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Biomedical subjects

K Detre

Publications and source records attributed to K Detre.

At least 55 records · Page 3Linked to original sources
PubMed1988

Degree of revascularization in patients with multivessel coronary disease: a report from the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

There is controversy regarding the application of angioplasty to patients with multivessel disease in whom all significant stenoses are not dilated. We analyzed the outcomes of 286 patients with multivessel disease and prior successful angioplasty at a mean follow-up duration of 26.2 months. End points analyzed included death, myocardial infarction, late revascularization, and angina pectoris. After successful angioplasty, 127 patients had no residual stenoses of 70% or greater (group 1) and 159 patients had one or more residual stenoses of 70% or greater (group 2). Because there were significant differences in baseline risk factors between the two groups, a logistic regression model was used to make the necessary adjustments in the analysis. Adjusted estimates of the risk of death, death/myocardial infarction, or presence of angina pectoris did not differ between the two groups. Group 2 patients, however, had more coronary artery bypass surgery during follow-up, while those in group 1 had more second PTCA procedures. Results suggest that angioplasty can be safely applied to patients with multivessel disease, even when all significant stenoses are not dilated.

Angioplasty, Balloon↗
PubMed1988

Five-year changes in coronary arteries of medical and surgical patients of the Veterans Administration Randomized Study of Bypass Surgery.

Progression of coronary artery disease was evaluated after 5 years of follow-up in 119 medically and 109 surgically treated randomized patients who adhered to their assigned therapy. Progression was defined as the appearance of a new lesion (greater than or equal to 50% stenosis) or worsening of a preexisting lesion in a coronary artery. Progression occurred in 36% (97 of 268) of the arteries in medical patients, in 38% (35 of 93) of the ungrafted arteries in surgical patients, in 74% (72 of 97) of the arteries with patent grafts at 5 years, and in 63% (29 of 46) of the arteries with closed grafts. After adjustment for the vessel system and the severity of disease at baseline, the risk of progression was three to six times higher in grafted arteries than in ungrafted arteries (p less than 0.01). For grafted arteries, the risk of progression was twice as high in arteries with patent grafts compared with those with closed grafts (p = 0.14). The majority (78%) of the progression in grafted arteries was to 100% occlusion. Proximal and distal progression rates in arteries with patent grafts were 74% and 11%, respectively. In the majority of arteries with closed grafts that progressed, the site of progression could not be determined. Regardless of treatment, the risk of progression was two times higher in the right coronary artery than in the left anterior descending or circumflex arteries. Progression risk was also twice as high in arteries with moderate disease at baseline compared with those with minimal or severe disease.

Coronary Angiography↗
PubMed1987

Ten-year effect of medical and surgical therapy on quality of life: Veterans Administration Cooperative Study of Coronary Artery Surgery.

The long-term effect of medical vs surgical therapy on quality of life was evaluated by New York Heart Association functional classification, severity of angina and exercise performance in 427 surviving patients with stable angina at 10 years. Surgically assigned patients had significantly more improvement in functional classification, relief of angina and exercise performance at 1 and 5 years than medically assigned patients. Relative to entry, functional classification was improved in 65% of surgically treated patients at 1 year and in 51% at 5 years, compared with 45% and 40%, respectively, of medically treated patients. Marked improvement in angina was observed in 49% of surgical patients at 1 year and in 41% at 5 years, vs 12% and 17%, respectively, in medical patients. At 10 years, quality of life was not significantly different in the 2 treatment groups: 52% of surgical patients had an improved functional classification, compared with 46% of medical patients, while 33% of surgical and 37% of medical patients had a marked improvement in angina. Exclusion of medical and surgical nonadherers had little effect on the 1- and 5-year comparisons. The 10-year treatment differences, however, were accentuated when 123 medically assigned patients who later underwent operation and who benefited from it were excluded from the analysis. In surgical patients, a strong association was observed between graft patency and functional class at 1 year, but not at 5 and 10 years. In general, patients with some or all grafts open had more improvement in functional classification than patients with all grafts closed.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1987

Risk factors for seroconversion to human immunodeficiency virus among male homosexuals. Results from the Multicenter AIDS Cohort Study.

