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Biomedical subjects

D B Pryor

Publications and source records attributed to D B Pryor.

At least 55 records · Page 3Linked to original sources
PubMed1991

Estimating the likelihood of severe coronary artery disease.

PURPOSE: To determine which clinical characteristics obtained by a physician during an initial clinical examination are important for estimating the likelihood of severe coronary artery disease, and to determine whether estimates based on these characteristics remain valid when applied prospectively and in different patient groups. PATIENTS AND METHODS: We examined clinical characteristics predictive of severe disease in 6,435 consecutive symptomatic patients referred for suspected coronary artery disease between 1969 and 1983. RESULTS: Eleven of 23 characteristics were important for estimating the likelihood of severe coronary artery disease. A model using these characteristics accurately estimated the likelihood of severe disease in an independent sample of 2,342 patients referred since 1983. The model also accurately estimated the prevalence of severe disease in large series of patients reported in the literature. CONCLUSIONS: These findings suggest that the clinician's initial evaluation can identify patients at high or low risk of anatomically severe coronary artery disease. Cost-conscious quality care is encouraged by identifying patients at higher risk for severe coronary artery disease who are most likely to benefit from further evaluation.

Adult↗
PubMed1990

Effect of Type A behavior on exercise test outcome in coronary artery disease.

The outcome of the diagnostic exercise test depends on such patient-related factors as age, maximum exercise heart rate, exercise time and severity of the underlying coronary artery disease (CAD). This study examined the hypothesis that type A behavior would affect the amount of effort expended, as indicated by the exercise time and the maximum heart rate achieved, thereby resulting in differences in exercise test outcome. A total of 1,260 patients with suspected CAD, all of whom had coronary angiography, a structured interview to assess type A behavior and a treadmill exercise test, participated. Of these patients, 818 (65%) had significant CAD, and 852 (68%) were type A. There were no differences between type A and B patients in either maximum heart rate or total exercise time. Among both type A and B subjects, 36% of treadmill tests were positive. Exercise test sensitivity was similar for both groups (69% for type A vs 72% for type B, p = 0.39). Similarly, specificity was similar for both groups (87% for type A vs 80% for type B, p = 0.09). Results did not change after using logistic regression to control for potential confounding factors. Thus, type A behavior does not need to be taken into account when interpreting exercise test outcome.

Adult↗
PubMed1990

Detection of restenosis after elective percutaneous transluminal coronary angioplasty using the exercise treadmill test.

To determine the value of a 6-month exercise treadmill test for detecting restenosis after elective percutaneous transluminal coronary angioplasty (PTCA), 303 consecutive patients with successful PTCA and without a recent myocardial infarction were studied. Among the 228 patients without interval cardiac events, early repeat revascularization or contraindications to treadmill testing, 209 (92%) underwent follow-up angiography, and 200 also had a follow-up treadmill test and formed the study population. Restenosis (greater than or equal to 75% luminal diameter stenosis) occurred in 50 patients (25%). Five variables were individually associated with a higher risk of restenosis: recurrent angina (p = 0.0002), exercise-induced angina (p = 0.0001), a positive treadmill test (p = 0.008), more exercise ST deviation (p = 0.04) and a lower maximum exercise heart rate (p = 0.05). However, only exercise-induced angina (p = 0.002), recurrent angina (p = 0.01) and a positive treadmill test (p = 0.04) were independent predictors of restenosis. Using these 3 variables, patient subsets could be identified with restenosis rates ranging from 11 to 83%. The exercise treadmill test added independent information to symptom status about the risk of restenosis after elective PTCA. Nevertheless, 20% of patients with restenosis had neither recurrent angina nor exercise-induced ischemia at follow-up. For more accurate detection of restenosis, the exercise treadmill test must be supplemented by a more definitive test.

Angiography↗
PubMed1990

Clinical judgment and therapeutic decision making.

Clinical decision making is under increased scrutiny due to concerns about the cost and quality of medical care. Variability in physician decision making is common, in part because of deficiencies in the knowledge base, but also due to the difference in physicians' approaches to clinical problem solving. Evaluation of patient prognosis is a critical factor in the selection of therapy, and careful attention to methodology is essential to provide reliable information. Randomized controlled clinical trials provide the most solid basis for the establishment of broad therapeutic principles. Because randomized studies cannot be performed to address every question, observational studies will continue to play a complementary role in the evaluation of therapy. Randomized studies in progress, meta analyses of existing data, and increased use of administrative and collaborative clinical data bases will improve the knowledge base for decision making in the future.

