemia (RRR = 54%; 95%CI = 39%, 66%) and for the combined criteria death or reinfarction (RRR = 46%; 95%CI=30%;58%). The frequency of strokes of any cause was significantly decreased by 66% (95%CI=28%;84%). No significant difference was observed for the incidence of major bleeding (relative risk RR =1.18, 95%CI = 0.73;1.90) but the confidence interval was large. The superiority of the primary angioplasty over thrombolysis in terms of the composite endpoint (mortality and reinfarction) was less with accelerated t-PA (RR=0.70, 95%CI=0.51;0. 97) than with streptokinase (RR=0.30, 95%CI=0.17;0.53). The biggest and most recent trial, Gusto 2B ( approximately approximately GUSTO-2B 97 approximately approximately ), which involved general as well as higly specialised centres, obtained less favorable results. REVIEWER'S CONCLUSIONS: This meta-analysis suggests that angioplasty provides a short-term clinical advantage over thrombolysis which may not be sustained. Primary angioplasty when available promptly at experienced centres, may be considered the preferred strategy for myocardial reperfusion. In most situations, however, optimal thrombolytic therapy should still be regarded as an excellent reperfusion strategy.

Angioplasty, Balloon, Coronary↗
PubMed2000

Evidence of clinical efficacy of homeopathy. A meta-analysis of clinical trials. HMRAG. Homeopathic Medicines Research Advisory Group.

OBJECTIVE: To establish, using a systematic review and meta-analysis, whether there is any evidence from randomised controlled clinical trials of the efficacy of homeopathic treatment in patients with any disease. DATA SOURCES: Published and unpublished reports of controlled clinical trials available up to June 1998, identified by searching bibliographic databases (Medline, Embase, Biosis, PsychInfo, Cinahl, British Library Stock Alert Service, SIGLE, Amed), references lists of selected papers, hand searching homeopathic journals and conference abstracts, and contacting pharmaceutical companies. TRIALS SELECTION: Trials were selected using an unblinded process by two reviewers. The selection criteria were randomised, controlled trials in which the efficacy of homeopathic treatment was assessed relative to placebo in patients using clinical or surrogate endpoints. Prevention trials or those evaluating only biological effects were excluded. One hundred and eighteen randomised trials were identified and evaluated for inclusion. Sixteen trials, representing 17 comparisons and including a total of 2,617 evaluated patients, fulfilled the inclusion criteria. DATA EXTRACTION: Data were extracted by two reviewers independently, using a summary form. Disagreements were resolved by a third person. DATA SYNTHESIS: The evidence was synthesised by combining the significance levels (P values) for the primary outcomes from the individual trials. The combined P value for the 17 comparisons was highly significant P = 0.000036. However, sensitivity analysis showed that the P value tended towards a non-significant value (P = 0.08) as trials were excluded in a stepwise manner based on their level of quality. CONCLUSIONS: There is some evidence that homeopathic treatments are more effective than placebo; however, the strength of this evidence is low because of the low methodological quality of the trials. Studies of high methodological quality were more likely to be negative than the lower quality studies. Further high quality studies are needed to confirm these results.

Homeopathy↗
PubMed2000

Trial summary software.

Medical practice is most strongly founded when based on the results of well conducted clinical trials. Clinical trial results normally enter the domain of medical knowledge and practice through their publication in scientific journals. This in itself poses problems of accessibility and selection. The results of this is a slow and selective diffusion of new medical facts which has a consequent cost in human lives and human suffering. In an attempt to shorten this information path initiatives such as the Cochrane collaboration produce and maintain systematic reviews by speciality of the current state of knowledge. The ability to store a representation of a clinical trial in a standard form seems to us to be a necessary condition for the efficient and reproducible preparation of systematic reviews. Furthermore the consequent increased accessibility of research results due to the existence of the summaries would itself be of great use. In this aim a relational database client server system was developed and we publish here the results of our preliminary findings, including the data model, which we feel is an important contribution to the future discussion and development of computer based representations of clinical trial protocols and results and their use in clinical decision making.

Clinical Trials as Topic↗
PubMed2000

Comparison of bioprosthesis and mechanical valves, a meta-analysis of randomised clinical trials.

