The fate of small side branches following drug eluting stent implantation

OBJECTIVES Although drug eluting stents (DES) have documented convenience in bifurcation lesions, possible unfavorable effects on small side branch ostium (SBO) remain a question. We aimed to explore the effects of DES on small jailed SBs (1.5-2.25 mm) which originated from the lesion on the main vessel and were not treated with either stenting or balloon dilatation. METHODS Angiographic data of 107 consecutive patients (129 SB) with Medina 1,1,1 or 1,1,0 lesions were evaluated at the time of procedure and at the follow-up. RESULTS Of all DES used, 70 (54.7%) was sirolimus-eluting, 39 (30.5%) was paclitaxel-eluting and 20 (14.8%) was zotarolimus-eluting. The diameter of SBs was 1.84 ± 0.41 mm with a stenosis of 20.7 ± 26.6% at SBO at baseline. The lesion at the SBO had progressed after the procedure when the pre vs postprocedure values and follow-up vs pre-procedure values are compared (20.7 ± 26.6% vs 29.4 ± 27.4%; p < 0.0001 and 25.4 ± 25.1 vs 20.7 ± 26.6%; p = 0.004 respectively). A significant reduction in stenosis was revealed over the follow-up (29.4 ± 27.4 vs 25.4 ± 25.1 respectively; p = 0.013). The severity of the disease at the SBO at baseline was the only parameter that affected the severity of SB stenosis in acute, longterm and follow-up. Additional parameters with influence on SB patency at different times were female gender, stent deployment with low pressure, cTFC of the main lesion, age, cTFC of the lesion, late loss index and the preprocedure TIMI flow grade of the SB. CONCLUSIONS Although there was a significant deterioration of SBO immediately after stenting, follow-up data showed that the lesion at SBO improved but remained worse than baseline.