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T L De Backer

Publications and source records attributed to T L De Backer.

10 recordsLinked to original sources
PubMed2001

Buflomedil for intermittent claudication.

BACKGROUND: Intermittent claudication is pain, caused by chronic occlusive arterial disease, that develops in a limb during exercise and is relieved with rest. Buflomedil is a vasoactive agent claimed to have beneficial effects on the microcirculation. It is used chiefly to treat peripheral vascular disease and to a lesser extent for cerebrovascular arterial disease. However, its clinical efficacy for intermittent claudication has not yet been critically examined. OBJECTIVES: To evaluate the available evidence on the efficacy of buflomedil for intermittent claudication. SEARCH STRATEGY: We searched Medline, International Pharmaceutical Abstracts (IPA) and the Cochrane Controlled Trials Register. Abbott Laboratories, the distributor of buflomedil, was asked to provide reports of controlled clinical trials. Reference lists of retrieved articles were checked, and enquiries sent to authors of known trials, to identify additional trials. Finally, we conducted a Science Citation Index search. SELECTION CRITERIA: Trial reports had to be double-blinded, randomized, and conformed to our PIO-criteria (Patients, Intervention, Outcome) to be considered for inclusion. Patients were required to have proven intermittent claudication (Fontaine stage II); the intervention was to be oral administration of buflomedil compared to placebo; and outcomes had to include pain-free walking distance (PFWD) and maximum walking distance (MWD) analysed by standardized exercise test. DATA COLLECTION AND ANALYSIS: Searches of bibliographic databases yielded three eligible randomized controlled trials (RCTs) and a meta-analysis referring to nine eligible trials. Two of these nine trials had already been identified; two had been published in journals not referenced in traditional bibliographic indexes; and five were unpublished. Despite multiple requests, only one of the five unpublished trials was provided by the author of the meta-analysis, the other four could not be retrieved. Four of the six eligible trials retrieved were subsequently excluded after quality evaluation. Data on walking distances were extracted from the two remaining trials. Differences in incremental gain between active and placebo groups for PFWD and MWD with their confidence intervals were calculated. MAIN RESULTS: Both RCTs showed moderate improvements in PFWD for patients on buflomedil. In one trial this improvement (75 m, 95% CI 37-114) was statistically significant, but in the other, with a wholly diabetic population, it was non-significant (81m, 95% CI -9-170) compared to placebo. For both RCTs the gains in MWD were statistically significant, but with wide confidence intervals (81 m, 95% CI 30-131; and 171 m, 95% CI 27-316 respectively). Pooling of the data was not attempted. REVIEWER'S CONCLUSIONS: There is little evidence available to evaluate the efficacy of buflomedil for intermittent claudication. Most available trials are of poor quality and were excluded. The two trials included showed moderately positive results but these are undermined by publication bias since we know of another four unpublished, irretrievable, and inconclusive studies. There is a lack evidence for the efficacy of buflomedil in intermittent claudication.

Administration, Oral↗
PubMed2001

Current management of primary pulmonary hypertension.

Primary pulmonary hypertension (PPH) is a rare disorder of the lung vasculature characterised by an increase in pulmonary artery pressure. Although the aetiology of this disease remains unknown, knowledge of the pathophysiology of the disease has advanced considerably. Diagnosis of PPH is largely by exclusion. The clinical symptoms associated with PPH are aspecific and similar to those seen in other cardiovascular and pulmonary diseases. Electrocardiography, echocardiography, pulmonary function tests, and a lung perfusion scan are necessary to exclude secondary forms of pulmonary hypertension and also help to confirm the diagnosis of PPH. A definite diagnosis of PPH is established by right-heart catheterisation which gives a precise measure of the blood pressure in the right side of the heart and the pulmonary artery, right ventricular function and cardiac output. Once a diagnosis of PPH is established, treatment involving drug therapy or surgery is commenced on the basis of the New York Heart Association functional class. Conventional treatment consists of lifetime administration of anticoagulants, oxygen, diuretics, and digoxin. Vasodilator therapy with calcium channel antagonists is indicated in patients who are 'vasoreactive' to acute vasodilator challenge as assessed by right-heart catheterisation. Promising results are obtained by continuous intravenous administration of epoprostenol (prostacyclin). Newer therapies for PPH include prostacyclin analogues, endothelin receptor antagonists, nitric oxide, phosphodiesterase-5 inhibitors, elastase inhibitors, and gene therapy. Surgical treatment consists of atrial septostomy, thromboendarterectomy, and lung or heart-lung transplantation.

