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Biomedical subjects

G Barbeau

Publications and source records attributed to G Barbeau.

18 recordsLinked to original sources
PubMed2001

Predictors of improvement in left ventricular function after percutaneous revascularization of occluded coronary arteries: a report from the Total Occlusion Study of Canada (TOSCA).

BACKGROUND: The Total Occlusion Study of Canada (TOSCA) is a multicenter, randomized trial evaluating the effect of stenting with > =1 heparin-coated stent on long-term patency after percutaneous coronary intervention by balloon angioplasty of occluded coronary arteries. The purpose of the current study was to compare the effect of stenting and balloon angioplasty on global left ventricular ejection fraction (LVEF) and regional wall motion and to examine what clinical and angiographic factors may have an effect on left ventricular function in this setting. METHODS AND RESULTS: Analysis at the core angiographic laboratory of paired baseline and follow-up left ventricular angiograms, as well as target vessel patency, was possible in 244 of 410 cases. An improvement in LVEF was observed in the entire group (59.4% +/- 11% to 61.0% +/- 11%, P =.003). The LVEF change was +1.84 +/- 7.54 in the stent group (P =.009) and 1.28 +/- 8.16 in the percutaneous transluminal coronary angioplasty group (P =.085). There was no significant intergroup difference. Patients with duration of occlusion < or =6 weeks had an improvement in LVEF (+2.98 +/- 8.68, P =.0006), whereas those with an occlusion duration of > 6 weeks had no improvement (+0.48 +/- 7.01, P not significant). Multivariate analysis revealed baseline LVEF <60%, duration of occlusion < or =6 weeks, and Canadian Cardiology Society angina class I or II to be independent predictors of improvement in LVEF. CONCLUSIONS: The restoration of coronary patency of nonacute occluded coronary arteries is associated with a small but significant improvement in regional and global left ventricular function, especially in patients with recent occlusions and depressed left ventricular function. In spite of significant effect on long-term patency, stenting of nonacute coronary occlusions does not result in significantly better left ventricular function compared with balloon angioplasty in this setting.

Angioplasty, Balloon, Coronary↗
PubMed1999

Primary stenting versus balloon angioplasty in occluded coronary arteries: the Total Occlusion Study of Canada (TOSCA).

BACKGROUND: Balloon angioplasty (PTCA) of occluded coronary arteries is limited by high rates of restenosis and reocclusion. Although stenting improves results in anatomically simple occlusions, its effect on patency and clinical outcome in a broadly selected population with occluded coronary arteries is unknown. METHODS AND RESULTS: Eighteen centers randomized 410 patients with nonacute native coronary occlusions to PTCA or primary stenting with the heparin-coated Palmaz-Schatz stent. The primary end point, failure of sustained patency, was determined at 6-month angiography. Repeat target-vessel revascularization, adverse cardiovascular events, and angiographic restenosis (>50% diameter stenosis) constituted secondary end points. Sixty percent of patients had occlusions of >6 weeks' duration, baseline flow was TIMI grade 0 in 64%, and median treated segment length was 30.5 mm. With 95.6% angiographic follow-up, primary stenting resulted in a 44% reduction in failed patency (10.9% versus 19.5%, P=0.024) and a 45% reduction in clinically driven target-vessel revascularization at 6 months (15.4% versus 8.4%, P=0.03). The incidence of adverse cardiovascular events was similar for both strategies (PTCA, 23.6%; stent, 23.3%; P=NS). Stenting resulted in a larger mean 6-month minimum lumen dimension (1.48 versus 1.23 mm, P<0.01) and a reduced binary restenosis rate (55% versus 70%, P<0.01). CONCLUSIONS: Primary stenting of broadly selected nonacute coronary occlusions is superior to PTCA alone, improving late patency and reducing restenosis and target-vessel revascularization.

Adolescent↗
PubMed1997

Clinical outcomes of patients more than one year following randomization in the Canadian Coronary Atherectomy Trial (CCAT).

