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N Meneveau

Publications and source records attributed to N Meneveau.

34 records · Page 2Linked to original sources
PubMed1997

Streptokinase vs alteplase in massive pulmonary embolism. A randomized trial assessing right heart haemodynamics and pulmonary vascular obstruction.

OBJECTIVE: The aim of the study was to test the efficacy of recombinant tissue plasminogen activator and streptokinase in massive pulmonary embolism, the primary endpoints being haemodynamic improvement and thrombus lysis, and the secondary endpoints efficacy and safety. DESIGN: Fifty patients with massive pulmonary embolism were randomly allocated either to a 100 mg 2 h infusion of recombinant tissue plasminogen activator followed by a 20 IU.kg-1.h-1 infusion of heparin, or to a 100,000 IU.h-1 12 h infusion of streptokinase after a initial bolus of 250,000 IU over 15 min, followed by heparin infusion of 10 IU.kg-1.h-1. Total pulmonary resistance and right ventricular ejection fraction were monitored over a 12 h period. Pulmonary vascular obstruction was assessed at 24 to 48 h and 10 days after thrombolytic therapy. RESULTS: Thrombolysis occurred more rapidly with recombinant tissue plasminogen activator than with streptokinase, but without any significant difference in terms of right heart haemodynamics at 12 h or in improvement of pulmonary vascular obstruction at 24-48 h or at 10 days. There was no significant difference in bleeding complication rates and no patients suffered intracranial haemorrhage. CONCLUSION: These results proved that, when the full dose of streptokinase has been given over 12 h, its efficacy is as good as that of 2 h of recombinant tissue plasminogen. A further trial aimed at comparing recombinant tissue plasminogen activator and streptokinase infused over a 2 h period is needed to determine whether a similar efficacy can be obtained.

Aged↗
PubMed1997

Influence of late reopening of the infarct-related artery on left ventricular remodelling after myocardial infarction. IRIS Study Group.

AIMS: This trial was undertaken to assess the impact of late reopening of the infarct-related artery on left ventricular remodelling in post-myocardial infarction patients. METHODS: One hundred and fifty seven patients with recent myocardial infarction were routinely submitted to delayed (second week) catheterization. They also underwent systematic angioplasty of a significantly narrowed infarct-related artery with a suitable anatomy, or reopening of a totally occluded infarct-related artery, and repeat follow-up catheterization after 4 months. Changes in left ventricular ejection fraction, left ventricular volumes, and percent of regional hypokinesia were assessed over the study period. RESULTS: One hundred and thirty-two patients had two interpretable left ventriculograms and two interpretable coronary angiograms. At initial angiography, 56 out of 96 patients with a patent infarct-related artery were successfully submitted to percutaneous coronary angioplasty, of whom 25 had restenosis and eight had total reocclusion at follow-up angiography. Percutaneous transluminal coronary angioplasty was not attempted in the remaining 40 patients due to unsuitable anatomy in 18 or a nonsignificant lesion in 22. The infarct-related artery was totally occluded in 36 patients at initial angiography, and successfully reopened by means of angioplasty in 19, of whom seven showed a reocclusion at follow-up angiography. The independent predictors of left ventricular enlargement, identified by means of multivariate regression analysis, were initial stroke volume index < 40 ml.m-2 (odds ratio = 6.3, 95% confidence interval = [2.5; 16.6]), initial end-systolic volume index > 50 ml.m-2 (odds ratio = 7.1, 95% confidence interval = [1.5; 25.8]), anterior infarct location (odds ratio = 4.1, 95% confidence interval = [1.4; 11.5]) and reocclusion of the infarct-related artery (odds ratio = 7.3, 95% confidence interval = [1.3; 27.3]). Angioplasty of a patent but significantly narrowed infarct-related artery was not found predictive. CONCLUSIONS: This study demonstrates that reocclusion of a previously open infarct-related artery, as well as the initial low stroke volume index, enlarged end-systolic volume index and anterior infarct location are independent predictors of long-term left ventricular enlargement. These results emphasize the impact of long-term sustained patency of the infarct-related artery on the prevention of left ventricular dysfunction. The need for a larger randomized trial is recognised.

