Impact of coronary bifurcation angle on stent malapposition in a randomized comparison between proximal optimization technique followed by side branch dilatation and kissing balloon inflation

Background: The impact of coronary bifurcation angle (BA) on incomplete stent apposition (ISA) after crossover stenting followed by side branch (SB) intervention has not been established.Methods: A total of 100 crossover stentings randomly treated with proximal optimization technique followed by short balloon dilation in the SB (POT-SBD group, 48 patients) and final kissing balloon technique (KBT group, 52 patients) were analyzed in the PROPOT trial. Major ISA with maximum distance > 400 mu m and its location was determined using optical coherence tomography before SB intervention and at the final procedure. The BA was defined as the angle between the distal main vessel and SB. Optimal POT was determined when the difference in stent volume index between the proximal and distal bifurcation was greater than the median value (0.86 mm(3)/ mm) before SB intervention.Result: Major ISA was more frequently observed in the POT-SBD than in the KBT group (35% versus 17%, p < 0.05). In the POT-SBD group, worsening ISA after SBD was prominent at the distal bifurcation. The BA was an independent predictor of major ISA (odds ratio 1.04, 95% confidence interval 1.00-1.07, p < 0.05) with a cut-off value of 59.5(degrees) (p < 0.05). However, the cases treated with optimal POT in the short BA (<60(degrees)) indicated the lowest incidence of major ISA. In the KBT group, BA had no significant impact.Conclusion: A wide BA has a potential risk for the occurrence of major ISA after POT followed by SBD in coronary bifurcation stenting.