BACKGROUND: The Canadian Coronary Atherectomy Trial (CCAT) assessed, in a randomized comparison, the clinical and angiographic outcomes following atherectomy with those following balloon angioplasty for the treatment of de novo lesions in the proximal one-third of the left anterior descending artery (LAD). Although the procedural success rate was somewhat higher and the postprocedure lumen larger in patients treated with atherectomy, lumen dimensions, restenosis rates and clinical outcomes were similar in the two groups at six months. To determine whether late differences emerged between the groups, clinical follow-up was obtained at a median of 18 (range 10 to 31) months after randomization. METHODS AND RESULTS: Patients were contacted monthly by telephone for the first six months. Subsequent follow-up information was obtained in 272 (99%) of the 274 randomized patients via a clinic visit or telephone interview with the patient and/or a relative. Additional information was obtained from the referring physician as required. There were no differences in adverse events between the two groups during follow-up. In patients randomized to atherectomy compared with balloon angioplasty, death occurred in 1.5% versus 2.2% (cardiac death 0.7% versus 0.7%); myocardial infarction in 5.1% versus 5.9% (Q wave 1.5% versus 1.5%); coronary bypass surgery in 13.1% versus 12.6%; and repeat target lesion intervention in 22.6% versus 21.5%. Persistent or recurrent Canadian Cardiovascular Society class III/IV angina not treated by a further intervention was present in 1.5% versus 2.2%. The combined end-point of death or nonfatal myocardial infarction occurred in nine (6.6%) versus 11 (8.1%) patients and any adverse cardiac event in 50 (36.5%) versus 53 (39.3%). Multivariate logistic regression indicated that unstable angina, reference vessel size and preprocedure minimum lumen diameter were the only variables independently associated with adverse events. CONCLUSIONS: The initial choice of directional atherectomy or balloon angioplasty had no impact on clinical outcome over a period of 18 months in this patient population. With either technique, just over 60% of patients with proximal LAD disease experienced sustained symptomatic improvement without an adverse event following a single procedure, and 80% achieved this status following a repeat percutaneous intervention.

Angioplasty, Balloon, Coronary↗
PubMed1993

A comparison of directional atherectomy with balloon angioplasty for lesions of the left anterior descending coronary artery.

BACKGROUND: Restenosis is a major limitation of coronary angioplasty. Directional coronary atherectomy was developed with the expectation that it would provide better results than angioplasty, including a lower rate of restenosis. We undertook a randomized, multicenter trial to compare the rates of restenosis for atherectomy and angioplasty when used to treat lesions of the proximal left anterior descending coronary artery. METHODS: Of 274 patients referred for first-time, non-surgical revascularization of lesions of the proximal left anterior descending coronary artery, 138 were randomly assigned to undergo atherectomy and 136 to undergo angioplasty; 257 of 265 eligible patients (97 percent) underwent follow-up angiography at a median of 5.9 months. Computer-assisted quantitative measurements of luminal dimensions were determined from the angiograms obtained before and immediately after the procedure and at follow-up. The primary end point of restenosis was defined as stenosis of more than 50 percent of the vessel's diameter at follow-up. RESULTS: Quantitative analysis showed that the procedural success rate was higher in patients who underwent atherectomy than in those who had angioplasty (94 percent vs. 88 percent, P = 0.061); there was no significant difference in the frequency of major in-hospital complications (5 percent vs. 6 percent). At follow-up, the rate of restenosis was 46 percent after atherectomy and 43 percent after angioplasty (P = 0.71). Despite a larger initial gain in the minimal luminal diameter with atherectomy (mean [+/- SD], 1.45 +/- 0.47 vs. 1.16 +/- 0.44 mm; P < 0.001), there was a larger late loss (0.79 +/- 0.61 vs. 0.47 +/- 0.64 mm; P < 0.001), resulting in a similar minimal luminal diameter in the two groups at follow-up (1.55 +/- 0.60 vs. 1.61 +/- 0.68, P = 0.44). The clinical outcomes at six months were not significantly different between the two groups. CONCLUSIONS: The role of atherectomy in percutaneous coronary revascularization remains to be fully defined. However, as compared with angioplasty, atherectomy did not result in better late angiographic or clinical outcomes in patients with lesions of the proximal left anterior descending coronary artery.

Aged↗
PubMed1990

Laser recanalization in high risk patients.

