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J Machecourt

Publications and source records attributed to J Machecourt.

At least 19 recordsLinked to original sources

[Coronary risk related to sport].

Regular physical activity is beneficial because it is associated with a 40% reduction in the risk of death or myocardial infarction. However, sport momentarily increases the risk of adverse cardiovascular events during the sporting activity. This increased risk is higher in the less accomplished sportsmen and in those with cardiovascular risk factors. Regular weekly exercise, even of mild to moderate intensity, has a protective effect. An adverse coronary event on exercise is observed in 1200 to 1500 patients per year in France. It results from underlying coronary artery disease which is often occult. In the under 35 year age group, although atherosclerotic plaque is already present, the possibility of a congenital anomalous coronary arterial anatomy should be considered. This can sometimes be detected by transoesophageal echocardiography. After 35 years of age, coronary arteriosclerosis is almost the only pathology observed. The probability of a coronary event is higher in under trained "veteran" with known classical cardiovascular risk factors, often occurring by "error" in the practice of an activity too intense for the level of physical fitness. It should be remembered that 50% of these complications occur in people who have experienced symptoms on exercise in the days or weeks before the event. This article also discusses which risk factors aggravate the risk in known coronary patients and what advice should be given to coronary patients who want to benefit from the effects of regular physical exercise.

Cardiovascular Diseases↗

[Pacemaker and intra cardiac defibrillator lead extraction techniques].

Percutaneous Pace-maker and ICD lead extraction techniques has been developped: by superior approach using locking stylet and more and more efficient outher sheats (laser assisted); and also by femoral approach using double lasso catheters (Needle's eye snare). Indication range has increased and is not only reserved for lead infection. Because of scar tissue holding the lead and also the impact of the distal tip, those techniques are not simples. Extraction recommandations do advise those procedures to be performed by expert physicians, in cardiac surgery centers, where complications can be managed and reduced. The use of laser assisted outher sheats will make lead extraction easier and will reduce complication rate. Alternative procedure in case of failure with superior approach remain femoral approach. All those techniques give a success rate of about 98 % for percutaneous lead extraction in an expert center.

Defibrillators, Implantable↗

[Value of memory functions in implantable prostheses].

The development of memory functions with memorised electrogrammes is one of the most important technical advances in cardiac pacemakers and defibrillators. These memory functions are very useful in the management of patients with implanted prostheses. In the case of defibrillators, the memory allows evaluation and validation of appropriate treatments (shock or asymptomatic antitachycardia stimulation) or inappropriate function. The memory can also help assess the efficacy of complementary antiarrhythmic therapy or radiofrequency ablation. The incorporation of memory functions in pacemakers is more recent but no less useful. The latest generation of pacemakers have not only a therapeutic but also a diagnostic role with respect to atrial and ventricular arrhythmias. They can lead to the prescription of an antiarrhythmic or anticoagulant drug in cases of sustained atrial fibrillation confirmed by the memorised electrogrammes. The memory function is also a great aid in reprogramming stimulators in cases of overdetection (V-A cross talk). They may also be activated by the patient in cases of sporadic paroxysmal symptoms. The latest development is that of a purely diagnostic prosthesis: the implantable Holter, whose main indication is in the investigation of unexplained syncope.

Atrial Fibrillation↗

[Strategy of investigation of coronary artery disease in diabetes: from screening to suspicion of acute coronary syndromes].

Coronary artery disease is a common and serious condition in diabetes and the prognosis of the diabetic without a history of cardiovascular disease is either the same or nearly as serious as that of a non-diabetic patient with a history of coronary disease. This is particularly true in women. The prognosis is even worse in the presence of silent myocardial ischaemia. Conversely, anti-ischaemic and anti-thrombotic therapy and myocardial revascularisation of most severely affected patients are effective. This justifies the recent recommendations (as those of the working group of the French Society of Cardiology and the ALFEDIAM) for the diagnosis of coronary artery disease in diabetes, even in asymptomatic patients. This is a two stage process: --First, the identification of patients who should be screened for ischaemia, diabetics with a priori an intermediate or high risk of the presence of CAD, with respect to the presence of markers easily identified on initial examination, like the presence of clinical macroangiopathy (femoral, carotid), of renal disease or ECG changes or the presence of several classical risk factors; --The second stage is the demonstration of myocardial ischaemia in patients identified to be at risk. This article reviews the advantages and limits of the tests available: ECG stress test, myocardial perfusion imaging on effort or under dipyridamole, stress echocardiography. Coronary angiography in asymptomatic patients is only recommended in the presence of significant ischaemia or with a poor prognosis (affecting over 20% of the myocardium or several myocardial territories). This should precede a myocardial revascularisation procedure. The prescription of coronary angiography may be more direct in some symptomatic patients.