Cardiology↗
PubMed1990

Cardiac rupture, mortality and the timing of thrombolytic therapy: a meta-analysis.

This study examined the relation between the risk of cardiac rupture and the timing of thrombolytic therapy for acute myocardial infarction. To test the hypothesis that cardiac rupture is prevented by early thrombolytic therapy but is promoted by late treatment, randomized controlled trials of thrombolytic agents for myocardial infarction were pooled. A logistic regression model including 58 cases of cardiac rupture among 1,638 patients from four trials showed that the odds ratio (treated/control) of cardiac rupture was directly correlated with time to treatment (p = 0.01); at 7 h, the odds ratio was 0.4 (95% confidence limits 0.17 to 0.93); at 11 h, it was 0.93 (0.53 to 1.60) and at 17 h, it was 3.21 (1.10 to 10.1). Analysis of data from the Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico (GISSI) trial independently confirmed the relation between time to thrombolytic therapy and risk of cardiac rupture (p = 0.03). Analysis of 4,692 deaths in 44,346 patients demonstrated that the odds ratio of death was also directly correlated with time to treatment (p = 0.006); at 3 h, the odds ratio for death was 0.72 (0.67 to 0.77); at 14 h, it was 0.88 (0.77 to 1.00) and at 21 h, it was 1 (0.82 to 1.37). Thrombolytic therapy early after acute myocardial infarction improves survival and decreases the risk of cardiac rupture. Late administration of thrombolytic therapy also appears to improve survival but may increase the risk of cardiac rupture.

Drug Administration Schedule↗
PubMed1990

Feasibility and cost-saving potential of outpatient cardiac catheterization.

To determine the feasibility and cost-saving potential of substituting outpatient for inpatient cardiac catheterization, 986 consecutive procedures were studied at a large referral hospital. Patients were classified prospectively as to their eligibility for outpatient cardiac catheterization according to published guidelines. Resource consumption was recorded, and cost savings were then calculated by analyzing the specific supply and personnel costs that could change as a result of inpatient versus outpatient status. Of the total of 986 patients who underwent diagnostic catheterization, 240 (24%) were outpatients, 279 (28%) were inpatients but had no exclusion criteria for outpatient catheterization and 467 (47%) were inpatients who had one or more exclusions for outpatient catheterization. The most common reasons for exclusion from outpatient catheterization were congestive heart failure (22%), unstable angina (15%), noncoronary heart disease (14%), recent myocardial infarction (11%) and severe noncardiac disease (9%). Inpatients with no exclusions for the outpatient procedure tended to be sicker than outpatients because they were older (p = 0.002), had a lower ejection fraction (p = 0.009) and had more triple vessel coronary artery disease (p less than 0.0001). The cost of the catheterization procedure itself was not different between inpatients and outpatients. Laboratory testing was more frequent among inpatients, however, and "room and board" costs were significantly higher. Although the difference in hospital charges for inpatients and outpatients was $580, a rigorous analysis indicated that the potential cost savings was only 38% of this amount, or $218 per eligible patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory Care↗
PubMed1990

Prognostic value of radionuclide angiography in medically treated patients with coronary artery disease. A comparison with clinical and catheterization variables.

To evaluate the usefulness of multiple measures from rest and exercise radionuclide angiography (RNA) in predicting cardiovascular death and cardiovascular events (death or nonfatal myocardial infarction) and to assess the prognostic usefulness of the RNA relative to clinical and catheterization data, we studied 571 stable patients with symptomatic coronary artery disease who had upright rest/exercise first-pass RNA within 3 months of catheterization and were medically treated. With a median follow-up of 5.4 years, 90 patients have died from cardiovascular causes, and 147 patients have either died or suffered a nonfatal myocardial infarction. Using the Cox regression model and a preselected group of RNA variables, the most important RNA predictor of mortality was exercise ejection fraction (chi 2 = 81, p less than 0.00001). Neither rest ejection fraction nor the change in ejection fraction from rest to exercise contributed additional predictive information. Two other RNA study variables, the change in heart rate from rest to exercise and rest end-diastolic volume index, did contribute additional prognostic information to the exercise ejection fraction (chi 2 = 23, p less than 0.0001). Compared with noninvasive clinical data (history, physical examination, electrocardiogram, and chest radiograph), RNA variables were considerably more predictive of mortality (chi 2 = 71 [clinical variables] versus chi 2 = 104 [RNA]). Remarkably, the strength of the relation of RNA variables with mortality was equivalent to that of the set of catheterization variables previously demonstrated in our large angiographic population to be prognostically important (chi 2 = 104 [RNA] versus chi 2 = 102 [catheterization variables]). The RNA contained 84% of the information provided by clinical and catheterization descriptors combined. Furthermore, the RNA contributed significant additional prognostic information to the clinical and catheterization data (chi 2 = 13.6, p = 0.0035). For cardiovascular events, the relative prognostic usefulness of the RNA was similar, although relations with this outcome were generally weaker. Descriptors from the rest/exercise RNA exhibit a powerful relation with long-term outcomes and can be useful in defining risk, even when clinical and catheterization data are available.

