Profiles and Prognostic Value of a Non-Invasive Liver Fibrosis Marker in Patients With Acute and Chronic Coronary Syndrome: Insights From the CLIDAS-PCI.

BACKGROUND: The Fibrosis-4 (Fib-4) index, a non-invasive liver fibrosis marker, is useful for assessing cardiovascular risk; however, its role and profiles in patients with acute coronary syndrome (ACS) and chronic coronary syndrome (CCS) remain unclear. METHODS AND RESULTS: We analyzed 5,150 patients (ACS: 2,274; CCS: 2,876) from the Clinical Deep Data Accumulation System-Percutaneous Coronary Intervention (CLIDAS-PCI) database. The Fib-4 index was calculated 1-3 months post-PCI to avoid acute-phase transaminase elevation. Patients were stratified into low (<1.3), intermediate (1.3-2.67), and high (>2.67) Fib-4 categories. Longitudinal changes were assessed every 6 months for 2 years. The primary outcome was 3-point major adverse cardiovascular events (3P-MACE): cardiovascular death, non-fatal myocardial infarction, and stroke. Compared with CCS, ACS patients had fewer comorbidities and more intensive medical therapy. The Fib-4 index was lower in ACS than in CCS (1.83 vs. 1.93; P<0.001), and this difference persisted throughout follow up. Kaplan-Meier analysis demonstrated clear risk stratification across Fib-4 categories in both ACS and CCS. A higher Fib-4 index was independently associated with increased 3P-MACE risk after adjustment for C-reactive protein levels and coronary syndrome type (adjusted hazard ratio 1.15; 95% confidence interval 1.12-1.19; P<0.001). CONCLUSIONS: The Fib-4 index efficiently stratifies cardiovascular risk in ACS and CCS, independent of systemic inflammation. ACS patients consistently exhibited lower Fib-4 values than CCS patients.