Late and Very Late Stent Thrombosis in Patients with Second-generation Drug-eluting Stents

Background: Second-generation drug-eluting stents (DES) are purported to have a lower risk of stent thrombosis than first-generation DES. However, few studies have examined the frequency of late stent thrombosis (LST) and very LST (VLST) in patients with second-generation DES, and the safety of discontinuation of dual antiplatelet therapy (DAPT) remains controversial.

Methods: We systematically searched MEDLINE, EMBASE, Cochrane Library, and clinicaltrials.gov to identify all reported cases of definite LST and VLST in patients with second-generation DES. Inclusion was restricted to cases with zotarolimus-eluting stents (ZES) and everolimus-eluting stents (EES) in which the time from percutaneous coronary intervention and time from discontinuation of DAPT to LST/VLST was reported.

Results: A total of 26 cases (15 ZES and 11 EES) in 11 publications were included. We identified 17 cases of LST and 9 cases of VLST. The median time from percutaneous coronary intervention to LST/VLST in ZES patients was 121 days (interquartile range [IQR], 89-292) and in EES patients was 364 days (IQR, 269-504). For the 5 patients who discontinued taking acetylsalicylic acid and clopidogrel simultaneously, the median time to event was 20 days (IQR, 10-60). For the 7 patients who discontinued taking clopidogrel but continued taking acetylsalicylic acid, the median time to event was 190 days (IQR, 135-303).

Conclusions: With only a few reported cases of LST/VLST in the literature, available data suggest that thrombotic events might be rare with second-generation DES. Moreover, LST/VLST appears to occur later after DAPT discontinuation in patients with second-generation DES than in those with first-generation DES.