Randomized controlled trial of vacuum therapy for intermittent claudication

OBJECTIVE: The "gold standard" treatment of intermittent claudication (IC) is supervised exercise therapy (SET). Intermittent vacuum therapy (IVT) has recently been promoted as an additional treatment of IC. During IVT, negative pressure and atmospheric pressure are alternatingly applied to the lower extremities, possibly resulting in improved circulation. The aim of this study was to determine a potential additional effect of IVT in IC patients undergoing a standardized SET program. METHODS: IC patients were recruited from three Dutch general hospitals between December 2015 and July 2017. They received a standardized SET program but were also randomly assigned to an intervention group receiving an IVT treatment (-50 mBar negative pressure) or a control group receiving a sham treatment (-5 mBar negative pressure). IVT was provided in a dedicated clinic during 12 sessions of 30 minutes during a 6-week period. The primary outcome measure was a change in maximal treadmill walking distance. Secondary outcome measures were a change in functional treadmill walking distance, 6-minute walk test, ambulatory ability, and quality of life. RESULTS: A total of 78 patients were randomized, of whom 70 were available for intention-to-treat analysis (control, n = 34; intervention, n = 36). At 6 and 12 weeks, increases in walking distance were of equal magnitude. Median (interquartile range) change in maximal treadmill walking distance during 12 weeks was +335 (205-756) meters in control patients and +250 (77-466) meters in intervention patients (P = .109), whereas functional treadmill walking distance increased +230 (135-480) meters and +188 (83-389) meters (P = .233), respectively. Mean ± standard deviation change in the 6-minute walk test was +36 ± 48 meters and +55 ± 63 meters (P = .823), respectively. Ambulatory ability and quality of life improved equally in both groups. CONCLUSIONS: IVT does not confer any additional beneficial effects in IC patients undergoing a standardized SET program

Incidence, natural course, and outcome of type II endoleaks in infrarenal endovascular aneurysm repair based on the ENGAGE registry data

Objective: The purpose of this study was to report the incidence, natural history, and outcome of type II endoleaks in the largest prospective real-world cohort to date. Methods: Patients were extracted from the prospective Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE). Two groups were analyzed: first, patients with an isolated type II endoleak; and second, patients with a type II endoleak who later presented with a type I endoleak. A health status analysis between patients with an early type II endoleak and patients with no endoleak was performed. Second, an attempt was made to identify risk factors in patients with a type II endoleak who later presented with a type I endoleak. Results: Through 5 years of follow-up, a total of 197 (15.6%) patients with isolated type II endoleaks were identified. Most were detected within the first 30 days (n = 73 [37.1%]) and through the first year (n = 73 [37.1%]), with the remainder being detected after 1 year of follow-up (n = 51 [25.8%]). Patients with a type II endoleak had a higher incidence of aneurysm growth and more secondary endovascular procedures (15.4% vs 7.5% at 5 years; P <.001). Overall survival was higher in the isolated type II endoleak group compared with patients with no endoleak (77.2% vs 67.0% at 5 years; P =.010). Twenty-two patients (10%) with a type II endoleak were diagnosed with a late type I endoleak (type IA, n = 10; type IB, n = 12), with a secondary intervention rate of 67.5% through 5 years. There was no difference in health status scores between patients with an early type II endoleak and patients without any type of endoleak at 1-year follow-up. Conclusions: In the ENGAGE registry, isolated type II endoleaks are present in 15.6% of patients during follow-up. The majority do not require secondary intervention, and an early isolated type II endoleak does not have an impact on health status through 1 year. However, a small group of patients with a type II endoleak will present with a type I endoleak, resulting in a high secondary intervention rate and significant risk of aneurysm-related complications

Meta-Analysis of Genome-Wide Association Studies for Abdominal Aortic Aneurysm Identifies Four New Disease-Specific Risk Loci

