Intravascular imaging guidance in complex PCI: a meta-analysis of randomized trials across complex lesion subsets

Background Recent randomized trials have reported conflicting results regarding the clinical benefit of intravascular imaging (IVI) in complex percutaneous coronary intervention (PCI). The aim of this research was to evaluate whether IVI guidance reduces target vessel failure (TVF) in complex PCI. Methods PubMed, Scopus, and the Cochrane Library were searched through June 2026 for randomized trials comparing IVI-guided with angiography-guided PCI in trial-defined complex PCI or extractable complex-lesion cohorts. Risk ratios (RRs) were pooled using random-effects models. Prespecified analyses evaluated left main, chronic total occlusion, bifurcation, and moderate-to-severely calcified lesions, with a sensitivity analysis excluding IVUS-CHIP. Secondary clinical outcomes and potential effect modification by imaging modality were evaluated in exploratory analyses. Results Fifteen trials, including 11,557 patients were analyzed. IVI reduced TVF (RR, 0.70; 95% confidence interval [CI], 0.56-0.86; number needed to treat, 26 [95% CI, 18-55]). Lesion-specific estimates consistently favored IVI but were not significant; all became significant after excluding IVUS-CHIP. IVI reduced target vessel revascularization (RR, 0.68; 95% CI, 0.53-0.87), target lesion revascularization (RR, 0.67; 95% CI, 0.52-0.85), and stent thrombosis (RR, 0.42; 95% CI, 0.24-0.73). All-cause mortality was not reduced, whereas IVI guidance showed a borderline association with 26% lower cardiovascular mortality (RR, 0.74; 95% CI, 0.54-1.00; p = 0.05). Effects were similar for intravascular ultrasound and optical coherence tomography (interaction p = 0.93). Conclusions IVI guidance reduced TVF, repeat revascularization, and stent thrombosis in complex PCI, with consistent but exploratory effects across major lesion subsets and a borderline association with lower cardiovascular mortality.