Adrenergic beta-Antagonists↗
PubMed1997

Planimetry of aortic valve area using multiplane transoesophageal echocardiography is not a reliable method for assessing severity of aortic stenosis.

OBJECTIVE: To assess the reliability of aortic valve area planimetry by multiplane transoesophageal echocardiography (TOE) in aortic stenosis. DESIGN: Study of the diagnostic value of aortic valve area planimetry using multiplane TOE, compared with catheterisation and the continuity equation, both being considered as criterion standards. SETTING: University hospital. PATIENTS: 49 consecutive patients (29 male, 20 female, aged 44 to 82 years, average 66.6 (SD 8.5)), referred for haemodynamic evaluation of an aortic stenosis, were enrolled in a prospective study. From this sample, 37 patients were eligible for the final analysis. METHODS: Transthoracic and multiplane transoesophageal echocardiograms were performed within 24 hours before catheterisation. At transthoracic echo, aortic valve area was calculated by the continuity equation. At TOE, the image of the aortic valve opening was obtained with a 30-65 degrees rotation of the transducer. Numerical dynamic images were stored on optical discs for off-line analysis and were reviewed by two blinded observers. Catheterisation was performed in all cases and aortic valve area was calculated by the Gorlin formula. RESULTS: Feasibility of the method was 92% (48/52). The agreement between aortic valve area measured at TOE (mean 0.88 (SD 0.35) cm2) and at catheterisation (0.79 (0.24) cm2) was very poor. The same discrepancies were found between TOE and the continuity equation (0.72 (0.26) cm2). TOE planimetry overestimated aortic valve area determined by the two other methods. Predictive positive and negative values of planimetry to detect aortic valve area < 0.75 cm2 were 62% (10/16) and 43% (9/21) respectively. CONCLUSIONS: Planimetry of aortic valve area by TOE is difficult and less accurate than the continuity equation for assessing the severity of aortic stenosis.

Adult↗
PubMed1996

[Long-term outcome of subvalvular aortic stenoses. A comparative study in adults and children].

The aim of the study was to determine the medium and long-term outcome of discrete subaortic stenosis after surgery: the data of two groups of patients classified according to age (children versus adults) at the time of diagnosis were compared retrospectively. Sixteen patients, with subaortic stenosis, were followed up clinically and by annual echocardiography for an average period of 5.7 +/- 3.6 years (range 1 day to 16 years) and patients in group II were aged 43.6 +/- 6 years (range: 3 to 17 years). Patients in group I were aged 5.4 +/- 4.2 years (range: 37 to 53 years). Four patients from group II had significant aortic incompetence. All but one patient had a membranous stenosis. Seven patients from group I and all in group II underwent surgery during the follow-up period. Four of the 5 adults in Group II were asymptomatic compared with only 1 in group I. Three patients of group II developed left ventricular dysfunction during the preoperative period compared with none in group I. Four patients in group II underwent aortic valve replacement compared with none in group I. Four of the 7 operated patients in group I had recurrence of subaortic stenosis, one of which was a tunnel form. Two reoperations were necessary in group I. There were no recurrences in group II. In conclusion, the poor outcome of adult subaortic stenosis has led to early surgical referral. This attitude should be nuanced in view of the risk of recurrence and of reoperation in childhood.

Adolescent↗
PubMed1995

[Efficacy and safety of thrombolytic therapy in the elderly with severe pulmonary embolism].

