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Biomedical subjects

R E Shaw

Publications and source records attributed to R E Shaw.

At least 55 records · Page 3Linked to original sources
PubMed1990

Coronary angioplasty in young adults: initial results and late outcome.

The initial and late outcome of coronary angioplasty was studied in 148 patients less than 40 years of age (mean 36.4 +/- 3). Angioplasty was performed on a single vessel in 70% of patients and on multiple vessels in 30%; it was performed on a totally occluded vessel in 20%. Angioplasty was successful in 90.5% of patients, unsuccessful but uncomplicated in 7.4% and complicated by myocardial infarction in 0.7%, emergency bypass surgery in 0.7% and death in 0.7%. At late (mean 3.7 +/- 3 years; range 0.5 to 11.5) follow-up study after successful angioplasty, 94% of patients were alive, 79% were free of angina and 85% had returned to work; late myocardial infarction occurred in 4%. Actuarial survival at 5 years was 95%, and 85% of patients were free from death, infarction or bypass surgery. A second angioplasty was performed in 29 patients (22%) (mean 6.1 +/- 8.4 months) and was successful in 27 (93%), with no deaths. Elective coronary bypass surgery was performed in 8.5% of patients, with perioperative infarction in 9% and no deaths. By univariate analysis, late death was more likely to occur in hypertensive patients (15% versus 2.5%; p less than 0.01) and diabetic patients (21.4% versus 3.6%; p less than 0.01). Cox proportional hazard regression analysis identified hypertension (p = 0.007) and diabetes (p = 0.04) as independent time-related predictors of subsequent death. Thus, early and late results after coronary angioplasty in young adults are favorable, but certain risk factors are important predictors of outcome. Late revascularization procedures (repeat angioplasty or surgery) for restenosis or disease progression are common.

Actuarial Analysis↗
PubMed1990

Bidirectional crossover and late outcome after coronary angioplasty and bypass surgery: 8 to 11 year follow-up.

Between March 1978 and July 1981, 217 symptomatic patients underwent coronary angioplasty as an alternative to coronary bypass surgery. Angioplasty was successful in 143 patients (66%), unsuccessful but uncomplicated in 65 (30%) and complicated in 9 (4%) by one or more of the following criteria: Q wave myocardial infarction (2%), emergency surgery (4%) or death (0.5%). Late follow-up evaluation was obtained in 213 patients at a mean of 9 +/- 1 years. Of patients in whom angioplasty was successful, 59 (42%) of 140 required another revascularization procedure (repeat angioplasty in 26% and bypass surgery in 16%). The actuarial survival rate at 5, 9 and 10 years after successful angioplasty was 98%, 93% and 92%, respectively. Of the 65 patients with unsuccessful and uncomplicated angioplasty (usually as a result of technical factors), 58 underwent elective bypass surgery within 2 months and 56 survived. These 56 surgical patients were compared with the 140 patients with successful angioplasty. Univariate analysis of prognostic factors did not reveal significant differences between these two groups. At late follow-up study, the successful angioplasty and the successful surgical groups had similar rates of survival (93% versus 95%, p = NS) and of death or infarction, or both (11% versus 12.5%, p = NS). Repeat revascularization was required more frequently after successful angioplasty than after surgery (42% versus 18%, p less than 0.001). Crossover from angioplasty to surgery occurred slightly more often than from surgery to angioplasty (16% versus 12.5%, p = NS). The time to crossover from angioplasty to surgery occurred earlier than from surgery to angioplasty (mean 21 versus 76 months, p less than 0.001).

Angioplasty, Balloon, Coronary↗
PubMed1990

Coronary angioplasty after coronary bypass surgery: initial results and late outcome in 422 patients.

From 1978 to 1988, coronary angioplasty was performed in 422 patients with prior coronary artery bypass surgery (264 patients with native coronary artery angioplasty and 158 patients with graft angioplasty). Angioplasty was successful in 84%, unsuccessful but uncomplicated in 11% and complicated by one or more major cardiac events in 5% (myocardial infarction 5%, emergency bypass surgery 2% and death 0.2%). Follow-up data were obtained in 99% of 356 patients with successful angioplasty. At a mean of 33 +/- 26 months, 92% were alive, 73% had improvement in angina and 61% were free of angina. One or more of the following late events occurred in 67 patients (19%): myocardial infarction (6%), elective reoperation (13%) and cardiac death (6%). Repeat angioplasty was performed in 27%, with a success rate of 89% and no deaths. Initial success rates were equal in native vessel versus graft angioplasty, but late outcome was less favorable with the latter because of a higher rate of infarction (11% versus 4%, p less than 0.05) and need for reoperation (19% versus 10%, p less than 0.05). The initial success rate was higher in vein grafts less than 1 year old compared with grafts 1 to 4 years or greater than 4 years after operation (92% versus 85% versus 83%, respectively) and adverse late events were less frequent after angioplasty in recent vein grafts (less than 1 year 13%, 1 to 4 years 35%, greater than 4 years 29%; less than 1 versus greater than 1 year, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1990

Percutaneous transluminal aortic valvuloplasty--the acute outcome and follow-up of 149 patients who underwent the double balloon technique.

