Late and very late stent thrombosis in patients with second-generation drug-eluting stents

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.

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.

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).

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.