Thrombolytic therapy leads to more rapid dissolution of thrombi in severe pulmonary embolism than conventional heparin therapy but is considered with much reserve in elderly patients because of the risk of haemorrhage, which is thought to be potentially greater in these subjects. The object of this study was to assess the efficacy and safety of thrombolytic therapy in patients over 70 years of age with severe pulmonary embolism, compared with patients under 70 years of age with the same condition. Eighty-nine patients with severe pulmonary embolism (Miller score > 17/34) were prescribed thrombolytic therapy in the absence of a contraindication without taking age into consideration. Fifty-three were under 70 years of age (54 +/- 15; range: 18 to 70 years) and 36 were over 70 years of age (78 +/- 5; range: 71 to 88 years). Apart from age, there was no difference in the clinical presentation of the two groups. Thrombolytic therapy was initiated with streptokinase 100,000 IU/hr for twelve hours after an initial bolus of 250,000 IU or with urokinase or plasminogen tissue activator in cases with a contraindication to streptokinase. An uncomplicated course was observed in the same percentage of cases in the two groups. The Miller score and mean pulmonary pressures fell in the same way in the two groups. Three patients died during the hospital period, two aged under 70 (3.7%) and one over 7 years of age (2.7%). Major bleeding occurred in 3 subjects under 70 (5.6%) and 5 subjects over 70 (13.8%) (p = 0.29).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Aortic valve replacement in the elderly: a comparative assay of potential risk factor modification.

From January 1989 to October 1992, 208 consecutive patients underwent isolated aortic valve replacement for calcified aortic stenosis in our department. Since the mean age of this patient population was 70 +/- 9 years, a retrospective clinical study was completed to assess the potential influence of advanced age on the independent predictors of early and late mortality. Hospital mortality was 6.2% (13 patients). Total follow up was 422.5 patient-years with a mean of 26 months. Nineteen patients died during the follow up period, equivalent to 4.5% per patient-year late mortality rate. Survival including hospital death was 88 +/- 2%, 86 +/- 2% and 79 +/- 4% at one, two and three years respectively. Eighteen variables as potential predictors of early and late mortality were studied. Predictors of hospital mortality were determined by logistic regression analysis, and those of late mortality by Cox proportional hazard model. Results were expressed as odds ratio (OR) or relative risk (RR). Age greater than 70 years (OR = 9.8, 95% CI = 1.2 to 80) and emergency surgery (OR = 8, 95% CI = 2.1 to 31) appeared as independent predictors of hospital mortality in multivariate analysis. Age above 75 years (RR = 3, 95% CI = 1.1 to 8.3), preoperative acute pulmonary edema (RR = 2.9, 95% CI = 1.1 to 7.7) and emergency surgery (RR = 4.2, 95% CI = 1.2 to 15) were independently associated with decreased late survival. Advanced functional class (NYHA III-IV) was shown to be an independent predictor of early or late mortality only in univariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Severe pulmonary embolism: value of clinical findings and complementary investigations].

Pulmonary embolism is severe when pulmonary arterial obstruction affects right heart haemodynamics and gas exchanges. The clinical signs are not very discriminating in the assessment of the severity of pulmonary embolism: shock, neurological signs and cyanosis are the most suggestive signs of severe embolism. Of the routine complementary investigations, normal blood gases does not exclude the diagnosis of even severe pulmonary embolism but when the pO2 is less than 50 mmHg the vascular obstruction is severe. The risk of haemorrhage due to thrombolysis, commonly used in severe pulmonary embolism, is greater after invasive investigations. This makes it preferable to resort to non-invasive investigation initially, echocardiography, spiral computed tomography or pulmonary scintigraphy, depending on which technique is available in an emergency. In a suggestive clinical setting, echocardiographic signs of right ventricular overload and visualisation of a thrombus in the right heart chambers or pulmonary artery on echocardiography or spiral computed tomography practically confirms the diagnosis of severe pulmonary embolism. Transoesophageal echocardiography is more sensitive than transthoracic echocardiography for the visualization of a thrombus in the pulmonary outflow tract, but is not always inoffensive in those patients in an unstable condition. Lung scintigraphy, when interpretable, provides the diagnosis of pulmonary embolism, shows the anatomic extension and allows follow-up of the outcome. However, the specificity of this investigation is problematic. Pulmonary angiography, coupled with catheterisation of the right heart, remains the reference investigation in the diagnosis of pulmonary embolism and its anatomical diffusion. It is reserved to situations in which echocardiography is difficult and scintigraphy is uninterpretable, notably in patients with previous cardiopulmonary disease.

Blood Gas Analysis↗
PubMed1995

[Complications of thrombolytic therapy in pulmonary embolism].

