The XIENCE nano everolimus eluting coronary stent system for the treatment of small coronary arteries: the SPIRIT Small Vessel trial.

Objectives: The SPIRIT Small Vessel (SV) was designed to evaluate the safety and effectiveness of the 2.25-mm XIENCE V everolimus eluting coronary stent system (EECSS), known as the XIENCE nano EECSS, in subjects with SVs and ischemic heart disease.

Background: The core sizes of XIENCE V EECSS are associated with low rates of restenosis and thrombosis in the general population, but the XIENCE nano EECSS has not been tested in the United States.

Methods: This prospective, single-arm, open-label study was conducted at 33 centers and in 150 patients in the United States. The primary endpoint was the target lesion failure (TLF) rate at 1 year, required to meet the prespecified performance goal (PG) of 20.4%, derived from historical data.

Results: The mean patient age was 63 years, 38% were women, 39.2% were diabetic, 49.3% had multivessel disease, and the reference vessel diameter was 2.13 ± 0.23 mm. The 1-year TLF rate was 8.1% in with an upper limit of the one-sided 95% confidence interval of 13.0%, which met the PG of 20.4% (P < 0.0001). At 1 year, the rate of cardiac death was 1.5%, the target vessel myocardial infarction rate was 1.5%, and clinically indicated target lesion revascularization rate was 5.1%. The 8-month angiographic in-stent late loss was 0.2 ± 0.4 mm, respectively. The 1-year academic research consortium defined definite/probable stent thrombosis rate was 1.5%.

Conclusions: Based on the 1-year clinical and 8-month angiographic SPIRIT SV data, the XIENCE nano EECSS is considered safe and effective in the treatment of SVs.