# Cystatin C to Left Ventricular Ejection Fraction Ratio as a Novel Predictor of Adverse Outcomes in Patients with Coronary Artery Disease: A Prospective Cohort Study

## TL;DR

This study shows that a new ratio of cystatin C to heart function (CLR) can predict poor outcomes in heart disease patients after a common heart procedure.

## Contribution

The study introduces the cystatin C to left ventricular ejection fraction ratio (CLR) as a novel predictor of adverse outcomes in coronary artery disease patients.

## Key findings

- High CLR is strongly associated with increased mortality and cardiovascular events after PCI.
- CLR is a better predictor of adverse outcomes in both stable and acute coronary disease patients.
- The optimal cut-off value for CLR is 0.019, with higher values indicating worse outcomes.

## Abstract

While both cystatin C and left ventricular
ejection fraction (LVEF) revealed established prognostic efficacy in coronary
artery disease (CAD), the relationship between cystatin C/left ventricular
ejection fraction ratio (CLR) and adverse clinical outcomes among patients with
CAD following percutaneous coronary intervention (PCI) remains obscure, to date.
Therefore, we sought to assess the predictive efficacy of CLR among CAD patients
who underwent PCI in current study.

A total of 14,733
participants, including 8622 patients with acute coronary syndrome (ACS) and 6111
patients with stable coronary artery disease (SCAD), were enrolled from a
prospective cohort of 15,250 CAD patients who underwent PCI and were admitted to the First Affiliated Hospital of Xinjiang Medical University from
2016 to 2021. The primary outcome of this study was mortality, including
all-cause mortality (ACM) and cardiac mortality (CM). The secondary outcomes were
major adverse cardiovascular events (MACEs), major adverse cardiac and
cerebrovascular events (MACCEs) and nonfatal myocardial infarction (NFMI). For
CLR, the optimal cut-off value was determined by utilizing receiver operating
characteristic curve analysis (ROC). Subsequently, patients were assigned into
two groups: a high-CLR group (CLR ≥0.019, n = 3877) and a low-CLR group
(CLR <0.019, n = 10,856), based on optimal cut-off value of 0.019. Lastly, the
incidence of outcomes between the two groups was compared.

The
high-CLR group had a higher incidence of ACM (8.8% vs. 0.9%), CM (6.7% vs.
0.6%), MACEs (12.7% vs. 5.9%), MACCEs (13.3% vs. 6.7%), and NFMIs (3.3% vs.
0.9%). After adjusting for confounders, multivariate Cox regression analyses
revealed that patients with high-CLR had an 8.163-fold increased risk of ACM (HR
= 10.643, 95% CI: 5.525~20.501, p
< 0.001), a
10.643-fold increased risk of CM (HR = 10.643, 95% CI:
5.525~20.501, p
< 0.001), a 2.352-fold increased risk
of MACE (HR = 2.352, 95% CI: 1.754~3.154, p
< 0.001),
a 2.137-fold increased risk of MACCEs (HR = 2.137, 95% CI:
1.611~2.834, p
< 0.001), and a 1.580-fold increased
risk of NFMI (HR = 1.580, 95% CI: 1.273~1.960, p
<
0.001) compared to patients with low-CLR.

The current study
indicated that a high CLR is a novel and powerful predictor of adverse long-term
outcomes in CAD patients who underwent PCI, and that, it is a better predictor
for patients wtih SCAD and ACS.

NCT05174143, http://Clinicaltrials.gov.