Prediabetes versus type 2 diabetes in patients with acute myocardial infarction and current smoking

Background Smoking is linked with increased risk of cardiovascular events among diabetic patients. Prediabetes is associated with increased risk for microvascular and macrovascular complications. We compared the 2-year clinical outcomes of current smoking between prediabetic and type 2 diabetes mellitus (T2DM) patients with acute myocardial infarction (AMI) after newer-generation drug-eluting stent (DES) implantation. Methods A total of 5161 AMI patients who were currently smoking were classified into normoglycemia (group A: 1,416), prediabetes (group B: 1,740), and T2DM (group C: 2,005) groups. The primary endpoint was major adverse cardiac events (MACEs), defined as all-cause death, recurrent myocardial infarction and any repeat revascularization. The secondary endpoint was the occurrence of stent thrombosis (ST) and stroke. Results The cumulative incidences of all primary and secondary endpoints including MACEs (adjusted hazard ratio [aHR]: 1.150; 95% confidence interval [CI]: 0.891–1.484; P = 0.284), ST, and stroke were similar between group B and group C. The cumulative incidences of MACEs (aHR: 1.385; 95% CI: 1.007–1.904; P = 0.045) and all-cause death or MI were significantly higher in group B than in group A. The cumulative incidences of MACEs (aHR: 1.572; 95% CI: 1.157–2.137; P = 0.004), all-cause death, Re-MI, and all-cause death or MI were significantly higher in group C than in group A. Conclusions Current smoking leads to worse clinical outcomes in patients with AMI and prediabetes, and thus, similarly to T2DM patients, more attention and more intensive treatment strategy including quitting smoking would be advantageous.