Cardiac Catheterization↗
PubMed1990

Studies of gastric ulcer disease by community-based gastroenterologists.

A community-based group of gastroenterologists examined 623 patients (541 prospectively and 82 retrospectively) with endoscopically diagnosed gastric ulcer disease during a 12-month period. Patients averaged 60 years of age; the majority were women (62%). Women were less likely to smoke, abuse alcohol, and were more likely to present with abdominal pain (p less than 0.05). Whereas patients presenting with bleeding or requiring transfusion were less likely to complain of pain (p less than 0.05), they were more likely to be taking aspirin or nonsteroidal anti-inflammatory drugs and have prior history of bleeding (p less than 0.05). Patients with a prior history of ulcer disease were more likely to smoke, present with pain and use acetaminophen (p less than 0.05). Patients with large ulcers were more likely to bleed, present with pain, and obstruct (p less than 0.05). Multiple gastric ulcers were seen in patients taking aspirin or nonsteroidal anti-inflammatory drugs (p less than 0.05).

Abdominal Pain↗
PubMed1989

Clinical correlates and prognostic significance of type A behavior and silent myocardial ischemia on the treadmill.

Type A patients with coronary artery disease (CAD) tend to ignore or underreport symptoms, especially during challenging tasks such as the treadmill exercise test. To determine whether type A CAD patients might be more likely than type B patients to have silent ischemia during exercise and consequently a worse prognosis, 403 patients with stable CAD who had significant coronary disease on angiography, a positive Bruce protocol treadmill test and a structured interview to assess type A behavior were studied. Median follow-up time was 6 years. Type A patients were more likely to experience silent ischemia during exercise than were type B patients (35 vs 25%, p = 0.05). Patients with silent ischemia during exercise had a history of fewer anginal episodes/week, and type A patients with silent ischemia were less likely to have had a history of typical angina. However, using the Cox model, there were no significant differences in survival between type A patients and B patients with silent ischemia (4-year survival 86 vs 79%, p = 0.44) and no significant differences in survival between type A patients with silent ischemia and type A patients with symptomatic ischemia (6-year survival 86 vs 80%, p = 0.59). Similar results were obtained for infarction-free survival. Type A patients are more likely than type B patients to have silent ischemia during exercise, but long-term survival is not affected.

Angina Pectoris↗
PubMed1989

A brief self-administered questionnaire to determine functional capacity (the Duke Activity Status Index).

To develop a brief, self-administered questionnaire that accurately measures functional capacity and assesses aspects of quality of life, 50 subjects undergoing exercise testing with measurement of peak oxygen uptake were studied. All subjects were questioned about their ability to perform a variety of common activities by an interviewer blinded to exercise test findings. A 12-item scale (the Duke Activity Status Index) was then developed that correlated well with peak oxygen uptake (Spearman correlation coefficient 0.80). To test this new index, an independent group of 50 subjects completed a self-administered questionnaire to determine functional capacity and underwent exercise testing with measurement of peak oxygen uptake. The Duke Activity Status Index correlated significantly (p less than 0.0001) with peak oxygen uptake (Spearman correlation coefficient 0.58) in this independent sample. The Duke Activity Status Index is a valid measure of functional capacity that can be obtained by self-administered questionnaire.

Activities of Daily Living↗
PubMed1989

Type A behavior and survival: a follow-up study of 1,467 patients with coronary artery disease.

Patients with documented coronary artery disease, admitted to Duke Medical Center between 1974 and 1980, were assessed for type A behavior pattern and were followed until 1984. The relation of type A behavior to survival was tested using data from coronary angiography to control for disease severity. Cox model regression analyses demonstrated an interaction (p less than 0.01) between type A behavior and an index of disease severity in the prediction of cardiovascular death. Among those with relatively poor left ventricular function, type A patients had better survival than type B. This difference was not present among patients with better prognoses. Type A behavior did not predict the subsequent incidence of nonfatal myocardial infarctions. Differential risk modification and differential selection into postinfarction status are possible explanations for the findings. These results need not conflict with the proposition that type A behavior plays a role in the pathogenesis of coronary artery disease.

