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Biomedical subjects

N Danchin

Publications and source records attributed to N Danchin.

At least 181 records · Page 10Linked to original sources
PubMed1994

[Treatment after myocardial infarction].

Advances in the treatment of the acute phase of myocardial infarction have lead to the need for adequate secondary treatment. beta-blockers have been largely demonstrated to be effective antianginal agents, acting on three determining factors: heart rate, systemic blood pressure and myocardial contractility. Used in secondary prevent treatment, beta-blockers lead to significant improvement in global post-myocardial infarction mortality, reduced from 9.4 to 7.6% and in reinfarction rates, reduced from 7.5 to 5.6%. Prescription of beta-blockers beyond the acute phase is an essential part of secondary prevention. For calcium antagonists however, there is no evidence of improved prognosis after myocardial infarction. There is no improvement in mortality or reinfarction rates. Class I antiarrhythmic drugs are not indicated as systematic treatment after myocardial infarction. Angiotensin converting enzyme inhibitors can reduce long-term mortality and late occurrence of congestive heart failure, particularly in patients with moderate to severe left ventricular dysfunction. Among the anti-thrombotic drugs, oral anticoagulants seem to offer no clear advantage over aspirin. Large trials of anti-arrhythmic agents have failed to demonstrate any clinical benefit in asymptomatic patients with ventricular ectopic beats, and the results of secondary prevention trials using amiodarone are still awaited. Myocardial revascularization using coronary bypass surgery or percutaneous transluminal coronary angioplasty should be proposed mainly in symptomatic patients or in subsets of patients with multi-vessel disease and altered left ventricular function. Finally, rehabilitation measures should be aimed at correcting cardiovascular risk factors and improving physical fitness.

Adrenergic beta-Antagonists↗
PubMed1994

Effect on early acute occlusion rate of adjunctive antithrombotic treatment with intravenously administered dipyridamole during percutaneous transluminal coronary angioplasty.

This study compared the acute occlusion and complication rates within 24 hours of coronary angioplasty in three groups of patients. In group 1, 178 procedures were performed by one operator who administered 30 mg of dipyridamole intravenously over 1 hour, starting immediately before the procedure; in group 2, 200 procedures were performed by the same operator before he administered dipyridamole; and in group 3, 599 procedures were performed during the same time period in the same catheterization laboratory by two other operators who did not administer dipyridamole. All patients received an intravenous bolus of heparin and aspirin. Baseline variables were similar in the three groups. The acute closure rate was 2.8% in group 1, 7.5% in group 2, and 5.2% in group 3 (p < 0.05 between groups 1 and 2); acute thrombosis was observed in 0.6%, 3.5%, and 3% of patients, respectively, in the three groups (p < 0.05 between group 1 and both groups 2 and 3), and acute dissection was noted in 2.2%, 4%, and 2% of patients, respectively (p = not significant). The cumulative rate of acute complications (death, acute myocardial infarction, or emergency coronary bypass surgery) was lower in group 1 (1.7%) than in group 2 (5.5%, p < 0.05) and group 3 (3.5%, p = not significant). Therefore in this retrospective study, adjunctive antithrombotic treatment with intravenously administered dipyridamole resulted in lower acute thrombosis and complication rates during the 24-hour period after the procedure than when heparin and aspirin therapy were used alone.

Acute Disease↗
PubMed1994

Long-term follow-up after coronary angioplasty in patients younger than 40 years of age.

Over an 11-year period, the initial and late outcomes of percutaneous transluminal coronary angioplasty (PTCA) were studied in 140 consecutive patients younger than 40 years of age (mean, 34 +/- 3 years; range, 23 to 39 years; 132 men). Before the procedure, 28% of the patients had unstable angina, and 44% had a history of prior myocardial infarction. Mean left ventricular ejection fraction was 64% +/- 10%, and 75% of the patients had one-vessel disease. Primary success was 86% (77% for the first 70 patients vs 93% for the last 70, p < 0.02). Complications were nine periprocedural myocardial infarctions, eight emergency coronary surgical procedures, and no deaths. During follow-up (mean, 6 +/- 3 years; range, 1 to 12 years), 39 (28%) of the 104 patients who had repeat coronary angiography had angiographic restenosis (all < 6 months after PTCA). Late events were 13 elective coronary surgical procedures (11 for restenosis, one for failed PTCA, and one for progression of coronary artery disease), 13 PTCAs on a new site, five deaths, and four nonfatal myocardial infarctions. Ten-year survival was 96% +/- 1%, and 10-year event-free survival (without myocardial infarction, elective coronary surgery, or repeat PTCA) was 58% +/- 6%. Among survivors, 88% were free of angina, and 93% had returned to work. In patients younger than 40 years of age, PTCA yields excellent long-term survival, provided that the eventuality of repeat procedures during the first months is accepted. In addition, PTCA for progression on a new site is not unusual after several years.

