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Chronic total coronary occlusion (CTO) is a frequent finding in patients with ischemic heart disease. Our aim was to compare first and second generation DES regarding long-term risk of in-stent restenosis and stent thrombosis.
We used data from the SCAAR registry (Swedish Coronary Angiography and Angioplasty Registry) for the PCI procedures performed in patients with CTO between 2003 and 2015 for stable angina, UA/NSTEMI and STEMI. The database contains information about all procedures performed in Sweden. We compared four groups of DES: paclitaxel- (PES, n=1,557), sirolimus- (SES, n=932), zotarolimus- (ZES, n=1,699) and everolimus-eluting stents (EES, n=2499). We modelled our data with multilevel Cox proportional-hazards regression with stents as the primary observational unit while patients and hospitals were treated as random-effect variables. To adjust for differences in patient’s characteristics the following variables were used: age, gender, hypertension, hyperlipidemia, smoking status, diabetes, severity of coronary artery disease, indication for PCI (stable angina, UA/NSTEMI and STEMI), stent length and stent diameter. The primary combined endpoint was time to first occurrence of either stent thrombosis or restenosis.
The total of 6,687 DES were implanted in 1,699 CTO patients. Median follow-up was 3.3 years. The total number of events was 567 of which 112 (19.6%) were stent thromboses. At one-year, unadjusted probability of combined event was 2.6% in ZES, 1.7% in EES, 3.5% in SES and 3.2% in PES group. Treatment with PES (adjusted HR 1.50; 95% CI 1.18 - 1.91; P=0.001) and SES (adjusted HR 1.37; 95% CI 1.06 - 1.77; P=0.018) was associated with higher risk for restenosis or stent thrombosis compared to EES. Similarly, treatment with PES (adjusted HR 2.22; 95% CI 1.32 - 1.70; P=0.002) and SES (adjusted HR 2.11; 95% CI 1.17 - 3.79; P=0.012) was associated with higher risk of stent thrombosis compared to EES. We found no differences between EES and ZES nor between SES and PES.
In this observational study, treatment of CTO with EES and ZES was associated with substantially lower risk of in-stent restenosis and stent thrombosis than PES and SES.