Prospectively applied EAPCI device success algorithm, comparison of angiography-derived FFR guided and usual care, and association with 1-year lesion-oriented clinical endpoints: the PIONEER IV trial

Background Device success is a critical endpoint in PCI, yet its heterogeneous definition limits comparability. The standardized European Association of PCI (EAPCI) device success algorithm was reported in 20201. In this algorithm, device success is evaluated using the following Step1-5: Step1 - attempted to cross lesion with assigned device; Step2 - any device was delivered and implanted to lesion; Step3 - device was implanted at the intended location; Step4 - the first assigned device was successfully implanted; Step5 - final residual % diameter stenosis (%DS) <20% using visual assessment or quantitative coronary angiography (QCA). However, this algorithm has not yet been prospectively applied using core-laboratory adjudication. In addition, the association between device success and lesion-oriented clinical endpoints (LOCE) remains insufficiently investigated. Purpose To prospectively evaluate the EAPCI device success algorithm, incorporating core-lab post-PCI QCA and angiography-derived fractional flow reserve (angio-FFR) into Step 5, and to assess its relationship with 1-year LOCE, in the PIONEER IV trial. Methods PIONEER IV is a multicenter, randomized trial comparing angio-FFR-guided PCI versus usual care using HT Supreme drug-eluting stents. An interim analysis was performed in the first 1270 patients of the total population of 2130. Step 5 of device success was adjudicated using four hierarchical definitions: (1)site-reported (visual residual %DS<20%); (2)core-lab QCA (residual %DS<20%); (3)core-lab angio-FFR (Δangio-FFR across the stent≤0.05); and (4)combined core-lab QCA + angio-FFR. Device success rates as per these definitions were also compared between the angio-FFR (A) and usual care (U) arms. LOCE was the composite of cardiovascular death, target-vessel myocardial infarction, and clinically and physiologically driven target-lesion revascularization. Results Among 1270 patients (1936 lesions), HT Supreme PCI was attempted in 1119 lesions. Site-reported device success rate was 95.2% with no difference between arms (P=0.651). Core-lab QCA reduced success rates to 88.7% (A: 90.3% vs U: 87.0%; P=0.082). Rates using Δangio-FFR≤0.05 were 93.8%, and significantly higher with angio-FFR guidance (A: 96.4% vs U: 91.3%; P<0.001). Combining QCA and angio-FFR reduced success to 84.7%, favoring angio-FFR guidance (A: 88.0% vs U: 81.5%; P=0.003). At 1 year, LOCE was consistently numerically lower in lesions with device success, particularly using the angio-FFR definition (Log-rank P=0.037). Conclusions Operator-reported device success is high, but core-lab QCA and angio-FFR reveal additional abnormalities, favoring angio-FFR-guided PCI. Standardized QCA and post-PCI angio-FFR may support device success as an early trial endpoint. The final patient is expected to complete the 1-year follow-up visit in June 2026. We plan to present device success and LOCE in the 2130-patient full cohort at ESC Congress 2026.