The main purpose of this meta-analysis was to compare the outcomes of patients who randomly received mechanical valves or bioprosthesis, over a long-term clinical follow-up. We found only three trials meeting our selection criteria with a total of 1229 patients (8069. 5 patient-yr). Bleeding was more frequent in patients with mechanical prostheses both after 5 yr (RR=2.6; IC=[1.9;3.5]; P<0.0001) and 11 yr (RR=1.6; IC=[1.2;2.2]; P<0.001) of follow-up. However, the increased risk of bleeding at 11 yr was only statistically significant with mechanical prostheses in the aortic position (RR=1.93; IC=[1.36;2. 74]; P=0.0002). Reoperation was significantly more frequent in patients with bioprosthesis after 11 yr follow-up (RR=0.4; IC=[0.3;0. 6]; P<0.001). Endocarditis was more frequent after 11 yr (RR=0.6; IC=[0.3;0.95]; P<0.05) in patients with mechanical prostheses but these results were heterogeneous between mitral and aortic valves. The choice of valve type does not significantly influence survival.

Bioprosthesis↗
PubMed2000

Comparison of long versus short duration of anticoagulant therapy after a first episode of venous thromboembolism: a meta-analysis of randomized, controlled trials.

OBJECTIVE: To assess the length of oral anticoagulant therapy (short versus long duration) after a first episode of venous thromboembolism (VTE). DESIGN: Meta-analysis of randomized controlled trials, comparing two durations of anticoagulation, identified in 1999 by a computerized search of the Cochrane Controlled Trial Register, Medline and Embase, completed by an extensive review of the references of pertinent articles. SETTING AND SUBJECTS: The meta-analysis was performed on literature data. Seven published controlled trials were included. Relative risks with 95% confidence intervals were computed using the relative risk logarithm method. Statistical significance was set up at 0.01 for the test of association. MAIN OUTCOME MEASURES: Outcomes are major haemorrhage and recurrence after a 12-month follow-up. RESULTS: For the recurrence end-point (sample size of 2304 patients), a duration treatment of 12-24 weeks seems preferable to a 3-6 week regimen, with a relative risk (RR) of 0.60 (95% CI: 0.45-0.79, P < 0.001). For the major haemorrhage end-point (1823 patients), the RR is not significantly different from 1 (RR = 1.43, 95% CI: 0.51-4.01, P = 0. 5). The results were similar for the subgroup 'permanent risk factors' or 'idiopathic VTE' (RR for recurrence = 0.48, 95% CI: 0. 34-0.68, P < 0.001). The tendency was similar, although not reaching statistical significance, for the 'temporary risk factors' subgroup (RR for recurrence = 0.34, 95% CI: 0.13-0.93, P = 0.035). CONCLUSIONS: After a first episode of VTE, a long-term treatment regimen allows a significant reduction in the incidence of recurrences without increasing the incidence of bleeding events.

Acute Disease↗
PubMed2000

Optimal duration of anticoagulant therapy after an episode of venous thromboembolism.

The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism (VTE) is still a matter of debate. It is essential to balance the desired effect of the anticoagulants in reducing recurrences against the risk of major bleeding. The aims of this paper are to describe the current concepts in this field. Recent data, based on randomized controlled trials, suggest that it is necessary to tailor the duration of anticoagulation individually according to the topography of VTE and the presence of risk factors. A 6-week treatment for patients with isolated calf vein thrombosis is sufficient. For proximal thrombosis and/or pulmonary embolism, a short anticoagulant course is sufficient in patients with temporary risk factors (3 months), and a longer anticoagulant course (6 months at least) is recommended for cases with permanent risk factors or idiopathic VTE. For these high-risk of recurrence patients, an assessment of low- or fixed-dose oral anticoagulation is necessary in order to reduce the bleeding risk. It is not possible to precisely determine the optimal duration with the available data. We have already performed a meta-analysis on summary data that suggests a long course of oral anticoagulant therapy is superior to a short course. An individual meta-analytic approach is needed to draw more precise conclusions on an interesting and important clinical topic.

Anticoagulants↗
PubMed2000

Prevention of venous thromboembolism in internal medicine with unfractionated or low-molecular-weight heparins: a meta-analysis of randomised clinical trials.

BACKGROUND: The prevention of venous thromboembolic disease is less studied in medical patients than in surgery. METHODS: We performed a meta-analysis of randomised trials studying prophylactic unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) in internal medicine, excluding acute myocardial infarction or ischaemic stroke. Deep-vein thrombosis (DVT) systematically detected at the end of the treatment period, clinical pulmonary embolism (PE), death and major bleeding were recorded. RESULTS: Seven trials comparing a prophylactic heparin treatment to a control (15,095 patients) were selected. A significant decrease in DVT and in clinical PE were observed with heparins as compared to control (risk reductions = 56% and 58% respectively, p <0.001 in both cases), without significant difference in the incidence of major bleedings or deaths. Nine trials comparing LMWH to UFH (4,669 patients) were also included. No significant effect was observed on either DVT, clinical PE or mortality. However LMWH reduced by 52% the risk of major haemorrhage (p = 0.049). CONCLUSIONS: This meta-analysis, based on the pooling of data available for several heparins, shows that heparins are beneficial in the prevention of venous thromboembolism in internal medicine.