Laser recanalization was attempted in 13 patients in whom the risk of surgical therapy was increased by severe angina, infection, absent venous conduit, or recent deep venous thrombosis, and in 4 patients at high risk for limb loss due to severe infrapopliteal arterial occlusive disease. Total occlusions of the superficial femoral, tibial, or peroneal arteries were treated. Recanalization was accomplished using Argon laser power and a Spectraprobe-PLR. Two patients also required common femoral artery endarterectomy to improve inflow. Laser recanalization was successful in 9 patients (53%), and 8 (47%) had relief symptoms. None of the 4 patients with tibial and peroneal artery occlusion had successful recanalization or limb salvage. Restenosis or reocclusion developed in 4 patients during the first year after successful recanalization, but only 1 had recurrent symptoms. Limb salvage was initially achieved in 5 of 8 recanalization failures by surgical reconstruction but 3 developed graft infections requiring graft removal in 2 and amputation in 1. Thus, laser recanalization can accomplish limb salvage in selected patients whose medical or surgical risks complicate arterial bypass surgery.

Adult↗
PubMed1989

Pharmacokinetics of mexiletine in the elderly.

The effect of advancing age on the kinetics of the antiarrhythmic agent mexiletine was studied by comparing various kinetic parameters calculated after administration of a single oral dose of mexiletine hydrochloride to seven elderly and eight young healthy volunteers. The rate of absorption of the drug from the gastrointestinal tract was significantly slower in the elderly (1.37 +/- 0.51 hr-1) than in the young group (2.25 +/- 0.79 hr-1). The mean values for elimination half-life and oral clearance were 12.3 +/- 3.7 hr and 10.3 +/- 5.4 mL/min/kg respectively in the young group and 14.4 +/- 4.5 hr and 8.5 +/- 2.9 mL/min/kg respectively in the elderly group. Neither of these parameters was significantly different between the two groups. The amount of mexiletine eliminated in urine up to 48 hours postdose was identical in both groups and represented less than 5% of the administered dose. It is concluded that the age-related modifications in the kinetics of mexiletine are not clinically important during chronic administration of the drug.

Adult↗
PubMed1986

Pharmacokinetics of a sustained-release product of indomethacin in the elderly.

The pharmacokinetics of indomethacin (Indo) was studied in 10 healthy elderly male volunteers (age 67-81 years) following the oral administration of a single 75-mg dose of a sustained release form of Indo. The total and free plasma and erythrocyte concentrations of Indo were determined by a specific high-pressure liquid chromatographic method. A maximum concentration (Cmax) of 4.28 +/- (SE) 0.43 micrograms/ml was reached after 1.85 +/- 0.22 h. The area under the plasma concentration versus time curve (AUC) was 22.83 +/- 2.70 micrograms ml-1 h and the plasma elimination half-life was 4.34 +/- 0.64 h. The maximum concentration of Indo in the red blood cells was 0.123 +/- 0.013 microgram/ml and was obtained at 1.95 +/- 0.14 h after drug administration. The erythrocyte concentrations of Indo represented 2.4% of the total plasma levels of Indo whereas only 1.3% of the drug was unbound to plasma proteins. The Cmax and AUC values determined in the elderly were approximately double the values reported in young adults for the same dose.

Administration, Oral↗
PubMed1985

Pharmacokinetics of ceftazidime in elderly volunteers.

The pharmacokinetics of ceftazidime after a 1-g bolus dose were studied in six elderly volunteers and 12 young subjects. Serum and urine samples were collected in serial order for 24 h and assayed by high-pressure liquid chromatography. The ceftazidime renal clearance was reduced in elderly subjects, a symptom related to normal aging of the kidneys. The decrease in volume of distribution in the elderly group may be explained by a reduction in total body water and an increase in fat tissue. Dosage adjustment is probably not necessary for otherwise healthy elderly patients requiring ceftazidime.

Adult↗
PubMed1984

Pharmacokinetics of sulfisoxazole in young and elderly subjects.

The pharmacokinetics of sulfisoxazole was studied in 6 elderly (age 63-75 years) and 7 young (age 22-37 years) healthy nonsmoking volunteers following the oral administration of 2 g of Gantrisin. The plasma levels of sulfisoxazole obtained in the postabsorption phase were higher in the elderly subjects. There was no significant variation between the two groups of volunteers in the absorption rate constant, Cmax, bioavailability, the fraction of the dose of sulfisoxazole excreted unchanged, the area under the plasma curve of the N4-acetyl conjugate formed, and in the apparent volume of distribution of the drug. The tmax value and plasma half-life of sulfisoxazole were significantly longer, and the total body and renal clearances of the drug decreased in the elderly subjects. Diminished renal function as estimated by the creatinine clearance and urinary flow may explain the slower elimination of sulfisoxazole in the elderly subjects. Therefore, advancing age should be considered as a factor in the adjustment of sulfisoxazole dosage.

