Abdominal aortic aneurysm (AAA) is a common disease with substantial heritability. In this study, we performed a genome-wide association meta-analysis from 14 discovery cohorts and uncovered 141 independent associations, including 97 previously unreported loci. A polygenic risk score derived from meta-analysis explained AAA risk beyond clinical risk factors. Genes at AAA risk loci indicate involvement of lipid metabolism, vascular development and remodeling, extracellular matrix dysregulation and inflammation as key mechanisms in AAA pathogenesis. These genes also indicate overlap between the development of AAA and other monogenic aortopathies, particularly via transforming growth factor β signaling. Motivated by the strong evidence for the role of lipid metabolism in AAA, we used Mendelian randomization to establish the central role of nonhigh-density lipoprotein cholesterol in AAA and identified the opportunity for repurposing of proprotein convertase, subtilisin/kexin-type 9 (PCSK9) inhibitors. This was supported by a study demonstrating that PCSK9 loss of function prevented the development of AAA in a preclinical mouse model.

Background: Population-based epidemiologic studies of aortic dissections (ADs) are needed. This study aimed to report clinical characteristics, incidences, and mortality rates for adult patients admitted to Danish hospitals with type A AD (TAAD) or type B AD (TBAD) from 1996 through 2016. Methods: We conducted a nationwide, population-based register study. All cases of AD registered with International Classification of Diseases, Tenth Revision codes in the Danish National Patient Registry at time of admission to a hospital with available medical records underwent validation. Data were merged between nationwide health registries including the cause of death registry. Patients with validated AD were matched 1:10 on sex and age with patients with hypertension from the general Danish population. Results: Of 5018 registered cases of AD, 4183 cases underwent review and 3023 (60.2%) were validated as AD. After exclusions, the distribution of validated TAAD and TBAD was 1620 (60.5%) and 1059 (39.5%; P <0.001), 67.5% and 67.0% of patients were men, and mean ages at dissection were 63.5±12.9 and 67.5±12.2 years ( P <0.001), respectively. The most prevalent comorbidities for TAAD were hypertension (55.2%), thoracic aortic aneurysms (14.6%), and chronic obstructive pulmonary disease (13.1%); for TBAD, the most prevalent comorbidities were hypertension (64.1%), aortic aneurysms at any location (7.5% to 12.0%), and chronic obstructive pulmonary disease (15.7%). The overall mean annual incidence rate was 4.2/100 000 patient-years. Incidence was significantly higher for TAAD (2.2/100 000) compared with TBAD (1.5/100 000; P <0.001). The 30-day mortality rates for validated TAAD and TBAD were 22.0% and 13.9% ( P <0.001), respectively, with no significant changes over time or between sexes. Adjusted 5-year overall mortality rates for TAAD and TBAD were hazard ratio 3.2 (2.9 to 3.5; P <0.001; aortic-related cause of death, 57.0%) and hazard ratio 2.1 (1.9 to 2.4; P <0.001; aortic-related cause of death, 42.8%), respectively, compared with the general hypertensive population. Among patients who survived 30 days from dissection, the adjusted 5-year overall mortality rates were hazard ratio 1.1 (1.0 to 1.3; P =0.12; aortic-related cause of death, 23.2%) and hazard ratio 1.4 (1.2 to 1.6; P <0.001; aortic-related cause of death, 25.6%) for TAAD and TBAD, respectively. Conclusions: Hypertension, aortic aneurysms, and chronic obstructive pulmonary disease were the most prevalent comorbidities. The 30-day mortality frequencies were consistent over time with no significant differences between sexes. The 5-year mortality rate was higher for TAAD than TBAD. If the patient survived 30 days from dissection, the mortality rate for patients with TAAD was comparable with that of the general hypertensive population, but the mortality rate was significantly higher in patients with TBAD.

Large abdominal aortic aneurysms (AAAs) present a significant mortality risk. While numerous medical interventions have been proposed, no drugs have convincingly reduced AAA progression, rupture rates, or repair risk. This systematic review and meta-analysis aimed to assess the impact of repurposed drugs or dietary supplements on slowing expansion rates, reducing the risk of rupture, or minimising the risk of repair for individuals with AAA. A systematic search was conducted in five databases. Both observational studies and randomised controlled trials were included. Unpublished data from two screening trials were incorporated. Risk of bias was assessed using the Newcastle-Ottawa scale and revised Cochrane risk of bias tool. Meta-analyses were performed for each identified drug subclass and were stratified by overall risk of bias. Results were reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Of 7 484 screened studies, 39 met the inclusion criteria. No studies on dietary supplements were included. A total of 84 cohorts were derived from the included studies, and twelve distinct drug groups underwent meta-analyses. Two drug groups, metformin and statins, were statistically significant in slowing AAA growth. No low risk of bias studies were included for these two drug groups, and the results had very high heterogeneity (I² > 80%). Both groups had a GRADE certainty of very low. Metformin, excluding high risk of bias studies, presented an estimated mean growth difference of AAA diameter between users and non-users of -0.73 mm/year, whilst statins had an overall estimated mean difference of -0.84 mm/year. This systematic review and meta-analysis suggests that metformin and statins may provide some effect in slowing AAA progression. However, no definitive evidence was found for any of the investigated drugs included in this study. Further research is needed to identify effective medical treatments for AAA progression with more robust methodology.