Adult↗
PubMed1994

Serial evaluation of dilated cardiomyopathy with exercise thallium-201 tomography: correlation with the evolution of left ventricular parameters.

The purpose of this prospective study was to correlate (1) the initial findings of exercise thallium-201 tomography with the evolution of left ventricular parameters at long term follow-up in patients with dilated cardiomyopathy and (2) the changes of exercise thallium-201 tomography repeated 1 year later. We studied 19 men with dilated cardiomyopathy and normal coronary angiogram. Two patients died and three patients had heart transplantation during follow-up. The other 14 patients were assessed at baseline and 1-year follow-up. Thallium-201 tomograms were divided into 20 segments for each patient. Two groups were defined according to the evolution of left ventricular ejection fraction: group 1 (n = 7) had unchanged or decreased ejection fraction at follow-up (24 +/- 11% at baseline versus 22 +/- 11% at follow-up, ns) and group 2 (n = 7) had improved ejection fraction at follow-up (25 +/- 9% at baseline versus 49 +/- 8% at follow-up, P < 0.03). The number of total abnormal segments at stress were not statistically different at baseline between groups 1 and 2, and in group 1 between baseline and follow-up. Group 2 at follow-up had a reduced number of total abnormal segments (P < 0.03). The percentage of reversibility was similar in both groups at baseline and follow-up. On exercise thallium-201 tomography, neither the presence nor the reversibility of stress myocardial perfusion abnormalities can predict improvement of left ventricular ejection fraction in dilated cardiomyopathy. However, regression of dilated cardiomyopathy is accompanied by a reduction of stress myocardial perfusion abnormalities.

Adult↗
PubMed1994

Comparison of T1 estimation techniques in cardiac MRI.

We have shown that the use of a simple combination of inversion recovery/spin-echo (IR/SE) sequences provides undeniably superior precision in quantitative in vivo myocardium T1 estimation than the standard multiple spin-echo approach. On a group of 25 healthy subjects, the T1 dispersion was, respectively, 3.8% for the IR/SE combination and 19.6% for the best SE pair combination. Moreover, repeated measurements were carried out on seven of the volunteers in order to assess T1 reproducibility. The mean intra-individual T1 precision was found to be 2.8% for the IR/SE pair and 20.0% for the best SE pair. The in vivo imaging work was supported and corroborated by a thorough treatment of the theoretical T1 errors. We also highlight the importance of quality control in quantitative MRI; a correction being required in the SE sequences to bring measured signal intensities into line with those predicted from simple theory.

Adult↗
PubMed1994

[Influence of the severity of coronary stenosis on the course of left ventricular function in case of subsequent coronary occlusion. Longitudinal coronarographic study].

In order to evaluate the consequences concerning left ventricular function of the spontaneous occlusion of coronary stenoses, the authors studied the clinical and angiographic characteristics of 30 consecutive patients (25 men, 5 women, mean age: 54) undergoing successive coronary arteriograms showing progression to complete occlusion of the anterior interventricular or right coronary between the two investigations. Two groups of patients were identified: Group I (n = 19) with occlusion of a previously moderate (< or = 50%) stenosis; Group II (n = 11) with occlusion of an initially tight stenosis (> 50%). At the time of the first angiogram, left ventricular ejection fraction (LVEF) was 60 +/- 13% in Group I and 58 +/- 9% in Group II (NS). Times between the two investigations were similar in the two groups (58 +/- 43 months and 54 +/- 57 months, NS). Between the two coronary arteriograms, 7 patients of Group I sustained an infarction as against 3 in Group II (NS). Impairment of LVEF developed in 16 patients of Group I (84%) as against 5 of Group II (45%) (p < 0.005). Global LVEF varied on average by -10.4 +/- 13.3% (p < 0.005) in Group I and -0.1 +/- 9.5% (NS) in Group II. This difference in variation in LVEF between the two groups was significant (p < 0.04). Spontaneous occlusion of moderate coronary stenoses results in certain cases in greater impairment of left ventricular function than the occlusion of tight stenoses. The development of a collateral circulation probably plays a protective role in the second group.

