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Biomedical subjects

D B Pryor

Publications and source records attributed to D B Pryor.

At least 91 records · Page 5Linked to original sources
PubMed1987

Exercise treadmill score for predicting prognosis in coronary artery disease.

To determine the prognostic value of the treadmill exercise test, we evaluated 2842 consecutive patients with chest pain who had both treadmill testing cardiac catheterization. The population was randomly divided into two equal-sized groups and the Cox regression model was used in one to form a treadmill score that was then validated in the other group. The final treadmill score was calculated as follows: exercise time--(5 X ST deviation)--(4 X treadmill angina index). Using this treadmill score, 13% of the patients were found to be at high risk; 53%, at moderate risk; and 34%, at low risk. The treadmill score added independent prognostic information to that provided by clinical data, coronary anatomy, and left ventricular ejection fraction: patients with three-vessel disease with a score of -11 or less had a 5-year survival rate of 67%, and those with a score of +7 or more had a 5-year survival rate of 93%. The treadmill score was useful for stratifying prognosis in patients with suspected coronary artery disease who were referred to us for catheterization, and may provide a useful adjunct to clinical decision making in the larger population of patients being evaluated for chest pain.

Adult↗
PubMed1987

The changing survival benefits of coronary revascularization over time.

Previous comparisons of medical and surgical therapy for coronary artery disease were performed in the 1970s and may need to be updated to reflect current treatment efficacy. The purpose of this investigation was to determine the impact on long-term patient survival of changes over time in medical and surgical therapy. Among 5125 patients referred for catheterization between 1969 and 1984, 2261 underwent surgery, and 2864 received medical therapy. Survival in both medically and surgically treated patients improved over time. The improvement in medical patients was due to less sick patients being treated (a decreasing baseline risk), while that observed in surgical patients was due to refinements in care. The rate of improvement in survival over time was much greater in surgical patients, and the difference as compared with medical therapy was highly significant (treatment interaction with time p less than .0001). Estimates of 5 year survival adjusted for baseline risk factors for a patient in 1977 with one-, two-, or three-vessel disease and an ejection fraction of 0.40 were 0.88, 0.80, and 0.64 in medically treated, and 0.88, 0.87, and 0.80 in surgically treated patients. Corresponding projected estimates for 1984 were unchanged for medical patients but improved for surgical patients (0.93, 0.92, and 0.90). Thus, the projected survival benefits of surgery in 1984 appear more significant for all categories of coronary artery disease because of a differential improvement in surgical therapy. These data are relevant to therapeutic decision making for current patients and emphasize the importance of continued analysis of this topic as treatment efficacies change over time.

Coronary Artery Bypass↗
PubMed1986

Prognostic implications of angiographically normal and insignificantly narrowed coronary arteries.

The clinical presentation and prognosis of 1,977 consecutive patients with normal coronary arteries or "insignificant" coronary artery disease (CAD) (no major epicardial artery with 75% or more luminal diameter narrowing) were examined. Compared with patients with significant CAD, these patients had a lower frequency of traditional cardiac risk factors and abnormalities on the rest and exercise electrocardiogram. Cardiac survival was 99% at 5 years of follow-up and 98% at 10 years for patients with normal or insignificantly narrowed coronary arteries. Patients with normal coronary arteries differed from those with insignificant CAD in their myocardial infarction free survival rate: 99% at 5 years and 98% at 10 years for patients with normal coronary arteries, compared with 97% at 5 years and 90% at 10 years for patients with insignificant CAD. A strong relation occurred between the amount of insignificant CAD and follow-up cardiac events (chi 2 = 21.5, p less than 0.0001). Cardiac risk factors were statistically related to the risk of follow-up cardiovascular events when considered alone (chi 2 = 4.93, p = 0.026), but this relation lost significance after adjusting for the effect of coronary anatomy. Patients in both groups continued to have cardiac symptoms that resulted in frequent hospitalizations, medication use and job disability. Almost 50% in any given year of follow-up could not perform activities of high metabolic equivalent requirement and 70% had continuing symptoms of chest discomfort. Although these patients are at low risk of death, many remain functionally impaired for years.

Coronary Angiography↗
PubMed1986

Medical, psychological and social correlates of work disability among men with coronary artery disease.

