The smokers paradox in patients with acute coronary syndrome: a systematic review Full Text
BMC Medicine, 08/26/2011
Evidence Based Medicine
Aune E et al. – The "smoker's paradox" was observed in some studies of acute myocardial infarction (AMI) patients in the pre–thrombolytic and thrombolytic era, whereas no studies of a contemporary population with acute coronary syndrome have found evidence for such a paradox.Methods
- Relevant studies published by September 2010 were identified through literature searches using EMBASE (from 1980), MEDLINE (from 1963) and the Cochrane Central Register of Controlled Trials, with a combination of text words and subject headings used.
- English–language original articles were included if they presented data on hospitalised patients with defined acute coronary syndrome, reported at least in–hospital mortality, had a clear definition of smoking status (including ex–smokers), presented crude and adjusted mortality data with effect estimates, and had a study sample of >100 smokers and >100 non–smokers.
- Two investigators independently reviewed all titles and abstracts in order to identify potentially relevant articles, with any discrepancies resolved by repeated review and discussion.
- A total of 978 citations were identified, with 18 citations from 17 studies included thereafter.
- Six studies (one observational study, three registries and two randomised controlled trials on thrombolytic treatment) observed a "smoker's paradox".
- Between the 1980s and 1990s these studies enrolled patients with acute myocardial infarction (AMI) according to criteria similar to the World Health Organisation criteria from 1979.
- Among the remaining 11 studies not supporting the existence of the paradox, five studies represented patients undergoing contemporary management.