Aims: To assess the effectiveness and safety of sirolimus-eluting stents (SES) in de novo native coronary lesions in small vessels (</= 2.5 mm).
Methods and results: PORTO was a multicentre, prospective registry, performed in 274 patients. Of these, 120 (43.8%) patients were diabetic. A total of 324 lesions were treated with 347 SES. The primary end-point was 6-month in-stent late luminal loss (LL); secondary end-points included in-stent and in-segment binary restenosis (BR), target lesion revascularisation (TLR), target vessel revascularisation (TVR) and major adverse cardiac events (MACE) rate at six months and one-year. Pre-specified subgroup analysis included the comparison between diabetic and non-diabetic patients, and patients with stents of different diameter (2.25 mm vs. 2.5 mm) and length (</= 18 mm vs. >/= 23 mm).The mean (SD) reference vessel diameter of the treated segment was 2.08 (0.33) mm and lesion length 11.04 (6.0) mm. After six months, LL was 0.07 (0.37) mm. BR was 5.1% in-stent and 9.1% in-segment. At one year, TLR was 5.6% and TVR was 9.0%. MACE rate was 2.6% at six months and 8.6% at one year with 2.3% cardiac death and 1.5% non-fatal myocardial infarction. Stent thrombosis rate at one year was 0.8% per protocol. There were more MACE in diabetic patients (12.8%) than in non-diabetic (5.4%, p=0.046), but no other significant differences in clinical and angiographic parameters were noted between the subgroups analysed.
Conclusions: The use of SES for lesions in very small coronary arteries proved to be safe and efficacious, irrespective of the size and length of the stents, with low restenosis and repeat revascularisation rates at one year.