2507 homosexual men who were seronegative for human immunodeficiency virus (HIV) at enrollment were followed for six months to elucidate risk factors for seroconversion to HIV. 95 (3.8%) seroconverted. Of men who did not engage in receptive anal intercourse within six months before baseline and in the six-month follow-up period, only 0.5% (3/646) seroconverted to HIV. By contrast, of men who engaged in receptive anal intercourse with two or more partners during each of these successive six-month intervals, 10.6% (58/548) seroconverted. No HIV seroconversions occurred in 220 homosexual men who did not practise receptive or insertive anal intercourse within twelve months before the follow-up visit. On multivariate analysis receptive anal intercourse was the only significant risk factor for seroconversion to HIV, the risk ratio increasing from 3-fold for one partner to 18-fold for five or more partners. Furthermore, data for the two successive six-month periods show that men who reduced or stopped the practice of receptive anal intercourse significantly lowered their risk of seroconversion to 3.2% and 1.8%, respectively. Receptive anal intercourse accounted for nearly all new HIV infections among the homosexual men enrolled in this study, and the hazards of this practice need to be emphasised in community educational projects.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Comparison of the logistic and Cox regression models when outcome is determined in all patients after a fixed period of time.

This paper presents an evaluation of the logistic and Cox regression models for a prospective study when the outcome is binary and is determined in all patients after a fixed period of time. The similarities and differences between the regression coefficients and test statistics are given for the two-sample case. Extension of results to the multivariate case and under product binomial sampling are discussed. The results are illustrated using data from a clinical trial designed to evaluate the effect of a lipid lowering drug on progression of coronary artery disease.

Coronary Disease↗
PubMed1987

Coordinating center follow-up in the Veterans Administration Cooperative Study of Coronary Artery Bypass Surgery.

In the VA Cooperative Study of Coronary Artery Bypass Surgery, follow-up by the participating investigators was completed in 1984 and annual centralized follow-up by the coordinating center for an additional 5 years was initiated in 1985. Follow-up was restricted to key outcomes that could be reliably obtained in most patients-survival, severity of angina, myocardial infarction and bypass surgery. Ninety-five percent of patients consented to annual follow-up by telephone or mail. At the first annual follow-up, 95% of all survivors were contacted; 95% were also contacted at the second follow-up. In the initial follow-up, survival status was known in all patients and severity of angina was recorded in 93% of survivors; all bypass operations and all but one infarct identified were documented by a discharge summary. Our results indicate that coordinating center follow-up was effective in a long-term study of a chronic disease and depended on the willingness of patients to participate, the experience of the interviewers, and the ability of the coordinating center to contact patients and retrieve outcome data. This report describes the methods used for the centralized follow-up of the surviving patients and summarizes the initial follow-up results. The limitations and advantages of this approach are also discussed.

Clinical Trials as Topic↗
PubMed1985

The 5 year effect of bypass surgery on relief of angina and exercise performance.

The 5 year effect of medical vs surgical treatment on symptoms and exercise performance was evaluated in patients with stable angina who entered the Veterans Administration Cooperative Study from 1972 to 1974. Severity of angina was evaluated by a physician-administered angina questionnaire and physical working capacity was assessed by exercise testing. Angina was substantially relieved in surgical patients at 1 year, with 78% having mild or no angina compared with only 28% at entry. The corresponding rates in medical patients showed little change: 38% at 1 year and 32% at entry. At 5 years the percentage of surgical patients with mild or absent angina decreased from the 1 year rate of 78% to 64%, whereas the medical group exhibited a small increase from 38% to 49%. Similar results were obtained by evaluating changes in angina compared to entry. At 1 year 49% of surgical patients were markedly improved compared with only 12% of medical patients. At 5 years the percentage of surgical patients who remained markedly improved decreased to 41%, whereas the medical group with marked improvement increased slightly from 12% at 1 year to 17% at 5 years. Medication requirements were markedly reduced in surgical patients with only a slight increase in medical patients. Exclusion of nonadherers from the analysis did not change the results. Exercise testing revealed comparable changes in physical performance. At 1 year surgical patients had fewer tests stopped by angina compared with medical patients (28% vs 64%), a higher estimated oxygen consumption (26 vs 21 ml/kg/min) and treadmill exercise duration (7.3 vs 4.9 min). Other measures of exercise performance were comparably improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1984