Adult↗
PubMed1982

Pharmacokinetics of nalidixic acid in old and young volunteers.

Plasma levels of active naphthyridine were measured in healthy old (mean age 77.3 years) and young (mean age 25.4 years) subjects following oral administration of 1 Gm nalidixic acid. The plasma levels of active naphthyridine, i.e., nalidixic acid and its metabolite 7-hydroxynalidixic acid, were generally higher in the old group, particularly in the elimination phase. Significant variations in the pharmacokinetic parameters were obtained between the two groups of volunteers. The plasma half-life of active naphthyridine averaged 11.5 hours in old subjects and 2.7 hours in the younger group. Diminished renal function in the geriatric group may explain the slower elimination of the drug in the old subjects. The mean values of the other parameters calculated were: apparent volume of distribution, 0.55 (old) and 0.47 (young) liter/kg body weight; area under the curve, 327.7 (old) and 156.3 (young) micrograms/ml x hr; total body clearance 2.9 (old) and 8.3 (young) liters/hr; absorption rate constant, 0.29 (old) and 0.52 (young) hr. -1

Adult↗
PubMed1981

Nalidixic acid-induced photodermatitis after minimal sun exposure.

More than 30 cases of bullous photodermatitis have already been associated with the administration of nalidixic acid. This reaction is reported in a 57-year-old woman whose sun exposure was minimal. Nalidixic acid-induced photoreactions generally occur in females; they affect mainly the dorsal surfaces of the hands, feet, and legs, and usually do not involve the face. Blistering is always reported, and erythema is common. Dosage regimen and duration of treatment have little influence on the onset and severity of the reaction, which is probably of allergic nature. Its duration may be long, from three to six weeks, reexposure to the sun may trigger the reappearance of blistering for several months, even in the absence of a drug rechallenge.

Female↗
PubMed1980

[Sexuality and medication in the elderly.].

A lot of drugs have been reported to have adverse effects on sexual functions. Interference with ejaculation in man, failure to reach orgasm in women, decreased libido can occur with any centrally acting drugs or drugs that act on the sympathetic nervous system. In fact, the incidence of adverse sexual effects of drugs is not well documented. The effects which lead to sexual dysfunction are mostly reported by patients which are themselves reluctant to discuss with their physician. Antihistaminics, antihypertensives, anticholinergics, antidepressants, antipsychotics and minor tranquilizer may have an adverse effect on sexual function. Because elderly people are prone to adverse drug effects, they arc expected to experience more side effects on their sexual life with commonly prescribed drugs than younger ones are to. Refraining drug use and attentive listening may help the patient restore his normal sexual life.

English Abstract↗
PubMedDate not supplied

Pharmacokinetics of ciprofloxacin in elderly subjects.

The pharmacokinetics of single-dose oral ciprofloxacin 500 mg was ascertained in 12 elderly and 12 young subjects. Mean age of the elderly volunteers was 75.4 years and the mean measured creatinine clearance in this group was 40.7 ml/min. Serum and saliva were collected in serial order for 24 hours (elderly) and 10 hours (young), and assayed for ciprofloxacin by high-performance liquid chromatography. The geriatric subjects had higher serum levels throughout the sampling period, with a peak level of 3.24 +/- 0.79 versus 2.26 +/- 0.75 micrograms/ml for the younger group (p less than 0.005; one-way analysis of variance). A twofold increase in the ciprofloxacin half-life may be partly explained by a decrease in the glomerular filtration rate, as shown by slower ciprofloxacin renal clearance (152.4 +/- 54.2 vs 395.6 +/- 139.0 for elderly and young subjects respectively; p less than 0.001). We concluded that in elderly patients, ciprofloxacin should be administered at an interval not less than every 12 hours to prevent accumulation and eventually toxicity.

Adult↗
PubMedDate not supplied

Pharmacological analysis of patient's charts in a long-term care hospital.

Pharmacological study of patient's medication record is a pharmaceutical task acknowledged by Quebec Pharmacy Act. Authors present here the sequence of this analysis and the selected criteria used to evaluate the drug utilization in their facility. Results show that 97 patients' medication records did not conform with screening criterion in regard to the number of drugs. Of these records 74 failed to pass the indepth criteria. Deficiencies were identified and evaluated with physicians. Pharmacist's recommendations were accepted and followed by physicians for 53% of the cases.

Drug Therapy↗