Association of smoking with restenosis and major adverse cardiac events after coronary stenting: A meta-analysis

BACKGROUND AND OBJECTIVE The association between smoking and clinical outcomes after coronary stenting is controversial. The aim of this meta-analysis was to assess the association between smoking and in stent restenosis (ISR), major adverse cardiac events (MACE), or major adverse cardiac and cerebrovascular events (MACCE) after coronary stenting. METHODS A search for studies published before December 2014 was conducted in PubMed, Embase, and Cochrane library. An inverse random weighted meta-analysis was conducted using logarithm of the odds ratio (OR) and its standard error for each study. RESULTS Ten studies investigated the association between smoking and ISR. Overall, smoking was not associated with ISR (OR: 1.05, 95% CI: 0.79-1.41; I(2) = 47.8%). Subgroup analysis also failed to show a significant association between smoking and ISR risk regardless of bare metal stent (BMS) and drug-eluting stent (DES) implantation. Eight studies explored the association between smoking and MACE, but no association was found (OR: 0.92, 95% CI: 0.77-1.10; I(2) = 25.5%), and subgroup analysis revealed that no distinct difference was found between BMS and DES implantation. Three studies investigated the association between smoking and MACCE and significant association was found (OR: 2.09, 95% CI: 1.43-3.06; I(2) = 21.6%). CONCLUSIONS Our results suggest that in patients undergoing percutaneous coronary intervention with stent implantation, smoking is not associated with ISR and MACE; however, smoking is an independent risk factor for MACCE.