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Biomedical subjects

R L Frye

Publications and source records attributed to R L Frye.

At least 91 records · Page 5Linked to original sources
PubMed1983

Coronary arteriography and coronary artery bypass surgery: morbidity and mortality in patients ages 65 years or older. A report from the Coronary Artery Surgery Study.

Of 2144 patients age 65 years or older entered into the registry of the Coronary Artery Surgery Study (CASS) who had coronary arteriography, 1086 underwent isolated coronary artery bypass grafting. Complications of angiography included death in four patients and nonfatal myocardial infarction in 17. Eight patients suffered neurologic complications, which were transient in five. The perioperative mortality was 5.2% (57 of 1086), which is significantly greater than the perioperative mortality of 1.9% (151 of 7827) in patients younger than 65 years entered in CASS (p less than 0.001). There was a trend toward an increased mortality rate with age; it was 4.6% (37 of 803) in patients age 65-69 years, 6.6% (16 of 241) in those 70-74 years and 9.5% (four of 42) in those 75 years or older. The duration of hospital stay after operation was significantly longer for the patients 65 years or older than for the patients younger than 65 (13.3 vs 11.4 days; p less than 0.001). Stepwise linear discriminant analysis identified five variables predictive of perioperative mortality: presence of 70% or more stenosis of the left main coronary artery and a left-dominant circulation, left ventricular end-diastolic pressure, a history of current cigarette smoking, pulmonary rales on auscultation, and presence of one or more associated medical diseases. A second linear discriminant analysis, incorporating 7658 CASS patients who underwent isolated coronary artery bypass surgery irrespective of age, examined whether age 65 years or older was an independent predictor of perioperative mortality. The variables selected, in order of significance, were congestive cardiac failure score, left main coronary artery stenosis and a left-dominant circulation, age 65 years or older, left ventricular wall motion score, sex and history of unstable angina pectoris. In patients 65 years or older, the mortality from coronary arteriography is low, whereas mortality from coronary artery bypass surgery is greater than that in CASS patients younger than 65 years.

Aged↗
PubMed1982

Cardiac-catheterization and cardiac-surgical facilities: use, trends, and future requirements.

Cardiac catheterizations and cardiac operations were evaluated in the population of Olmsted County, Minnesota, from 1973 through 1980, and trends in this region were compared with nationwide trends based on data from several sources. The rates of coronary arteriography and coronary-artery bypass operations in Olmsted county have increased over time, but overall, the rates of catheterization and operation appeared to be leveling off. For the country as a whole, the data appear to show similar trends, but there are wide differences among regions in the rates of operation and catheterization. In 1980 40 per cent of hospitals with cardiac-catheterization laboratories and 55 per cent of those with facilities for open-heart surgery were doing fewer than the suggested minimum numbers of these procedures necessary to achieve optimum results. The data support the view that further growth in the number of cardiac centers should be avoided. We believe there is a need for continued evaluation of the use of cardiac services if quality is to be protected and costs controlled.

Adult↗
PubMed1982

A platelet-inhibitor-drug trial in coronary-artery bypass operations: benefit of perioperative dipyridamole and aspirin therapy on early postoperative vein-graft patency.

To prevent occlusion of aortocoronary-artery-bypass grafts, we conducted a prospective, randomized-double-blind trial comparing dipyridamole (instituted two days before operation) plus aspirin (added seven hours after operation) with placebo in 407 patients. Vein-graft angiography was performed in 360 patients (88 per cent) within six months of operation (median, eight days). Within one month of operation, 3 per cent of vein-graft distal anastomoses (10 of 351) were occluded in the treated patients, and 10 per cent (38 of 362) in the placebo group; the proportion of patients with one or more distal anastomoses occluded was 8 per cent (10 of 130) in the treated group and 21 per cent (27 of 130) in th placebo group. This benefit in graft patency persisted in each of over 50 subgroups. Early postoperative bleeding was similar in the two groups. In this trial dipyridamole and aspirin were effective in preventing graft occlusion early after operation.

Adult↗
PubMed1982

Strong family history and cigarette smoking as risk factors of coronary artery disease in young adults.