Characteristics and outcome of medical nonadherers in the Veterans Administration Cooperative Study of Coronary Artery Surgery.

During a 7-year follow-up period in the Veterans Administration Study of Bypass Surgery, 75 (24%) of 311 medically assigned patients without left main disease "crossed over" to surgical treatment. Nineteen baseline, clinical, electrocardiographic and angiographic characteristics of the 75 crossover patients were compared with those of the 236 patients who adhered to medical treatment. At entry into the study, the crossover group contained more patients with severe angina than did the medical adherers group (p less than 0.05) and fewer patients with electrocardiographic evidence of previous myocardial infarction (p less than 0.05). Other entry characteristics were similar in distribution among those in the medical-adherer and crossover groups. The 2 major reasons for crossover were persistence or progression of angina, which occurred in 43 and 37% of the 75 crossover patients, respectively. There was no relation between progression of symptoms and angiographic progression of coronary narrowing. Thus, crossover was not determined by more severe coronary narrowing, but was associated with more severe symptoms and a lower incidence of infarction. The medically randomized patients who later underwent surgery (medical "nonadherers") experienced the same relief of angina 1 year after surgery as did the surgically randomized patients who initially received surgery (surgical "adherers"); however, their overall 7-year survival was lower (77% for medical nonadherers vs 83% for surgical adherers; difference not significant).

Clinical Trials as Topic↗
PubMed1983

Percutaneous transluminal coronary angioplasty: report of complications from the National Heart, Lung, and Blood Institute PTCA Registry.

The complications reported in the first 1500 patients enrolled in the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty (PTCA) Registry are analyzed. Data were contributed from 73 centers between September 1977 and April 1981. PTCA was successful in 63% of attempts. Five hundred forty-three in-hospital complications occurred in 314 patients (21%). The most frequent complications were prolonged angina in 121, myocardial infarction (MI) in 72, and coronary occlusion in 70. One hundred thirty-eight patients (9.2%) had major complications (MI, emergency surgery or in-hospital death). One hundred two patients (6.8%) required emergency surgery, usually for coronary dissection or coronary occlusion. Sixteen patients (1.1%) died in-hospital; the mortality rate was 0.85% in patients with one-vessel disease and 1.9% in those with multivessel disease. The mortality rate was significantly higher in patients who had had bypass surgery (p less than 0.001). Nonfatal complications were significantly influenced by the presence of unstable angina (p less than 0.001) and initial lesion severity greater than 90% diameter stenosis (p less than 0.001). This report delineates and assesses the complications encountered with PTCA during its initial 3 1/2-year clinical experience. These results support the relative safety of PTCA as a method of nonsurgical myocardial revascularization in carefully selected patients.

Adult↗
PubMed1982

Percutaneous transluminal coronary angioplasty: report from the Registry of the National Heart, Lung, and Blood Institute.

