Impact of stent thickness on clinical outcomes in small vessel and bifurcation lesions: a RAIN-CARDIOGROUP VII sub-study

Background The clinical impact of stent strut thickness in coronary bifurcation lesions in small vessels has not been assessed in a real-world population. Methods and results All 506 patients enrolled in the RAIN study, undergoing PCI in a vessel with a diameter 2.5 mm or less were retrospectively evaluated and divided into two groups according to stent strut thickness: 74 μm (n = 206) versus 81 μm (n = 300); 87.1% of the lesions involved bifurcations. TLF [defined as a composite of myocardial infarction (MI) and target lesion revascularization (TLR)] was the primary endpoint, with MACE (a composite of death, MI and TLR), its components and stent thrombosis the secondary endpoint. After 16 (14-18) months, a lower incidence of TLF (4.3 vs. 9.8%, P = 0.026) and ST (1.0 vs. 3.0%, P = 0.042) was seen in the 74 μm group, whereas MACE occurred in 60 of 506 patients, with no statistical difference between the two groups (9.7 vs. 13.3%, P = 0.070). At multivariate analysis, chronic renal failure increased the risk of TLF while thinner strut was an independent protective factor (hazard ratio 0.51, CI 0.17-0.85, P = 0.005). Conclusion In this real-world population, patients being treated for small vessels lesions with thinner strut stents had lower rates of TLF, MI and ST.