Efficacy and safety of drug-coated balloons according to coronary vessel size. A report from the BASKET-SMALL 2 trial

Introduction: In BASKET-SMALL 2, drug-coated balloons (DCB) were non-inferior to drug-eluting stents (DES) in de-novo stenosis of small coronary vessels (≤ 2.75 mm) regarding clinical endpoints up to 36 months.

Aim: In the present subgroup analysis, we aimed to analyze the effect of the two treatment strategies in different vessel sizes.

Material and methods: Patients were analyzed according to the size of the device used (small > 2.5 mm vs. very small ≤ 2.5 mm). The primary endpoint was major adverse cardiac events (MACE), while secondary endpoints were target vessel revascularization (TVR), non-fatal myocardial infarction, cardiac death, and all-cause mortality, all at 36 months. Interactions for the different groups were assessed with Cox regression analysis.

Results: Overall, 758 patients were enrolled in this analysis, of which 437 (58%) had very small vessel disease. There were similar results in both treatment groups for the primary endpoint in both small and very small vessels (DCB vs DES, MACE at 3 years in small vessels HR = 1.31, 95% CI: 0.74-2.32, p = 0.355, and very small vessels HR = 0.82, 95% CI: 0.49-1.39, p = 0.468). Second generation paclitaxel-eluting stents showed significantly higher rates for MACE (p = 0.041), TVR (p = 0.004) and non-fatal myocardial infarction (p = 0.036) compared to DCB in very small coronary arteries at 3 years, while results were similar in small coronary arteries.

Conclusions: Efficacy and safety of DCB are similar irrespective of vessel size. However, there is a beneficial effect of DCB over paclitaxel-eluting stents regarding TVR, non-fatal myocardial infarction and MACE that is most pronounced in very small coronary arteries.