PubMed Health⌕ Search

Biomedical subjects

T Lefèvre

Publications and source records attributed to T Lefèvre.

At least 37 records · Page 2Linked to original sources
PubMed2000

Coronary angioplasty using 5 French guiding catheters: preliminary experience.

In a retrospective study of 40 patients, we evaluated the effectiveness of the new 5 Fr 0.058" lumen diameter guiding catheter in routine PTCA. A total of 54 balloon angioplasties were performed. The mean age was 62.1+/-12.8 years, with 71% men. The artery dilated was the LAD in 50%, the RCA in 37%, and the circumflex in 13%. Sixty percent of the lesions dilated were proximal lesions, with only 25% defined as distal lesions. Significant calcifications were present in 20% of the lesions. Stents were implanted in 96%, and mean stent length was 14.0 mm, ranging from 8 to 24 mm. Mean balloon diameter was 2.7 mm, ranging from 2.0 to 3.5 mm. The procedure was a success in 95%, with only two failures. No other complications occurred. We concluded that the 0.058" 5 Fr guiding catheter could be suitable in the majority of noncomplex, selected PTCA cases. However, limitations and advantages over the standard 6 Fr technique are yet to be defined.

Aged↗
PubMed2000

Systematic use of transradial approach or suture of the femoral artery after angioplasty: attempt at achieving zero access site complications.

Access site complications occur in 5-15% of cases according to the various series. The predictive factors most often reported in the literature are the size of the puncture site and the intensity of the antiplatelet or anticoagulant treatment associated with the angioplasty procedure. Six senior cardiologists in a high volume Cardiology center (>1,500 procedures a year) with an individual experience >500 procedures in either the radial approach or the percutaneous suture of the femoral artery with the Techstar/Prostar system, conducted a prospective study from January 1 to December 31, 1999. The aim of this study was to eliminate the occurrence of access site complications by using either one of two techniques that were at the operator's discretion, i.e., systematic radial approach, or percutaneous suture of the femoral artery. A total of 956 patients were included over the study period; 60.7% of these patients had percutaneous arterial closure of the femoral artery and the remaining 39.3% were treated via the radial approach; 88.7% were stented. The patients were administered a mean 9,000 IU of heparin during the procedure; 1.9% had been fibrinolyzed and Reopro was used in 5.9%. No complications were documented in the radial group. Of the 580 patients in the femoral suture group, 96.9% had femoral suture, immediately effective in 508 cases (90.4%). Only 3 patients required additional prolonged compression. One significant hematoma (0.2%) necessitating blood transfusion was reported in the femoral group. Infection at the puncture site with subsequent antibiotic treatment was reported in 2 patients (0.3%). No further access site complications were observed at one-month follow-up. After completion of the learning curve, the two techniques (radial approach and percutaneous arterial suture) permit the almost total elimination of access site complications.

Aged↗
PubMed2000

[Immediate revascularization by angioplasty and coronary stents in patients over age 80 with myocardial infarction].

The aim of this study was to assess the results of revascularisation by angioplasty and stenting in octogenarians in the acute phase of myocardial infarction. One hundred and four patients over 80 years of age were identified between January 1995 and April 1995 out of 906 patients admitted within 24 hours of the onset of myocardial infarction. The average age was 85 +/- 4 years with a female predominance (63.4%) and a high incidence of cardiogenic shock (28.8%). Ninety eight patients underwent angioplasty with coronary stenting in 81 patients (82.6%) within 39 +/- 35 min of hospital admission. A primary success was obtained in 96% of cases with restitution of TIMI 3 flow in 83.6% of cases. Hospital mortality was 26.5%, highly influenced by the presence of cardiogenic shock (60.7% versus 12.8% without shock). Univariate analysis showed cardiogenic shock (p < 0.0001) and ejection fraction (p = 0.009) to be predictive of mortality, and a tendency in favour of TIMI 3 flow (p = 0.07) and stent implantation (p = 0.09). Complications were rare: 1% of minor cerebrovascular accidents and 4% of vascular complications. There were no cases of emergency bypass surgery and only one patient had a recurrence of ischaemia at 30 days. The authors conclude that the results at 1 month in a high risk group of octogenarians seem to be in favour of an invasive management with coronary stenting in the acute phase of myocardial infarction.

Aged↗
PubMed1999

[Thoracic radiodermatitis in interventional cardiology. Apropos of 6 cases].

The aim of this study is to describe thoracic radiodermatitis, a rare but not to be forgotten complication of interventional cardiology. The appearances are variable, from often oval-shaped erythema to cutaneous necrosis, with risk of chronic ulceration and malignant degeneration. The authors report 6 cases observed in 1997 after coronary angioplasty. Complex and long procedures are the main causes of this complication. Prevention requires a contribution from all the medical cardiological team, for the diagnosis, determining the indication of the type of revascularisation and for limiting the dose of X-radiation administered.