Anticoagulants↗
PubMed1999

Identification of responders to a therapy: an example of validation of a predictive model.

The general objective of randomized clinical trials is to assess if the treatment effect on a given population is clinically meaningful. In this way, one obtains an average estimate of the treatment effect over the trial population. However, a growing need for medical practitioners is to be able to predict with sufficient precision the efficiency of a given treatment for a given patient. There is little information in the literature about this issue. We have previously proposed a treatment-startified Cox model including interaction between treatment and patient's covariates, to identify and predict the responders to a therapy. In this paper, we focus on the assessment of the predictive power of the model. The performance of the predictive model for a population and for an individual was statistically validated internally and externally from several aspects. The prediction correlates well with the observation. Thus, we suggest that this approach would be useful in identifying and predicting the responders to a therapy, subject to an appropriate and more extensive validation process in real setting.

Female↗
PubMed1999

Implication of evidence-based medicine in prescription guidelines taught to French medical students: current status in the cardiovascular field.

OBJECTIVES: To study how satisfactory the contents of introductory courses in cardiovascular therapeutics, given to medical students in France, are with respect to the concepts of evidence-based medicine. METHODS: Medical school lecturers were asked to provide written course material used as part of medical school courses. Best-available evidence was classified as existent (including two therapeutic subclasses: indicated and contraindicated), and nonexistent. Four scores (from 0 to 10) were given, according to conformity with best-available evidence, and citation of randomized clinical trials (RCT), meta-analyses and therapeutic objectives. RESULTS: Thirty-four written documents were obtained from 43 faculties. Although the score (mean +/- SEM) of conformity with best-available evidence was 5.43 +/- 0.28 for the existent best-available evidence class, the corresponding scores for the citation of RCT, meta-analyses, and therapeutic objectives were, respectively, 1 +/- 0.2, 0.16 +/- 0.07, and 2.7 +/- 0.3. The four scores were highest when the best-available evidence belonged to the indicated class, intermediate when best-available evidence was nonexistent, and lowest for the contraindicated class (P < .05). These scores were significantly higher when the printed material was intended for specialists. CONCLUSION: Despite some limitations, the extent of agreement with the best-available evidence is only moderate. Pathophysiologic reasoning is largely preferred to justify the choice of therapeutics recommended to medical students.

Analysis of Variance↗
PubMed1999

Severe morbidity after coronary artery surgery: development and validation of a simple predictive clinical score.

AIMS: To develop a predictive clinical risk score of post-operative morbidity after coronary artery bypass grafting. METHODS AND RESULTS: Data were collected retrospectively from 679 patients undergoing emergency or planned bypass surgery between 1 January and 31 December 1996. The incidence of morbidity was 23%. Multivariate stepwise logistic regression analysis on two-thirds of the patients identified eight independent risk factors for severe morbidity. Six of these were pre-operative: symptomatic right heart failure, previous ventricular arrhythmias, previous coronary bypass surgery, chronic pulmonary disease, ST changes on pre-operative electrocardiogram, body mass index <24 kg. m-2, and two were intra-operative factors: the surgeon who operated, and the cardiopulmonary bypass time. A predictive clinical risk score was developed with the six pre-operative risk factors. The negative predictive value of the model is 87% and the area under the receiver operating characteristic curve is 0.77. When tested on the remaining patients not used for developing the model, the area under the curve is 0.65. CONCLUSION: This pre-operative risk score provides a simple method of risk stratification for patients undergoing coronary artery surgery. However, as for all predictive models, the performance of the score decreases when applied to a population other than that used to develop it.

Adult↗
PubMed1998

Clinical effects of beta-adrenergic blockade in chronic heart failure: a meta-analysis of double-blind, placebo-controlled, randomized trials.

