The primary hypothesis is that angiography-derived FFR-guided strategy will show non-inferior rate of patients-oriented composite outcomes (POCO) at 12 months after randomization, compared with IVUS-guided strategy in patients with CAD.
2. Study population and sample size calculation Sample size calculation based on the event rates of previous trials, investigators predicted the rates of POCO at 12 months after PCI will be 7% in the Angiography-derived FFR-guided arm, and 8% in the IVUS-guided arm
- Primary endpoint: patient-oriented composite outcome (a composite of all-cause death, MI, any revascularization) at 12 months after PCI
- Design: non-inferiority, delta = 2.5%
- Sampling ratio: angiography-derived FFR-guided strategy: IVUS-guided strategy = 1:1
- Type I error (): One-sided 2.5%
- Accrual time: 2 years
- Total time: 3 years (accrual 2 years + follow-up 1 years)
- Assumption: POCO 7.0% vs. 8.0% in angiography-derived FFR or IVUS-guided strategy, respectively
- Statistical power (1- ): 80%
- Primary statistical method: Kaplan-Meier survival analysis with log-rank test
- Estimated attrition rate: total 5%
- Stratification in Randomization: Presence of diabetes mellitus (35% of patients in each group) Based on the above assumption, we would need total 1,872 patients (936 patients in each group) with consideration of an attrition rate.
3.Research Materials and Indication for Revascularization For the angiography-derived FFR-guided strategy arm, Criteria for revascularization: angiography-derived FFR 0.80. For the IVUS-guided strategy arm, the criterion for revascularization is MLA 3mm2 or [3mm2 < MLA 4mm2 and plaque burden > 70%].
