Relevance of ultrasound detection and assessment of vascular calcifications in chronic kidney disease

Introduction: Chronic kidney disease (CKD) affects approximately 10% of the Spanish population and constitutes an independent cardiovascular risk factor. Vascular calcifications, especially in the abdominal aorta, are significantly associated with increased cardiovascular mortality in patients with CKD. This systematic review evaluates the evidence on the usefulness of ultrasound to detect and assess vascular calcifications in patients with CKD, and its relevance as a cardiovascular risk factor. Methods: A systematic search of multiple electronic databases was conducted until July 2024. Original studies published between 2000 and 2024 evaluating the use of ultrasound to detect vascular calcifications in adult patients with CKD at any stage were included. Reviews, letters, editorials, animal studies and those not published in English or Spanish were excluded. Methodological quality was assessed using the Newcastle-Ottawa scale for observational studies and the Cochrane tool for clinical trials. Results: Twenty-eight studies were included with a total of 50 to 3,000 participants per study. Most were observational studies, with 3 randomised clinical trials. Ultrasound showed good correlation with computed tomography (r=0.65-0.82) to quantify aortic and femoral calcifications. The presence of aortic calcifications was associated with increased risk of cardiovascular mortality (HR 1.8-3.2) in patients with advanced CKD and on haemodialysis. Iliac/femoral calcifications were associated with increased risk of cardiovascular events (RR 1.6-2.4) in patients with stage 3-5 CKD. Incorporation of ultrasound assessment of calcifications into CKD-specific risk algorithms significantly improved their predictive performance. Discussion: Ultrasonography emerges as a valuable tool for the detection of vascular calcifications due to its non-invasive nature, low cost and ability to perform repeated assessments. However, limitations such as heterogeneity in assessment methods, variable sample sizes and lack of long-term follow-up in some studies were identified. Further research is needed to standardise protocols and assess the long-term impact of interventions based on ultrasound detection of calcifications. Conclusions: Ultrasonography is an effective and accessible tool for detecting and assessing vascular calcifications in patients with CKD, providing relevant prognostic information for cardiovascular risk stratification. Its consideration as a first-line tool in nephrological practice is recommended. However, large-scale prospective studies are needed to definitively validate its prognostic value in different stages of CKD and to evaluate the efficacy of early interventions based on these findings.