This study identifies the medical, psychologic and social factors that independently affect employment in patients with coronary artery disease (CAD). At coronary angiography, extensive clinical, psychological and social profiles were collected on 814 men younger than 60 years with documented CAD. Clinical factors studied included measures of symptom severity, prior myocardial infarction, coronary anatomy and left ventricular function. Psychosocial factors studied included the Minnesota Multiphasic Personality Inventory (MMPI), Zung Depression and Anxiety Scales, a type A structured interview, Jenkins Activity Survey and measures of education and social support. Multiple logistic regression analyses were used to assess the relative strength of the relation between these different factors and the patients' employment status. Many single factors differed between the 204 men (25%) who were disabled and the 610 (75%) who were not. Disabled men were less educated but no different in age, marital status or number of dependents. Disabled men had lower ejection fractions and higher indexes of angina, previous myocardial infarction and coexisting vascular disease. Disabled men also were more depressed and anxious and had lower ego strength and higher hypochondriasis scores on the MMPI, but were no different in type A behavior. By multivariable analysis, the most significant (p less than 0.01) independent predictors of work disability were, in decreasing order of importance, low education level, history of myocardial infarction, high levels of depression and high levels of hypochondriasis. It is concluded that psychological and social factors are strongly related to work status in patients with CAD, and may be more important than medical factors.

Anxiety↗
PubMed1986

Predicting outcome in coronary disease. Statistical models versus expert clinicians.

To study the accuracy with which long-term prognosis can be predicted in patients with coronary artery disease, prognostic predictions from a data-based multivariable statistical model were compared with predictions from senior clinical cardiologists. Test samples of 100 patients each were selected from a large series of medically treated patients with significant coronary disease. Using detailed case summaries, five senior cardiologists each predicted one- and three-year survival and infarct-free survival probabilities for 100 patients. Fifty patients appeared in multiple samples for assessing interphysician variability. Cox regression models, developed using patients not in the test samples, predicted corresponding outcome probabilities for each test patient. Overall, model predictions correlated better with actual patient outcomes than did the doctors' predictions. For three-year survival, rank correlations were 0.61 (model) and 0.49 (doctors). For three-year infarct-free survival predictions, correlations with outcome were 0.48 (model) and 0.29 (doctors). Comparisons by individual doctor revealed Cox model three-year survival predictions were better than those of four of five doctors (model predictions added significant [p less than 0.05] prognostic information to the doctor's predictions, whereas the converse was not true). For infarct-free survival, the Cox model was superior to all five doctors. Where predictions were made by multiple doctors, the interphysician variability was substantial. In coronary artery disease, statistical models developed from carefully collected data can provide prognostic predictions that are more accurate than predictions of experienced clinicians made from detailed case summaries.

Coronary Disease↗
PubMed1986

Value of sonographic screening for gallstones in patients with chest pain and normal coronary arteries.

The prevalence of sonographically detectable gallstones in patients with chest pain and normal coronary arteries was compared with the prevalence of gallstones in patients referred to sonography for nonbiliary disease. Among 545 patients with chest pain and normal coronary arteriograms, 101 (18.5%) were referred for sonographic examination of the gallbladder. This test group was compared to a matched control group (n = 101) undergoing abdominal sonography for nonbiliary disease. Six patients (5.9%) in the test group and eight patients (7.9%) in the control group were found to have gallstones by accepted sonographic criteria. Studies based on oral cholecystogram screening of healthy populations have claimed a prevalence of cholelithiasis of 2.3%-6.2% for males and 2.3%-12% for females. The authors were unable to demonstrate a higher prevalence of sonographically identified gallstones in patients with chest pain and normal coronary arteries than in patients examined for nonbiliary disease. The frequency of gallstones in this test group is comparable to that reported for a screened population of healthy men and women.

Adult↗
PubMed1986

Utilization of lung scans by clinicians.

To determine the effect of clinical assessments and lung scan results on the management of patients, we studied 566 consecutive patients referred for lung scans because of suspected pulmonary embolism. Prior to the lung scan, the clinician was asked to estimate the probability of pulmonary embolus. Two or three days later the physician was contacted to determine how the patient was managed. The results of the lung scan strongly influenced patient management. Patients with high probability lung scans were treated for pulmonary embolism regardless of the clinical pretest estimate. Low and intermediate probability lung scans resulted in most patients not being treated for pulmonary embolism and not referred for pulmonary angiography. Only 55 of the 566 patients were referred for pulmonary angiography, and approximately one-half of these patients had lung scans with an intermediate probability for pulmonary embolism.

Anticoagulants↗
PubMed1985

Prognostic significance of precordial ST-segment depression during inferior acute myocardial infarction.

To study the mechanism and prognostic importance of precordial ST-segment depression during inferior acute myocardial infarction, 162 patients admitted during 1969 through 1982 were identified. Patients with ST depression in leads V1, V2 and V3 had significantly larger infarctions as assessed by a QRS scoring system. Hospital mortality was 4% (3 of 75) among patients without ST depression, and 13% (11 of 87) in patients with ST depression. The relation between the amount of ST depression and hospital mortality was significant (p less than 0.001 by logistic regression), and remained significant (p less than 0.003) after adjusting for other potentially prognostic factors. Among patients discharged from the hospital, the 5-year survival was 92% in those without precordial ST depression and 80% in those with precordial ST depression (p = 0.058 by the Cox model). Precordial ST-segment depression on the admission electrocardiogram during an inferior acute myocardial infarction indicates a larger infarction, predicts a higher hospital mortality and suggests a worse long-term prognosis after discharge.

