PubMed Health⌕ Search

Biomedical subjects

Y Cottin

Publications and source records attributed to Y Cottin.

At least 55 records · Page 3Linked to original sources
PubMed2001

An approach for integrating heterogeneous information sources in a medical data warehouse.

In recent years, medical professionals are witnessing an explosive growth in data collected by various organizations and institutions. At the same time, the ongoing developments of networking technologies provide doctor with the capability to access these data across the boundaries of interconnected computers. In this paper we present a medical data warehousing methodology that aims to use data semantics to regroup and merge patients' medical data from different health information systems, which may be autonomous and heterogeneous. The proposed solution takes into account European laws concerning the security and anonymity of personal data.

Database Management Systems↗
PubMed2001

Long-term prognostic value of 201Tl single-photon emission computed tomographic myocardial perfusion imaging after coronary stenting.

BACKGROUND: The prognostic value of (201)Tl myocardial imaging has been demonstrated in several studies concerning patients with a known significant coronary artery disease. However, the evolution of a coronary stenosis after stenting is difficult to predict. This study was designed to assess the prognostic value of (201)Tl single-photon emission computed tomography (thallium SPECT) perfusion imaging in patients after intracoronary stenting. METHODS: One hundred fifty-two patients were studied. They were followed up during 40 +/- 13 (mean +/- SD) months after thallium SPECT. Stent-related events were studied after thallium stress testing and included cardiovascular death, myocardial infarction, and revascularization. Stress thallium imaging was performed 5 +/- 2 months after stenting, and ischemia was considered to be present if at least 2 contiguous segments were showing reversible defects. RESULTS: Only 3 (3%) among the 105 nonischemic patients had major cardiac events during the follow-up versus 13 (28%) of the 47 ischemic patients (P < .001) after thallium SPECT. The relative risk of major cardiac events for patients with significant ischemia was 10.5 compared with nonischemic patients (P < .001). Fourteen (30%) of the ischemic patients and 8 (8%) among the nonischemic patients underwent iterative revascularization (P < .001). Therefore, only 11 (10%) of the nonischemic patients had major cardiac events or revascularization compared with 24 (51%) of the ischemic patients (P < .001). CONCLUSIONS: Absence of ischemia on thallium SPECT imaging at 5 months after coronary stenting indicates a low risk for cardiovascular events or interventional procedure. These results may have important clinical implications in patient treatment.

Angioplasty, Balloon, Coronary↗
PubMed2001

Could heart rate variability predict outcome in patients with severe head injury? A pilot study.

Despite major improvements in the resuscitation of patients with head injury, the outcome of patients with head trauma often remains poor and difficult to establish. Heart rate variability (HRV) analysis is a noninvasive tool used to measure autonomic nervous system (ANS) activity. The aim of this prospective study was to investigate whether HRV analysis might be a useful adjunct for predicting outcome in patients with severe head injury. Twenty patients with severe head trauma (Glasgow Coma Scale [GCS] or= 10) to HRV in patients characterized by a worsened neurologic state (GCS < 10). Statistical analysis used the Kruskal-Wallis test, P < .05. To assess whether HRV could predict evolution to brain death, receiver operating characteristic (ROC) curves were generated the day after trauma for Total Power, natural logarithm of high-frequency component of spectral analysis (LnHF), natural logarithm of low-frequency component of spectral analysis (LnLF), and root mean square for successive interval differences (rMSSD). Seven patients died between Day 1 and Day 5 after trauma. Six of those had progressed to brain death. In these six patients, at Day 1, Global HRV and parasympathetic tone were significantly higher. Referring to the area under the rMSSD ROC curve, HRV might provide useful information in predicting early evolution of patients with severe head trauma. During the awakening period, global HRV and the parasympathetic tone were significantly lower in the worsened neurologic state group. In conclusion, HRV could be helpful as a predictor of imminent brain death and a useful adjunct for predicting the outcome of patients with severe head injury.

Accidental Falls↗
PubMed2001

A novel 32P deployable balloon system inhibits formation of neointima in porcine coronary arteries after balloon-overstretching injury.