BACKGROUND: beta-Blockers have improved symptoms and reduced the risk of cardiovascular events in studies of patients with heart failure, but it is unclear which end points are most sensitive to the therapeutic effects of these drugs. METHODS AND RESULTS: We combined the results of all 18 published double-blind, placebo-controlled, parallel-group trials of beta-blockers in heart failure. From this combined database of 3023 patients, we evaluated the strength of evidence supporting an effect of treatment on left ventricular ejection fraction, NYHA functional class, hospitalizations for heart failure, and death. beta-Blockers exerted their most persuasive effects on ejection fraction and on the combined risk of death and hospitalization for heart failure. beta-Blockade increased the ejection fraction by 29% (P<10(-9)) and reduced the combined risk of death or hospitalization for heart failure by 37% (P<0.001). Both effects remained significant even if >90% of the trials were eliminated from the analysis or if a large number of trials with a neutral result were added to the analysis. In contrast, the effect of beta-blockade on NYHA functional class was of borderline significance (P=0.04) and disappeared with the addition or removal of only 1 moderate-size study. Although beta -blockade reduced all-cause mortality by 32% (P=0.003), this effect was only moderately robust and varied according to the type of ss-blocker tested, ie, the reduction of mortality risk was greater for nonselective beta-blockers than for beta1-selective agents (49% versus 18%, P=0.049). However, selective and nonselective beta-blockers did not differ in their effects on other measures of clinical efficacy. CONCLUSIONS: These analyses indicate that there is persuasive evidence supporting a favorable effect of beta-blockade on ejection fraction and the combined risk of death and hospitalization for heart failure. In contrast, the effect of these drugs on other end points requires additional study.

Adrenergic beta-Antagonists↗
PubMed1998

Antibiotic prophylaxis for permanent pacemaker implantation: a meta-analysis.

BACKGROUND: Infection remains a serious complication after permanent pacemaker implantation. Antibiotic prophylaxis is frequently prescribed at the time of insertion to reduce its incidence, although results of well-designed, controlled studies are lacking. METHODS AND RESULTS: We performed a meta-analysis of all available randomized trials to evaluate the effectiveness of antibiotic prophylaxis to reduce infection rates after permanent pacemaker implantation. Reports of trials were identified through a Medline, Embase, Current Contents, and an extensive bibliography search. Trials that met the following criteria were included: (1) prospective, randomized, controlled, open or blind trials; (2) patients assigned to a systemic antibiotic group or a control group; (3) end point events related to any infection after pacemaker implantation: wound infection, septicemia, pocket abscess, purulent secretion, right infective endocarditis, inflammatory signs, a positive culture, septic pulmonary embolism, or repeat operation for an infective complication. Seven trials met the inclusion criteria. They included 2023 patients with established permanent pacemaker implantation (new implants or replacements). The incidence of end point events in control groups ranged from 0% to 12%. The meta-analysis suggested a consistent protective effect of antibiotic pretreatment (P=.0046; common odds ratio: 0.256, 95% confidence interval: 0.10 to 0.656). CONCLUSIONS: Results of the present meta-analysis suggest that systemic antibiotic prophylaxis significantly reduces the incidence of potentially serious infective complications after permanent pacemaker implantation. They support the use of prophylactic antibiotics at the time of pacemaker insertion to prevent short-term pocket infection, skin erosion or septicemia.

Adult↗
PubMed1998

Cytomegalovirus prophylaxis with antiviral agents in solid organ transplantation: a meta-analysis.

BACKGROUND: The aim of this meta-analysis was to assess the efficacy of antiviral agents to prevent, in solid organ transplant recipients, cytomegalovirus infection and symptomatic disease and to decrease the incidence of acute rejection, graft loss, and death. METHODS: Of the studies identified, 13 met the following inclusion criteria: prospective randomized study, in adults or pediatric recipients of a solid organ transplant, where one group in the study received a prophylactic treatment with acyclovir and/or ganciclovir begun before the cytomegalovirus infection and a control group was not treated or receive placebo. RESULTS: Prophylactic treatment was found to be associated with a significant decrease of cytomegalovirus disease compared with placebo or no treatment, using the logarithm of relative risk method (relative risk=0.50; 95% confidence interval, 0.40-0.62; P-value for chi-square association <0.001). Prophylactic treatment decreased also the rate of cytomegalovirus infection (relative risk=0.74; 95% confidence interval, 0.62-0.88; P<0.001). Our analysis failed to show a significant decrease of graft loss, acute rejection, and death in the prophylactic treatment group. Subgroup analysis based on the type of antiviral agent (acyclovir or ganciclovir) and on the type of organ (kidney or liver) gave comparable results. CONCLUSION: The use of antiviral agents for the prevention of cytomegalovirus disease and cytomegalovirus infection in solid organ transplantation is supported by this meta-analysis.

Acyclovir↗