Humans↗
PubMed2000

Oral vasoactive medication in intermittent claudication: utile or futile?

OBJECTIVE: To evaluate the role of orally administered vasoactive medication in the management of intermittent claudication. SETTING: We limited our study to the products on the market in Belgium: cinnarizine, cyclandelate, isoxsuprine, naftidrofuryl, pentoxifylline, xanthinol nicotinate and buflomedil. DATA SOURCES: We conducted a systematic literature search involving Medline, International Pharmaceutical Abstracts, the Cochrane Library, direct contact with marketing companies and key authors, snowballing and Science Citation Index search. We looked for randomised placebo-controlled trials (RCTs) in patients with Fontaine stage II, in which pain-free and/or maximal walking distance were measured using a standardised exercise test. For isoxsuprine and xanthinol nicotinate, no trials conforming to these criteria were found. Thirty-six trials on cinnarizine, cyclandelate, buflomedil, naftidrofuryl and pentoxifylline met our inclusion criteria. STUDY SELECTION: After quality assessment, 26 trials were excluded, mainly because of short trial duration (less than 12 weeks), small sample size (less than 30 patients) and/or failure to report details on variability (standard deviation or confidence limits). For cinnarizine and cyclandelate, none of the three selected RCTs was included. DATA EXTRACTION: For buflomedil, of six published RCTs, two were included after quality assessment, each showing a marginally positive effect of buflomedil versus placebo. For naftidrofuryl, nine RCTs were selected; six were included of which five showed a significant positive result. The likelihood of publication bias and the heterogeneity of the results within and between trials precluded a meta-analysis. For pentoxifylline, of the 18 selected RCTs, only two could be included, both with inconclusive results. CONCLUSION: A national consensus conference, based on this review, concluded that health resources should be allocated to prevention and rehabilitation of intermittent claudication rather than to reimbursement of these products with doubtful efficacy.

Administration, Oral↗
PubMed2000

Relationship between arterial elasticity indices and carotid artery intima-media thickness.

Functional and structural changes of the arterial wall appear to serve as early hallmarks of the hypertensive disease process. Structural vascular changes can be studied by the determination of the intima-media wall thickness (IMT) at the carotid artery. The elastic behavior of the proximal and distal parts of the arterial tree can be assessed from noninvasively recorded radial artery waveforms. The aim of the study was to compare large (proximal, C1) and small (distal, C2) artery elasticity indices in two age-matched study groups with high- and low-normal blood pressure (BP) and to assess the relation between elasticity indices and IMT. A total number of 22 subjects with high-normal BP (40 +/- 2 years; BP, 147 +/- 2.5/84 +/- 1.5 mm Hg) and 22 matched controls with low-normal BP (40 +/- 2 years; BP, 123 +/- 1.9/69 +/- 1.5 mm Hg) were enrolled. The IMT was echographically determined at the common carotid artery by the leading-edge technique. Large artery (C1) and small artery (C2) elasticity indices were calculated from a third-order, four-element model of the arterial circulation. In the group with high-normal BP large and small artery elasticity indices were significantly decreased versus controls with low-normal BP (C1: 1.63 +/- 0.08 v 1.99 +/- 0.09 mL/mm Hg, P < .01; C2: 0.059 +/- 0.005 v 0.076 +/- 0.007 mL/ mm Hg, P < .05) and IMT increased significantly (0.607 +/- 0.039 v 0.516 +/- 0.027 mm, P < .05). Moreover, there was an inverse relationship between IMT and small artery elasticity index (r = -0.60, P = .004). In subjects with a high-normal BP there is already a change in the IMT of the carotid artery versus normotension. The IMT is related to the small artery elasticity index (C2).

Adult↗
PubMed2000

Cardiac involvement in pheochromocytoma.

We report the details of a 40-year-old farmer, a cigarette smoker, who was admitted with general malaise, nausea, vomiting, upper abdominal pain, with ST-elevation on ECG suggestive of an acute anterolateral myocardial infarction. He was treated with nitrates, heparin, beta-blockade and angiotensin-converting enzyme (ACE) inhibitors. Because of the presence of some blood while vomiting no thrombolysis was given and abdominal echography was performed. This revealed a nodular mass at the right adrenal gland. Urinary catecholamines and abdominal magnetic resonance imaging confirmed the suspected diagnosis of pheochromocytoma. Before adrenectomy, a coronary angiography under alpha blocker therapy was performed, which demonstrated no significant coronary artery disease, although the patient showed ST-elevations on ECG. Pathological examination of the adrenal tumor was compatible with a diagnosis of pheochromocytoma. Postoperatively urinary catecholamines dropped dramatically, and the ECG normalised slowly over time. After 8 months the patient is still well. Blood pressure is well controlled with no antihypertensive drugs and exercise testing shows no evidence of myocardial ischaemia.