Acute Disease↗

[Role of atrial stimulation in the treatment of paroxysmal atrial fibrillation].

Preventive treatments for atrial fibrillation by stimulation have been developed for several years now, mainly due to the relative failure of anti-arrhythmic treatments. They are based on the hypothetical effects of stimulation by controlling cardiac frequency, abolishing bradycardia-dependent extrasystoles, by the inhibition of atrial automatic foci with "overdrive", and by the modification of intra- or inter-atrial conduction delays as well as by remodelling the arrhythmogenic substrate. It is clear that an undeniable effect exists for the prevention of atrial fibrillation, even for the risk of cerebral vascular accident, by physiological stimulation (DDD/DDDR) compared to pure ventricular stimulation (VVI/VVIR) in a heterogenous global population of stimulated patients. For the moment, there is not sufficient proof of a positive effect for the emerging sites of cardiac stimulation, either atrial mono-site or double site in the populations at high risk of atrial fibrillation, with or without associated bradycardia. Some new prevention algorithms by "overdrive" are under development but for the moment only a few preliminary studies seem to show a slight benefit. It is clear that at present stimulation should be reserved only for cases of atrial fibrillation associated with a classic indication for implantation. In these patients it is recommended to position the probes in an optimal manner in order to counteract conduction disorders, choosing an adapted double chamber stimulator with prevention algorithms. That said, the patient should be clearly warned that the long term success rate is no more than 50%.

Algorithms↗

Local delivery of nadroparin for the prevention of neointimal hyperplasia following stent implantation: results of the IMPRESS trial. A multicentre, randomized, clinical, angiographic and intravascular ultrasound study.

BACKGROUND: We hypothesized that intramural delivery of nadroparin, a low molecular weight heparin, would prevent in-stent restenosis by inhibiting neointimal hyperplasia in an angioplasty model free of arterial remodelling. METHODS AND RESULTS: In a prospective randomized multicentre trial, 250 patients submitted to balloon angioplasty followed by stent implantation were randomized into control group (no local drug delivery) or intramural delivery of nadroparin (2 ml of 2500 anti-Xa-units/ml with a microporous catheter). An ancillary intravascular ultrasound substudy was performed to supplement angiographic data with specific measurements of in-stent neointimal hyperplasia. The primary end-point was the late loss in minimal luminal diameter on the 6 month follow-up angiogram. Secondary end-points included feasibility and safety of local nadroparin delivery, and major adverse cardiac events at 8 weeks and 6 months follow-up. Local delivery of nadroparin was successful in 124 patients (99.2% success rate) and was not associated with an increase in stent thrombosis, coronary artery dissection, side branch occlusion, distal embolization or abrupt arterial closure. At angiographic follow-up, the late loss in lumen diameter was 0.84 +/- 0.62 mm in the control group compared to 0.88 +/- 0.63 mm in the nadroparin group (P=0.56). Angiographic restenosis rate (defined as a >50% diameter stenosis) did not differ in the control group (20%) compared to the nadroparin group (24%). The average area of neointimal tissue within the stent was 2.86 +/- 0.64 mm(2) vs 2.90 +/- 0.53 mm(2) (P=0.57), control vs nadroparin groups. There was no difference in major adverse cardiac events at any time (88.8% vs 89.6% event free survival at 6 months, control vs nadroparin). CONCLUSION: Intramural delivery of nadroparin with a microporous catheter after stent deployment was feasible and safe but had no effect in reducing restenosis or the occurrence of major adverse clinical events over 6 months.

Adult↗

Biodistribution, dosimetry, and safety of myocardial perfusion imaging agent 99mTcN-NOET in healthy volunteers.

