Assessing the effectiveness of primary angioplasty compared with thrombolysis and its relationship to time delay: a Bayesian evidence synthesis

Assenburg, C., Bravo-Vergel, Y., Palmer, S., Fenwick, E., de Belder, M., Abrams, K.R. and Sculpher, M. (2007) Assessing the effectiveness of primary angioplasty compared with thrombolysis and its relationship to time delay: a Bayesian evidence synthesis. Heart, 93, pp. 1244-1250. (doi: 10.1136/hrt.2006.093336)

Abstract

<i>Background</i>: Meta-analyses of trials have shown greater benefits from angioplasty than thrombolysis after an acute myocardial infarction, but the time delay in initiating angioplasty needs to be considered. <i>Objective</i>: To extend earlier meta-analyses by considering 1- and 6-month outcome data for both forms of reperfusion. To use Bayesian statistical methods to quantify the uncertainty associated with the estimated relationships. <i>Methods</i>: A systematic review and meta-analysis published in 2003 was updated. Data on key clinical outcomes and the difference between time-to-balloon and time-to-needle were independently extracted by two researchers. Bayesian statistical methods were used to synthesise evidence despite differences between reported follow-up times and outcomes. Outcomes are presented as absolute probabilities of specific events and odds ratios (ORs; with 95% credible intervals (CrI)) as a function of the additional time delay associated with angioplasty. <i>Results</i>: 22 studies were included in the meta-analysis, with 3760 and 3758 patients randomised to primary angioplasty and thrombolysis, respectively. The mean (SE) angioplasty-related time delay (over and above time to thrombolysis) was 54.3 (2.2) minutes. For this delay, mean event probabilities were lower for primary angioplasty for all outcomes. Mortality within 1 month was 4.5% after angioplasty and 6.4% after thrombolysis (OR = 0.68 (95% CrI 0.46 to 1.01)). For non-fatal reinfarction, OR = 0.32 (95% CrI 0.20 to 0.51); for non-fatal stroke OR = 0.24 (95% CrI 0.11 to 0.50). For all outcomes, the benefit of angioplasty decreased with longer delay from initiation. <i>Conclusions</i>: The benefit of primary angioplasty, over thrombolysis, depends on the former’s additional time delay. For delays of 30–90 minutes, angioplasty is superior for 1-month fatal and non-fatal outcomes. For delays of around 90 minutes thrombolysis may be the preferred option as assessed by 6-month mortality; there is considerable uncertainty for longer time delays.

• Item Type: Articles
• Keywords: Acute myocardial infarction, primary coronary angioplasty, thrombolytics, meta-regression.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fenwick, Professor Elisabeth
• Authors: Assenburg, C., Bravo-Vergel, Y., Palmer, S., Fenwick, E., de Belder, M., Abrams, K.R., and Sculpher, M.
• Subjects: R Medicine > R Medicine (General); R Medicine > RC Internal medicine
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Centre for Population and Health Sciences; College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Health Economics and Health Technology Assessment
• Journal Name: Heart
• Publisher: BMJ Publishing Group
• ISSN: 1355-6037
• Copyright Holders: Copyright © 2007 BMJ Publishing Group
• First Published: First published in Heart 93:1244-1250
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.