Abstract Body (Do not enter title and authors here): Background:
Optical coherence tomography (OCT) offers superior imaging resolution compared to conventional angiography and has been linked to improved outcomes in percutaneous coronary intervention (PCI). Although prior studies support the overall benefits of OCT-guided PCI (OGP), its efficacy specifically in patients with complex coronary lesions—such as chronic total occlusions (CTO), severely calcified lesions, and bifurcations—remains unclear. These lesion types are clinically significant due to their association with increased procedural complications, suboptimal stent deployment, and higher rates of restenosis. To address this critical knowledge gap, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing OGP versus angiography-guided PCI (AGP) in this high-risk population.

Methods:
We performed a systematic search of MEDLINE, Cochrane Library, Google Scholar, ScienceDirect, and ClinicalTrials.gov through May 2025. Extracted outcomes included major adverse cardiovascular events (MACE), all-cause mortality, cardiac mortality, myocardial infarction, ischemia-driven target vessel revascularization, target lesion revascularization (TLR), stroke, and stent thrombosis. This study was registered with PROSPERO (CRD42024599058).

Results:
Five RCTs comprising 5,737 patients (OGP: 2,738; AGP: 2,999) with complex coronary lesions were included. Compared to AGP, OGP was associated with a significant reduction in MACE (RR: 0.71, p = 0.0001), all-cause mortality (RR: 0.58, p = 0.009), cardiovascular mortality (RR: 0.43, p = 0.003), TLR (RR: 0.53, p = 0.007), and stroke (RR: 0.17, p = 0.02). No significant differences were observed in periprocedural myocardial infarction or overall myocardial infarction between the two groups. However, procedural time was significantly longer in the OGP group (MD: 16.14 minutes, p = 0.0008).

Conclusions:
This meta-analysis demonstrates that OCT-guided PCI significantly improves important clinical outcomes in patients with complex coronary lesions. These findings support the incorporation of OCT into routine PCI practice for anatomically challenging lesions, where conventional angiography may be insufficient for optimal procedural planning and execution.