Adrenal Gland Neoplasms↗
PubMed1999

Primary pulmonary hypertension with fatal outcome in a young woman and review of the literature.

A 32-year-old female is described, who was admitted with symptoms of severe right heart failure. The most likely diagnosis of pulmonary embolism was excluded. Echocardiography and left-right catheterisation confirmed the diagnosis of primary pulmonary hypertension. A possible mediator in the process of PPH could be the appetite suppressants she had taken for some months after her second pregnancy. Before further pharmacologic tests could be performed the patient died in circulatory collapse. Postmortem pathological examination confirmed the diagnosis of PPH by the presence of narrowed pulmonary arterioles, media hypertrophy, thrombotic lesions and normal surrounding pulmonary parenchyma. The literature on primary pulmonary hypertension is revised with special emphasis on diagnosis and treatment algorithms.

Adult↗
PubMed1993

Influence of arterial blood pressure and aldosterone on left ventricular hypertrophy in moderate essential hypertension.

In a group of 36 untreated patients with mild-to-moderate essential hypertension (office systolic blood pressure [SBP] 160 +/- 3.4 mm Hg, office diastolic blood pressure [DBP], 102 +/- 1.5 mm Hg), 24-hour ambulatory blood pressure monitoring, and determination of left ventricular (LV) mass index according to the formula of Devereux were performed. After an overnight fast, blood samples were taken for the determination of serum aldosterone levels and plasma renin activity. Urinary catecholamine concentrations were assayed from 24-hour urine collections. Left ventricular mass index (143.7 +/- 8 g/m2) did not correlate significantly with either office SBP or office DBP. The correlation of LV mass index with mean 24-hour SBP (145 +/- 3 mm Hg) was statistically significant: r = 0.395, p = 0.026. However, the best correlation was obtained with mean 24-hour DBP (90 +/- 3 mm Hg) with r = 0.499 (p = 0.004). Urinary catecholamine levels did not correlate with LV mass index. In addition, LV mass index correlated significantly with plasma renin activity (r = 0.346, p = 0.050) and serum aldosterone levels (r = 0.559, p = 0.0009). There was a strongly significant correlation between LV mass index and serum aldosterone levels even after adjustment for mean 24-hour SBP (r = 0.496, p = 0.005) and DBP (r = 0.514, p = 0.004). These results demonstrate that ambulatory blood pressure determinations but not office blood pressure parameters correlate well with left ventricular hypertrophy in essential hypertension. Nonhemodynamic factors are important determinants of left ventricular mass as well.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Influence of the arterial blood pressure and nonhemodynamic factors on left ventricular hypertrophy in moderate essential hypertension.

In a group of 36 untreated patients with mild to moderate essential hypertension (office systolic and diastolic blood pressures (BPs) 160 +/- 3.4 and 102 +/- 1.5 mm Hg, respectively), a 24-hour ambulatory BP monitoring and determination of left ventricular (LV) mass index according to the formula of Devereux were performed. After an overnight fast, blood samples were taken for the determination of serum aldosterone, plasma renin activity and serum parathyroid hormone. Urinary catecholamines were sampled for 24 hours. LV mass index (143.7 +/- 8 g/m2) did not correlate significantly either with office systolic or diastolic BP. The correlation of LV mass index with mean 24-hour systolic BP (145 +/- 3 mm Hg) was statistically significant: r = 0.395, p = 0.026. However, the best correlation was obtained with mean 24-hour diastolic BP (90 +/- 3 mm Hg) with r = 0.500 (p = 0.004). Urinary catecholamines were not correlated with LV mass index. LV mass index correlated significantly with plasma renin activity (r = 0.346, p = 0.050), and aldosterone (r = 0.559, p = 0.001). There was a very significant correlation between LV mass index and parathyroid hormone (r = 0.719, p = 0.00001) even after adjustment for mean 24-hour systolic and diastolic BPs. These results clearly demonstrate that ambulatory BP determinants but not office BP parameters are well correlated with LV hypertrophy in essential hypertension. Nonhemodynamic factors are important determinants of LV mass as well. Besides the renin-angiotensin-aldosterone system, parathyroid hormone appears to play an important role in cardiac hypertrophy.

Adult↗