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Biomedical subjects

N Danchin

Publications and source records attributed to N Danchin.

At least 73 records · Page 4Linked to original sources
PubMed2001

Detection and prediction of acute heart transplant rejection with the myocardial T2 determination provided by a black-blood magnetic resonance imaging sequence.

OBJECTIVES: This study aimed to determine whether the myocardial T2 relaxation time, determined using a black-blood magnetic resonance imaging (MRI) sequence, could predict acute heart transplant rejection. BACKGROUND: The use of black-blood MRI sequences allows suppression of the confusing influence of blood signal when myocardial T2 is calculated to detect myocardial edema. METHODS: A total of 123 investigations, including cardiac MRI and myocardial biopsy, were performed 8 +/- 11 months after heart transplantation. Myocardial T2 was determined using an original inversion-recovery/spin-echo sequence. RESULTS: A higher than normal T2 (> or = 56 ms) allowed an accurate detection of the moderate acute rejections evidenced at baseline biopsy (> or = International Society for Heart and Lung Transplantation grade 2): sensitivity, 89% and specificity, 70% (p < 0.0001). T2 was increased in grade 2 (n = 11) compared with grade 0 (n = 49, p < 0.05), grade 1A (n = 34, p < 0.05) and grade 1B (n = 21, p < 0.05); T2 was further increased in grade 3 (n = 8) compared with grade 2 (p < 0.05). In addition, in patients without rejection equal to or greater than grade 2 at baseline, a T2 higher than normal (> or = 56 ms) was correlated with the subsequent occurrence of equal or greater than grade 2 rejection within the next three months: sensitivity 63% (12/19) and specificity 78% (64/82) (p = 0.001). CONCLUSIONS: Myocardial T2 determined using a black-blood MRI sequence, is sufficiently sensitive to identify most of the moderate acute rejections documented with biopsy at the same time, but is also a predictor of the subsequent occurrence of such biopsy-defined rejections.

Adolescent↗
PubMed2001

[Distribution and treatment of cardiovascular risk factors in coronary patients: the Prevenir Study].

The aim of this study was to evaluate the distribution and hospital treatment of cardiovascular risk factors in coronary patients. A transverse observational study was carried out in 77 cardiological centres throughout France. All patients with a history of myocardial infarction or of unstable angina during the month of January 1998 were enrolled. The clinical features of 1334 patients (71.4% men, 746 myocardial infarction, 588 unstable angina) on hospital admission were analysed. The prevalence of smoking, dyslipidaemia, hypertension and obesity was 49, 45, 42, 19 and 11% respectively in the men and 17, 46, 63, 23 and 10% respectively in the women. The number of treatable risk factors slightly decreased in the oldest age group. The prevalence of hypertension increased with age whereas smoking and dyslipidaemia decreased in both men and women. Obese and diabetic patients had more risk factors than the others. A little less than half of patients with dyslipidaemia were under no preventive measures (diet and/or lipid-lowering drugs) and 40% of men with a previous history of coronary artery disease continued to smoke. The authors conclude that men over 85 and women over 75 years of age have fewer risk factors than other age groups and the type of risk factor varies with age. The treatment of dyslipidaeamia and smoking is still inadequate and should be improved.

Adult↗
PubMed2001

[Blood pressure control after acute coronary events. Results of the PREVENIR study].

OBJECTIVE: The difficulty in controlling hypertension in coronary patients has been underlined. The aim of the study was to assess blood pressure profile (BP) at hospital discharge in a large population of survivors of an acute coronary syndrome. DESIGN AND METHODS: An observational study was conducted in France in 77 cardiological centers. The medical records of all patients admitted in these hospitals on January 1998 for a myocardial infarction or unstable angina and who survived were studied. Clinical characteristics and BP at hospital discharge were recorded. Patients with blood pressure > or = 140/90 mmHg were considered as uncontrolled hypertensives (HT). RESULTS: Data were available in 1327 of the 1394 patients recruited: at hospital discharge, 344 patients (25.9%) were controlled and 431 (32.4%) were uncontrolled hypertensives. Among these patients, 406 (94.1%) had systolic blood pressure > or = 140 mmHg, 139 (32.2%) had diastolic blood pressure > or = 90 mmHg and 292 patients (67.7%) had systolic blood pressure > or = 140 mmHg and diastolic blood pressure < 90 mmHg. Pulse pressure in controlled hypertensives (51.02 +/- 10.93 mmHg) was quite similar to that in normotensives (47.81 +/- 9.84 mmHg) whereas pulse pressure was significantly higher in uncontrolled hypertensives (65.86 +/- 13.29 mmHg). CONCLUSION: At hospital discharge after a coronary event, arterial hypertension is uncontrolled in 32.4% of patients mainly because of poor systolic blood pressure control. Achieving normal blood pressure throughout the hospitalisation should improve long term blood pressure control, reduce pulse pressure and improve the prognosis in this high risk population.