Thrombolysis in massive embolism is associated with a number of complications, mainly haemorrhagic, justifying an evaluation of the individual risk/benefit ratio before prescription. Major bleeding episodes, the most serious complication, are observed in 8 to 15% of cases and result from mechanisms involving the coagulation factors, platelet function and the vessel wall. In over 70% of cases, they are directly related to sites of vascular puncture, especially for the carrying out of pulmonary angiography which triples the haemorrhagic risk. Uncontrolled hypertension, the prescription of active oral anticoagulants at the time of thrombolysis, low body weight, diabetes, female gender, and ages over 70 have also been identified as factors predictive of bleeding. The prevention of haemorrhage is based on strict observance of the contraindications of thrombolysis and the limitation of early vascular puncture sites, especially femoral, for pulmonary angiography. In cases of haemorrhage, treatment requires interruption of thrombolysis and heparin, the neutralisation of circulating plasmin, inactivation of plasminogen and correction of fibrinogen-induced deficits. Allergic reaction may also occur during thrombolysis, especially with the use of streptokinase. They are usually mild and be prevented by prior routine administration of steroids. The same applies to hypotensive episodes, also more common with streptokinase and rapidly reversible by transient interruption of thrombolysis.

Blood Coagulation Factors↗
PubMed1994

[Radiotherapy of cancer of the rectum].

As soon as there is a tumor extension into the perirectal fibro fatty tissue (T3 stage) the chance to cure the rectal cancer is no more than 65%. The aim of adjuvant treatment is to reduce the risk of local recurrence and metastasis. Postoperative irradiation does not have a definitive effect on local control, and its tolerance is poor; it may not be recommended. The efficacy of combined postoperative irradiation and chemotherapy has not been definitively proved. Moreover, this approach leads to high toxicities and may not be recommended routinely. On the contrary, preoperative irradiation definitely improves the local control, reducing the risk of recurrence up to 50%. It is commonly indicated as soon as the rectal cancer is at the T3 stage. The efficacy of combined preoperative irradiation and chemotherapy is under evaluation. Irradiation is also indicated for patients with rectal cancer at the first stage or as palliative treatment.

Combined Modality Therapy↗
PubMed1994

Temporal variability and correlation with geometric parameters in vasospastic angina: a quantitative angiographic study.

Long-term changes in vasocontractility were examined in 23 coronary segments from 20 patients with variant angina using computer-based quantitative coronary angiography and ergonovine provocation tests repeated at an interval of 42 +/- 14 months. Measurements of vasospasticity at the sites of fixed stenoses were compared with values predicted by an elementary geometric theory based on the assumption that the cross-sectional area of a vessel wall is constant regardless of its state of vasoconstriction. While all patients were symptomatic initially, only 11 remained symptomatic at follow-up. At the initial provocation test, the response was correctly predicted in four segments, was lower than expected in one, and was stronger in 18. At follow-up, only one of the four segments in which the response had been initially predicted correctly again showed the predicted response and the remaining three showed a response weaker than expected; the one segment which was initially hypocontractile remained hypocontractile at follow-up; and of the 18 segments which were initially hypercontractile, 12 exhibited hypercontractility again, four had the predicted value and the remaining two showed hypocontractility. In only one of 23 segments did the geometric theory predict the behaviour of vasospasticity at the site of fixed stenosis on both tests. Vasospastic responsiveness is a dynamic process demonstrating temporal variability and is not directly predicted by geometric theory.

Angina Pectoris, Variant↗
PubMed1994

[Value of blood assay of tumor markers for detecting recurrence of colorectal cancer].

Clinicians have at least 12 serial tumoral markers for the follow-up of colorectal cancer patients. The literature analysis indicates that serial carcinoembryonic antigen determination (CEA), is the most effective. The determination of other markers together with CEA does not add any benefit. CEA determination seems to be associated with a high rate of recurrence resection. However, the influence on overall survival of a planned follow-up including CEA determination is missing.

Biomarkers, Tumor↗
PubMed1993

Intracoronary pressure and flow velocity with sensor-tip guidewires: a new methodologic approach for assessment of coronary hemodynamics before and after coronary interventions.

