Association between the C-Reactive Protein–Albumin–Lymphocyte (CALLY) Index and Adverse Clinical Outcomes in CAD Patients after PCI: Findings of a Real-World Study

Background: The C-reactive protein–albumin–lymphocyte (CALLY) index is a novel inflammatory biomarker, and its association with the prognosis of coronary artery disease (CAD) after percutaneous coronary intervention (PCI) has not previously been studied. Therefore, this study aimed to investigate the effect of using the CALLY index on adverse outcomes in CAD patients undergoing PCI. Methods: From December 2016 to October 2021, we consecutively enrolled 15,250 CAD patients and performed follow-ups for primary endpoints consisting of all-cause mortality (ACM) and cardiac mortality (CM). The CALLY index was computed using the following formula: (albumin × lymphocyte)/(C-reactive protein (CRP) × 104). The average duration of the follow-up was 24 months. Results: A total of 3799 CAD patients who had undergone PCI were ultimately enrolled in the present study. The patients were divided into four groups according to the CALLY index quartiles: Q1 (≤0.69, n = 950), Q2 (0.69–2.44, n = 950), Q3 (2.44–9.52, n = 950), and Q4 (>9.52, n = 949). The low-Q1 group had a significantly higher prevalence of ACM (p < 0.001), CM (p < 0.001), major adverse cardiac events (MACEs) (p = 0.002), and major adverse cardiac and cerebrovascular events (MACCEs) (p = 0.002). Kaplan–Meier analysis revealed that a low CALLY index was significantly linked with adverse outcomes. After univariate and multivariate Cox regression analysis, the risk of ACM, CM, MACEs, and MACCEs decreased by 73.7% (adjust hazard risk [HR] = 0.263, 95% CI: 0.147–0.468, p < 0.001), 70.6% (adjust HR = 0.294, 95% CI: 0.150–0.579, p < 0. 001), 37.4% (adjust HR = 0.626, 95% CI: 0.422–0.929, p = 0.010), and 41.5% (adjust HR = 0.585, 95% CI: 0.401–0.856, p = 0.006), respectively, in the Q4 quartiles compared with the Q1 quartiles. Conclusions: This study revealed that a decreased CALLY index was associated with worse prognoses for CAD patients after PCI. The categorization of patients with a decreased CALLY index could provide valuable evidence for the risk stratification of adverse outcomes in CAD patients after PCI. Clinical Trial Registration: The details are available at http://www.chictr.org.cn (Identifier: NCT05174143).