Rationale: Abdominal aortic aneurysm (AAA) is a complex disease with both genetic and environmental risk factors. Together, 6 previously identified risk loci only explain a small proportion of the heritability of AAA. Objective: To identify additional AAA risk loci using data from all available genome-wide association studies (GWAS). Methods and Results: Through a meta-analysis of 6 GWAS datasets and a validation study totalling 10,204 cases and 107,766 controls we identified 4 new AAA risk loci: 1q32.3 (SMYD2), 13q12.11 (LINC00540), 20q13.12 (near PCIF1/MMP9/ZNF335), and 21q22.2 (ERG). In various database searches we observed no new associations between the lead AAA SNPs and coronary artery disease, blood pressure, lipids or diabetes. Network analyses identified ERG, IL6R and LDLR as modifiers of MMP9, with a direct interaction between ERG and MMP9. Conclusions: The 4 new risk loci for AAA appear to be specific for AAA compared with other cardiovascular diseases and related traits suggesting that traditional cardiovascular risk factor management may only have limited value in preventing the progression of aneurysmal disease

Abdominal aortic aneurysm is associated with a variant in low-density lipoprotein receptor-related protein 1

Abdominal aortic aneurysm (AAA) is a common cause of morbidity and mortality and has a significant heritability. We carried out a genome-wide association discovery study of 1866 patients with AAA and 5435 controls and replication of promising signals (lead SNP with a p value &lt; 1 × 10-5) in 2871 additional cases and 32,687 controls and performed further follow-up in 1491 AAA and 11,060 controls. In the discovery study, nine loci demonstrated association with AAA (p &lt; 1 × 10-5). In the replication sample, the lead SNP at one of these loci, rs1466535, located within intron 1 of low-density-lipoprotein receptor-related protein 1 (LRP1) demonstrated significant association (p = 0.0042). We confirmed the association of rs1466535 and AAA in our follow-up study (p = 0.035). In a combined analysis (6228 AAA and 49182 controls), rs1466535 had a consistent effect size and direction in all sample sets (combined p = 4.52 × 10-10, odds ratio 1.15 [1.10-1.21]). No associations were seen for either rs1466535 or the 12q13.3 locus in independent association studies of coronary artery disease, blood pressure, diabetes, or hyperlipidaemia, suggesting that this locus is specific to AAA. Gene-expression studies demonstrated a trend toward increased LRP1 expression for the rs1466535 CC genotype in arterial tissues; there was a significant (p = 0.029) 1.19-fold (1.04-1.36) increase in LRP1 expression in CC homozygotes compared to TT homozygotes in aortic adventitia. Functional studies demonstrated that rs1466535 might alter a SREBP-1 binding site and influence enhancer activity at the locus. In conclusion, this study has identified a biologically plausible genetic variant associated specifically with AAA, and we suggest that this variant has a possible functional role in LRP1 expression

Shared Genetic Risk Factors of Intracranial, Abdominal, and Thoracic Aneurysms

Background: Intracranial aneurysms (IAs), abdominal aortic aneurysms (AAAs), and thoracic aortic aneurysms (TAAs) all have a familial predisposition. Given that aneurysm types are known to co‐occur, we hypothesized that there may be shared genetic risk factors for IAs, AAAs, and TAAs. Methods and Results: We performed a mega‐analysis of 1000 Genomes Project‐imputed genome‐wide association study (GWAS) data of 4 previously published aneurysm cohorts: 2 IA cohorts (in total 1516 cases, 4305 controls), 1 AAA cohort (818 cases, 3004 controls), and 1 TAA cohort (760 cases, 2212 controls), and observed associations of 4 known IA, AAA, and/or TAA risk loci (9p21, 18q11, 15q21, and 2q33) with consistent effect directions in all 4 cohorts. We calculated polygenic scores based on IA‐, AAA‐, and TAA‐associated SNPs and tested these scores for association to case‐control status in the other aneurysm cohorts; this revealed no shared polygenic effects. Similarly, linkage disequilibrium–score regression analyses did not show significant correlations between any pair of aneurysm subtypes. Last, we evaluated the evidence for 14 previously published aneurysm risk single‐nucleotide polymorphisms through collaboration in extended aneurysm cohorts, with a total of 6548 cases and 16 843 controls (IA) and 4391 cases and 37 904 controls (AAA), and found nominally significant associations for IA risk locus 18q11 near RBBP8 to AAA (odds ratio [OR]=1.11; P=4.1×10−5) and for TAA risk locus 15q21 near FBN1 to AAA (OR=1.07; P=1.1×10−3). Conclusions: Although there was no evidence for polygenic overlap between IAs, AAAs, and TAAs, we found nominally significant effects of two established risk loci for IAs and TAAs in AAAs. These two loci will require further replication