UNLABELLED: 99mTcN-NOET (bis[N-ethoxy,N-ethyl]dithiocarbamato nitrido technetium (V)) has been proposed for myocardial perfusion imaging. Biodistribution, safety, and dosimetry were studied in 10 healthy volunteers (5 at rest and 5 during exercise). METHODS: Biodistribution was studied by acquiring dynamic images up to 60 min after injection and whole-body images up to 24 h after injection. The MIRDOSE3 analysis program was used for radiation dosimetry calculations. RESULTS: Safety parameters measured to 48 h after injection revealed no clinically significant changes. Cardiac uptake of 99mTcN-NOET was high (2.9%-3%), with biologic half-life of 210-257 min on average. Lung uptake of 99mTcN-NOET was higher (10%-20%) but, on average, biologic half-life was shorter (1-77 min). Clearance from the blood was rapid (5% by 5 min). Radiation dosimetry calculations indicated an effective absorbed dose of 5.11 x 10(-3) mSv/MBq at rest and 5.38 x 10(-3) mSv/MBq after exercise. CONCLUSION: 99mTcN-NOET exhibits high cardiac uptake and an estimated effective absorbed dose comparable with that of the other 99mTc-labeled compounds used in myocardial perfusion imaging.

Adult↗

[Which coronary tests to use in asymptomatic diabetics?].

Coronary artery disease is a common, serious and insidious complication of diabetes. Myocardial ischaemia is often silent. All diabetics do not have the same coronary risk and, therefore, it is important to determine which investigations to perform and which patients. This strategy is justified because it allows identification of these cases which require a medical or an invasive (angioplasty, surgical revascularisation) approach, as these interventions may improve the prognosis. The first stage is clinical (investigation of cardiovascular risk factors). When more than two risk factors are found, further investigations are justified. Exercise stress testing provide reassuring diagnostic and prognostic data when maximal and negative. When sub-maximal, impossible or significantly ischaemic, a second investigation is useful. Holter ECG recording with analysis of ST variation lacks sensitivity and, above all, specificity. The diagnostic value of perfusion myocardial scintigraphy in the diabetic is not as good as that observed in the general population, but its prognostic value remains good. Ischaemia involving over 20% of the myocardium justifies therapeutic investigation. Stress echocardiography has been validated in the diagnosis and prognosis of coronary artery disease and its sensitivity and specificity are probably the same as those of scintigraphy. The authors conclude that the asymptomatic diabetic requires clinical and staged paraclinical investigation to assess prognosis and, depending on the results, the adoption of a beneficial therapeutic strategy.

Cardiovascular Agents↗

Long-term additive prognostic value of thallium-201 myocardial perfusion imaging over clinical and exercise stress test in low to intermediate risk patients : study in 1137 patients with 6-year follow-up.

BACKGROUND: The exercise treadmill test (ETT) and Tl201 single proton emission computed tomography (SPECT) are of short- to medium-term prognostic value in coronary heart disease. We assessed the long-term prognostic value of these tests in a large population of patients with low- to intermediate risk of cardiac events. METHODS AND RESULTS: One thousand one hundred thirty-seven patients (857 men, age 55+/-9 years) referred for typical (62.1%) or atypical (22.4%) chest pain, or suspected silent ischemia (15.5%), were followed up for 72+/-18 months. Overall mortality was higher after strongly positive (ST depression >2 mm, or >1 mm for a workload </=75 W) (2. 36%/y) or nondiagnostic ETT (1.63%/y) than after normal (0.85%/y) or positive ETT (1.37%/y) (P=0.002), and after abnormal SPECT than after normal SPECT (1.60%/y versus 0.68%/y, P=0.001). The major cardiac event rate (cardiac death or myocardial infarction [MI]) was 0.88%, 1.59%, 2.10%, and 2.13%/y after negative, positive, strongly positive, and nondiagnostic ETT, respectively (P=0.003), and 0.56%, 1.43%, and 2.05%/y in patients with 0, 1 to 2, and >/=3 abnormal segments on SPECT, respectively (P<0.002). An abnormal SPECT was predictive of MI (P<0.001), whereas ETT was not. In multivariate analysis, SPECT was of incremental prognostic value over clinical and ETT data for predicting overall mortality and major cardiac events. CONCLUSIONS: The incremental predictive value of SPECT is maintained over 6 years and is particularly relevant after positive, strongly positive, and nondiagnostic ETT.