Double balloon percutaneous transluminal aortic valvuloplasty (PTAV) was performed on 149 patients (76 male (51%), mean age 76 +/- 11 years) whose symptoms included severe congestive heart failure in 127 cases (82%), syncope in 21 (14%) and angina in six (4%). Significant changes (P less than 0.05) in peak systolic (83 +/- 36 to 38 +/- 30 mmHg) and mean gradient (68 +/- 25 to 36 +/- 21 mmHg), and aortic valve area (0.6 +/- 0.2 to 1.0 +/- 0.4 cm2) were achieved in 130/149 patients (87%). Complications included an overall in-hospital mortality of 13%, (10.0% excluding the six deaths occurring in 18 moribund patients), a neurologic deficit incidence of 3%, and surgical arterial entry site repair 3.0% (14/47) of patients. Multivariate analysis identified congestive heart failure (NYHA Class IV), left ventricular ejection fraction, cardiac output and coronary artery disease as independent variables significantly affecting in-hospital mortality. Predictors of poor long-term survival were degree of heart failure, and coronary artery disease. The cumulative probability of survival at 24 months was 52 +/- 5% (excluding non-cardiac deaths, was 66 +/- 3%). Follow-up (mean time: 16 +/- 7 months) of 130 patients discharged alive revealed 41 late deaths (26 cardiac related). Sixty-two patients (70%) were symptomatically improved; 17 patients had symptom recurrence and underwent repeat valvuloplasty, and 10 patients valve replacement. Follow-up catheterization of 18 asymptomatic patients revealed that 11 patients had silently restenosed. These data indicate that aortic valvuloplasty is a palliative therapy for elderly patients, who are poor surgical candidates, with symptomatic calcific aortic stenosis with reasonable clinical success and long-term survival when considering their clinical status, but with a significant restenosis rate.

Aged↗
PubMed1990

Unstable angina and coronary angioplasty.

Of 2,122 consecutive patients undergoing elective coronary angioplasty from 1982 to 1985, 62% had stable angina pectoris (SAP), and 38% had unstable angina pectoris (UAP). There were differences between the two groups in clinical and morphological factors and in initial and late results of angioplasty. UAP patients were more likely than SAP patients to be smokers and to have had prior myocardial infarctions. Lesions in UAP patients were more severe, longer, more eccentric, more irregular, and more likely to have intracoronary thrombi than were lesions in SAP patients. Coronary angioplasty success was achieved in 84% of UAP and in 88% of SAP patients (p less than 0.05), and complications occurred in 6.7% of UAP and in 4.7% of SAP patients (p less than 0.05). Hospital death rates were low and similar, 0.2% for both groups. Follow-up (mean, 37 months) showed recurrent Canadian Cardiovascular Society (CCVS) class III/IV angina in 30.1% of UAP and in 25.2% of SAP patients (p less than 0.05). There was a return to work in 86% of UAP and in 91% of SAP patients (p less than 0.05). When UAP patients' durations of symptoms were further fractionated, it was found that the earlier angioplasty was performed after onset of angina, the lower was the success rate and the higher the complication rate and incidence of late follow-up untoward events. When coronary angioplasty was performed within 1 week of onset of angina ("early"), success was 79.1%; when angioplasty was performed 2 weeks or more after onset of angina ("later"), success was 86.3%. Major cardiac events occurred in 11.5% in the early group and in 4.8% in the later group (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1989

Risk factors, time course and treatment effect for restenosis after successful percutaneous transluminal coronary angioplasty of chronic total occlusion.

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 (greater than or equal to 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 greater than 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).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1989

Silent ischemia: evaluation by exercise and redistribution tomographic thallium-201 myocardial imaging.

