The role of coronary CT angiography (CCTA) in improving outcomes among patients undergoing percutaneous coronary intervention (PCI) for obstructive coronary artery disease (CAD) remains unclear. A retrospective cohort study using the TriNetX U.S. Research Network identified adults (≥18 years) who underwent de novo PCI (2013-2025). Patients with prior or presenting PCI, coronary artery bypass grafting, or acute coronary syndrome were excluded. Those with CCTA within 1 year before PCI were compared to those without CCTA. After 1:1 propensity score matching, 4936 patients remained in each group. The primary outcome was a composite of all-cause mortality, myocardial infarction (MI), or heart failure (HF) at 1 and 5 years. Baseline characteristics were well-balanced post-matching. CCTA prior to PCI was associated with lower rates of the composite outcome at 1 year (9.6% vs. 13.0%; hazard ratios (HR) 0.74, 95% CI 0.66-0.83) and 5 years (16.1% vs. 23.7%; HR 0.79, 95% CI 0.72-0.86). Reductions were mainly driven by lower MI and mortality rates. HF showed no difference at 1 year but was significantly lower at 5 years (HR 0.85, 95% CI 0.76-0.95). Pre-procedural CCTA within 1 year of PCI was associated with improved cardiovascular outcomes at 1 and 5 years, suggesting potential benefits from enhanced anatomical assessment and medical optimization before revascularization.