Adult↗
PubMed1985

Prognostic value of a coronary artery jeopardy score.

The prognostic value of a coronary artery jeopardy score was evaluated in 462 consecutive nonsurgically treated patients with significant coronary artery disease, but without significant left main coronary stenosis. The jeopardy score is a simple method for estimating the amount of myocardium at risk on the basis of the particular location of coronary artery stenoses. In patients with a previous myocardial infarction, higher jeopardy scores were associated with a lower left ventricular ejection fraction. When the jeopardy score and the number of diseased vessels were considered individually, each descriptor effectively stratified prognosis. Five year survival was 97% in patients with a jeopardy score of 2 and 95, 85, 78, 75 and 56%, respectively, for patients with a jeopardy score of 4, 6, 8, 10 and 12. In multivariable analysis when only jeopardy score and number of diseased vessels were considered, the jeopardy score contained all of the prognostic information. Thus, the number of diseased vessels added no prognostic information to the jeopardy score. The left ventricular ejection fraction was more closely related to prognosis than was the jeopardy score. When other anatomic factors were examined, the degree of stenosis of each vessel, particularly the left anterior descending coronary artery, was found to add prognostic information to the jeopardy score. Thus, the jeopardy score is a simple method for describing the coronary anatomy. It provides more prognostic information than the number of diseased coronary arteries, but it can be improved by including the degree of stenosis of each vessel and giving additional weight to disease of the left anterior descending coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1985

Randomized trials of coronary artery bypass surgery: impact on clinical practice at Duke University Medical Center.

Trends in practice patterns at Duke University Medical Center were assessed in patient groups comparable to those enrolled in the three major randomized trials of coronary artery bypass grafting (CABG). In addition, changes in practice patterns that appeared unrelated to the randomized trials were examined. Most patients with 75% or greater left main stenosis have been treated surgically after publication of the Veterans Administration Cooperative Study, but little change was noted in the proportion of patients with 50% left main stenosis who have been treated surgically. A trend towards selection of surgical therapy for patients with three-vessel disease and normal left ventricular function was evident before the publication of the European Coronary Surgery Study, although one-third of patients in this category continue to be treated nonsurgically after publication of the results of the trial. For the past decade, most patients who would have been eligible for the Coronary Artery Surgery Study have been treated nonsurgically. We have also documented trends in practice patterns that are independent of the results of randomized trials. The advent of percutaneous transluminal angioplasty has provided another therapeutic alternative that has been used increasingly. In addition, growing numbers of patients with advanced age, unstable angina, or markedly depressed left ventricular ejection fraction are being evaluated with cardiac catheterization despite the lack of supporting randomized trials. Randomized trials have placed our understanding of the effects of CABG on a sound foundation, but it is evident that clinicians continue to consider many other factors when therapeutic decisions are made.

Academic Medical Centers↗
PubMed1984

"Left main equivalent" coronary artery disease: its clinical presentation and prognostic significance with nonsurgical therapy.

The clinical characteristics and nonsurgical prognosis of 55 patients with "left main (LM) equivalent" coronary artery disease (CAD) were evaluated and defined as: (1) greater than or equal to 75% diameter reduction of the left anterior descending coronary artery (LAD) before the takeoff of any large septal perforator or anterolateral (diagonal) branches; (2) greater than or equal to 75% diameter reduction of the left circumflex artery (LC) before the takeoff of any large marginal branch; and (3) absence of greater than or equal to 50% stenosis of the LM coronary artery. Compared with nonsurgically treated patients with greater than or equal to 75% stenosis of the LM artery, patients with LM equivalent CAD had a shorter duration of symptoms (median of 51 months vs 66 months) and more often had a Q wave on the electrocardiogram (60 vs 39%). Survival in patients with LM equivalent CAD (78% at 1 year and 55% at 5 years) was better than that in patients with LM disease with nonsurgical therapy (65% at 1 year and 40% at 5 years) (p = 0.02), although the rate of freedom from cardiovascular events was not significantly different. Compared with other nonsurgically treated patients with 2- or 3-vessel CAD involving the LAD and LC (28 and 42%, respectively, with progressive angina), patients with LM equivalent CAD had more severe anginal symptoms (55% with progressive angina) and a longer duration of symptoms (medians of 20 months in 2-vessel CAD, 36 months in 3-vessel CAD and 51 months in LM equivalent CAD).(ABSTRACT TRUNCATED AT 250 WORDS)

Constriction, Pathologic↗
PubMed1984

Prognostic indicators from radionuclide angiography in medically treated patients with coronary artery disease.