Adult↗
PubMed1993

Usefulness of quantitative and qualitative angiographic lesion morphology, and clinical characteristics in predicting major adverse cardiac events during and after native coronary balloon angioplasty. CARPORT and MERCATOR Study Groups.

Major, adverse cardiac events (death, myocardial infarction, bypass surgery and reintervention) occur in 4 to 7% of all patients undergoing coronary balloon angioplasty. Prospectively collected clinical data, and angiographic quantitative and qualitative lesion morphologic assessment and procedural factors were examined to determine whether the occurrence of these events could be predicted. Of 1,442 patients undergoing balloon angioplasty for native primary coronary disease in 2 European multicenter trials, 69 had major, adverse cardiac procedural or in-hospital complications after > or = 1 balloon inflation and were randomly matched with patients who completed an uncomplicated in-hospital course after successful angioplasty. No quantitative angiographic variable was associated with major adverse cardiac events in univariate and multivariate analyses. Univariate analysis showed that major adverse cardiac events were associated with the following preprocedural variables: (1) unstable angina (odds ratio [OR] 3.11; p < 0.0001), (2) type C lesion (OR 2.53; p < 0.004), (3) lesion location at a bend > 45 degrees (OR 2.34; p < 0.004), and (4) stenosis located in the middle segment of the artery dilated (OR 1.88; p < 0.03); and with the following postprocedural variable: angiographically visible dissection (OR 5.39; p < 0.0001). Multivariate logistic analysis was performed to identify variables independently correlated with the occurrence of major adverse cardiac events. The preprocedural multivariate model entered unstable angina (OR 3.77; p < 0.0003), lesions located at a bend > 45 degrees (OR 2.87; p < 0.0005), and stenosis located in the middle portion of the artery dilated (OR 1.95; p < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1993

Results of percutaneous transluminal coronary angioplasty of either the left anterior descending or left circumflex coronary artery in patients with chronic total occlusion of the right coronary artery.

The acute and long-term results of percutaneous transluminal coronary angioplasty (PTCA) of the left coronary artery in 106 patients (group 1) with chronic occlusion of the right coronary artery were compared with those of 106 patients matched for sex (92 male) and age (56 +/- 10 years) undergoing left PTCA with a normal right coronary artery (group 2). Before the procedure, group 1 had more unstable angina (42 vs 29%; p < 0.05), more frequent prior myocardial infarction (80 vs 25%; p < 0.001), and a lower left ventricular ejection fraction (56 +/- 10% vs 65 +/- 11%; p < 0.005). Acute results were not different in the 2 groups with respect to primary success (group 1: 93%; and group 2: 89%) and complications (group 1: 2 with emergency coronary surgery, and 4 with periprocedural myocardial infarction and no death; and group 2: 1 with emergency coronary surgery, 1 death, and 3 with periprocedural myocardial infarction). At 6 months, 79 patients in group 1 and 71 patients in group 2 had reangiography; the rate of restenosis was 35% in group 1 and 42% in group 2. In both groups, left ventricular ejection fraction increased significantly in patients without restenosis (58 +/- 12% vs 63 +/- 10%, p < 0.001 [n = 44] in group 1; and 66 +/- 9% vs 70 +/- 10%, p < 0.001 [n = 29] in group 2). In group 1, improvement was significant only for patients without collaterals to the occluded right coronary artery (59 +/- 10% vs 66 +/- 7%; p < 0.003 [n = 24]).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1993

Synchronized inversion recovery-spin echo sequences for precise in vivo T1 measurement of human myocardium: a pilot study on 22 healthy subjects.

An ECG-triggered, two-sequence MRI technique is proposed for the precise measurement of proton T1 relaxation times of the human myocardium at a field strength of 0.5 T. The combination of an inversion recovery (IR) sequence and a spin echo (SE) sequence is not new. It is, however, rarely used in quantitative in vivo cardiac studies. Our approach employs a synchronization of the 90 degrees read pulse to the systolic period. In a study of 22 healthy volunteers, the globally measured T1 value was estimated to be 714 +/- 23 ms. Four of the volunteers also underwent additional imaging scans for the purposes of reproducibility assessment. The T1 precision was found to be 3.9 +/- 1.1% for the IR/SE combination and 16.9 +/- 5.3% for a combination of SE sequences. Total imaging time for the IR and SE sequences was 19.2 +/- 3.0 mins. The relative rapidity of this classic technique and the T1 precision obtained give this technique an obvious application in the discrimination of normal and diseased myocardium. In the same study, valuable supplementary tissue characterization is provided by T2, calculated from the SE sequence. T2 was evaluated to be 50 +/- 3 ms.