UNLABELLED: To compare the amount of myocardium jeopardized during silent ischemia and painful ischemia, 112 consecutive patients undergoing coronary arteriography with ischemia demonstrated by exercise and redistribution tomographic thallium-201 myocardial imaging (SPECT) were divided into two groups: 84 patients without anginal pain (silent ischemia) and 28 with pain (painful ischemia). The SPECT apical, mid and basal ventricular levels of the short-axis view and the apical portion of the long-axis view were divided into 20 segments. The results were 1) 7.4 +/- 4.7 ischemic segments in silent ischemia and 7.6 +/- 3.7 in painful ischemia (p = NS) with 4.7 +/- 3.6 segments in silent ischemia undergoing total redistribution compared with 5.4 +/- 3.4 in painful ischemia (p = NS); 2) no difference in the incidence of single, double or triple vessel disease between silent and painful ischemic groups; 3) similar anatomic distribution of ischemic segments between the two groups; 4) more positive exercise electrocardiographic (ECG) changes in painful ischemia (70%) than in silent ischemia (32%) (p less than 0.001) with equal amounts of ischemia associated with positive and negative exercise ECG findings. CONCLUSIONS: 1) 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. 2) Positive and negative exercise ECG findings were associated with similar amounts of ischemic myocardium.

Angina Pectoris↗
PubMed1989

Education of patients undergoing coronary angioplasty: factors affecting learning during a structured educational program.

A structured educational program for patients undergoing coronary angioplasty was designed and administered to 97 patients undergoing their first procedure. Knowledge, coping style, social support, health locus of control, IQ, and demographic and medical factors were assessed before the procedure. Risk factor knowledge, anxiety, and medical status were assessed before discharge, and at 6 months and 2 years after angioplasty. Total knowledge mean score for all patients was higher at discharge (p less than 0.05). There was no significant difference between knowledge scores at baseline and at either 6 months or 2 years. Analyses revealed that patients with a repressive coping style learned less during hospitalization (p less than 0.05). No factors predicted retention of knowledge at 6 months or 2 years. These results indicate that a structured educational approach may have beneficial effects on immediate knowledge gain, although these results are not sustained. Coping assessment may provide information valuable for understanding differences in knowledge retention.

Adult↗
PubMed1989

The setting of coronary angioplasty in multivessel disease: current status and future directions.

In summary, the use of coronary angioplasty in the setting of multivessel coronary disease has become more common in recent years. Reports indicate that, in carefully selected patients, a high initial success rate and low incidence of complications can be achieved. We have presented a schema for the triage of multivessel disease patients. Examples of each subgroup have been presented to illustrate the basis for this categorization. Our experience using this schema at the San Francisco Heart Institute has been valuable in understanding the initial and long-term results of coronary angioplasty in these patients. 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.

Angioplasty, Balloon, Coronary↗
PubMed1988

Transluminal coronary angioplasty in the treatment of silent ischemia.

Fifty-four asymptomatic patients with positive thallium exercise tests underwent coronary angiography followed by coronary angioplasty (PTCA), as the primary therapy for silent ischemia. The procedure was technically successful in 89% of these patients. Emergency bypass graft surgery was necessary in 2 (3.6%) and q-wave myocardial infarction occurred in 1 (1.8%) of these. All fifty-four patients have been followed for a mean of 35 months since angioplasty. Of the 48 patients with initially successful PTCA, 12 had either clinical restenosis (9/14 or 19%) or a new lesion (3/48 or 6%) during follow-up, which required a repeat PTCA. At the longest follow-up, 46 (85%) had been successfully treated with on or more PTCA procedures. Two patients (3.6%) had sustained late q-wave myocardial infarction and two additional patients reported angina pectoris. There were no deaths. Angioplasty as a primary therapy for silent ischemia appears efficacious, with success and restenosis rates comparable to those in the symptomatic population. Event-free survival is improved, compared with natural history data for patients with silent ischemia from other studies. Prudent risk/benefit analysis may help to define subgroups most likely to benefit from this intervention.

Adult↗
PubMed1988

In-hospital cardiac mortality after acute closure after coronary angioplasty: analysis of risk factors from 8,207 procedures.

Cardiac death consequent to acute vessel closure after coronary angioplasty occurred in 13 of 294 closures from 8,207 consecutive procedures performed at two centers since 1981 (0.16% cardiac mortality rate). To determine the predictors of cardiac death after acute coronary closure, 50 clinical, angiographic and procedural variables were analyzed by an observer unaware of the clinical outcome for each of the 13 patients who died and also 100 patients randomly chosen, in whom vessel closure after angioplasty did not result in death during hospitalization. Univariate analysis found female gender (p less than 0.0001), collateral channels from the vessel dilated (p less than 0.0001), use of balloon counterpulsation (p less than 0.0002), pre- and postprocedural hypotension (p = 0.0003 and p = 0.003, respectively), jeopardy score greater than or equal to 2.5 (p = 0.003), left ventricular hypertrophy (p = 0.013), hypertension (p = 0.02), diabetes (p = 0.02) and multivessel disease (p = 0.03) to be predictive of death. Multivariate analysis found collateral vessels, female gender and multivessel disease to be independent predictors of death. Thus, cardiac death after elective coronary angioplasty is very rare in experienced centers and occurs most often in women with a large amount of potentially ischemic myocardium. Hypotension often precedes the fatal closure event. Close attention to the amount of potentially ischemic myocardium and to the fluid volume status of these patients would seem to be especially warranted.