BACKGROUND: Intracoronary radiation has shown the potential to reduce formation of neointima in porcine models of restenosis. OBJECTIVE: To investigate the feasibility, safety, and efficacy of a new 'deployable-balloon' device with radioisotope 32P integrated into the balloon material. METHODS: Ten swine were subjected to balloon-overstretching injury in 20 coronary arteries and were randomly allocated to receive a radiation dose of 0, 15, or 20Gy prescribed to 1 mm from the surface of the radioactive balloon material. The animals were killed 4 weeks after the procedure. Their coronaries were perfusion fixed and stained. Vessel parameters (area of intima and length of fracture) and area of thrombus area were analyzed by computer-aided histomorphometry. RESULTS: Radiation treatment with the new 32P balloon device was performed without complications. The lengts of fracture for the three groups were similar (NS). Formation of neointima after balloon injury was less in members of the radiated groups than it was in controls (area of intima/length of fracture was 0.70 +/-0.12 mm for controls, 0.08+/-0.13mm with 15 Gy, and 0.07+/-0.17 mm with 20 Gy; P < 0.001). Vessels treated with 20 Gy had a greater total area of thrombus (0.00+/-0.00 versus 0.51+/-0.98 mm2, P< 0.01). CONCLUSIONS: Intracoronary radiation therapy using a new 32P deployable-balloon system is feasible and safe. A radiation dose of 15 Gy was sufficient to inhibit neointimal response in the porcine coronary-balloon-injury model.

Angioplasty, Balloon, Coronary↗
PubMed2001

[Secondary effects of brachytherapy in the treatment of coronary restenosis].

Brachytherapy is proposed for the treatment or prevention of coronary restenosis with encouraging results, especially in intra-stent restenosis. The results of the first clinical studies show benefit, for example those of the American SCRIPPS trial with a 3 year follow-up. However, recent reports in the literature have described secondary effects associated with this technique: 1) stenoses occurring at the limits of the irradiated segments which are attributed to a proliferative effect of low doses on damaged tissue; 2) late occlusions at the irradiated site: their incidence is estimated at 9% at 6 months. The mechanisms of these thromboses are not understood but delayed re-endothelialisation probably plays a rôle; 3) finally, irradiation is associated with uncovered dissection probably related to delayed healing. Other long-term trials are necessary to provide a more complete assessment of the secondary effects of brachytherapy, especially with regards to their mechanisms, prevention and treatment.

Angioplasty↗
PubMed2000

Anti-restenotic effect of copper-62 liquid-filled balloon in porcine coronary arteries: novel use of a short half-life positron emitter.

PURPOSE: To determine the efficacy of the use of copper-62, a positron emitter with a half-life of 9.7 minutes, as an intracoronary brachytherapy (IRBT) source in the prevention of neointima formation (NF) following overstretch balloon injury (BI) in the porcine model. METHODS AND MATERIALS: Sixteen swine were treated after BI to their left anterior descending (LAD), left circumflex (LCX), and/or right coronary artery (RCA). Twelve of the injured arteries received placebo and 10 received 25 Gy, delivered to 0.5 mm from the surface of the treatment balloon filled with liquid (62)Cu. Dosimetry was based on Monte Carlo calculations. Two weeks after treatment, the animals were sacrificed, and the treated coronaries were perfusion-fixed and stained. Intimal area (IA) and medial fracture length (FL) were analyzed by computer-aided histomorphometry. RESULTS: The ((62)Zn/(62)Cu) generator, together with a rapid concentration process, was successful in delivering the short-lived (62)Cu at the high concentration required for intravascular brachytherapy (IVBT). The fracture length in the two groups was similar (2.10 +/- 0.57; 2.02 +/- 0.77; p = NS). Arteries studied showed significant reduction in NF (IA: 0.23 +/- 0.47 mm(2) vs. 1.08 +/- 0.57 mm(2); p < 0.01. IA/FL = 0.09 +/- 0.17 mm vs. 0.51 +/- 0.21 mm; p < 0.01). CONCLUSIONS: This study demonstrated that use of liquid (62)Cu as an IVBT source is safe and feasible. All 16 swine tolerated the treatment well with no radiation-induced side effects or symptoms throughout the 2-week period. The isotope delivered the dose necessary to inhibit NF in the porcine coronary BI model.

