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Biomedical subjects

G Hudon

Publications and source records attributed to G Hudon.

At least 37 records · Page 2Linked to original sources
PubMed1993

Advantages and limitations of serial coronary arteriography for the assessment of progression and regression of coronary atherosclerosis. Implications for clinical trials.

BACKGROUND: Clinical trials with angiographic end points have been used to assess whether interventions influence the evolution of coronary atherosclerosis because sample size requirements are much smaller than for trials with hard clinical end points. Further studies of the variability of the computer-assisted quantitative measurement techniques used in such studies would be useful to establish better standardized criteria for defining significant change. METHODS AND RESULTS: In 21 patients who had two arteriograms 3-189 days apart, we assessed the reproducibility of repeat quantitative measurements of 54 target lesions under four conditions: 1) same film, same frame; 2) same film, different frame; 3) same view from films obtained within 1 month; and 4) same view from films 1-6 months apart. Quantitative measurements of 2,544 stenoses were also compared with an experienced radiologist's interpretation. The standard deviation of repeat measurements of minimum diameter from the same frame was very low (0.088 mm) but increased to 0.141 mm for measurements from different frames. It did not increase further for films within 1 month but increased to 0.197 mm for films 1-6 months apart. Diameter stenosis measurements were somewhat more variable. Measurement variability for minimum diameter was independent of vessel size and stenosis severity. Experienced radiologists did not systematically overestimate or underestimate lesion severity except for mild overestimation (mean 3.3%) for stenoses > or = 70%. However, the variability between visual and quantitative measurements was two to three times higher than the variability of paired quantitative measurements from the same frame. CONCLUSIONS: Changes of 0.4 mm or more for minimum diameter and 15% or more for stenosis diameter (e.g., 30-45%), measured quantitatively, are recommended as criteria to define progression and regression. Approaches to data analysis for coronary arteriographic trials are discussed.

Clinical Trials as Topic↗
PubMed1991

Clinical, physiologic, anatomic and procedural factors predictive of restenosis after percutaneous transluminal coronary angioplasty.

In a recent prospective double-blind placebo-controlled trial, a combination of aspirin and dipyridamole was not associated with a reduction in the rate of restenosis within the 1st 6 months after coronary angioplasty. The purpose of this study was to determine whether clinical, anatomic or procedural factors were predictive of the observed restenosis rates in that prospective trial. A total of 247 patients and 280 segments underwent follow-up angiography and quantitative coronary angiographic analysis between 4 and 7 months after coronary angioplasty. Two baseline clinical characteristics--angina class and duration of angina in months--were related to the rate of restenosis by univariate analysis. Patient-related stepwise logistic regression analysis identified severity of angina as the only clinical predictor of restenosis. Three univariate baseline anatomic characteristics--percent diameter stenosis before angioplasty, stenosis greater than 10 mm in length and calcific stenosis--and two early postangioplasty characteristics--residual percent diameter stenosis and residual mean pressure gradient--were predictive of restenosis. Of these, only two--length of stenosis and residual percent diameter stenosis--were independently related to restenosis by multivariate analysis and only the former is identifiable before the procedure. It is concluded that in prospective studies in contrast to retrospective studies, few clinical and anatomic factors appear to be predictive of restenosis after coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1990

A controlled clinical trial to assess the effect of a calcium channel blocker on the progression of coronary atherosclerosis.

To determine whether calcium channel blockers influence the progression of coronary atherosclerosis, 383 patients age 65 years or less with 5-75% stenoses in at least four coronary artery segments were selected at random within 1 month of coronary arteriography to participate in double-blind therapy with a placebo or nicardipine 30 mg three times daily. Coronary events (5 deaths, 22 myocardial infarctions, and 28 unstable anginas) occurred in 28 of 192 nicardipine patients and 23 of 191 placebo patients (p = NS). At 24 months coronary arteriography was repeated in 335 patients. Progression, defined as a 10% or more worsening in diameter stenosis, measured quantitatively, was found in 147 of 1,153 lesions (12.7%) in 168 nicardipine patients and in 170 of 1,170 lesions (14.5%) in 167 placebo patients (p = NS). Ninety-two nicardipine patients (55%) and 95 placebo patients (57%) had progression at one or more sites (p = NS). Regression, that is, an improvement by 10% or more in diameter stenosis, was seen in 140 of 2,323 lesions (6.0%) overall, with no significant intergroup difference. Among the 217 patients with 411 stenoses of 20% or less in the first study, such minimal lesions progressed in only 15 of 99 nicardipine patients compared with 32 of 118 placebo patients (15% versus 27%, p = 0.046). In this subgroup, 16 of 178 minimal lesions in nicardipine patients and 38 of 233 minimal lesions in placebo patients progressed (p = 0.038). By stepwise logistic-regression analysis, baseline systolic blood pressure (p = 0.04) and the change in systolic blood pressure between baseline and 6 months (p = 0.002) correlated with progression of minimal lesions. This suggested blood pressure reduction may account for the beneficial action of nicardipine. These results suggested nicardipine has no effect on advanced coronary atherosclerosis but may retard the progression of minimal lesions.

Adult↗
PubMed1989

Comparison by quantitative angiographic assessment of coronary stenoses of one view showing the severest narrowing to two orthogonal views.