Aged↗
PubMed1999

Stenting small coronary arteries.

Stenting of small coronary arteries was long contra-indicated because of a high rate of subacute occlusion. We report a single-center registry including 190 patients stented with 2.5 mm balloons. Procedural success was 98% and subacute occlusion rate was 2.6%. Clinical follow-up showed a 24.5% repeat intervention rate. These results seemed acceptable, warranting stent implantation in small arteries in the case of acute or threatened closure. New stent designs and coatings may contribute to the improvement of outcomes and to the decrease in subacute occlusion and restenosis rates.

Angioplasty, Balloon, Coronary↗
PubMed1998

One-month results of coronary stenting in patients > or = 75 years of age.

Coronary artery bypass operations are associated with increased morbidity and mortality in the elderly. Similarly, it has been shown that coronary angioplasty is associated with a higher risk of complications in the elderly than in younger patients. The purpose of this study was to evaluate the 1-month outcome of elderly patients (>75 years old) who were included in the Stenting without Coumadin French Registry. From December 1992 to March 1995, 2,900 patients (mean age 61+/-11 years) were included in this registry. All patients were treated with ticlopidine (250 to 500 mg/day) for 1 month from the day of percutaneous transluminal angioplasty, aspirin (100 to 250 mg/day) for >6 months, and low-molecular-weight heparin (antiXa 0.5 to 1 IU/ml) for 1 month in phase II, 15 days in phase III, and 7 days in phase IV. No heparin was given in phase V. The study group included 233 patients (8.0%) > 75 years old (mean age 79+/-4), 44 (18%) of whom were women. All patients underwent dilatation of a native coronary vessel. One hundred seventeen had unstable angina (50.2%), 20 had postmyocardial infarction ischemia (8.6%), and 6 had acute myocardial infarction (2.6%). Indications for stenting were de novo lesion in 63 patients (27.0%), restenosis in 38 (16.3%), suboptimal result in 48 (20.6%), nonocclusive dissection in 56 (24.0%), and occlusive dissection in 28 (12.0%), respectively. Stented coronary arteries were the left anterior descending in 109 (46.8%), the right in 80 (34.3%), the left circumflex in 40 (17.2%), and the left main in 4 (1.7%). Palmaz-Schatz stents were used in 228 patients (82.0%), AVE microstents in 38 (13.7%), and other stents in 12 (4.3%). More than 1 stent was used in 48 patients (17.3%). The mean diameter of the balloon used for stenting was 3.31+/-0.38 mm and maximal inflation pressure was 12.2+/-2.9 atm. At one-month follow-up, vascular complications occurred in 5 patients, requiring surgery in 2 (1.3%), acute closure occurred in 1 (0.4%), subacute closure in 3 (1.3%), emergency or planned coronary artery bypass graft surgery in none, acute myocardial infarction in 4 (1.7%), stroke in 1 (0.4%), and death in 8 (3.4%). The composite end point of a major cardiac event was observed in 13 cases (5.6%). Coronary stenting using ticlopidine and aspirin appears to be a particularly safe approach in this high-risk subset.

Aged↗
PubMed1998

B-type Ca2+ channels activated by chlorpromazine and free radicals in membrane of human atrial myocytes.

The present study demonstrates that background or B-type calcium channel activity can be recorded in excised inside-out and cell-attached membrane patches from human atrial myocytes. In control conditions, with Ba2+ or Ca2+ as charge carrier, single-channel activity spontaneously appeared in irregular bursts separated by quiescent periods of 2-17 min, in nearly 25% of tested patches. Channel activity was recorded at steady-state applied membrane potentials including the entire range of physiological values, and displayed no "rundown" in excised patches. During activity, a variety of kinetic behaviors could be observed with more or less complex gating patterns. This type of channel activity was triggered or markedly increased when chlorpromazine (CPZ 20 or 50 microM) was applied to internal face of inside-out patches, with a proportion of active patches of approximately 25%. CPZ-activated channels were potential-independent in the physiological range of membrane potential. In 96 mM Ba2+ solution, three conductance levels: 23, 42 and 85 pS were routinely observed in the same excised membrane patch, sometimes combining to give a larger level. As previously observed by Wang et al. (1995) in membrane of rat ventricular myocytes, increasing free-radicals level and metabolic poisoning readily enhanced B-type channel activity in human atrial myocytes. Application of H2O2 (from 0.1-10 mM) in cell-attached mode induced an activation of Ba2+ permeable channel activity in a dose-dependent manner, with an estimated EC50 of 9.7 mM. In the same type of experiments, 10 mM deoxyglucose also induced similar Ba2+ permeable channel activity. When 500 microM CPZ were applied to myocytes studied in the whole-cell configuration and maintained at a holding potential of -80 mV in the presence of 5 mM external Ca2+, a noticeable inward current could be observed. The mean CPZ-activated current density determined from seven myocytes was 0.63 pA/pF.