Animals↗
PubMed2000

Intracoronary brachytherapy not associated with changes in major side branches.

Intravascular radiation (IR) is emerging as a potential solution for the prevention and treatment of restenosis. Subacute thrombosis late coronary occlusion of the target lesion after intracoronary brachytherapy has been described in two studies. None of these studies assessed in detail the evolution of side branches following IR. The purpose of this study was to determine the frequency of side-branch occlusion in patients undergoing IR. We evaluated the procedural and 6-month follow-up angiograms of 170 consecutive patients enrolled in the GAMMA-I and WRIST studies who presented a major side branch (diameter > 1.5 mm) at the treated lesion. Major side branches treated during the procedure and/or total occlusion of the main branch were excluded for analysis. Sixty-three patients (control = 30, irradiated = 33) were identified and side branches were classified in one of three categories: no significant stenosis, > 50% stenosis, and occluded. The baseline patient and lesion characteristics were similar among the classified groups. No difference was observed between the control and irradiated arteries after the procedure for side-branch occlusion (14% and 9%, P = NS). A significant decrease of restenosis was observed after IR compared to control (20% vs. 70%: P < 0.001). The patency rates and rates of side-branch occlusion were similar between the two groups. However, in the control group, 50% of the side-branch occlusions that occurred after the procedure were patent at 6-month follow-up. In contrast, in the irradiated group, the incidence of side-branch occlusion increased from 9% to 15% at 6-month follow-up in the irradiated group. Low doses of radiation applied to noninjured side branches are not associated with adverse effects. The absence of restoration patency followed by IR is most likely a consequence of a delayed healing process.

Aged↗
PubMed2000

A novel platinum-iridium, potentially gamma radioactive stent: evaluation in a porcine model.

In-stent restenosis (ISR) is a major problem within stented arteries. Surface treatment of stents with platinum and gold were found to have the maximum charge with least neointima formation (NF). This study was designed to evaluate platinum (maximum electrical charge) as a material to make stents to reduce NF. Iridium was added to make an alloy suitable for stent manufacture, with the potential to make the stent radioactive. We implanted the novel platinum-iridium (PI) stent in 10 porcine coronaries and compared to the Palmaz-Schatz (PS) stent implanted in 8 coronary arteries. Six weeks after implantation, angiography of the stented vessel was performed before sacrifice. The coronaries were perfusion-fixed and stained, and vessel parameters were analyzed by computer-aided histomorphometry. The thrombus formation and the inflammatory response was less in the PI stent (0.04 +/- 0.1 vs. 0.24 +/- 0.2, P = 0.005; and 1.1 +/- 0.5 vs. 2.4 +/- 0.3, P < 0.001). The NF from PI-stented arteries was smaller in size than the PS controls (1.9 +/- 0.6 mm(2) vs. 2.4 +/- 0.4 mm(2), P = 0.06). However, PI stents presented with higher recoil than the PS stent (16% vs. 5%, P < 0.001). Platinum-iridium is a highly biocompatible material with high performance, low inflammatory response with small NF. This stent does not lead to thrombus formation and has the potential (due to the presence of iridium) to be irradiated to form a gamma radioactive stent. Cathet. Cardiovasc. Intervent. 51:364-368, 2000.

Animals↗
PubMed2000

Vascular repair after balloon overstretch injury in porcine model effects of intracoronary radiation.

