Differential effect of side branch intervention on long-term clinical outcomes according to side branch stenosis after main vessel stenting: Results from the COBIS (Coronary Bifurcation Stenting) Registry II

Abstract

BACKGROUND: Indication of side branch (SB) intervention after main vessel (MV) stenting is not established for coronary bifurcation lesions. METHODS: We evaluated 2017 patients who were treated with 1-stent technique or MV stenting as a first strategy. Patients undergoing SB intervention after MV stenting (SB intervention group, n=929) were compared to those treated with MV stenting only (no-SB intervention group, n=1088). RESULTS: During a median follow-up of 37months, cardiac death or myocardial infarction (MI) tended to occur less frequently in the SB intervention group than in the no-SB intervention group (1.8% versus 2.9%: adjusted hazard ratio [HR] 0.53: 95% confidence interval [CI] 0.25-1.11: P=0.09). There was a significant interaction between SB intervention and SB stenosis after MV stenting (P for interaction <0.01). Among 1077 patients with diameter stenosis of SB >/=50% after MV stenting, SB intervention was associated with a lower risk of cardiac death or MI (1.2% versus 4.2%: adjusted HR 0.22: 95% CI 0.09-0.52: P<0.01). However, among 940 patients with diameter stenosis of SB <50%, there was no significant difference in cardiac death or MI between the SB intervention group and the no-SB intervention group (3.5% versus 2.2%: adjusted HR 1.36: 95% CI 0.58-3.20: P=0.48). CONCLUSIONS: The effect of SB intervention differed according to SB stenosis after MV stenting. SB intervention may reduce cardiac death or MI in bifurcation lesions with diameter stenosis of SB >/=50% after MV stenting.