Biomedical subjects
Publications and source records attributed to R Ligon.
Combination lovastatin and probucol reduced total cholesterol (27%) and low-density lipoprotein levels (30%), but did not prevent restenosis or clinical events during the first 6 months after percutaneous transluminal coronary angioplasty.
The Learning Resources Center of the University of California, San Diego School of Medicine has begun to investigate the potential of virtual reality (VR) as a tool for medical education. We are currently integrating VR with communications, animation, and visualization technologies to form a hybrid learning and training environment. Our program development reflects a curriculum-based strategy with emphasis on instructional objectives and educational outcomes. Demonstrated need, feasibility of a technology-based solution, and appropriateness of resource allocation are primary considerations. As the VR world is built, comparative analyses are being made of control strategies, display options, and interface design.
Patients with multivessel coronary artery disease and left ventricular dysfunction represent a high-risk subgroup in whom coronary artery bypass grafting has been shown to improve survival compared with that of medically treated patients. The comparative benefits and risks of coronary angioplasty and bypass surgery in this subgroup of patients are unclear. This study retrospectively analyzes 100 consecutive patients treated with bypass surgery compared with a matched, concurrent cohort of 100 treated with multivessel angioplasty. Early results favored angioplasty; a hospital stay of 12.8 days was noted in the bypass group compared with 4.3 days in the angioplasty group (p < 0.001). In-hospital mortality rates were similar in the bypass (5%) and angioplasty (3%) groups (p = NS). Stroke was observed significantly more often in the bypass group (7 vs 0%). However, late follow-up favored bypass patients; repeat revascularization procedures and late myocardial infarction occurred more frequently during follow-up in the angioplasty group. During 5-year follow-up, superior relief from disabling angina (99 vs 89%; p = 0.01) and a trend toward improved survival (76 vs 67%; p = 0.09) were observed in the bypass group as compared with the angioplasty group. Multivariate correlates of late mortality included age and incomplete revascularization, but not mode of revascularization. Thus, in patients with multivessel coronary artery disease and left ventricular dysfunction, early results favor angioplasty, whereas late follow-up favors bypass surgery. However, late survival was similar in both groups of patients who were completely revascularized.
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The efficacy and risk of reperfusion strategies for myocardial infarction in patients with prior coronary artery bypass surgery are uncertain. In this study 72 patients with prior bypass grafting underwent direct percutaneous transluminal coronary angioplasty without antecedent thrombolytic therapy. There were 26 anterior and 46 inferior infarctions, including 11 patients (15%) in cardiogenic shock. The baseline ejection fraction was less than 40% in 47 (65%) patients. Angioplasty was successful in 41 of 48 (85%) vein grafts and 24 of 24 (100%) arteries (difference not significant) at 5.1 +/- 4.0 hours from the onset of symptoms (79% treated less than 6 hours). There were no urgent bypass operations, strokes or transfusions. In-hospital survival was 90% (nonshock 95% vs shock 64%, p less than 0.01). Symptomatic acute reclosure occurred in 1 patient. Predischarge coronary arteriography in 34 patients demonstrated continued vessel patency in 32 infarct vessels (94%), although 5 of these vessels were redilated for restenoses. Predischarge paired ventriculography in 26 patients showed an increase in ejection fraction from 44 +/- 16% to 51 +/- 18% (p less than 0.01). One- and 3-year actuarial survival was 89 and 87%. Thus, prior coronary surgery should not preclude reperfusion therapy by direct angioplasty, which can be accomplished with low procedural risk, improvements in ventricular function and excellent in-hospital and late survival.
The influence of multivessel coronary artery disease on the outcome of reperfusion therapy for myocardial infarction has not been fully characterized. Direct coronary angioplasty without antecedent thrombolytic therapy was performed during evolving myocardial infarction in 285 patients with multivessel coronary artery disease at 5.2 +/- 4.2 h after the onset of chest pain. Two vessel disease was present in 163 patients (57%) and three vessel disease in 122 (43%). An anterior infarct was present in 123 patients (43%), cardiogenic shock in 33 (12%) and age greater than or equal to 70 years in 59 (21%). Angioplasty of the infarct-related vessel was successful in 256 patients (90%), including 92% with two vessel and 88% with three vessel disease (p = NS). Emergency bypass surgery was needed in six patients (2%). In-hospital death occurred in 33 patients (12%), including 13 with two vessel and 20 with three vessel disease (p less than 0.05). The mortality rate was only 4% in the subgroup of 101 patients who met entry criteria for thrombolytic trials. The in-hospital mortality rate was 45% in patients in shock and 7% in patients not in shock (p less than 0.01). Logistic regression analysis identified shock and age greater than or equal to 70 years as independently associated with in-hospital death. In 135 patients who underwent predischarge left ventriculography, global ejection fraction increased from 50% to 57% (p less than 0.001) and regional wall motion in the infarct zone improved in 59% of patients. Follow-up data were available in 251 patients (99%) at a mean of 35 +/- 19 months.(ABSTRACT TRUNCATED AT 250 WORDS)
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Between June 1982 and August 1987, 45 patients underwent percutaneous transluminal coronary angioplasty within the internal mammary artery graft (group 1) or had coronary angioplasty performed beyond the graft insertion with the internal mammary artery used as a conduit (group 2). Previous coronary artery bypass surgery was performed at a mean of 29.8 months (range 2 to 199) in group 1 and 51.3 months (range 2 to 134) in group 2. Sixteen (62%) of 26 patients in group 1 and 17 (71%) of 24 patients in group 2 had multivessel angioplasty; multilesion angioplasty was performed in 20 patients (77%) in group 1 and in 19 patients (79%) in group 2. Within group 1, 12 (37.5%) of 32 lesions were in the body of the internal mammary artery graft and 20 lesions (62.5%) occurred at the distal anastomosis. Angioplasty was successful in 30 (94%) of 32 attempts in group 1 and in 25 (96%) of 26 attempts in group 2. Procedure-related complications were limited to emergent bypass surgery in one patient in group 2. At a mean follow-up period of 12.7 months in group 1 and 18.2 months in group 2, 39 (90%) of the 45 patients had no or only mild angina. There were two late cardiac deaths (mortality rate 4.9%) in the 41 patients with successful angioplasty. The results of this study demonstrate that percutaneous transluminal coronary angioplasty of internal mammary artery grafts combined with multilesion angioplasty is technically feasible, can be performed with a high primary success rate and a low incidence of complications and achieves sustained clinical improvement in the majority of patients.