ALT-to-Lymphocyte Ratio as a Predictor of Long-Term Mortality in Patients with Normal Liver Function Presenting Coronary Artery Disease after Undergoing PCI: A Retrospective Cohort Study

Background: Alanine aminotransferase (ALT) is referred as liver transaminase and predominantly expressed by hepatocytes. Previous evidences showed that high levels of ALT were reversely associated with short- and long-term outcomes in patients with myocardial infarction. Besides, low lymphocyte has been demonstrated to be significantly correlated with adverse clinical outcomes in coronary artery disease (CAD). However, evidences about the relationship between ALT-to-lymphocyte ratio (ALR) and outcomes in CAD patients with normal liver function are limited. The aim of this study was to assess the relationship between ALR and clinical outcomes in patients with CAD.

Methods: This is a retrospective cohort study, and a total of 3561 patients were enrolled in Clinical Outcomes and Risk Factors of Patients with CAD after percutaneous coronary intervention (PCI), from January 2013 to December 2017. After excluding patients with liver dysfunction, we finally enrolled 2714 patients. These patients were divided into two groups according to ALR value: the lower group (ALR < 14.06, n = 1804) and the higher group (ALR ≥ 14.06, n = 910). The average follow-up time was 37.59 ± 22.24 months.

Results: We found that there were significant differences between the two groups in the incidence of all-cause mortality (ACM) (P < 0.001) and cardiac mortality (CM) (P=0.010). Kaplan-Meier survival analysis suggested that CAD patients with higher ALR tended to have an increased accumulated risk of ACM and CM (log rank P < 0.001 and P=0.006, respectively). Multivariate Cox regression analysis showed that ALR was an independent predictor of ACM (hazard ratio (HR) = 2.017 (95% confidence interval (CI): 1.289-3.158), P=0.002) and CM (HR = 1.862 (95% CI: 1.047-3.313), P=0.034). We did not find significant difference in the incidence of major adverse cardiovascular events (MACEs) and major adverse cardiovascular and cerebrovascular events (MACCEs) between the two groups after adjustments of confounders.

Conclusion: Our results indicate that ALR is an independent predictor of long-term adverse outcomes in CAD patients who underwent PCI.