Circulating miRNAs as Biomarkers for Diagnosis, Surveillance, and Postoperative Follow-Up of Abdominal Aortic Aneurysms

•miRNAs are good candidates as circulating biomarkers (stability in human blood and high sensitivity/specificity of expression evaluation). •Numerous reports have recently demonstrated differential expression of miRNAs in cardiovascular, peripheral arterial, and aneurysmal disease. •A total of 25 reports, published from 2012 to 2022, were included in this review (N = 1,259 patients with AAA, 90% men). •The following miRNAs were identified in more than 2 references: miR-145, miR-24, miR-33, miR-125, let-7, miR-15, miR-191, miR-29, and miR-133. •These 9 miRNAs are implicated in known pathogenetic mechanisms for AAA. Background To provide a summary of the current state of research in English medical literature on circulating miRNAs as biomarkers for abdominal aortic aneurysm (AAA). Additionally, for the most commonly mentioned circulating miRNAs in the literature, to attempt a documentation of the biological mechanisms underlying their role in AAA development. Methods A literature search was undertaken in the MEDLINE database. Only reports that involved peripheral blood samples (whole blood, plasma, and serum) were included. The following terms were used in combination: microrna, mirna, AAA, human, circulating, plasma, serum, endovascular, and endovascular aneurysm repair (EVAR). Results A total of 25 reports, published from 2012 to 2022 were included with a total of 1,259 patients with AAA, predominantly men (N = 1,040, 90%). Six of these reports recruited healthy donors who underwent ultrasound screening for AAA as control samples. The majority of studies were undertaken in plasma samples and the most preferred microRNA profiling method was real - time quantitative polymerase chain reaction (qRT-PCR). The following 9 miRNAs (out of a total of 76) were studied in more than 2 references: miR-145, miR-24, miR-33, miR-125, let-7, miR-15, miR-191, miR-29, and miR-133. Conclusions The 9 miRNAs described in this study, are implicated in known pathogenetic mechanisms of AAA, such as atherosclerosis, vascular smooth muscle cell (VSMCs) phenotype switch and apoptosis, vascular inflammation, extracellular matrix (ECM) degradation, and lipid metabolism. Identifying disease-specific miRNAs, in combination with other clinical parameters, as indicators of AAA, is crucial for early diagnosis as well as follow-up of AAAs. For future research on miRNAs as AAA biomarkers, strict case and control group definitions, sample acquisition protocols, and miRNA expression profiling techniques are warranted. To provide a summary of the current state of research in English medical literature on circulating miRNAs as biomarkers for abdominal aortic aneurysm (AAA). Additionally, for the most commonly mentioned circulating miRNAs in the literature, to attempt a documentation of the biological mechanisms underlying their role in AAA development. A literature search was undertaken in the MEDLINE database. Only reports that involved peripheral blood samples (whole blood, plasma, and serum) were included. The following terms were used in combination: microrna, mirna, AAA, human, circulating, plasma, serum, endovascular, and endovascular aneurysm repair (EVAR). A total of 25 reports, published from 2012 to 2022 were included with a total of 1,259 patients with AAA, predominantly men (N = 1,040, 90%). Six of these reports recruited healthy donors who underwent ultrasound screening for AAA as control samples. The majority of studies were undertaken in plasma samples and the most preferred microRNA profiling method was real - time quantitative polymerase chain reaction (qRT-PCR). The following 9 miRNAs (out of a total of 76) were studied in more than 2 references: miR-145, miR-24, miR-33, miR-125, let-7, miR-15, miR-191, miR-29, and miR-133. The 9 miRNAs described in this study, are implicated in known pathogenetic mechanisms of AAA, such as atherosclerosis, vascular smooth muscle cell (VSMCs) phenotype switch and apoptosis, vascular inflammation, extracellular matrix (ECM) degradation, and lipid metabolism. Identifying disease-specific miRNAs, in combination with other clinical parameters, as indicators of AAA, is crucial for early diagnosis as well as follow-up of AAAs. For future research on miRNAs as AAA biomarkers, strict case and control group definitions, sample acquisition protocols, and miRNA expression profiling techniques are warranted.