Natural History of Side Branches Jailed by Drug‐Eluting Stents

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.