Secondary end points include safety of OCT in the context of angioplasty for ACS , percentage of patients in whom OCT reveals suboptimal result of stenting , percentage of patients in whom a change in procedural strategy is decided based on OCT data , correlation between quantitative measures by OCT and FFR , determination of a threshold for quantitative OCT measure that best predicts FFR 0.90 , and identification of OCT variables that predict postprocedure FFR .