Intravascular Imaging Versus Angiography in Complex Percutaneous Coronary Intervention

Background: Intravascular imaging (IVI; IVUS and OCT) is increasingly used to optimise percutaneous coronary intervention (PCI) in complex lesions, but its impact on hard clinical endpoints versus angiography-guided PCI remains debated. Hypothesis: We hypothesised that IVI-guided PCI improves hard clinical endpoints compared with angiography-guided PCI in patients undergoing intervention for complex coronary lesions. Methods: We searched PubMed, Embase, and Cochrane (through April 2026) for RCTs comparing IVI- vs angiography-guided PCI. The primary endpoint was major adverse cardiovascular events (MACE); secondary outcomes included all-cause and cardiovascular mortality, myocardial infarction (MI), target-vessel revascularisation (TVR), target-lesion revascularisation (TLR), and stent thrombosis. Random-effects pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated; heterogeneity was assessed using I 2 . Results: Fourteen RCTs comprising 14,524 patients (7,531 IVI-guided; 6,993 angiography-guided) were analysed. Compared with angiography, IVI guidance significantly reduced the risk of MACE (RR 0.65; 95% CI: 0.53-0.81; I 2 = 77%), cardiovascular mortality (RR 0.71; 95% CI: 0.52-0.97; I 2 = 39%), and MI (RR 0.85; 95% CI: 0.72-0.99; I 2 = 1%). Furthermore, IVI-guided PCI was associated with lower rates of TVR (RR 0.62; 95% CI: 0.46-0.83; I 2 = 65%), TLR (RR 0.65; 95% CI: 0.52-0.81; I 2 = 47%), and stent thrombosis (RR 0.44; 95% CI: 0.25-0.77; I 2 = 0%). No significant differences were observed in all-cause mortality (RR 0.88; 95% CI: 0.74-1.05; I 2 = 0%) or target-vessel MI (RR 0.72; 95% CI: 0.50-1.03; I 2 = 64%). In subgroup analyses, IVUS and OCT showed comparable benefit on MACE (RR 0.63, 95% CI: 0.47-0.84; and RR 0.68, 95% CI: 0.53-0.87; interaction p=0.70). In Asian trials, intravascular imaging guidance was associated with a significant reduction in MACE (RR 0.59, 95% CI 0.50-0.69), cardiovascular mortality (RR 0.54, 95% CI 0.37-0.79), any MI (RR 0.69, 95% CI 0.54-0.88), and TLR (RR 0.52, 95% CI 0.40-0.68) compared with angiography guidance, wheares European trials showed no significant benefit for same outcomes, with MACE results showing a significant subgroup interaction. Conclusion: In patients undergoing complex PCI, IVI guidance significantly improves clinical outcomes compared with angiography, with marked reductions in MACE, cardiovascular mortality, target-vessel revascularisation, and stent thrombosis. These data support intravascular imaging as a primary strategy in optimising stent deployment and mitigating long-term ischaemic risk.