Remnant Cholesterol Levels at Diagnosis May Predict Acute Coronary Syndrome Occurrence During Follow-Up in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

<b>Background/Objectives</b>: Previous studies have revealed the predictive potential of remnant cholesterol (RC) for acute coronary syndrome (ACS) occurrence in the general population. However, whether this association applies to patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), in which a lipid paradox exists, remains unclear. We investigated whether RC levels at diagnosis could predict ACS occurrence during follow-up in patients with AAV. <b>Methods</b>: This study included 139 patients with AAV. ACS was defined as ST-elevation myocardial infarction (STEMI), non-STEMI, or unstable angina occurring after AAV diagnosis. RC levels were calculated as (total cholesterol)-(low-density lipoprotein cholesterol)-(high-density lipoprotein cholesterol). Patients were categorised into three groups by RC tertiles: highest (≥26.2 mg/dL), middle (19.1-26.1 mg/dL), and lowest (≤19.0 mg/dL) tertile groups. <b>Results</b>: The median age of the 139 patients (male, 31.7%) was 58.0 years. During follow-up, six, two, and one patients were diagnosed with ACS in the highest, middle, and lowest tertile groups, respectively. Patients in the highest tertile group exhibited a significantly lower ACS-free survival rate than those in the lowest tertile (<i>p</i> = 0.030). In the multivariable Cox hazards model, male sex (hazard ratio [HR] 9.054, 95% confidence interval [CI] 1.786-45.910), Birmingham vasculitis activity score (HR 1.147, 95% CI 1.033-1.274), and the highest tertile of RC levels (HR 10.818, 95% CI 1.867-62.689) were significantly and independently associated with ACS occurrence during follow-up in patients with AAV. <b>Conclusions</b>: Our findings indicate that RC levels at diagnosis may predict ACS occurrence during follow-up in patients with AAV, regardless of the traditional cardiovascular risk factors.