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Biomedical subjects

C D Furberg

Publications and source records attributed to C D Furberg.

At least 199 records · Page 11Linked to original sources
PubMed1984

Effect of long-term prophylactic treatment on survival after myocardial infarction.

Survivors of the acute phase of a myocardial infarction still have an increased risk of dying, primarily due to causes directly attributable to their coronary heart disease. This review of randomized clinical trials of various interventions with the potential to prolong life in these patients is an attempt to answer a vitally important question. What, if anything, can be done to improve the long-term prognosis in patients who have survived the initial one or two weeks after suffering an acute myocardial infarction? Seven classes of intervention are considered: anticoagulants, platelet-active drugs, lipid-lowering regimens, antiarrhythmic agents, physical exercise, calcium antagonists and beta-blockers. So far only beta-blockers have been shown to have a favorable effect on long-term survival. Many of the trials reviewed had design limitations; in particular, the sample size was often too small for the results to be conclusive.

Adrenergic beta-Antagonists↗
PubMed1984

Effect of propranolol in postinfarction patients with mechanical or electrical complications.

In "post hoc" subgroup analyses, a simple classification system for patients, based on the presence or absence of findings indicative of electrical and/or mechanical complications early during short-term hospitalization, was applied to the data from the Beta-Blocker Heart Attack Trial (BHAT). In the largest subgroup of BHAT patients who had no reported complications, the 25 month mortality was low and the observed benefit of propranolol therapy small. Patients with electrical complications only had intermediate mortality and a pronounced effect of treatment was observed. Those with mechanical complications had the highest mortality and experienced an intermediate relative benefit of beta-blocker treatment. They also reported the most adverse effects. Post hoc analyses should always be interpreted cautiously. It is important to determine whether these findings are present in other completed beta-blocker trials. On the basis of these analyses alone it is suggested that the present practice of prescribing beta-blockers in postinfarction patients should not be altered.

Arrhythmias, Cardiac↗
PubMed1983

Effect of antiarrhythmic drugs on mortality after myocardial infarction.

The theoretical potential for a preventive or prophylactic effect of antiarrhythmic drugs (excluding beta blockers) in the treatment of coronary patients with ventricular arrhythmias has not been realized. Randomized controlled clinical trials conducted during the early hospital phase after an acute myocardial infarction as well as after discharge have not demonstrated an effect on patient survival. Three possible explanations exist. First, treatment of ventricular arrhythmias does not improve prognosis. Although this explanation is supported by the overall trial results, it is contrary to massive evidence from animals, clinical and epidemiologic studies. Second, treatment of ventricular arrhythmias does prolong life but benefit has not been observed in the trials. Limitations in applied methods, including insufficient sample sizes, may have obscured a true favorable intervention effect. Third, control of ventricular arrhythmias helps some patients but harms others. Concomitant treatment with digitalis and diuretics and, possibly, arrhythmogenic properties of the investigational drugs themselves might have confounded the overall results. The second in particular, but also the third explanation, are the most plausible. Only 1 of the 20 controlled clinical trials considered for this review required presence of ventricular arrhythmias as an entry criterion. All trials were small; the largest number of patients enrolled in a single trial was 610 and the highest number of deaths in a trial was 49. To resolve the uncertainty, increased attention to methodologic issues, such as selection of appropriate study populations, intervention strategies and larger sample sizes, is required.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Arrhythmia Agents↗
PubMed1983

Effect of beta-blocker therapy on recurrent nonfatal myocardial infarction.

Comparing the effects of long-term beta-blocker trials on nonfatal myocardial infarction (MI) is difficult because of differences in diagnostic criteria and in methods of reporting and classifying events. Analysis of available data indicates that the relative effect of beta blockers on the incidence of nonfatal MI is not different among the reviewed long-term trials. Pooling of trial results indicates that beta-blocker therapy has a beneficial effect on nonfatal MI incidence that is of the same magnitude (25%) as that for all-cause mortality.

Adrenergic beta-Antagonists↗
PubMed1983

What do subgroup analyses reveal about differential response to beta-blocker therapy? The Beta-Blocker Heart Attack Trial experience.

Results based on small subgroups are prone to much random variation and firm conclusions based on subgroup analyses should be avoided. Caution is advisable, especially with regard to post hoc and multiple analyses. Subgroup findings for which a reasonable biologic explanation can be given and those supported by independent results from other subgroups within the trial are more likely to be real. The strongest support for a subgroup finding in one trial is a replication from another trial. Post hoc analyses from the Beta-Blocker Heart Attack Trial suggest, and are supported by the Norwegian Timolol Study, that myocardial infarction patients older than age 60 years and those with arrhythmic and other complications not severe enough to preclude treatment benefit the most in absolute terms from beta blockers.

Adrenergic beta-Antagonists↗
PubMed1982

Clinical trials.

Explore the source record for details and available documents.

Bibliographies as Topic↗
PubMed1980

Clinical trials of platelet-active drugs in coronary heart disease: summary of design features.

The basic design features of eight clinical trials of platelet-active drugs in the secondary prevention of myocardial infarction are reviewed. Study populations are compared with regard to size, time of enrollment after the qualifying infarction and the length of follow-up. Differences in the drug regimens in terms of dose are given and there are comments on the selection of response variables, the withdrawal of patients from analysis and repeated significance testing.

Aspirin↗
PubMedDate not supplied

Lessons from overviews of cardiovascular trials.

Overviews of clinical trials in the cardiovascular field have been critically reviewed. Six reasons for the overviews were identified. An impression, at least from a scientific viewpoint, is that the pooled analyses have been valuable. Six potential problems are discussed and recommendations given based on lessons learned. These include the avoidance of three types of biases--publication bias, overviewer bias and investigator bias. The role of time-dependent treatment effects, the complex issue of 'mixing of apples and oranges' and the problem of errors are also addressed.

Cardiovascular Agents↗