Elevated remnant cholesterol predicts poor outcome in patients with premature acute coronary syndrome: a retrospective, single-center study.

Abstract

Background: The association between remnant cholesterol (RC) and recurrent cardiovascular events following acute coronary syndrome (ACS) is well-documented. However, RC-stratified analysis specifically focusing on patients with premature ACS (PACS), defined as initial disease onset occurring at ≤ 55 years of age in men or ≤ 65 years of age in women, remains limited.

Objectives: This study aimed to elucidate the clinical characteristics and subsequent cardiovascular events in patients with PACS, comparing those with high RC levels to those with low RC levels.

Methods: In this retrospective cohort study, 820 PACS patients were consecutively recruited between January 2019 and January 2020. RC was calculated as total cholesterol minus high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol. Patients with RC levels ≥ 66.6 percentile were classified as high RC. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including cardiovascular death, myocardial infarction (MI), stroke, ischemia-driven revascularization, or hospitalization for unstable angina or heart failure.

Results: Among the 820 patients enrolled, 277 (33.8%) were classified as high RC and 543 (66.2%) as low RC. The high RC group exhibited a higher prevalence of traditional risk factors, including diabetes (33.6% vs. 27.3%, p = 0.04), hypertension (68.2% vs. 61.3%, p = 0.04), and hyperlipidemia (43.3% vs. 31.3%, p = 0.001). Levels of glucose (p < 0.001), hemoglobin A1C (p = 0.005), triglyceride (p < 0.001), total cholesterol (p < 0.001) and LDL-C (p = 0.017) were significantly higher in the high RC group, while HDL-C levels were lower (p = 0.001). Over 3 years of follow-up, the high RC group had a significantly higher cumulative incidence of MACCE (16.2% vs. 10.9%; adjusted HR 1.68, 95% CI 1.10-2.59; p = 0.02). The increased risk was primarily driven by higher rates of hospitalization for unstable angina (12.3% vs. 7.9%; adjusted HR 1.69, 95% CI 1.03-2.75; p = 0.03) and composite cardiac events (14.8% vs. 9.8%; adjusted HR 1.75, 95% CI 1.12-2.73; p = 0.01).

Conclusions: In hospitalized PACS patients, the cumulative incidence of MACCE was significantly higher in the high RC group compared to the low RC group over a median follow-up of nearly 3 years. The incremental risk in the high RC group was mainly attributable to higher rates of hospitalization for unstable angina and composite cardiac events. Therefore, close attention should be paid to RC levels, and further exploration is warranted.