Comparison of three-year clinical outcomes with nonextended versus extended dual antiplatelet therapy between first- and second-generation drug-eluting stent implantation in patients with acute myocardial infarction: Data from the infarct prognosis study registry

Background: The difference of the clinical outcomes between nonextended (≤12 months) and extended (>12 months) dual antiplatelet therapy (DAPT) remains unclear in patients with acute myocardial infarction (AMI) implanted by different generations of drug-eluting stent (DES). Methods: We identified 790 consecutive patients with AMI who were free from major adverse cardiac events for 12 months after first-generation (n = 537) or second-generation DES (n = 253) implantation; each DES generation group was further divided into nonextended and extended DAPT. Results: During follow-up (median: 40 months), nonextended DAPT in the first-generation DES group showed a higher rate of cardiac death or MI than was observed in the extended DAPT group (14% vs 2%, P < 0.001). However, in the second-generation DES group, there was no difference in the occurrence of cardiac death and MI between the extended and nonextended groups (4% vs 3%, P = 0.809). Nonextended DAPT was the most significant predictor of cardiac death and MI for first-generation DES implantation [hazard ratio (HR) = 5.47, 95% confidence interval (CI) = 1.53-19.59, P = 0.009] but not for second-generation DES implantation [HR = 3.21, 95% CI = 0.21-50.65, P = 0.401]. Conclusion: This study suggested that the clinical outcomes between nonextended and extended DAPT might be different depending on the generation of implanted DESs in patients with AMI.