Cathepsin S Levels and Survival Among Patients With Non-ST-Segment Elevation Acute Coronary Syndromes

J Am Coll Cardiol. 2022 Sep 6;80(10):998-1010. doi: 10.1016/j.jacc.2022.05.055.

Abstract

Background: Patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) are at high residual risk for long-term cardiovascular (CV) mortality. Cathepsin S (CTSS) is a lysosomal cysteine protease with elastolytic and collagenolytic activity that has been involved in atherosclerotic plaque rupture.

Objectives: The purpose of this study was to determine the following: 1) the prognostic value of circulating CTSS measured at patient admission for long-term mortality in NSTE-ACS; and 2) its additive value over the GRACE (Global Registry of Acute Coronary Events) risk score.

Methods: This was a single-center cohort study, consecutively recruiting patients with adjudicated NSTE-ACS (n = 1,112) from the emergency department of an academic hospital. CTSS was measured in serum using enzyme-linked immunosorbent assay. All-cause mortality at 8 years was the primary endpoint. CV death was the secondary endpoint.

Results: In total, 367 (33.0%) deaths were recorded. CTSS was associated with increased risk of all-cause mortality (HR for highest vs lowest quarter of CTSS: 1.89; 95% CI: 1.34-2.66; P < 0.001) and CV death (HR: 2.58; 95% CI: 1.15-5.77; P = 0.021) after adjusting for traditional CV risk factors, high-sensitivity C-reactive protein, left ventricular ejection fraction, high-sensitivity troponin-T, revascularization and index diagnosis (unstable angina/ non-ST-segment elevation myocardial infarction). When CTSS was added to the GRACE score, it conferred significant discrimination and reclassification value for all-cause mortality (Delta Harrell's C: 0.03; 95% CI: 0.012-0.047; P = 0.001; and net reclassification improvement = 0.202; P = 0.003) and CV death (AUC: 0.056; 95% CI: 0.017-0.095; P = 0.005; and net reclassification improvement = 0.390; P = 0.001) even after additionally considering high-sensitivity troponin-T and left ventricular ejection fraction.

Conclusions: Circulating CTSS is a predictor of long-term mortality and improves risk stratification of patients with NSTE-ACS over the GRACE score.

Keywords: GRACE; NSTE-ACS; cathepsin S; reclassification; residual risk; risk stratification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Coronary Syndrome* / diagnosis
  • Cathepsins* / blood
  • Cohort Studies
  • Humans
  • Non-ST Elevated Myocardial Infarction* / diagnosis
  • Prognosis
  • Risk Assessment
  • Stroke Volume
  • Troponin T
  • Ventricular Function, Left

Substances

  • Troponin T
  • Cathepsins
  • cathepsin S