Benefit from earlier thrombolytic therapy is certain, but what is the magnitude of benefit?

Abstract

Abundant evidence exists to confirm that fibrinolytic treatment saves lives in patients with acute myocardial infarction and that the earlier the treatment the higher the benefit obtained.' There is also evidence to suggest that administration of fibrinolytic treatment, under certain conditions, before hospital admission may lead to further improvement in patients' prognosis with no significant additional risk.2-4 John Rawles attempts to quantify the benefit of earlier fibrinolytic treatment using the data from the 311 patients included in the GREAT trial, which evaluated the feasibility, safety, and efficacy of domiciliary fibrinolysis by general practitioners.5 Such quantification is essential if providers of health care are to make an informed decision on whether to allocate resources to domiciliary fibrinolysis. The magnitude of the benefit is controversial, and the trial that could fully resolve this will never be performed for obvious ethical reasons. This trial would require randomising patients to, say, four or five groups, each group having a predetermined delay from diagnosis of acute myocardial infarction to fibrinolytic treatment. Thus, the only available way to assess the magnitude of benefit of earlier fibrinolytic treatment compared with later treatment is to retrospectively analyse data from fibrinolytic studies, performing indirect comparisons of the randomised groups or using an epidemiological approach.