The smoker’s paradox after successful fibrinolysis: reduced risk of reocclusion but no improved long-term cardiac outcome

Abstract

In smokers treated with fibrinolysis for ST-elevation myocardial infarction (STEMI) a paradoxical beneficial short-term outcome has been reported. This was attributed to favorable clinical and angiographic baseline variables and a better response to fibrinolysis. During follow-up infarct artery reocclusion is an important prognosticator. We studied the effects of smoking on reocclusion and long-term cardiac outcome after successful fibrinolysis. In the Antithrombotics in the Prevention of Reocclusion In COronary Thrombolysis trials (APRICOT-1 and -2) 499 STEMI patients with an open infarct artery <48 h after fibrinolysis received randomized antithrombotic treatment until 3-month follow-up angiography. Five-year clinical follow-up was complete. Current smokers (317 patients, 64%) had favorable clinical (age 54 vs. 60 years, P < 0.01) and angiographic (single vessel disease 61% vs. 49%, P = 0.02) baseline characteristics. Reocclusion rates were 21% (67/317) in smokers versus 32% (59/182) in non-smokers (P < 0.01). Five-year infarct-free cardiac survival did not differ: 82% vs. 85%. Reocclusion (HR 2.41, 95%CI 1.05-5.56, P = 0.04) independently predicted cardiac mortality. Smoking was independently associated with a reduced risk of reocclusion (OR 0.58, 95%CI 0.37-0.91, P = 0.02), but not with improved 5-year cardiac outcome (HR 1.34, 95%CI 0.79-2.25, P = ns). After successful fibrinolysis, smoking is independently associated with a more than 40% reduced risk of reocclusion, which is an independent predictor of adverse outcome. However, even with more favorable baseline characteristics smokers did not have improved 5-year cardiac outcome in this low-risk population.