Prognostic value of a novel indicator integrating C-reactive protein-triglyceride glucose index and coronary physiological burden in patients undergoing PCI: a prospective cohort study

Background Patients with coronary artery disease (CAD) continue to face residual cardiovascular risk despite receiving guideline-directed optimal therapy. Both systemic metabolic-inflammatory dysregulation, reflected by the C-reactive protein-triglyceride glucose index (CTI), and coronary physiological burden, assessed by the quantitative flow ratio (QFR), are critical determinants of prognosis. However, the combined prognostic value of these two factors in patients after percutaneous coronary intervention (PCI) remains unclear. This study aimed to evaluate the prognostic value of an integrated index combining CTI with residual coronary physiological burden in patients undergoing PCI. Methods This single-center registry study (ChiCTR2100042363) consecutively enrolled 1,468 patients with CAD who underwent PCI between March 2021 and February 2022. A novel integrated index, μCTI, was derived from the CTI and the sum of the residual QFR in the three major coronary vessels. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), defined as a composite of all-cause death, non-fatal myocardial infarction (MI), ischemia-driven revascularization (IDR), or stroke. Results During a median follow-up of 24 months, a total of 185 MACCE (12.6%) occurred. In multivariable Cox regression, each standard deviation increase in μCTI was independently associated with a 79% rise in MACCE risk [adjusted hazard ratio (HR) = 1.79, 95% CI: 1.54–2.07, p < 0.001]. Furthermore, MACCE risk progressively increased across ascending μCTI quartiles (P for trend < 0.001). Restricted cubic spline (RCS) analysis revealed a linear relationship between μCTI and MACCE risk (P for nonlinear = 0.058). Conclusion The composite μCTI acts as an independent predictive biomarker and delivers supplementary risk stratification information for patients after PCI. This combined index could serve as an auxiliary tool to identify individuals at elevated risk of MACCE beyond single metabolic-inflammatory or coronary physiological indicators.