Preclinical carotid atherosclerosis is independently associated with cardiovascular events and mortality in type 1 diabetes

To evaluate whether carotid atherosclerosis predicts future cardiovascular events (CVE) and mortality in adults with type 1 diabetes (T1D) in primary prevention. Cohort study in adults with T1D participating in a cardiovascular risk assessment program that included carotid ultrasound. Eligibility criteria included age ≥ 40 years, diabetic kidney disease regardless of age or diabetes duration, or type 1 diabetes duration ≥ 10 years in the presence of at least one additional cardiovascular risk factor.The primary endpoint was the first CVE. A secondary endpoint was a composite of CVE plus all-cause mortality. Carotid plaque burden and outcomes were analyzed using Kaplan–Meier curves and Cox regression models. 701 individuals were followed for a mean of 5.85 years (mean age 48.5 years; T1D duration 27 years; 51.9% males). Carotid plaques were identified in 40.4%. During follow-up, 45 CVE occurred (18 coronary artery disease, 14 peripheral artery disease, 6 stroke, 3 heart failure, 4 deaths) along with 5 non-cardiovascular deaths. Event-free survival declined progressively with increasing plaque burden (log-rank p < 0.001). In unadjusted analyses, the presence of any plaque was associated with increased risk of CVE (HR 3.14, 95%C I 1.69–5.84) and of the composite endpoint (HR 3.07, 95% CI 1.71–5.51). After multivariable adjustment for demographic, metabolic, and microvascular factors, a high plaque burden (≥ 3 plaques) remained associated with CVE (HR 3.38, 95% CI 1.37–8.38) and with the composite endpoint (HR 2.64, 95% CI 1.13–6.21). Preclinical carotid atherosclerosis in adults with T1D was independently associated with an increased risk of cardiovascular events and mortality. These findings support the potential role of carotid ultrasound as a complementary tool for cardiovascular risk assessment in individuals with T1D. What is currently known about this topic? Cardiovascular risk prediction in individuals with type 1 diabetes remains suboptimal. Although these patients are at increased risk of cardiovascular disease, the prognostic value of subclinical markers, such as carotid atherosclerosis detected by ultrasound, has not been well established. What is the key research question? Does the presence and burden of carotid artery plaques predict future cardiovascular events and mortality in adults with type 1 diabetes without prior cardiovascular disease? What is new? In this study, carotid plaques were detected in approximately 40% of participants. A higher plaque burden showed a clear dose–response association with reduced event-free survival and increased cardiovascular risk, supporting its independent prognostic value. How might this study influence clinical practice? Carotid ultrasound may improve cardiovascular risk stratification in type 1 diabetes by identifying individuals at higher risk who could benefit from intensified preventive strategies.