This study is based on 435 consecutive patients age 50 or less who had coronary arteriography. There were 335 patients with coronary artery disease and 100 with normal coronary arteries. Risk factors reviewed were "packet-years" of cigarette smoking, family history of coronary disease in first-degree relatives 50 years of age or less, age- and sex-corrected serum cholesterol and triglycerides, hypertension, and diabetes. By univariate analysis, each risk factor except hypertension and diabetes was significantly more frequent in patients with coronary disease than in those without. By multivariate analysis of all risk factors in patients with and without coronary disease, the male or female patient with coronary disease could best be identified by the strong family history, cigarette smoking history, and age- and sex-corrected serum cholesterol. The percentage of patients with coronary disease when the three risk factors were present was 95%, two factors present 88%, one factor present 67%, none of the three 25%, strong family history alone 90%, smoking alone 66%, and serum cholesterol greater than 80th centile alone 52%.

Adult↗
PubMed1982

Left ventricular performance before and after aortocoronary artery bypass surgery.

Left ventricular performance was studied before and late (mean 12-17 months) after aortocoronary artery bypass surgery by quantitative, computer-based videoangiography. We measured total function (left ventricular ejection fraction, volumes and end-diastolic pressure) at rest (in 60 patients) and before and after exercise (abnormal exercise hemodynamics preoperatively in 32 patients) and regional function (peak rate of systolic wall thickening) at rest (in 60 patients) and before and after administration of nitroglycerin (in 19 patients). Total left ventricular function at rest is usually unchanged postoperatively. Exercise hemodynamics are more sensitive indexes of performance and, if abnormal, usually improve postoperatively if revascularization has been complete and extensive myocardial infarction has not occurred. Regional myocardial function usually improves postoperatively if the bypass graft to the region is patent and has a blood flow of more than 60 ml/min (measured late postoperatively by videodensitometry) and if no previous infarction was present in the region. Myocardial infarction and graft blood flow of 40 ml/min or less are the two main factors that prevent improvement in abnormal regions defined by the regional wall thickening method when bypass grafts are patent. Regions supplied by occluded grafts show decreases in regional function. The preoperative wall-thickening response to administration of nitroglycerin can be used to distinguish ischemia and significant myocardial infarction and to predict the successful response to aortocoronary bypass graft surgery.

Blood Pressure↗
PubMed1982

[Correlation of the coronary heart disease risk factors and coronary angiographic data].

The findings for 14 risk variables were correlated with the results of coronary angiography in 8807 patients enrolled in the multicenter Coronary Artery Surgery Study. Discriminant function analysis revealed that age, sex, cigarette smoking and level of blood cholesterol best distinguished between the groups with (6688 patients) and without (2119 patients) coronary artery disease (CAD). The relative risk for CAD in patients with the combination of cigarette smoking and an elevated cholesterol level was high in women 55 years old or younger and in men 35 years old or younger. Few women 45 years old or younger (7 out of 97) had CAD when neither of these risk factors were present. Despite these correlations, only limited gains accrued from the use of discriminant function analysis in correctly allocating patients into disease and nondisease groups. Extent and severity of disease in 15298 patients with CAD were significantly (p less than 0.001) but modestly correlated with age, sex, blood cholesterol level and history of diabetes or hypertension. No positive correlation occurred between the arteriographic measures of disease and the cigarette smoking history. Thus, factors influencing the presence of disease may differ from those influencing its extent and severity.

Adult↗
PubMed1981

The natural history of idiopathic dilated cardiomyopathy.

Between 1960 and 1973, a total of 104 patients at the Mayo Clinic had a diagnosis of idiopathic dilated cardiomyopathy on the basis of clinical and angiographic criteria; these patients were followed up for 6 to 20 years. Twenty-one percent of the patients had a history of excessive consumption of alcohol, 20 percent had had a severe influenza-like syndrome within 60 days before the appearance of cardiac manifestations and 8 percent had had rheumatic fever without involvement of cardiac valves several years before; thus, possible etiologic risk factors of infectious-immunologic type may be important. Eighty patients (77 percent) had an accelerated course to death, with two thirds of the deaths occurring within the first 2 years. Twenty-four patients (23 percent) survived, and 18 of them had clinical improvement and a normal or reduced heart size. Univariate analysis at the time of diagnosis revealed three factors that were highly predictive (p less than 0.01) of the clinical course: age, cardiothoracic ratio on chest roentgenography and cardiac index. Systemic emboli occurred in 18 percent of the patients who did not receive anticoagulant therapy and in none of those who did; thus, anticoagulant agents should probably be prescribed unless their use is contraindicated.

Alcohol Drinking↗
PubMed1981

Chronic congestive heart failure. Eight steps in management.