The purpose of this investigation was to determine which variables obtained when performing radionuclide angiography predict subsequent survival or total events (cardiovascular death or nonfatal myocardial infarction) in stable patients with symptomatic coronary artery disease (CAD). Univariable and multivariable analyses of 6 variables, including ejection fraction (EF) at rest and exercise, change in EF with exercise, development of ischemic chest pain or electrocardiographic changes, left ventricular (LV) wall motion abnormalities and exercise time were examined in 386 patients followed up to 4.5 years. Univariate analyses revealed that the exercise EF was the variable most closely associated with future events (p less than 0.01), followed by EF at rest, wall motion abnormalities and exercise time. Multivariable analyses revealed that once the exercise EF was known, no other radionuclide variables contributed independent information about the likelihood of future events. Multivariable analyses also revealed that the exercise EF describes much of the prognostic information of coronary anatomy. Our findings suggest that the radionuclide angiogram is useful in predicting future events in patients with stable CAD, although examination in conjunction with other clinical descriptors will be necessary to further quantify this contribution.

Cardiac Output↗
PubMed1984

Factors affecting sensitivity and specificity of exercise electrocardiography. Multivariable analysis.

Unlike the predictive value of a diagnostic test, which depends on the prevalence of disease in the population tested, its sensitivity and specificity have been assumed to be constants. This assumption was examined in patients who had both exercise electrocardiography and cardiac catheterization. The effects on sensitivity of factors from clinical history, catheterization, and exercise performance were defined by multivariable logistic regression analysis in 1,401 patients with coronary disease; effects on specificity were defined by a similar analysis in 868 patients without coronary disease. Five factors had significant, independent effects on exercise electrocardiographic sensitivity: maximal exercise heart rate, number of diseased coronary arteries, type of angina, and the patient's age and sex. Only maximal exercise heart rate had a significant, independent effect on exercise electrocardiographic specificity. Thus, the sensitivity and specificity of exercise electrocardiography vary with clinical history, extent of disease, and treadmill performance; the sensitivity and specificity of other diagnostic tests may also vary.

Adult↗
PubMed1984

The effect of crossovers on estimates of survival in medically treated patients with coronary artery disease.

Among 1661 consecutive patients with significant coronary artery disease treated medically at the Duke University Medical Center, 239 have undergone aortocoronary bypass surgery after at least 6 months of medical management. The purpose of this investigation was twofold: (1) to identify the distinguishing characteristics of these treatment crossovers; and (2) to illustrate a method of estimating the effect that withdrawing the crossovers from the analysis would have on the survival of the medically managed patients. Of 81 baseline characteristics compared, 25 were significantly (p less than 0.05) different between crossovers and noncrossovers. These included five characteristics that had previously been determined to be independent predictors favoring improved survival in medically treated coronary artery disease. A Cox regression analysis identified six variables independently associated with the time until crossover surgery. Crossover patients were younger and had superior ventricular function. A hazard score, which summarized in a single variable the overall risk of mortality, was developed from the prognostic baseline characteristics. Crossover patients had significantly (p = 0.003) lower hazard scores and hence would have been expected to have a superior survival compared with noncrossover patients. In our series, survival in the medically treated patients would likely have been higher had the crossovers remained in the medical group.

Coronary Artery Bypass↗
PubMed1984

Clinical characteristics and long-term survival of patients with variant angina.

We studied 109 consecutive patients with variant angina who underwent cardiac catheterization over an 11 year period. All patients were followed for at least 6 months or until death, and 46 patients (22 treated medically and 24 treated surgically) were followed for 5 years or more. Of the 62 patients initially treated medically, 14 had nonfatal myocardial infarctions (12 within 1 month of catheterization) and 12 died (six within 6 months). Survival probabilities at 1, 3, and 5 years were 0.88, 0.84, and 0.77, respectively. Of the 48 surgically treated patients (including four patients initially treated medically and one initially treated with coronary angioplasty), four had nonfatal infarctions (three in the perioperative period) and three died (all in the perioperative period). The survival probability in these patients at 1 year was 0.94 and remained unchanged at 3 and 5 years. Only one nonfatal infarction and no deaths have occurred in the group of surgically treated patients subsequent to hospital discharge. Three additional patients were treated with coronary angioplasty. The single most important prognostic factor in medically treated patients was the presence or absence of fixed obstructive coronary artery disease. Infarction-free survival probabilities at 1 and 3 years in the 23 patients without significant coronary artery disease were 1.0 and 0.89, compared with 0.51 and 0.46 in the 39 patients with significant coronary disease. Analysis by the Cox model showed that variant angina patients had a higher probability of death and nonfatal infarction than did those with nonvariant angina coronary disease if other important prognostic variables were held constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris, Variant↗