Adolescent↗
PubMed1998

Stenting in acute myocardial infarction.

The limitations (recurrent ischaemia, restenosis, reocclusion) of percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (MI) can be addressed by stenting. The preliminary results of stenting are favourable (Stent PAMI, STENTIM, ZWOLLE trials). We report the results of the ICPS registry including 519 patients directly treated with angioplasty and stenting at the acute phase of myocardial infarction, with a repeat MI rate of 1% and a mortality of 3.7% in the non-shock group.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Calculation of the regurgitation fraction in mitral insufficiency by Doppler echocardiography using a study of the zone of flow convergence].

The aim of this study was to propose a new method for calculating the regurgitation fraction of mitral insufficiency by the proximal isovelocity surface area (PISA) method and to compare it with the value of the catheter regurgitation fraction. Thirty-five patients (21 men and 14 women) aged 59 +/- 13 years with isolated mitral insufficiency were studied. Analysis of the proximal isovelocity surface area enabled calculation of an instantaneous maximum regurgitant flow, surface of the regurgitant orifice and the regurgitant volume. The regurgitant fraction was calculated by dividing the regurgitant volume by the sum of the regurgitant volume and aortic stroke volume measured by Doppler echocardiography. These parameters were compared with the corresponding catheter data and the angiographic grade of mitral insufficiency. The echocardiographic and catheter studies were performed within 1.7 +/- 1.2 days. There was a statistically significant correlation between the instantaneous maximum regurgitant flow calculated by the PISA method and the catheter regurgitant flow (r = 0.88; p = 0.0001); between the regurgitant volume calculated by the PISA method and the catheter regurgitant volume (r = 0.85; p = 0.0001) and the regurgitation fraction calculated by the PISA method and the catheter regurgitant fraction (r = 0.82; p = 0.0001). A regurgitant fraction by the PISA method of > 45% corresponded to severe mitral regurgitation (> or = angiographic grade 3 and/or a catheter regurgitant fraction > or = 50%) with a sensitivity of 88% and a specificity of 100%. The PISA method should form part or routine quantification of mitral insufficiency.

Adult↗
PubMed1997

[Management of myocardial infarction in patients over 75 years of age compared to patients under 75 years of age. Apropos of 594 consecutive cases admitted between 1991 and 1994].

This study analyses the patients consecutively admitted for myocardial infarction between January 1991 and December 1994. The study population consisted of 594 patients divided into two groups: 446 patients under the age of 75 years and 178 patients over the age of 75 years. The sex-ratio showed a male predominance (84%) before 75 years, and a female predominance (57%) after 75 years. A history of angina was more frequent in elderly patients (45% vs 30%, p < 0.001), who were admitted later (22.5% vs 46.6% before the 6th hour, p < 0.001). Thrombolysis was administered in 49.6% of subjects under the age of 75 years and in 17.3% of elderly patients. The course was uneventful in 56.7% of subjects under the age of 75 years and in 28.2% of elderly patients. Mortality was 6-fold higher in this group (22% vs 3.7%, p < 0.01). The cause of death was usually heart failure with a 10-fold higher frequency of cardiogenic shock (13.5% vs 1.4%, p < 0.001). Coronary angiography was performed in 81.4% of subjects under the age of 75 years and in 30% of the elderly patients. Multi-vessel lesions were more frequent in elderly subjects (78.4% vs 47.5%, p < 0.01). Revascularization by angioplasty or bypass graft was performed with a similar frequency (50%) in the two groups of patients investigated by coronary angiography. The mortality of myocardial infarction was high in the elderly, usually due to heart failure, and partly explained by the severity of the coronary lesions; in contrast, elderly patients were less frequently submitted to active management (thrombolysis-coronary angiography), while recent data of the literature argue in favour of primary angiography in these patients.

Aged↗
PubMed1996

Left radial approach for coronary angiography: results of a prospective study.

