1/7. Practical application of adult Treatment Panel III guidelines: three illustrative case histories.The adult Treatment Panel III (ATP III) guidelines continue to emphasize intensive treatment for persons at risk for coronary heart disease (CHD). The newest feature is a focus on primary prevention in persons with multiple risk factors; the updated guidelines recognize diabetes as a CHD risk equivalent. These groups of people already are at high risk and can benefit from increased intensive treatment to lower serum low-density lipoprotein cholesterol (LDL-C) levels. The ATP III guidelines establish lower targets for LDL-C and triglyceride levels and higher targets for the high-density lipoprotein cholesterol level. The guidelines also combine several risk factors to estimate the probability of CHD with use of the Framingham risk point-scoring formula and emphasize the multifactorial benefits of drug therapy as an adjunct to lifestyle changes.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
2/7. Creative novation behaviour therapy as a prophylactic treatment for cancer and coronary heart disease: Part I--Description of treatment.This paper describes a novel method of behaviour therapy applied to cancer-prone and coronary heart disease-prone patients in a prophylactic manner, to reduce the probability of their dying of cancer or coronary heart disease. The treatment can also be applied to patients already suffering from cancer in order to prolong their lives. The methods used are described in considerable detail, together with the rationale leading to their adoption. In Part II of this paper are the results of several studies showing that the methods are surprisingly successful in preventing death in cancer-prone and coronary heart disease-prone probands, and prolonging life in patients already suffering from terminal disease.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
3/7. exercise stress testing in the patient with coronary artery disease. Part II.Cardiac exercise stress testing has both diagnostic and prognostic implications. ECG changes, hemodynamic responses, and symptoms during exercise are clues to the functional capacity, severity of coronary artery disease, and probability of future coronary events. The time and workload required for a positive response to exercise and the length of time the ECG changes persist during recovery are indicators of the degree of coronary disease and are useful in predicting future coronary events.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
4/7. How did the acute ischemic heart disease predictive instrument reduce unnecessary coronary care unit admissions?The use of the acute ischemic heart disease predictive instrument reduced coronary care unit (CCU) admissions for patients without acute ischemic heart disease by 30%. One hypothesis holds that it reinforced physicians' correctly low estimates of the probability of acute ischemia, supporting a decision against CCU admission, another that it lowered physicians' over-high probability estimates for acute ischemia so that CCU admission was felt to be unnecessary. The authors asked 86 physicians to estimate the probability of acute ischemia for each of three study cases and to decide on CCU admission. For the low-probability case, the mean of physicians' probability estimates for acute ischemia was 46%, vs. the predictive instrument's calculated probability of 19% (p less than 0.00001), a 142% over-estimation by the physicians. For the medium-probability case, the mean of physicians' estimates was 54%, vs. the calculated probability of 58% (not significant). For the high-probability case, the mean of physicians' estimates was 82%, vs. the calculated probability of 78% (not significant). All cases for which physicians considered not admitting to the CCU corresponded to their probability estimates of acute ischemia's being in a threshold range of approximately 10 to 30%. These results support the hypothesis that the mechanism by which the predictive instrument reduces unnecessary CCU admissions is by downward correction of physicians' overly-high suspicions of acute cardiac ischemia into a threshold range for which CCU admission is considered unnecessary.- - - - - - - - - - ranking = 11keywords = probability (Clic here for more details about this article) |
5/7. Reliability of Bayesian probability analysis for predicting coronary artery disease in a veterans hospital.To assess the accuracy of Bayesian probability analysis for the prediction of coronary artery disease, post-test probabilities were generated by the application of three Bayesian algorithms to the clinical and noninvasive test results of 199 patients undergoing angiography in a veterans' hospital. All assumed conditional independence but each used different pre-test and conditional probabilities. Two statistical approaches were employed: (1) Sorting of patients in ascending deciles of probability and comparing expected and observed probabilities in each decile. (2) Calculation of normally distributed reliability statistics which do not depend on probability subsets and the comparison of resulting probability distributions using these statistics. Both statistical approaches revealed that the Bayesian algorithms overestimated disease probability when it was high and underestimated it when low. Though all three algorithms were frequently incorrect, they differed significantly in their accuracies, suggesting that errors in Bayesian analysis are caused by factors other than the assumption of independence. The errors may be due to differences in sensitivity and specificity of tests applied in different institutions.- - - - - - - - - - ranking = 9keywords = probability (Clic here for more details about this article) |
6/7. Bayes' theorem--a review.Formal probability analysis based on Bayes' theorem greatly enhances the diagnostic capabilities of exercise testing in the detection of coronary artery disease. The pretest characteristics of a patient must be considered along with the test results in arriving at a post-test probability of disease. The essential concepts of probability analysis have broad applications in the entire field of medicine.- - - - - - - - - - ranking = 3keywords = probability (Clic here for more details about this article) |
7/7. Localization of coronary artery disease with exercise electrocardiography: correlation wit thallium-201 myocardial perfusion scanning.In 61 patients with single vessel coronary artery disease (70 percent or greater obstruction of luminal diameter in only one vessel) and no previous myocardial infarction, the sites of ischemic changes on 12 lead exercise electrocardiography and on thallium-201 myocardial perfusion scanning were related to the obstructed coronary artery. The site of exercise-induced S-T segment depression did not identify which coronary artery was obstructed. In the 37 patients with left anterior descending coronary artery disease S-T depression was most often seen in the inferior leads and leads V4 to V6, and in the 18 patients with right coronary artery disease and in the 6 patients with left circumflex artery disease S-T depression was most often seen in leads V5 and V6. Although S-T segment elevation was uncommon in most leads, it occurred in lead V1 or a VL, or both, in 51 percent of the patients with left anterior descending coronary artery disease. A reversible anterior defect on exercise thallium scanning correlated with left anterior descending coronary artery disease (probability [p] less than 0.0001) and a reversible inferior thallium defect correlated with right coronary or left circumflex artery disease (p less than 0.0001). In patients with single vessel disease, the site of S-T segment depression does not identify the obstructed coronary artery; S-T segment elevation in lead V1 or aVL, or both, identifies left anterior descending coronary artery disease; and the site of reversible perfusion defect on thallium scanning identifies the site of myocardial ischemia and the obstructed coronary artery.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |