# Vitamin D Deficiency as an Independent Predictor for Plaque Vulnerability and All-Cause Mortality in Patients with High-Grade Carotid Disease

## TL;DR

Vitamin D deficiency is linked to unstable carotid artery plaques and higher mortality in patients with severe carotid artery disease.

## Contribution

This study identifies vitamin D deficiency as a novel predictor of plaque instability and mortality in high-grade carotid artery stenosis patients.

## Key findings

- Vitamin D deficiency was associated with echolucent or mixed plaque morphology and symptomatic carotid artery stenosis.
- Deficiency predicted major adverse cardiovascular events and all-cause mortality with adjusted hazard ratios of 1.6 and 2.2, respectively.
- Lower vitamin D levels were observed in symptomatic patients and those with unstable plaque characteristics.

## Abstract

Objectives: The mechanisms linking vitamin D deficiency to carotid artery stenosis (CAS) remain unclear. Data on cardiovascular outcomes in CAS patients with vitamin D deficiency are limited. We investigated the association of vitamin D deficiency with carotid plaque morphology and patient outcomes in high-grade CAS. Methods: A total of 332 patients undergoing carotid endarterectomy for symptomatic (n = 113, 34%) or asymptomatic (n = 219, 66%) CAS were included. Preoperative vitamin D levels were measured, and duplex sonography was used to assess luminal narrowing. Associations of vitamin D with clinical presentation were analyzed using univariate and multivariate linear regression. For vitamin D deficiency and the prediction of major adverse cardiovascular events (MACE) and all-cause mortality, the Cox proportional hazard regression model was used. Results: The median age was 69 years (interquartile range (IQR) 64–74), and 94 (29.3%) patients were female. Vitamin D deficiency was present in 84 (25%) patients. Symptomatic patients had significantly lower vitamin D levels (41.2 nmol/L, IQR 25.1–63.5) than asymptomatic patients (51.6 nmol/L, IQR 30.5–74.3, p = 0.011). Patients with echolucent (44.9 nmol/L, IQR 27.4–73.7) or mixed plaques (39.2 nmol/L, IQR 22.9–63.5) had lower vitamin D levels than those with echogenic plaques (52.3 nmol/L, IQR 34.1–75.7). Vitamin D deficiency predicted MACE and all-cause mortality with an adjusted HR of 1.6, 95% CI of 1.1–2.6, and p = 0.030 and an HR of 2.2, 95% CI of 1.3–3.6, and p = 0.002, respectively, in a multivariable Cox proportional hazard regression model. Conclusions: A deficiency in vitamin D was correlated with unstable plaque characteristics and symptomatic CAS. Furthermore, vitamin D deficiency was associated with long-term adverse cardiovascular outcomes and mortality, suggesting its potential as a modifiable risk factor for improved risk stratification in patients undergoing carotid endarterectomy.