The use of miniaturized pressure and velocity sensors mounted on angioplasty guidewires allows the simultaneous measurement of coronary blood flow velocity and transstenotic pressure gradient, 2 parameters that, combined, should perfectly characterize stenosis hemodynamics. The aim of this article is assessment of the changes in coronary blood flow velocity observed with a Doppler-tipped angioplasty guidewire in 35 patients undergoing balloon angioplasty. We also report our initial experience in 16 patients with the combined use of sensor-tip pressure and Doppler guidewires, and we discuss the application of new methodologic approaches for the study of the coronary circulation allowed by these techniques, such as the instantaneous assessment of the flow velocity/pressure and pressure gradient/flow velocity relations. Before and after angioplasty, flow velocity measurements were obtained distal to the stenosis, both in baseline conditions and after intracoronary injection of 8-12.5 mg of papaverine. The Doppler guidewire was left in place during the dilation procedure and the Doppler signal was continuously recorded during balloon inflation and after deflation to monitor the development of collateral flow, the restoration of flow after balloon deflation, the phase of postocclusive reactive hyperemia, and, incidently, the development of flow-limiting complications. Merits and pitfalls of several flow velocity parameters (average peak velocity, coronary flow velocity reserve, diastolic/systolic velocity ratio), as well as of parameters derived from the combination of pressure and velocity measurements (transstenotic pressure gradient/flow velocity relation and instantaneous diastolic hyperemic flow velocity/pressure relation) were evaluated in 35 patients with, and 37 without, significant coronary stenoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Maximal blood flow velocity in severe coronary stenoses measured with a Doppler guidewire. Limitations for the application of the continuity equation in the assessment of stenosis severity.

In vitro and animal experiments have shown that the severity of coronary stenoses can be assessed using the continuity equation if the maximal blood flow velocity of the stenotic jet is measured. The large diameter and the low range of velocities measurable without frequency aliasing with the conventional intracoronary Doppler catheters precluded the clinical application of this method for hemodynamically significant coronary stenoses in humans. This article reports the results obtained using a 12 MHz steerable angioplasty guidewire in a consecutive series of 52 patients undergoing percutaneous coronary angioplasty (61 coronary stenoses). The ratio between coronary flow velocity in a reference segment and in the stenosis was used to estimate the percent cross-sectional area stenosis. A Doppler recording suitable for quantitation was obtained in the stenotic segment in only 10 of 61 arteries (16%). The time-averaged peak velocity increased from 15 +/- 5 to 115 +/- 26 cm/sec from the reference normal segment to the stenosis. Volumetric coronary flow calculated from the product of mean flow velocity and cross-sectional area was similar in the stenosis and in the reference segment (33.2 +/- 14.9 vs 33.5 +/- 17.0 mL/min, respectively, difference not significant). The percent cross-sectional area stenosis and minimal luminal cross-sectional area derived from the Doppler velocity measurements using the continuity equation and calculated with quantitative angiography were also similar (Doppler, 86.7 +/- 5.1% and 1.00 +/- 0.48 mm2; quantitative angiography, 85.9 +/- 7.9% and 1.02 +/- 0.50 mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Safety of thrombolytic therapy in elderly patients with massive pulmonary embolism: a comparison with nonelderly patients.