This study aimed to develop a prediction tool to identify abdominal aortic aneurysms (AAAs) at increased risk of rupture incorporating demographic, clinical, imaging, and medication data using artificial intelligence (AI). A development and validation study for individual prognosis using AI in a case-control design. From two Danish hospitals, all available ruptured AAA cases between January 2009 and December 2016 were included in a ratio of 1:2 with elective surgery controls. Cases with previous AAA surgery or missing preoperative scans were excluded. Features from computed tomography angiography scans and hospital records were manually retrieved. The sample was divided randomly and evenly into developmental and internal validation groups. A SHapley Additive exPlanations Feature Importance Rank Ensembling (SHAPFire) AI tool was developed using a gradient boosting decision tree framework. The final SHAPFire AI model was compared with models using (1) solely infrarenal anterior-posterior diameter and (2) all available features. The study included 637 individuals (84.8% men, mean age 73 ± 7 years, 213 ruptured AAAs). The SHAPFire AI incorporated 20 of 68 available features, and aneurysm size, blood pressure, and relationships between height and weight were given highest rankings. The receiver operating characteristic curve for the SHAPFire AI model displayed a significant increase in accuracy identifying ruptured AAA cases compared with the conventional model based solely on diameter with areas under the curves of 0.86 ± 0.04 and 0.74 ± 0.03 (P = .008), respectively. SHAPFire AI was comparable in performance with the model using all features. This study successfully developed a SHAPFire AI tool to identify AAAs at increased risk of rupture with significantly higher accuracy than diameter alone. External validation of the model is warranted before clinical implementation.

BACKGROUND: Abdominal aortic aneurysms (AAA) present with high morbidity and mortality when they occasionally rupture. No medical therapy has successfully been proven to reduce AAA growth, though both metformin and statins have been identified as potential treatments in multiple meta-analysis. This study aimed to investigate a potential relationship between statin use and AAA growth rates and risk of undergoing repair, rupture, or death. METHODS: The study population included all men with screening-detected AAAs (30–55 mm) from the 2 large, population-based, randomized screening trials; the Viborg Vascular Screening trial (inclusion, 2008–2011) and the Danish Cardiovascular Screening trial (inclusion, 2014–2018). The clinical database was supplemented with data from the nationwide Danish Healthcare Registries, including prescription and outcome data. Statin exposure was quantified by defined daily doses (DDD). The primary outcome was AAA growth rate, whereas secondary outcomes included the need for repair and a composite of repair, rupture, and all-cause death. Growth rates were calculated using linear regression. To evaluate the risk of repair, patients were followed from inclusion until surgery, rupture, death, 5-year follow-up, or December 31, 2021. RESULTS: A total of 998 aneurysmal men (median age, 69.5 [interquartile range (IQR), 67–72] years; median AAA diameter, 35.4 [IQR, 32–41.2] mm) were included. Statin use was significantly associated with reduced AAA growth rate; an increase of 1 DDD statin per day was associated with an adjusted change in growth rate of −0.22 mm/year [95% CI, −0.39 to −0.06]; P =0.009). The 5-year adjusted hazard ratio for undergoing repair per doubling of statin dose presented a significantly reduced adjusted hazard ratio (HR) of 0.82 ([95% CI, 0.70–0.97]; P= 0.023), which was significant after 2.5 years. Statin use was associated with a significantly lower risk of the composite outcome (surgery, rupture, and death) in a dose-dependent manner, with an adjusted HR of 0.83 ([95% CI, 0.73–0.94]; P =0.003) per doubling of statin dose. Findings were robust in a variety of sensitivity analyses. CONCLUSIONS: High-dose statin use was associated with decreased AAA growth rates and lowered risk of undergoing repair, rupture, and death. This nonrandomized study suggests that patients with AAA could benefit from high-dose statin use, beyond only targeting associated risk factors.