Impact of early versus late clopidogrel discontinuation on stent thrombosis following percutaneous coronary intervention with first- and second-generation drug-eluting stents.

Premature antiplatelet therapy discontinuation (ATD) after drug-eluting stent (DES) implantation is known to predict stent thrombosis (ST). However, recent data suggest that a shorter antiplatelet therapy duration is safe with newer generation DESs. The study aimed to compare the impact of early and late clopidogrel ATDs on ST in a real-world registry of first- and second-generation DES use. A total of 6,236 patients who underwent DES implantation were analyzed retrospectively: 4,217 received first-generation DESs (sirolimus- and paclitaxel-eluting stents) and 2,019 received second-generation DESs (everolimus-eluting stents). Within each DES cohort, patients were categorized into timing of clopidogrel discontinuation within 1 year: early (<3 months), late (3 to 12 months), and continued. ST rates and clinical outcomes at 1 year were analyzed. There were 341 patients (8.1%) in the first-generation DES group and 126 patients (6.2%) in the second-generation DES group who discontinued clopidogrel within the first year. Definite and probable ST rates were 3.8% for early ATD, 2.5% for late ATD, and 0.5% for continued (p = 0.001) in the first-generation DES cohort, whereas there were no definite or probable ST events in early and late ATDs and 0.5% for continued in the second-generation DES cohort. Major adverse cardiac event rates were 9.9% for early ATD, 5.6% for late ATD, and 0.9% for continued (p <0.001) in the first-generation DES cohort and 5.5% for early ATD, 7.4% for late ATD, and 1.5% for continued (p <0.001) in the second-generation DES cohort. In conclusion, ATD within the first year is associated with increased ST events with first-generation DESs, whereas ATD appears safe with second-generation DESs with regard to ST. However, ATD is associated with greater mortality and major adverse cardiac events in both first- and second-generation DESs. Thus, this study supports ATD if required based on physician discretion with the use of second-generation DESs but cannot rule out potential benefit for longer duration of dual antiplatelet therapy even when second-generation DESs are used.