OBJECTIVES: The aim of the study was to prospectively estimate the safety of thrombolytic therapy in elderly patients with massive pulmonary embolism in comparison with that in nonelderly patients. BACKGROUND: In massive pulmonary embolism, lysis of thrombi can be achieved faster with thrombolytic therapy than with conventional heparin therapy, but it is administered with great caution in elderly patients because the risk of bleeding is thought to be higher than in nonelderly patients. Yet, thrombolytic therapy might be of value in elderly patients also, in allowing potentially more rapid improvement than is achieved with conventional heparin therapy. METHODS: Eighty-nine patients with massive pulmonary embolism defined as Miller score > or = 17/34 underwent thrombolytic therapy without consideration of age if they had no contraindication for such treatment. Fifty-three patients were < or = 70 years old (mean age +/- SD 54 +/- 15 years; range 18 to 70), and 36 patients were > or = 71 years old (78 +/- 5 years; range 71 to 88). Except for mean age, there were no significant differences between the two treatment groups, particularly in terms of clinical presentation, average Miller score and pulmonary artery pressure regimen. Thrombolytic therapy was administered in the form of streptokinase at a dose of 100,000 IU/h over 12 h, with an initial injection of 250,000 IU over 15 min. Heparin was introduced 12 h after initiation of thrombolytic therapy. Urokinase or tissue-type plasminogen activator was used only in case of contraindication to streptokinase. RESULTS: The frequency of uncomplicated clinical course was the same in both treatment groups. Surgical embolectomy was necessary in three nonelderly patients (5.6%) and one elderly patient (2.7%). Changes in pulmonary pressure regimen and Miller score were identical in both groups. Three patients died during the in-hospital course: two nonelderly patients (3.7%) and one elderly patient (2.7%). Minor bleeding occurred in five nonelderly (9.4%) and five elderly (13.8%) patients (p = 0.74). Major bleeding was observed in three nonelderly (5.6%) and five elderly (13.8%) patients (p = 0.29). Bleeding subsequent to early invasive procedure accounted for six (75%) of eight patients with major bleeding: two nonelderly patients (one of whom died) and four elderly patients. No intracranial hemorrhage was observed. No predisposing factor for bleeding was identified, except the need for early vascular access for pulmonary angiography through the femoral approach or for percutaneous insertion of an intracaval device for partial interruption of the inferior vena cava. CONCLUSIONS: Thrombolytic therapy administered for massive pulmonary embolism in patients free of contraindication yields similar results and carries a similar risk for bleeding complications in elderly compared with nonelderly patients. Limiting early invasive procedures may result in less frequent major bleeding complications.

Adolescent↗
PubMed1993

[Instantaneous pressure-velocity relationship of the coronary flow, alternative to coronary reserve measurement: a feasibility study and reproducibility of the method].

Animal experimentation has shown that the instantaneous pressure-velocity of coronary blood flow in the hyperaemic phase has a linear relationship. The slope of this regression evaluates coronary reserve independently of haemodynamic variables and the X-intercept (zero flow pressure or Pf = 0) determines the intra-myocardial back pressure which could influence the regulation of coronary flow. The object of this study was to evaluate the instantaneous pressure-velocity relationship of coronary flow in clinical practice and to analyse the reproducibility of this parameter. Forty-nine patients were divided into two groups, depending on whether their coronary arteries were angiographically normal (n = 34) or atheromatous with stenosis > or = 35% of the reference diameter (n = 15). Recordings of coronary flow velocity were made with a Doppler transducer mounted on a 0.018 inch guide wire. The slope of the diastolic linear segment of the pressure-velocity relationship was determined at the peak of papaverine-induced vasodilation from 4 consecutive cycles by a regression analysis. The pressure value at 0 flow was obtained by extrapolation of the regression slope to the axis of aortic perfusion pressure. A good quality spectral recording allowing reliable analysis of the velocity profile was obtained in 88% of cases (44/49). The high values of the correlation coefficient observed with each measurement of the slope confirm the applicability of linear regression analysis to the pressure-velocity relationship. The slope of the pressure-velocity relationship was significantly lower in patients with coronary stenosis (1.7 +/- 0.7 cm/s/mmHg in normal vessels versus 0.7 +/- 0.3 cm/s/mmHg in stenotic arteries, p < 10(-4)), and, similarly, the pressure at zero flow was also reduced (36.9 +/- 16 mmHg versus 25.5 +/- 12 mmHg, p = 0.03). A statistically significant correlation was observed between the slope values and coronary flow reserve but no correlation was demonstrated between the slope and intraluminal surface area of angiographically normal coronary arteries or the slope and degree of stenosis of atheromatous vessels. The linear regression slope and the pressure at zero flow were lower when the pressure-velocity relationship was measured during long diastolic periods induced by the injection of adenosine. In addition, the curvilinear appearances of the pressure-velocity relationship observed during these long periods suggest that the linear regression model is not applicable throughout the whole range of pressures and velocities, especially for the lowest values.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