Adult↗

Myocardial infarction and Turner's syndrome.

This paper reports the case of a patient with Turner's syndrome, who developed a myocardial infarction at the age of 36. Turner's syndrome, associated with gonadal insufficiency, increases atherosclerotic cardiovascular risks that must be assessed during the patient's follow-up.

Adult↗

A randomized evaluation of early revascularization to treat shock complicating acute myocardial infarction. The (Swiss) Multicenter Trial of Angioplasty for Shock-(S)MASH.

AIM: To test whether emergency revascularization improves survival in patients with acute myocardial infarction and shock. METHODS AND RESULTS: Patients with acute myocardial infarction and early shock were randomized either to undergo emergency angiography, followed immediately by revascularization when indicated, or to receive initial medical management. In five of the nine participating centres, patients with shock but not randomized were entered in a registry. Only 55 patients could be randomized. Of the 32 patients in the invasive group, 30 (94%) underwent early angiography, 27 (84%) PTCA, and one (4%) CABG. Twenty-two (69%) died within 30 days in the invasive group vs 18/23 (78%) in the medically managed group (ns, RR=0.88, 95% confidence interval 0.6-1.2). Among the registry patients, 24/51 were excluded from randomization solely because of patient or physician preference for the invasive approach: 23 (96%) of them underwent emergency angiography, 21 (88%) PTCA, and 12 (50%) died within 30 days. Among the remaining registry patients (n=27) only nine (33%) underwent early angiography, nine (33%) PTCA and 20 (74%) died. CONCLUSION: We failed to demonstrate that emergency PTCA significantly improves survival in patients with acute myocardial infarction and early cardiogenic shock. Because the study was stopped prematurely, due to an insufficient patient inclusion rate, a clinically meaningful benefit of early reperfusion may have been missed.

Aged↗

Prediction of cardiovascular events in clinically selected high-risk NIDDM patients. Prognostic value of exercise stress test and thallium-201 single-photon emission computed tomography.

OBJECTIVE: We evaluated the prognostic value of an exercise stress test and thallium-201 scintigraphy for the prediction of cardiac events in selected high-risk NIDDM patients. RESEARCH DESIGN AND METHODS: NIDDM patients (n = 158, 105 men, aged 63 +/- 9 years) with two or more of the following criteria were prospectively included: age > or = 65 years, active smoking, hypertension > 160/95 mmHg, hypercholesterolemia (cholesterol > 5.70 mmol/l or LDL > 3.10 mmol/l), peripheral artery disease, abnormal rest electrocardiogram, or microalbuminuria (20-200 micrograms/min). An exercise-stress scintigraphy was performed in 77 patients able to exercise, while a dipyridamole scintigraphy was performed in 80 patients unable to exercise. Follow-up was 23 +/- 17 months. Major end points were cardiac deaths or nonfatal myocardial infarction. RESULTS: The annual event rate was 7.31% (deaths: 8, myocardial infarction: 14). Independent predictors of events were as follows: an age > 60 (P = 0.02), an abnormal rest electrocardiogram (P = 0.02), microalbuminuria (P = 0.001), the inability to exercise (P = 0.009), and the presence of more than two defects on scintigraphy (P = 0.001). A cardiac death occurred in 1.3% of patients able to exercise versus 8.8% of patients unable to exercise (odds ratio = 6.8, P = 0.001). Among patients unable to exercise, large perfusion defects corresponded to an annual mortality rate of 22.3%. Conversely, the negative predictive value of a normal scintigraphy for the occurrence of death was 97%. CONCLUSIONS: Inability to exercise and large perfusion defects on thallium-201 scan are major predictors of future death and myocardial infarction in high-risk NIDDM patients.

Activities of Daily Living↗

[Evaluation of a clinical and scintigraphic management strategy for cardiac risk before abdominal aorta surgery. Apropos of 982 surgical patients].