Data have been collected from 34 centers in the United States and Europe performing percutaneous transluminal coronary angioplasty since September 1977. The procedure was carried out in 631 patients, with an average age of 51 years (range 23 to 76), of whom 80 percent had single vessel coronary disease, 17 percent had double or triple vessel disease and 3 percent had stenosis of the left main coronary artery. Coronary angioplasty was successful (greater than 20 percent decrease of coronary stenosis) in 59 percent of the stenosed arteries. The mean degree of stenosis was reduced from 83 to 31 percent. Emergency coronary bypass operation was required in 40 patients (6 percent). Myocardial infarction occurred in 29 patients (4 percent). In-hospital death occurred in six patients (1 percent), three with single vessel and three with multivessel disease. Ninety-one patients have been followed up for at least 1 year after coronary angioplasty. Of the 65 patients with an initially successful angioplasty, 83 percent were in improved condition compared with their status before angioplasty. Thus, the initial satisfactory results obtained in a few centers have now been confirmed in many centers using transluminal coronary angioplasty.

Adult↗
PubMed1982

The problem of attributing deaths of nonadherers: the VA coronary bypass experience.

In the VA Coronary Artery Surgery Study 84 of the 354 patients randomized to medical treatment had subsequent bypass surgery during a 6-year follow-up period. Of these, 18 had left main disease. The remaining 66 of 311 without left main disease crossed over to surgery at a constant rate of about 4% per year. The traditional assumption that patients who crossed over were at greater risk of dying than those who adhered was not substantiated by an analysis of known baseline risk factors. Crossover was not related to number of vessels diseased or other angiographic or noninvasive risk factors but was related to severity of angina which was not a risk factor in this study. These findings lend support to the validity of analyzing our survival data by the crossover method where nonadherers are counted as lost to follow-up at the time of treatment change.

Clinical Trials as Topic↗
PubMed1982

An international collaborative clinical study mechanism for resuscitation research.

Recent experimental and clinical studies of cardiac arrest, suggesting a brain damage ameliorating effect of thiopental loading, stimulated the development of an international randomized clinical trial of brain resuscitation. Twelve collaborating hospitals in 9 countries are testing the efficacy of post-cardiac arrest thiopental loading (30 mg/kg body wt). The methodology for assessing insult and outcome data, as well as risk and benefit monitoring, is described. This clinical trial will be completed in 1983 and is expected to provide valuable data about the efficacy of thiopental loading. The study mechanism is now well-established and ready for the evaluation of future promising brain resuscitation therapies.

Clinical Trials as Topic↗
PubMed1981

Effect of bypass surgery on survival in patients in low- and high-risk subgroups delineated by the use of simple clinical variables.

A multivariate risk function was developed on data from all 508 medical patients in the Veterans Administration (VA) randomized study of coronary bypass surgery. The variables, in order of importance, were ST-segment depression on resting ECG, history of myocardial infarction, history of hypertension and New York Heart Association functional classification III or IV. These noninvasive variables have been reported to be risk factors in natural-history studies of coronary heart disease (CHD). Applying the risk function to medical and surgical patients of the 1972-1974 cohort yielded a 5-year probability of dying for each patient. Investigation of treatment effects in approximate terciles obtained by collapsing the probability distribution into low-, middle- and high-risk groups showed that surgery was beneficial for patients in the high-risk tercile even after removal of patients with left main coronary artery disease (17% surgical vs 34% medical mortality at 5 years; p less than 0.01). This finding was accentuated when patients in the 10 hospitals with the lowest operative mortality (3.3%) were compared. Mortality results in the low-risk tercile favored medical treatment (medical vs surgical mortality 7% vs 17%; p less than 0.05). The risk function predicted mortality well not only for te VA medical group, but also for an independent symptomatic CHD population from the University of Alabama arteriography registry. This report further delineates the advantages and limitations of coronary bypass surgery in CHD patients with chronic stable angina.

Coronary Artery Bypass↗
PubMed1980

A computer program for comparing survival experience of two groups after adjustment for relevant covariates.

A computer program is described which evaluates the difference in survival between two groups of patients based on the methods of Mantel [1] and Hankey and Myers [3]. Life table analysis is based on the stratification of prognostic variables. In addition, an adjusted survival curve is computed for one group of patients relative to the other group based on differences in the distribution of these variables. Plots of cumulative survival curves are optionally provided.

Computers↗