OBJECTIVES: The purpose of this study was to evaluate the effect of IR on thrombus formation and dissection repair following overstretch balloon injury in porcine coronary arteries. BACKGROUND: Exposure of blood to the injured arterial wall after percutaneous transluminal coronary angioplasty (PTCA) induces thrombus formation and inflammation in the dissection plane. Neointima formation is related to smooth muscle cell (SMC) proliferation and migration into the preformed thrombus. Intracoronary radiation (IR) with doses of 10 to 25 Gy using either beta or gamma emitters can prevent neointima accumulation by reducing SMC proliferation. However, there are some indications that IR may delay the process of dissection repair after PTCA. The purpose of this study was to evaluate the effect of IR on thrombus formation and dissection repair after overstretch balloon injury in porcine coronary arteries. METHODS: Forty porcine coronaries were injured by balloon overstretch followed by either 0 or 18 Gy of 90Y prescribed to 1.2 mm from the balloon center. The animals were euthanized 14 days after treatment, and intimal area (IA) and IA corrected for medial fracture length (IA/FL) were quantified by digital image analysis. Dissections were quantified by tracing the length, thickness and area behind the dissection flap. The rate of dissections was calculated for each group. Thrombi were identified and designated as intraluminal thrombus or thrombus within dissection planes (mural thrombus), and area measurements were obtained. RESULTS: The irradiated group showed a significant reduction of IA/FL (0.55 +/- 0.29 vs. 0.05 +/- 0.09; p < 0.001). No difference was observed in the rate of dissection between control and irradiated arteries (77% vs. 88%, respectively). The control group showed a smaller dissection area (0.19 +/- 0.28 mm2 vs. 0.32 +/- 0.29 mm2; p < 0.05) with smaller mural thrombi (0.03 +/-0.01 mm2 vs. 0.29 +/- 0.30 mm2; p < 0.001). A strong correlation between dissection area and neointima area was observed only in the control group (R2 = 0.474; p < 0.003; alpha0.05 = 0.862). A positive correlation between mural thrombus and dissection area was observed only in the irradiated group (R2 = 0.889; p < 0.001; alpha0.05 = 1.00). CONCLUSIONS: These results suggest that the dissection area may be a useful parameter by which to quantify the extent of injury and repair after IR and may indicate an incomplete healing process after IR at this time point.

Angioplasty, Balloon, Coronary↗
PubMed2000

Dobutamine stress echocardiography identifies anthracycline cardiotoxicity.

BACKGROUND: Anthracyclines are effective anti-cancer agents, but their therapeutic value is limited by their myocardial toxicity. We assessed the physiological responses of stress echocardiography at low doses of dobutamine (DSE) in patients treated with anthracycline. METHODS AND RESULTS: In a prospective study, 28 patients were studied before and 1 month after the end of chemotherapy. All patients had normal ejection fraction (EF) at rest before therapy and the mean dose of anthracycline was 212+/-15 mg/m(2). Echocardiographic Doppler studies were performed before and during dobutamine infusion (5 and 10 microg/kg per min). Rest echocardiography demonstrated a significant decrease of EF between the two examinations in ejection fraction (67+/-3% vs. 61+/-3%, P<0.001). The increase of the EF during dobutamine infusion was higher after chemotherapy compared to the initial examination (19+/-3% vs. 29+/-3%: P<.05). No difference in EF was observed at 10 microg/kg per min between before and after chemotherapy. In contrast, at rest no difference in diastolic parameters was observed between the two examinations. Moreover, a significant decrease of the peak E and the ratio E/A was observed during dobutamine infusion after chemotherapy (93+/-4 cm/s vs. 79+/-5 cm/s and 1.3+/-0.1 vs. 1.0+/-0.1, respectively;P<0.05). CONCLUSION: Stress echocardiography may prove to be a sensitive technique and useful non-invasive approach for evaluating subclinical anthracycline cardiotoxicity.

Adult↗
PubMed2000

Could heart rate variability analysis become an early predictor of imminent brain death? A pilot study.

UNLABELLED: Physiology of brain death is characterized by major disturbances of autonomic nervous system (ANS) activity which can lead to graft dysfunction. These findings exhibit the importance of early diagnosis of brain death to improve transplantation outcome. The aim of this prospective study was to assess whether heart rate variability (HRV) analysis, a noninvasive method to investigate ANS activity in comatose patients, could achieve this goal. A total of 14 brain-injured patients were included in the study as soon as they exhibited the clinical signs of imminent brain death. The electrocardiogram was then recorded from two leads with a Holter digital monitor. The clinical diagnosis of brain death was considered after an autonomic storm had occurred. HRV was assessed from 6 h before to 6 h after brain death in both time domain and spectral analysis, estimating either global ANS activity (index of variability, total power), parasympathetic activity (percentage of delta of R-R interval >50 ms, root mean square for successive interval differences, LnHF) or sympathetic activity (LnLF). Hourly averages of these variables were compared by using one-way analysis of variance. To assess whether HRV could per se diagnose brain death, receiver operating characteristic curves were generated for total power, root mean square for successive interval differences, and LnHF. We observed, for 6 h before brain death, a progressive extinction of the influence of the ANS on cardiovascular regulation. There was no activity in the two components of the ANS as soon as brain death occurred. HRV analysis appeared to be a very sensitive but a less specific method of diagnosing brain death. IMPLICATIONS: A total of 14 brain-injured patients with the clinical criteria of imminent brain death were enrolled for electrocardiogram recording and heart rate variability analysis (a noninvasive method to investigate autonomic nervous system activity). For 6 h before brain death, we observed a progressive extinction of autonomic nervous system activity which was not present as soon as brain death was clinically evoked.