The incidence of major cardiac events (death, infarction) is over 5% after programmed aortic vascular surgery. The aim of this study was to evaluate a management strategy of this risk based on the clinical status and targeted indication of myocardial scintigraphy, coronary angiography and myocardial revascularisation. A first phase (1991-1993, 451 patients) confirmed the prognostic value of clinical (age, previous cardiac history, diabetes, hypertension, electrocardiogrammes) and scintigraphic features: the cardiac mortality was 1.25% in patients with a low clinical risk (70.3% of cases) and 4.5% in patients with a high clinical risk (2 factors, 29.3% of cases) (p < 0.01). In the latter group, the mortality was zero after normal myocardial scintigraphy and 7.2% after abnormal myocardial scintigraphy (p < 0.01) and 12.5% in cases with reversible defects (p < 0.01). During the second phase of the study (1994-1997, 531 patients) coronary angiography was performed in patients with a high clinical risk and abnormal scintigraphy (10.9% of cases). This led to a myocardial revascularisation in 3.6% of patients. The cardiac mortality was then the same in the low and high a priori clinical risk: 2.3 and 2.8% (NS). The use of simple clinical criteria enables surgery in the majority of candidates for aortic vascular surgery, scintigraphy being reserved for about one patient in ten with myocardial revascularisation in less than 4% of cases. The operative cardiac mortality then decreases to under 2.5%.

Aged↗

"Rescue" abciximab for complicated percutaneous transluminal coronary angioplasty.

We studied the in-hospital outcome of 138 consecutive patients who received abciximab as a "rescue" intervention for complicated coronary angioplasty in a high-risk clinical setting. "Rescue" treatment with abciximab was associated with clinical and angiographic success rates of 83% and 84%, respectively, whereas the risk of bleeding was higher in patients of low body weight.

Abciximab↗

Metabolic myocardial viability assessment with iodine 123-16-iodo-3-methylhexadecanoic acid in recent myocardial infarction: comparison with thallium-201 and fluorine-18 fluorodeoxyglucose.

The best test presently available to ascertain residual viability within an infarct-related area involves the use of fluorine-18 fluorodeoxyglucose (FDG) to detect the persistence of some cellular metabolism. Rest reinjection of thallium-201 is a less accurate alternative but is easy to perform. Iodinated fatty acids, which are used with standard gamma cameras, are proposed as markers of cellular metabolism. This study was performed to assess the value of 16-iodo-3-methylhexadecanoic acid (MIHA) as a marker of the residual cellular metabolism by comparison with FDG in patients with a recent myocardial infarction, and to evaluate its contribution compared with the 201Tl stress-redistribution-reinjection technique. Stress-redistribution-reinjection 201Tl imaging, rest MIHA imaging and glucose-loaded FDG imaging were performed in 22 patients with recent myocardial infarction. Out of the 628 myocardial segments obtained from the left ventricular analysis, 400 were hypoperfused (relative uptake <0.75 of maximum uptake on stress 201Tl imaging), 177 of which were severely hypoperfused (relative uptake <0.50). Receiver operating characteristic (ROC) curves for predicting metabolic myocardial viability with FDG were derived from the results in respect of (a) 201Tl activity during exercise, redistribution and reinjection and (b) MIHA uptake, using the two FDG thresholds most commonly considered to define metabolic viability (0.50 and 0.60). Analysis of the 400 hypoperfused segments demonstrated that 201Tl reinjection was the most accurate test in predicting the presence of myocardial viability (area under the ROI curves=0.85 and 0.86 at the 0.50 and 0.60 FDG thresholds, respectively; P<0.05 vs other tests). The global predictive values of MIHA and 201Tl reinjection were, respectively, 0.87 and 0.89 at the 0.50 FDG threshold (NS), and 0.82 and 0.87 at the 0.60 FDG threshold (NS). When only the 177 severely hypoperfused segments were considered, 201Tl reinjection remained the most accurate test (accuracy 0.84 at the 0.50 FDG threshold and 0.82 at the 0.60 FDG threshold), while the accuracy of MIHA decreased significantly (0.78 at the 0.50 FDG threshold and 0.73 at the 0.60 FDG threshold, P<0.05 vs 201Tl reinjection). In all circumstances, MIHA was less specific than 201Tl reinjection for the detection of metabolic viability. In conclusion, in patients with recent myocardial infarction, MIHA accurately detects the persistence of metabolic viability, but is not superior to 201Tl.

Deoxyglucose↗