Adult↗
PubMed1993

Usefulness of exercise SPECT-thallium to detect asymptomatic restenosis in patients who had angina before coronary angioplasty.

The usefulness of exercise single photon emission computed tomography (SPECT)-thallium for detecting asymptomatic restenosis was assessed prospectively in 62 patients with angina before angioplasty, who underwent < or = 6-month re-angiography and exercise SPECT-thallium imaging. Among patients with restenosis, nine had recurrence of angina but eight did not. These two subgroups had equivalent percentages of restenosis (71 +/- 16% vs 64 +/- 16%, NS) and extent of reversible thallium defects (2.8 +/- 1.7 vs 4.1 +/- 2.6, NS), and both subgroups had poorer hemodynamic responses to exercise compared with patients without restenosis (maximal) rate-pressure product [X 100], 258 +/- 54 and 239 +/- 33 vs 302 +/- 61; p < 0.05 and p < 0.01, respectively). Exercise testing detected fewer patients with restenosis compared to exercise SPECT-thallium imaging, especially among asymptomatic patients (25% vs 100%, p < 0.005). Asymptomatic restenosis occurs frequently, induces an amount of stress ischemia equivalent to that of symptomatic restenosis, and is efficiently detected by exercise SPECT-thallium with rest-reinjection but not by exercise testing.

Aged↗
PubMed1993

Visual versus quantitative assessment of the severity of coronary artery stenoses: can the angiographer's eye be reeducated?

The percent reduction of intraluminal diameter of 102 coronary stenoses before (n = 26), immediately after (n = 24), and 6 months after (n = 52) coronary balloon angioplasty as assessed by two observers experienced in quantitative coronary angiography and by automated measurement by means of the Cardiovascular Angiographic Analysis System (CAAS) was compared. Two hundred twenty-seven still frames were selected for analysis by CAAS and displayed for assessment by each of the observers, who were unaware of CAAS results. Comparisons with CAAS measurements were made for all still frames ("per view" analyses) and for each coronary stenosis after averaging the values obtained for a given coronary segment ("per stenosis" analyses). Intraobserver variability was tested on 21 still frames from 10 stenoses, assessed 6 weeks apart by one observer. Intraobserver variability was 5% (r = 0.98); interobserver variability was 6% (r = 0.94). Per view analyses showed that observer measurements correlated well with CAAS measurements (r = 0.89 and r = 0.90); the accuracy was -0.9% and -0.7% for observers 1 and 2, and the precision was 9% and 8%, respectively; for per stenosis analyses, the accuracy was -0.5% and -0.8% (r = 0.92 and 0.94) and the precision 7% and 6%, respectively. There was no difference in the accuracy and precision of visual assessment for lesions with < 50%- or > 50%-diameter stenoses. The occurrence of restenosis was likewise detected visually with a high sensitivity and specificity compared with CAAS.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1993

Cardioprotective effect of intracoronary nifedipine during percutaneous transluminal coronary angioplasty. A French double-blind cross-over multicentre study.

The aim of this double-blind, placebo-controlled, cross-over study was to assess the cardioprotective effect of intracoronary nifedipine during percutaneous transluminal coronary angioplasty balloon occlusion. A balloon inflation without drug injection was initially made to ascertain that a shift of the ST segment (> or = 2 mm, 0.08 s after the J point) appeared (inclusion criterion). Two other balloon inflations were preceded by intracoronary injection of either 0.2 mg nifedipine or placebo, distal to the stenosis through the balloon catheter. The evaluation criteria were (1) time to ST segment shift, and (2) maximal amplitude of ST segment shift caused by balloon occlusion. Comparison of the data used an analysis of variance. Sixty-seven patients (mean age 54 +/- 8 years; 54 male, 13 female) were studied; 50 patients had 1-, 16 patients 2- and 1 patient 3-vessel disease. The dilated vessel was the left anterior descending coronary artery (n = 51), the right coronary artery (n = 12) and the left circumflex coronary artery (n = 4). Balloon inflation time was 100 +/- 31 s in the nifedipine group and 93 +/- 29 s in the placebo group. Five patients were excluded (procedure stopped after the first inflation in 1 and ST segment shift < 2 mm during the first inflation in 4). The time to 2-mm ST segment shift was longer in the nifedipine group than in the placebo group (62 +/- 40 s versus 51 +/- 40 s, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Alcohol consumption and primary dilated cardiomyopathy. Comparison with a population of patients with coronary disease].

