Showing papers by "Richard E. Shaw published in 1989"
TL;DR: Advances in technology and operator experience, and increased use of angiography early after myocardial infarction have led to greater use of percutaneous transluminal coronary angioplasty (PTCA) for chronic, total coronary artery occlusions, to better assess long-term outcome.
Abstract: Advances in technology and operator experience, and increased use of angiography early after myocardial infarction have led to greater use of percutaneous transluminal coronary angioplasty (PTCA) for chronic, total coronary artery occlusions. To better assess long-term outcome, 257 consecutive patients with successful PTCA of a total occlusion with late angiographic follow-up from 484 patients (53%) with PTCA success were reviewed. The mean ± standard deviation patient age was 54 ± 10 years, 79% were men, the duration of total occlusion was 11 ± 15 weeks and the post-PTCA diameter stenosis was 24 ± 12%. Eighty-two, 27 and 63% of patients received long-term aspirin, dipyridamole and warfarin therapy, respectively. Angiography at 8 ± 8 months demonstrated restenosis (≥50% diameter stenosis) in 41% of patients restudied within 6 months and in 66% of patients restudied within 12 months by life table analysis. In multivariate regression analysis of 19 variables, 2 were independently correlated with the occurrence of restenosis: post-PTCA diameter stenosis > 30% (p = 0.02) and coronary artery dilated (left anterior descending and right coronary arteries greater than the left circumflex coronary artery) (p = 0.05). In log rank analysis that also considered the timing of angiographic detection of restenosis, dilatation of a proximal left anterior descending stenosis was also a significant predictor of restenosis (p = 0.01), and dilatation within 4 weeks of the presumed time of occlusion was only weakly predictive (p = 0.11). Thirty-five patients (27% of those with restenosis) had reocclusion at the site of PTCA, but only 3 patients (2%) had an associated myocardial infarction. There was no relative beneficial effect of any treatment on the risk of restenosis. Thus, (1) restenosis after PTCA of chronic total occlusion is very common; (2) restenosis is predicted by the angioplasty results and angioplasty site; (3) the clinical detection of restenosis does not appear to plateau at 6 months; (4) reocclusion is not uncommon, but seldom results in myocardial infarction; and (5) there was no apparent relative treatment effect of aspirin, dipyridamole or warfarin.
115 citations
TL;DR: Patients with silent and painful ischemia during exercise have similar amounts of ischemic myocardium demonstrated by tomographic thallium-201 imaging and similar extent of angiographically documented coronary artery disease despite the absence of pain and the lower incidence of positive exercise ECG findings in silent ischemIA.
67 citations
TL;DR: The concept that intracoronary stenting may reduce restenosis is based largely on the supposition that, by forcing and maintaining the obstructive atheroma out of the normal arterial lumen, turbulence and hence platelet deposition would be reduced and a large amount of myointimal proliferation would be required to recreate an obstruction of physiologic consequence.
Abstract: The incidence of restenosis after coronary angioplasty for treatment of chronic total coronary occlusion is unacceptably high. 1 The pathophysiology of restenosis after coronary angioplasty may be conceptually divided into an exuberant myointimal proliferation, 2 and a residual partial obstruction that serves as a platform for atheroma regrowth and may potentiate that process by augmenting blood flow turbulence and platelet deposition. The techniques of atherectomy or laser ablation 3 may lessen the likelihood of restenosis by minimizing the residual stenosis, although currently each may require supplemental balloon angioplasty to achieve this result. However, the effect of these techniques on later myointimal proliferation in human beings is largely unknown. The concept that intracoronary stenting 4 may reduce restenosis is based largely on the supposition that, by forcing and maintaining the obstructive atheroma out of the normal arterial lumen, turbulence and hence platelet deposition would be reduced 5 and a large amount of myointimal proliferation would be required to recreate an obstruction of physiologic consequence.
8 citations
TL;DR: It is important that this paradigm (or a similar classification schema) be adopted to assist clinicians in making judgments about alternative approaches in patients with multivessel disease and to provide a common organization for the dissemination of research findings and collaboration among members of the medical community.
4 citations