Although radial approach has been shown to be feasible for coronary angiography, angioplasty, and even stent placement, there have been no prospective evaluations of ease and safety of left radial approach for coronary angiogram. We examined procedural duration and success as well as complications in 415 consecutive patients. Radial artery occlusion was assessed immediately post-procedure and at 2 month follow-up using echo-Doppler measurements. Procedure failure rate was 9%, mean time for sheath insertion was 4.7 +/- 4.7 min, and mean procedure duration was 19.1 +/- 8.2 min. No major complications occurred. Asymptomatic radial artery occlusion was noted in 71% of the first 49 patients, decreased to 24% in the next 119 receiving 2,000-3,000 units of heparin, and to 4.3% in the last 210 receiving 5000 (p < 0.05). Comparison with the femoral approach in the same laboratory suggested that the radial approach took longer, but provided similarly high-quality results without great difficulty in coronary cannulation. Hence, the left radial approach for coronary angiography (with heparin administration) allows immediate ambulation and may be especially useful for outpatients and when the femoral approach is not possible.

Aged↗
PubMed1996

Can we optimize our angiographic views every time? Qualitative and quantitative evaluation of a new functionality.

RATIONALE AND OBJECTIVES: For determining the optimum angulations of the x-ray beam with respect to the vascular morphology of a given patient, the authors present a solution combining a single-plane angiographic system and a dedicated procedure. METHODS: The clinical evaluation of the vessel profiling acquisitions focuses on qualitative appraisal and quantitative analysis of conventional and optimum projections. RESULTS: The qualitative evaluation demonstrates the pitfall for an operator to discern optimum from conventional projections. The 70% of preferences for vessel profiling bear witness to the constraints imposed occasionally by the optimum angulations, which may be impracticable for various reasons. However, vessel profiling yields lesions inspection at an optimum view, free of geometric foreshortening. Moreover, there is less risk of superimposition with other branches. From a quantitative standpoint, vessel profiling unveils the lesion with a length significantly longer than in conventional view. CONCLUSIONS: Vessel profiling offers a qualitative optimization of angiographic images and more exact quantitative analysis.

Angiocardiography↗
PubMed1996

[Optimization of coronary angiographic views. Qualitative and quantitative evaluation of a new system].

A coronary angiographic view is said to be "optimal" when the directing radius of the X-ray beam is perpendicular to the long axis of a stenosis. The object was to fulfill two criteria: 1) the accurate calculation of the spatial orientation of the stenosis to obtain the optimal position, 2) rapid and optimal positioning of the angiographic material with easy rotation around the axis of the stenosis. Two combined solutions were proposed:the Advantx L/C (GE Medical systems) angiocardiographic system with three motorised axes of rotation and a specific software. This software takes into account two longitudinal axes of the stenosis traced by the operator in two conventional incidences and then determines the angles of optimal positioning (accuracy +/-5 degrees). During 97 consecutive coronary angiograms, the software was used in 23 cases (24%) and judged to be useful in 16 cases (70%). In 2 of the 23 cases (8%) the mechanical angles calculated could not be used, the incidences being incompatible with the patient's position. During the angiograms, the best two images of stenosis (one conventional, one optimal) were retained to form a pair of images. Eight observers analysed 37 pairs of images shown side by side. 65% of the images selected from each pair as being the best descriptive appearance of the stenosis came from the optimised system. During quantitative analysis, only the length of stenosis differed statistically between the two modes of acquisition (1.26 +/- 0.36 mm; p = 0.0014). This system is useful during coronary angiography for providing optimal views of stenosis free from any geometric distorsion and without superimposition of adjacent branches.

Coronary Angiography↗
PubMed1994

[Electron microscopic comparison of the antithrombotic potential of 2 low osmolality iodine contrast media in percutaneous transluminal coronary angioplasty].

The antithrombogenic potentials of two low osmolality iodine contrast media, ioxaglate (Iox), an ionic product, and iopamidol (Iop), a non-ionic product, were compared in a multicentre, randomised, double-blind study in 64 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) by scanning electron microscopy for the presence of thrombotic material on the guiding catheter (GC) and guide wires (GW). The procedure was strictly standardised: stable angina, type A coronary lesions; aspirin administration (at least 300 mg the day before and on the day of angioplasty); heparinisation (10000 IU at the beginning of the procedure); same GCs (Marathon Baxter 8F), same GWs (Veriflex USCI 0.014). The tips of the catheters and guide wires were scanned by an electronic microscope in a double-blind protocol. The scores for the number of erythrocytes (RBCs), platelets (PLs) and constituted thrombi (THi) were; thickness scored from 0 to 3, the % surface covered and an index of volume combining these two parameters. The clinical and angiographic characteristics of the 2 groups were strictly comparable. The time that the GCs and GWs were in the circulation were 30.0 +/- 2.3 vs 32.6 +/- 3.0 minutes for the former, and 18.6 +/- 1.8 vs 17.1 +/- 1.4 minutes for the later in the Iox and Iop groups, respectively (NS). An angiographic filling defect was not observed in any of the patients in the Iox group and in 4 patients (13%) in the Iop group (NS). The number of thrombotic elements observed on the GCs (RBCs, PLs, THi) was negligible in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