Ten-year clinical outcomes of drug-eluting stents with different polymer coating strategies by degree of coronary calcification: a pooled analysis of the ISAR-TEST 4 and 5 randomised trials.

BACKGROUND
Long-term data concerning the efficacy of different polymer-coating strategies of new-generation drug-eluting stents (DES) in patients with coronary artery calcification (CAC) are scant.


AIMS
We aimed to investigate 10-year outcomes by degree of CAC after new-generation DES implantation with different polymer-coating strategies.


METHODS
We analysed individual patient and lesion characteristics of patients randomised to treatment with polymer-free sirolimus-eluting, biodegradable-polymer sirolimus-eluting and permanent-polymer zotarolimus- or everolimus-eluting stents. Endpoints of interest at 10 years were all-cause mortality, myocardial infarction (MI), target lesion revascularisation (TLR) and definite or probable stent thrombosis (ST) according to the degree of CAC (no, mild, moderate or severe) and coating strategy (polymer-free vs biodegradable-polymer vs permanent-polymer).


RESULTS
A total of 4,953 patients with 6,924 lesions were included. No, mild, moderate or severe CAC was present in 24.5%, 41.8%, 25.8% and 8.0% of patients, respectively. At 10-year follow-up, overall event rates were high, with an incremental increase according to the degree of CAC (all-cause mortality: no 25.3%, mild 32.1%, moderate 41.7%, severe CAC 46.5%; adjusted [adj.] p=0.004; TLR: no 17.4%, mild 16.5%, moderate 19.8%, severe CAC 28.7%; adj. p=0.001; MI: no 4.9%, mild 5.9%, moderate 6.0%, severe CAC 10.5%; adj. p=0.02; and ST: no 1.3%, mild 1.4%, moderate 1.8%, severe CAC 3.6%; adj. p=0.57). In patients with moderate-severe CAC, event rates were comparable, regardless of the DES polymer-coating strategy.


CONCLUSIONS
At 10 years after PCI with new-generation DES, there was an incremental increase in adverse events by degree of coronary calcification. These detrimental effects do not seem to be impacted by different polymer-coating strategies.