Natural History of Side Branches Jailed by Drug‐Eluting Stents

Abstract

Stent deployment across side branch (SB) ostium is common in daily practice. The present study investigated the natural history of SBs jailed by drug-eluting stents (DES). The thrombolysis in myocardial infarction (TIMI) flow grades of 271 consecutive SBs jailed by DES in 196 patients was assessed immediately after the procedure and at 9 months of follow-up. Patients receiving any SB intervention were excluded. Of 271 jailed SBs, occlusion occurred in 6.27% and deterioration of flow occurred in 6.27% immediately after stenting. In patients with these SB changes, periprocedural myocardial infarction was more likely than in those without (10.0% vs. 1.8%, P = 0.017), while there was no increase of cardiac death or life-threatening complications such as stent thrombosis and Q-wave myocardial infarction (Q MI) during follow-up. At 9 months, angiography showed that one-third of the initially obstructed SBs were still occluded. In contrast, flow was maintained in almost all (98.6%) SBs with early TIMI flow grade 3 and there was no delayed occlusion of these branches. Multiple regression analysis showed that lesion complexity (Medina bifurcation class, calcification, and preprocedural TIMI grade 2 flow in the SB) and technical factors (jailing by overlapping stents) were related to SB occlusion or flow deterioration. Jailed SBs showing good flow after stenting had a favorable angiographic and clinical outcome after 9 months of follow-up. However, preprocedural lesion complexity and technical factors should be considered to avoid SB occlusion/flow deterioration associated with periprocedural myocardial infarction.