Adult↗
PubMed2000

[The best of non-invasive cardiac imaging in 1999].

The term non-invasive and non-echographic myocardial imaging is used to describe the advances in nuclear cardiology and magnetic resonance imaging underlying the most recent developments in investigating the myocardium. The value of new techniques such as rapid CT scan and cardiological applications of the synchroton are described. The main clinical applications of these techniques in the present and future are reviewed, especially with regards to ischaemic heart disease.

Humans↗
PubMed2000

[Specific factors of diabetes in the rehabilitation of coronary patients].

This prospective controlled trial included two groups of subjects with coronary artery disease: one of 33 patients with non-insulin-dependent diabetes mellitus (6 females and 27 males, mean age 57 +/- 9 years, left ventricular ejection fraction of 56 +/- 14%) and the control group of 33 subjects without diabetes (3 females and 33 males, mean age of 57 +/- 11 years, LVEF of 58 +/- 11%). Before training heart rate was faster for patients with diabetes at rest (72 +/- 11 vs 66 +/- 81 bpm, p = 0.03) and at the end of the stress test (127 +/- 15 versus 118 +/- 18 bpm, p = 0.03). After rehabilitation, resting heart rate and peak heart rate were similar. However cardiovascular capacities improvement was better in subjects without diabetes mellitus, especially concerning peak VO2 (28.98 +/- 8.88 versus 22.78 +/- 6.28 mL/min/kg, p < 0.01) and mechanical power (138 +/- 48 versus 118 +/- 23 watts, p < 0.01). Two groups were retrospectively distinguished among diabetic patients: one group of 17 patients showing a VO2 improvement superior to 5% and a second group non improved (VO2 < 5%). For the second group the two selective factors were higher fasting glycemia (1.83 +/- 0.75 versus 1.31 +/- 0.38 g/L, p = 0.01) and higher hemoglobin A1C (8.05 +/- 2.04 vs 6.62 +/- 1.03%, p = 0.02). Heart rate variability was not significantly different for these two groups: changes in autonomic nervous system cannot explain resistance of diabetic subjects to training. On the other hand, principal aim must be the equilibrium of glycemia in the management of diabetes.

Aged↗
PubMed2000

[Randomized comparison of 4F and 6F catheters for diagnostic coronary angiographies via the femoral approach].

The use of 6F catheters has been validated for coronary angiography. The use of small-caliber catheters is a more recent development. The aim of this study was to assess the feasibility, the cost and complications of coronary angiography using the femoral approach with 4F catheters. The authors undertook a randomized prospective study of 4F Care Infiniti catheters (N = 100) and 6F Spertorque Plus catheters (N = 100) in hospitalised patients. Criteria of non-inclusion were valvular pathology, acute myocardial infarction, aorto-coronary bypass or aorto-femoral bypass procedures. No statistical difference was observed between the two groups with respect to feasibility, to duration of the procedure, or of irradiation or to cost. The quality of the angiograms was good except in one patient in the 4F group; 4 patients in the 6F group required a 4F catheter to complete their examination. Left ventricular catheterisation was more difficult with 4F catheters (p = 0.016). Use of 4F catheters was associated with injection of significantly less contrast (p = 0.00007), reduced the duration of compression (p < 10(-6)) and its complications (p = 0.004). The authors conclude that 4F catheters are safe and well tolerated. They are associated with less patient morbidity, without any loss in quality of the angiogrammes. Other studies in valvular heart disease and after coronary bypass surgery should lead to the generalisation of their use in all coronary patients.

Aged↗