Quantitative coronary arteriographic measurements were compared in 2 orthogonal views with the view that clearly showed the stenosis at its most severe in 147 lesions from 147 patients before, immediately after and 6 months after PTCA. In 21 of 147 patients (14%), 2 views could not be measured for technical reasons, even though all angiographers had tried to film 2 views. Lesion severity was slightly worse for 1 compared with 2 views (3.3 +/- 3.3% before PTCA, 3.6 +/- 3.8% after PTCA and 3.1 +/- 3.8% at follow-up). Similarly, minimal diameter was less for 1 view (0.11 +/- 0.09 mm before PTCA, 0.15 +/- 0.12 mm after PTCA and 0.13 +/- 0.09 mm at 6 months). When this systematic difference was taken into account, the 2 methods were within +/- 0.1 mm for minimal diameter in 288 of 376 measurements (77%) and within +/- 0.2 mm in 96%. For percent diameter stenosis the 2 methods were within +/- 5% in 90% and within +/- 10% in all but 2.7% (10 of 376). Thus, for routine clinical assessment, measurement of 1 view is adequate; for research purposes orthogonal views may sometimes be required.

Angiography↗
PubMed1987

Design features of a controlled clinical trial to assess the effect of a calcium entry blocker upon the progression of coronary artery disease.

This report presents the design and methodological features of a double-blind, randomized, placebo-controlled, trial in 383 patients with coronary artery disease. The study's principal objective is to determine whether chronic treatment with a calcium entry blocker can retard the progression of coronary artery disease. The study population consists of patients with coronary artery disease and a baseline coronary arteriogram that qualifies them as being at high risk for disease progression. After satisfying all entry criteria, patients were randomized to receive either the calcium entry blocker nicardipine or placebo. All indicated concomitant medications except calcium entry blockers are permitted. Patients are being followed clinically for 24 months before undergoing a second coronary arteriogram. The effect of the treatments on a variety of clinical and angiographic parameters will be determined.

Adult↗
PubMed1987

Outpatient peripheral angioplasty: survey of complications and patients' perceptions.

We report our experience with a total of 79 peripheral angioplasties performed in 64 patients on an outpatient basis between July 1983 and April 1985. Review of the medical files and a telephone inquiry in 58 subjects (72 angioplasties) revealed no major complications, a low rate of minor complications (1.5%), and a high degree of patient satisfaction (99%).

Adult↗
PubMed1986

Percutaneous transluminal angioplasty of the lower abdominal aorta.

Percutaneous transluminal angioplasty (PTA) of the lower abdominal aorta was performed in 14 patients aged 29-66 years (mean, 50). The disease was largely isolated to the distal aorta in this group. There were 13 women and 1 man; all were heavy smokers. Initial success, defined as improved or subsided clinical symptoms, improved ankle/arm indices, and improved angiogram, was achieved in all but one patient who thrombosed at the puncture site. At a mean follow-up period of 16 months (range, 1-58), a persistent beneficial effect was maintained in all patients. These results suggest that PTA is a safe alternative to surgery in patients with signs and symptoms of aortoiliac disease secondary to a significant but short stenotic segment of the lower abdominal aorta.

Adult↗
PubMed1985

[Multifocal percutaneous transluminal coronary and aortic angioplasty. Apropos of a case].

The authors report a case of percutaneous transluminal angioplasty performed successfully in 2 stages on the right coronary artery and the abdominal aorta in a woman with a post-infarction angina and intermittent claudication. The invasive and non-invasive control investigations at 6 and 18 months after coronary dilatation confirmed good clinical results and the stability of the excellent result of the immediate postoperative angiographic control. As for the aortic dilation, the persistent functional improvement nearly 2 years later was sufficient evidence of the success of the procedure.

Angina Pectoris↗
PubMed1985

[Superior venacavography at the patient's bedside].

Acute onset of superior vena cava syndrome in critically ill patients, hours after cardiac surgery, needs angiographic documentation without delay in order to proceed with appropriate treatment. Bedside diagnostic venacavography was done for two patients in the surgical intensive care unit with a simple and safe method using a central venous catheter already in place.

Aged↗
PubMed1982

Percutaneous transluminal coronary angioplasty in patients with variant angina.

Among the first 83 patients treated with percutaneous transluminal coronary angioplasty (PTCA) at our institution, typical variant angina was recognized beforehand in five cases and was discovered within 4 months of PTCA in six others. All patients had a 65-95% proximal left anterior descending coronary artery stenosis and only one had a coronary lesion greater than 50% in other coronary arteries. Before PTCA, all patients were premedicated with calcium-antagonist drugs. Thirteen of 15 PTCAs, including three of four repeat PTCAs, were technically successful. However, variant angina recurred after successful PTCA in three of the five patients in whom it was documented beforehand and in an additional two of two patients with variant angina before a successful repeat PTCA. Overall, among the nine patients with variant angina after successful PTCA, five had restenosis at the site of PTCA and two others developed severe lesions adjacent to the site of PTCA within 4 months of the procedure. The three patients without restenosis have been treated with calcium-antagonist drugs from soon after PTCA and have remained angina-free. These results suggest that PTCA is technically feasible in patients with variant angina who have organic lesions, but symptoms due to coronary spasm usually persist or recur, often with restenosis.

Adult↗
PubMed1982

Abdominal aortic angioplasty: a case report with angiographic follow-up.

Two women with typical clinical and angiographic findings of aorto-iliac occlusive disease underwent a successful percutaneous transluminal angioplasty of a severe stenosis of the lower abdominal aorta. One of them in whom control aortograms provide information on the mechanism of balloon angioplasty is reported here.

Angiography↗