Adult↗
PubMed2000

Inhibition of the sodium-hydrogen exchanger with cariporide to prevent myocardial infarction in high-risk ischemic situations. Main results of the GUARDIAN trial. Guard during ischemia against necrosis (GUARDIAN) Investigators.

BACKGROUND: The transmembrane sodium/hydrogen exchanger maintains myocardial cell pH integrity during myocardial ischemia but paradoxically may precipitate cell necrosis. The development of cariporide, a potent and specific inhibitor of the exchanger, prompted this investigation of the potential of the drug to prevent myocardial cell necrosis. METHODS AND RESULTS: A total of 11 590 patients with unstable angina or non-ST-elevation myocardial infarction (MI) or undergoing high-risk percutaneous or surgical revascularization were randomized to receive placebo or 1 of 3 doses of cariporide for the period of risk. The trial failed to document benefit of cariporide over placebo on the primary end point of death or MI assessed after 36 days. Doses of 20 and 80 mg every 8 hours had no effect, whereas a dose of 120 mg was associated with a 10% risk reduction (98% CI 5.5% to 23.4%, P=0.12). With this dose, benefit was limited to patients undergoing bypass surgery (risk reduction 25%, 95% CI 3.1% to 41.5%, P=0.03) and was maintained after 6 months. No effect was seen on mortality. The rate of Q-wave MI was reduced by 32% across all entry diagnostic groups (2.6% versus 1.8%, P=0.03), but the rate of non-Q-wave MI was reduced only in patients undergoing surgery (7.1% versus 3.8%, P=0.005). There were no increases in clinically serious adverse events. CONCLUSIONS: No significant benefit of cariporide could be demonstrated across a wide range of clinical situations of risk. The trial documented safety of the drug and suggested that a high degree of inhibition of the exchanger could prevent cell necrosis in settings of ischemia-reperfusion.

Aged↗
PubMed2000

Long-term outcome in patients treated by intracoronary stenting with ticlopidine and aspirin, and deleterious prognostic role of unstable angina pectoris.

Compared with stable clinical conditions, unstable angina carries an increased risk of immediate and delayed cardiac adverse events after balloon coronary angioplasty. The influence of stent use in reducing these differences remains unknown. We analyzed the early (30 days) and late outcome of a cohort of 459 consecutive patients who underwent stent placement with ticlopidine and aspirin as antithrombotic regimen according to the presence (group 1, n = 151) or absence (group 2, n = 308) of unstable angina at rest (Braunwald classes II and III). Group 1 patients were older and more likely to be current or former smokers. In group 2, prior myocardial infarction was more frequent. Procedural, in-hospital results, and early outcome were similar in the 2 groups. However, over the long term, the incidence of myocardial infarction (11% vs 6%, p <0.04), target lesion revascularization (19% vs 13%, p <0.04), or any revascularization (30% vs 20%, p <0.01) was significantly higher in group 1. Kaplan-Meier probabilities of survival without myocardial infarction (85% vs 91%, p <0.05), survival without revascularization of the target lesion (73% vs 83%, p <0.01), survival without any revascularization (65% vs 77%, p <0.006), and survival without any events (61% vs 73%, p <0.009) were significantly worse in group 1. In addition, Cox multivariate analysis showed that unstable angina at rest was an independent predictor of target lesion revascularization, of survival without any revascularization, and without any events. Thus, unstable angina at rest remains an adverse prognostic indicator in patients treated with intracoronary stents, particularly with regard to subsequent requirement of revascularization procedures and event-free survival.

Aged↗
PubMed2000

Dipyridamole and exercise SPET provide different estimates of myocardial ischaemic areas: role of the severity of coronary stenoses and of the increase in heart rate during exercise.

In patients unable to perform a maximal exercise test, dipyridamole single-photon emission tomography (SPET) has a higher capacity than exercise SPET to detect coronary artery disease (CAD). However, in patients with myocardial ischaemia who are able to perform a maximal exercise test, it is not known whether these two tests may be equally used to assess the areas of myocardial ischaemia. This study was aimed at comparing the results provided by dipyridamole and exercise SPET in CAD patients with documented exercise myocardial ischaemia. Forty CAD patients who had undergone exercise thallium-201 SPET and who had myocardial ischaemia documented by an unequivocally positive exercise test underwent an additional 201Tl SPET study after dipyridamole infusion and low-level (40 W) exercise. The extent of defects was compared between the two tests and predictors of discrepant results were sought among data from exercise testing and coronary angiography. The extent of SPET defects was equivalent between the two tests in only 11 patients (28%), larger defects being observed with exercise in 18 [average difference: 12%+/-5% of left ventricle (LV)] and with dipyridamole in 11 (average difference: 15%+/-11% of LV). The best independent predictors of discrepancies between the two tests were: (1) increase in heart rate at exercise SPET, with defects being smaller at exercise than after dipyridamole in none of the patients with an increase >60 bpm (0/14), but in 42% of the others (11/26; P=0.004); and (2) an ischaemic territory related to a <70% coronary stenosis, for which SPET defects were always induced at exercise (10/10) but in only 30% (3/10) with dipyridamole (P=0.0004). Exercise and dipyridamole SPET provide different estimates of myocardial ischaemic areas. Dipyridamole allows the unmasking of perfusion abnormalities in patients who have low increases in heart rate at exercise SPET. However, dipyridamole is also much less efficient at inducing perfusion abnormalities in the ischaemic areas supplied by coronary stenoses of intermediate severity at rest angiography.