Alcohol consumption was compared between 23 men admitted to hospital with idiopathic dilated myocardiopathy (DCM) and 46 men with coronary artery disease. Duration of regular daily alcohol, heavy daily alcohol, mean daily alcohol consumption, in particular consumption of wine were higher in patients with DCM. Among the biological markers, only serum levels of immunoglobulin A and bilirubin were increased in pts with DCM.

Alcohol Drinking↗
PubMed1993

Radionuclide assessment of regional differences in left ventricular wall motion and myocardial perfusion in idiopathic dilated cardiomyopathy.

Regional variations in left ventricular contractility and myocardial perfusion are frequent in idiopathic dilated cardiomyopathy and might result from an increase in left ventricular wall stress responsible for regional wall motion abnormalities. The aim of the study was to perform radionuclide studies in patients with idiopathic dilated cardiomyopathy to assess regional left ventricular wall motion and myocardial perfusion abnormalities in this myocardial disease. We studied 29 men referred with idiopathic dilated cardiomyopathy and normal coronary angiograms. Rest radionuclide left ventriculography and exercise thallium-201 tomography were performed in all patients. The thallium-201 tomograms were divided into 20 segments for each patient. Mean left ventricular ejection fraction was 27 +/- 11%; 17 patients had diffuse hypokinesia (mean left ventricular ejection fraction: 24 +/- 9%) and 12 patients had predominant regional hypokinesia (mean left ventricular ejection fraction: 32 +/- 12%). Of all 580 tomographic segments, 186 had a reduction of thallium-201 uptake at exercise. Among them, reversibility was found in 53%. On the whole, 68% (158/232) of anterior, inferior and apical segments had a perfusion abnormality, compared with 8% (28/348) of septal and lateral segments (P < 0.0001). Left ventricular wall motion and myocardial perfusion abnormalities are heterogeneous and not evenly distributed in dilated cardiomyopathy. The alterations are predominant on the myocardial regions delineating the antero-posterior axis of the left ventricle. These findings suggest the possible role of increased left ventricular wall stress on this axis.

Cardiomyopathy, Dilated↗
PubMed1993

Luminal narrowing after percutaneous transluminal coronary angioplasty. A study of clinical, procedural, and lesional factors related to long-term angiographic outcome. Coronary Artery Restenosis Prevention on Repeated Thromboxane Antagonism (CARPORT) Study Group.

BACKGROUND: The renarrowing process after successful percutaneous transluminal coronary angioplasty (PTCA) is now believed to be caused by a response-to-injury vessel wall reaction. The magnitude of this process can be assessed by the change in minimal lumen diameter (MLD) at follow-up angiography. The aim of the present study was to find independent patient-related, lesion-related, and procedure-related risk factors for this luminal narrowing process. A model that accurately predicts the amount of luminal narrowing could be an aid in patient or lesion selection for the procedure, and it could improve assessment of medium-term (6 months) prognosis. Modification or control of the identified risk factors could reduce overall restenosis rates, and it could assist in the selection of patients at risk for a large loss in lumen diameter. This population could then constitute the target population for pharmacological intervention studies. METHODS AND RESULTS: Quantitative angiography was performed on 666 successfully dilated lesions at angioplasty and at 6-month follow-up. Multivariate linear regression analysis was performed to obtain variables with an independent contribution to the prediction of the absolute change in minimal lumen diameter. Diabetes mellitus, duration of angina < 2.3 months, gain in MLD at angioplasty, pre-PTCA MLD, lesion length > or = 6.8 mm, and thrombus after PTCA were independently predictive of change in MLD. Overall prediction of the model was poor, however, percentage-correct classification for a predicted change between -0.1 to -0.4 mm was approximately 10%. Lesions showing no change or regression (change > -0.1 mm) and lesions showing large progression (< or = -0.4 mm) were more predictable (correct classification, 59.5% and 49.7%, respectively). CONCLUSIONS: Renarrowing after successful PTCA as determined with contrast angiography is a process that cannot be accurately predicted by simple clinical, morphological, and lesion characteristics.

Angioplasty, Balloon, Coronary↗