C-reactive protein-to-serum albumin ratio as a novel predictor of long-term outcomes in coronary artery disease patients who have undergone percutaneous coronary intervention: analysis of a real-world retrospective cohort study

Background: C-reactive protein (CRP) has been proposed as a contributor to the pathogenesis of coronary artery disease (CAD) and inflammatory reactions, which are associated with a decrease in serum albumin, and it has been reported that the CRP-to-serum albumin ratio (CAR) can predict CAD severity in inpatient ischemic cardiomyopathy (ICM) patients. However, the relationship between the CAR and long-term adverse outcomes in CAD patients after percutaneous coronary intervention (PCI) is still unknown.

Methods: A total of 3561 CAD patients enrolled in the Outcomes and Risk Factors of Patients with Coronary Heart Disease after PCI: an investigation based on case records and follow-up (CORFCHD-ZZ), a retrospective cohort study conducted from January 2013 to December 2017, and 1630 patients meeting the study inclusion criteria were divided into two groups based on the CAR (CAR < 0.186; n = 1301 and CAR ≥ 0.186; n = 329). The primary outcome was long-term mortality, including all-cause mortality (ACM) and cardiac mortality. The average follow-up time was 37.59 months.

Results: We found that there were significant differences between the two groups in the incidences of ACM (P < 0.001) and cardiac mortality (P = 0.003). Cox multivariate regression analyses demonstrated that CAR was an independent predictor of ACM [hazard ratio, 2.678; (95% confidence interval (CI), 1.568-4.576); P < 0.001] and cardiac mortality (hazard ratio, 2.055; 95% CI, 1.056-3.998; P = 0.034) in CAD patients after PCI.

Conclusion: This study revealed that the CAR is an independent and novel predictor of long-term adverse outcomes in CAD patients who have undergone PCI.