Management of chronic heart failure should include clinical evaluation to confirm the diagnosis and to search for treatable causes, bed rest to reduce work of the heart, digitalis therapy to improve myocardial contractility and/or rate control with atrial fibrillation, and restriction of sodium intake and administration of diuretics to reduce congestion. Vasodilators may be helpful, and anticoagulation is recommended to prevent thromboembolism. In highly selected patients with refractory heart failure, cardiac transplantation may be considered.

Chronic Disease↗
PubMed1981

Association of risk factor variables and coronary artery disease documented with angiography.

Stepwise linear discrimination was used to analyze risk factors in 431 consecutive patients who underwent coronary angiography to determine which variables were most closely associated with coronary artery disease. Twenty-one risk factors were considered: total plasma cholesterol and triglycerides; the cholesterol and triglyceride content of high-density lipoproteins (HDL), low-density lipoproteins (LDL) and very low density lipoproteins (VLDL); and the percentage of total cholesterol and triglycerides in each fraction. Age, smoking history, family history, hypertension, diabetes mellitus and relative weight were also considered. Coronary artery disease was assessed using three standard grading scores. There were significant differences in risk factors between males and females. In males, LDL cholesterol and age were selected by multivariate analysis. In females, the ratio of HDL cholesterol to total cholesterol, as well as relative weight, family history, age and smoking were selected. The discriminating value of HDL cholesterol as the percentage of total cholesterol was significantly greater than that of HDL cholesterol itself. Despite highly significant associations between risk factors and the presence of coronary artery disease, the discrimination did not provide sufficient separation of the groups to give results that are useful diagnostically in individual patients.

Adult↗
PubMed1981

Platelet survival and the development of coronary artery disease in the young adult: effects of cigarette smoking, strong family history and medical therapy.

Cigarette smoking or a strong family history of coronary disease was present in 46 of 50 symptomatic patients with coronary artery disease who were younger than 50 years of age. We recorded a shortened platelet survival half-life (less than 92 hours) with 51Cr in 60% of these patients, in 56% of apparently normal persons of the same age who smoked or had a strong family history of coronary disease, and in only 14% of normal persons who did not smoke and had no family history (p less than 0.01). Lengthening of the shortened platelet survival toward normal occurred in coronary patients given dipyridamole plus aspirin and in apparently normal smokers who discontinued smoking (p less than 0.01). The study suggests a possible relationship among cigarette smoking, strong family history of coronary disease and platelet activation in the process of coronary atherogenesis in the young adult.

Adult↗
PubMed1981

Improvement of left ventricular exercise hemodynamic function after aorta-coronary artery bypass grafting.

In 39 patients with coronary artery disease and angina pectoris, exercise hemodynamic evaluation, left ventriculography, and coronary arteriography were performed both before and 3 to 36 months (mean 17 months) after aorta-coronary artery bypass grafting. Of the 32 patients with abnormal exercise hemodynamic responses before operation, 11 returned to normal at the postoperative study (Group N) and 21 remained abnormal (Group A). Preoperative characteristics (mean age, functional class, prior myocardial infarction, left ventriculographic appearance, mean ejection fraction, and mean number of vessels diseased) were similar in the two groups. Of the perioperative and postoperative characteristics examined (mean number of grafts, operative myocardial infarction, postoperative functional class, treadmill test result, and adequacy of left coronary artery revascularization), only the adequacy of left coronary artery revascularization differed between Groups N and A. Eight of 11 Group N and only three of 20 Group A patients had complete revascularization, with patent grafts, of the left coronary artery. We conclude that improved exercise hemodynamic function does occur in some patients after aorta-coronary artery bypass operations. Such improvement is most likely when all major lesions of the left coronary artery are completely revascularized.

Coronary Artery Bypass↗
PubMed1980

Use of the cardiac-catheterization laboratory in a defined population.

We evaluated trends in the use of the cardiac-catheterization laboratory from 1973 through 1977 in a well-circumscribed population in southeastern Minnesota. A total of 346 patients (248 male and 98 female patients) underwent coronary arteriography, left ventriculography, or cardiac catheterization, and there were 369 visits to the catheterization laboratory. The total number of catheterization-laboratory visits per 10,000 population increased from 4.3 in 1973 to 11.5 in 1977. According to individual category, the rates for coronary arteriography increased more than fourfold during the five-year period, whereas the rates for cardiac catheterization period, whereas the rates for cardiac catheterization showed no substantial change. On the basis of the 1977 rate for all visits to the catheterization laboratory and under conditions similar to those in this community, a population of approximately 230,000 would be required to ensure use of a catheterization laboratory at the suggested minimum level of 300 adult examinations per year.

Angiography↗