Adult↗
PubMed1987

Percutaneous transluminal angioplasty of stenotic coronary artery bypass grafts: 5 years' experience.

In a 60 month period (January 1981 to December 1985), 82 patients (79% male with a mean age of 60 years) had 83 saphenous vein grafts and 5 internal mammary artery grafts with a total of 101 stenotic sites treated with percutaneous transluminal coronary angioplasty. The mean time between bypass surgery and angioplasty was 51.2 months. The procedure was technically successful in 85% of patients, 86% of grafts and 85% of the sites attempted. In these cases, the mean diameter stenosis was reduced from 77 +/- 14 to 27 +/- 20% (p less than 0.001), the mean pressure gradient from 49 +/- 16 to 7 +/- 6 mm Hg (p less than 0.001). Emergency coronary artery bypass graft surgery was necessary in one patient (1.2%) whereas myocardial infarction occurred in three patients (3.6%). There were no hospital deaths. Clinical follow-up was obtained in all 82 patients. Before angioplasty, 23% were in Canadian Cardiovascular Society functional class II, 60% in class III and 17% in class IV. With a mean clinical follow-up period of 21.4 +/- 2.3 months, 71% are in class I, 17% in class II and 12% in class III. There were two deaths, 3 months or more after angioplasty, one probably due to graft closure. So far, angiographic follow-up (at 7.9 +/- 2.1 months) has been available in 26 patients. Ten patients (with 10 grafts) exhibited graft restenosis; six of them have had second successful repeat angioplasty. Among the many variables analyzed, statistically significant predictors of success were a higher measured balloon/graft ratio (p less than 0.001), smaller diameter graft (p less than 0.001), and shorter lesion length (p less than 0.01). The only predictor of complication was diffuseness of disease in the graft (p less than 0.05). The statistically significant predictors of recurrence were the residual stenosis after the initial angioplasty (p less than 0.01) and the measured balloon/graft ratio (p less than 0.01). Angioplasty of coronary artery grafts appears to be a feasible and efficacious procedure with a low complication rate. The technique is a satisfactory alternative to repeat surgery in selected patients.

Adult↗
PubMed1986

Balloon angioplasty of coronary bifurcation lesions: the kissing balloon technique.

Initial experience with the technique of "kissing balloon" angioplasty is described in 52 patients undergoing coronary angioplasty. Guiding catheters employing both the femoral and brachial approach were used in all but two of the coronary angioplasties and, in addition, the bilateral femoral approach was used in the renal and peripheral angioplasties. Initial success was achieved in 51 (98%) patients. Abrupt closure requiring urgent coronary revascularization occurred in one patient six hours following the completion of the procedure. Another patient developed a new Q-wave on the electrocardiogram and moderate elevation of CPK-MB fraction following the procedure due to loss of a diagonal branch. No deaths occurred in this series. Angiographic restenosis developed in ten patients. In the recurrence group, five had repeat kissing balloon angioplasty, two had repeat single vessel angioplasty, and three patients chose elective surgical revascularization. Based on our experience, the technique of kissing balloon coronary angioplasty can be performed safely utilizing the brachio-femoral technique. The risk of major side branch occlusion can be minimized with this technique and the overall complication rate does not significantly differ from that of our experience in single vessel coronary angioplasty. Patient selection criteria are based upon the angiographic relationship of the major branch to the side branch and is important in determining the initial and long-term success of this technique.

Adult↗
PubMed1986

Structural support for the perception of growth.

Previous studies have shown that the effects of a particular class of geometric transformations, known as cardioidal strain, are perceived as growth when applied to a variety of animate and even inanimate objects. The current study demonstrates that the effects of these growth transformations are not completely independent of the object undergoing change, but depend critically on certain structural characteristics. When cardioidal strain is applied to a straight-line, right-angle, robotlike structure, there is no consistent effect on the age level of the figure. However, as the structural contours become more curved and less angular, the effects of this transformation are seen as increasingly more like growth. In contrast, the effects of a shear transformation are not perceived as growth on any of the profiles. These findings are examined in light of the critical physical properties that may be responsible for this notion of biological forms as well as their implications for our understanding of the information about events.

Age Factors↗