Adult↗
PubMed1989

The evolution of medical and surgical therapy for coronary artery disease. A 15-year perspective.

To elucidate the factors associated with improved survival following coronary artery bypass surgery, we studied 5809 patients receiving medical or surgical therapy for coronary artery disease. Three factors were associated with a significant surgical survival benefit: more severe coronary disease, a worse prognosis with medical therapy, and a more recent operative date. Patients with more extensive coronary obstruction had the greatest improvement in survival. Patients with a poor prognosis because of factors such as older age, severe angina, or left ventricular dysfunction had a reduction in risk that was proportionate to their overall risk on medical therapy. Survival with surgery progressively improved over the study period and by 1984 surgery was significantly better than medical therapy for most patient subgroups. Thus, contemporary coronary revascularization is associated with improved longevity in many patients with ischemic heart disease, especially in those with adverse prognostic indicators.

Age Factors↗
PubMed1989

Randomized, double-blind comparison of famotidine with ranitidine in treatment of acute, benign gastric ulcer disease. Community-based study coupled with a patient registry.

A multicenter, double-blind, randomized controlled trial comparing the efficacy and safety of famotidine with ranitidine in the treatment of acute, benign gastric ulcer disease was coupled with a community-based gastric ulcer disease registry. One hundred ninety-five patients with endoscopically documented gastric ulcer disease were enrolled in the trial and randomly allocated to treatment with either famotidine 40 mg at bedtime or ranitidine 150 mg twice a day. Healing rates were similar in both groups: at four weeks 49% vs 48%, at six weeks 71% vs 69%, and at eight weeks 83% vs 81% for famotidine and for ranitidine, respectively. Pain relief, antacid tablet use, and adverse experiences were also similar in the two groups. Only 25% of patients entered in the gastric ulcer registry were enrolled in the trial. Given that patients with more severe or complicated gastric ulcer disease should be excluded from controlled trials of new drugs, the screening criteria used in the present study be excluded from findings being representative of a quarter of the patients seen in these practices. Therefore, coupling a patient registry with a clinical trial helps determine the applicability of its results. Famotidine 40 mg at bedtime is an effective and well-tolerated treatment of acute, benign gastric ulcer disease and is comparable in efficacy and safety to ranitidine 150 mg twice a day.

Clinical Trials as Topic↗
PubMed1989

Data for cardiovascular modeling.

Data are required for a meaningful approach to quality and cost-conscious cardiovascular care. How to identify the types of data available and their sources, advantages and limitations to their use, issues involved in combining data from different sources for decision modeling and some possible solutions are discussed in this summary of the Working Group on Data for Cardiovascular Modeling.

Cardiovascular Diseases↗
PubMed1989

Painless exercise ST deviation on the treadmill: long-term prognosis.

To evaluate the clinical correlates and long-term prognostic significance of silent ischemia during exercise, 1,698 consecutive symptomatic patients with coronary artery disease who had both treadmill testing and cardiac catheterization were studied. These patients were classified into three groups: Group 1 = patients with no exercise ST deviation (n = 856), Group 2 = patients with painless exercise ST deviation (n = 242) and Group 3 = patients with both angina and ST segment deviation during exercise (n = 600). Patients with exercise angina had a history of a longer and more aggressive anginal course (with a greater frequency of angina, with nocturnal episodes and/or progressive symptom pattern) and more severe coronary artery disease (almost two-thirds had three vessel disease). The 5 year survival rate among the patients with painless ST deviation was similar to that of patients without ST deviation (86% and 88%, respectively) and was significantly better than that of patients with both symptoms and ST deviation (5 year survival rate 73% in patients with exercise-limiting angina). Similar trends were obtained in subgroups defined by the amount of coronary artery disease present. In the total study group of 1,698 patients, silent ischemia on the treadmill was not a benign finding (average annual mortality rate 2.8%) but, compared with symptomatic ischemia, did indicate a subgroup of patients with coronary artery disease who had a less aggressive anginal course, less coronary artery disease and a better prognosis. Thus, silent ischemia during exercise testing in patients with symptomatic coronary artery disease represents an intermediate risk response in the spectrum of exercise-induced ischemia.

Adult↗