Coronary Angiography↗
PubMed2000

A comparison of the overall first-pass kinetics of thallium-201 and technetium-99m MIBI in normoxic and low-flow ischaemic myocardium.

The specific impact of ischaemia on the myocardial kinetics of thallium-201 and technetium-99m 2-methoxy-2-isobutylisonitrile (MIBI) remains a matter of debate. Using an isolated heart model perfused with red blood cell-enhanced perfusate, we compared the overall first-pass kinetics of 201Tl and MIBI under haemodynamically stable conditions of low-flow ischaemia (> 50% reduction in normal coronary flow and a > or = 20 mmHg fall in systolic contraction pressure, n = 10) and normoxia (n = 11). For both 201Tl and MIBI, we found that under ischaemic conditions (as compared with normoxia) there was a higher initial net extraction fraction (201Tl: 0.78 +/- 0.03 vs 0.72 +/- 0.06, P = 0.006; MIBI: 0.49 +/- 0.10 vs 0.39 +/- 0.11, P = 0.03), a lower clearance rate in the 30 min following extraction (% decrease in cardiac uptake: 201Tl: 30 +/- 12 vs 47 +/- 14, P = 0.02; MIBI: 5 +/- 5 vs 13 +/- 11, P = 0.02) and a higher retention fraction at 30 min (20lTl: 0.54 +/- 0.10 vs 0.39 +/- 0.12, P = 0.004; MIBI: 0.46 +/- 0.08 vs 0.33 +/- 0.12, P = 0.01). Multivariate analyses, however, revealed that all myocardial kinetic parameters of both tracers were dependent only on coronary flow rates, without any additional significant impact of the presence of ischaemia or states of contractility or oxidative metabolism. We conclude that the myocardial fractional retention of both 201Tl and MIBI is strongly correlated with the decrease in coronary flow during ischaemia. This inverse relationship with coronary flow derives from both the flow-dependent increase in the initial myocardial extraction and the decrease in the subsequent myocardial washout of the tracers.

Animals↗
PubMed2000

Homocysteine, vitamins B6, B12, folate, and risk of coronary artery disease in patients undergoing diagnostic coronary angiography.

Homocysteine and vitamins B were correlated with coronary artery disease in patients undergoing diagnostic coronary angiography. 160 patients having > or =1 stenosis (G1), 55 patients having normal coronary arteries (G2) and 171 healthy volunteers (G3) were prospectively recruited. Homocysteine levels were significantly higher in patients, particularly in those with normal coronary angiograms, than in healthy subjects (13.8 +/-6.3 micromol/L in G1 (p < 0.0001) and 15.2 +/- 8.8 micromol/L in G2 (p < 0.0001) versus 10.1 +/- 3.1 micromol/L in G3). Homocysteine levels were not related to the extent of coronary artery disease. In patients with normal angiogram, vitamin B12 and folate levels were significantly higher compared with the other groups (p < 0.05 and p < 0.001, respectively) showing that vitamin B deficiency was not involved in the hyperhomocysteinemia. In conclusion, homocysteine and vitamins B levels do not contribute to discriminate for the presence of coronary artery disease in patients undergoing diagnostic coronary angiography. Homocysteine levels, however, were higher in patients referred for coronary angiography than in healthy controls.

Aged↗
PubMed2000

The TETAMI trial: the safety and efficacy of subcutaneous enoxaparin versus intravenous unfractionated heparin and of tirofiban versus placebo in the treatment of acute myocardial infarction for patients not thrombolyzed: methods and design.

Patients with acute myocardial infarction (AMI) who do not receive early reperfusion therapy are at high risk of reinfarction or death, and the efficacy and safety of antithrombotic therapy in this group of patients has not been evaluated. Enoxaparin is a low-molecular-weight heparin (LMWH) that has previously been shown to reduce the incidence of ischemic events in patients with unstable angina or non-Q-wave MI. The principal aims of the TETAMI study are to investigate the efficacy and safety of treatment with enoxaparin or tirofiban (a glycoprotein IIb/IIIa receptor antagonist) alone or in combination for 2 to 8 days in patients with AMI who are not eligible for early reperfusion therapy. In this 2 by 2 factorial design study approximately 900 patients will be randomly assigned, in a blinded manner, to one of four treatments: enoxaparin alone, enoxaparin plus tirofiban, unfractionated heparin (UFH), or UFH plus tirofiban, with appropriate matched placebos. The primary end point is the composite of death, recurrent AMI, and recurrent angina, analyzed at 30 days after AMI. The design and methods of the TETAMI study are described in this article.

Adult↗
PubMed2000

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↗