Impact of the number of conventional criteria used for complex PCI definition on ischemic outcomes: a meta-analysis of randomized controlled trials

Background Patients undergoing complex percutaneous coronary intervention (PCI) are at increased risk of ischemic events independent of dual antiplatelet therapy (DAPT) duration. It remains unclear whether the ischemic risk is influenced by the full or partial use of the six conventional criteria for defining complex PCI. Purpose To perform a meta-analysis of randomized trials to investigate the risk of ischemic outcomes associated with the number of conventional criteria used to define complex PCI. Methods We searched for randomized trials comparing DAPT duration regimens in patients undergoing complex or non-complex PCI. Conventional criteria included treatment of three vessels, ≥3 lesions treated, ≥3 stents implanted, bifurcation treated with 2 stents, total stent length >60 mm, or chronic total occlusion (CTO) as target lesion. A conventional definition of complex PCI was considered when all six criteria were applied, whereas a non-conventional definition was defined as any classification that included more, fewer, or none of these criteria, deviating from the conventional one. The main outcomes of interest, myocardial infarction (MI), definite/probable stent thrombosis (ST), and all-cause mortality, were analyzed as per number of conventional criteria and according to whether a conventional or non-conventional definition was applied. Results Eight studies with a total of 52,941 patients undergoing complex (n= 14,780) or non-complex PCI (n= 38,161) were included. The risk of MI increased proportionally to the number of conventional complex PCI criteria used in the trials with a risk ratio [RR] varying from 1.24 (1 criterion) to 1.86 (6 criteria) with a p for subgroups differences of 0.01, whilst the risk of ST and all-cause death did not. No differences in ischemic outcomes were observed when using conventional versus non-conventional definitions of complex PCI. Conclusions In patients undergoing complex PCI treated with different durations of DAPT, regardless of whether a conventional or non-conventional definition is used, the use of more than one of the conventional criteria to define complex PCI is associated with a higher risk of MI, but not of ST and all-cause death.Myocardial Infarction acc to criteria n.