Few countries offer organized screening of siblings of patients with abdominal aortic aneurysms (AAAs), although a hereditary trait is well known to exist. Male relatives, but not female, are invited within the population-based screening programs for elderly men in Sweden. Evidence regarding the optimal age to screen siblings is scarce. The aim of this study was to describe the age at detection in siblings found with AAAs.
All patients treated for AAAs in two Swedish counties were screened for siblings. Consenting siblings aged 80 and younger were examined (N = 529) with ultrasound and were interviewed per protocol.
In the cohort of 529 siblings to AAA patients, 53 siblings were diagnosed with AAAs (sisters 16/276 [5.8%] and brothers 37/253 [14.6%]). The prevalence of AAAs in the siblings 65 years of age or younger was 16/207 (7.7%). One-third of the siblings found with AAAs were young (16/53 [30%]). Among the young siblings with AAAs, 8/16 (50%) had an aneurysm larger than 50 mm or were already surgically treated. The prevalence of AAAs in siblings older than 65 years of age was 37/322 (12%).
The AAA prevalence in this sibling cohort is strikingly high compared to the prevalence in the population (in Sweden, 1.4%-2.2% in 65-year-old men). The young ages among diagnosed siblings reinforce that male siblings of AAA patients should be screened before age 65 (before the population-based program) and that structured programs for female siblings are called for.
The most commonly used predictor of rupture of an abdominal aortic aneurysm (AAA) is the diameter; however, this does not estimate the true risk for each patient. Why women with AAAs have an increased growth rate, weaker aortic wall, and increased risk for rupture is yet unclear. It is likely that geometrical and biomechanical properties contribute to found gender differences. Several studies have shown that peak wall stress (PWS) and peak wall rupture risk (PWRR), predicted by a finite element (FE) analysis of AAAs derived from computed tomography (CT), is a better predictor of rupture than maximum diameter. The purpose of this study was to investigate if women with AAAs have an increased PWS and PWRR using an FE model compared to men.
Fifteen men and 15 women (AAAs 4-6 cm) were included. AAA geometry was derived from CT scans, and PWS and PWRR were estimated using the FE method. Comparisons were made by t test and Mann-Whitney test.
Mean age (women 73 years old vs men 71 years old) and mean AAA diameter was similar (49.7 mm vs 50.1 mm) for women and men. PWS did not differ for women 184 and men 198 kPa. PWRR was 0.54 (0.28-0.85) for women and 0.43 (0.24-0.66) for men, P = .06.
This is the first analysis of stress and strength of the aneurysm wall with a gender perspective. The reported higher rupture risk for women has previously not been tested with geometrical and biomechanical properties. PWS did not differ, but the PWRR was slightly higher in women. However, the difference did not reach statistical significance, probably due to the small sample size. In summary, the results in the present study suggest that differences in biomechanical properties could be a contributing explanation for the higher rupture risk reported for female patients with AAAs.
To evaluate if ticagrelor, an effective platelet inhibitor without known non-responders, could inhibit growth of small abdominal aortic aneurysms (AAAs).
In this multi-centre randomized controlled trial, double-blinded for ticagrelor and placebo, acetylic salicylic acid naïve patients with AAA and with a maximum aortic diameter 35-49?mm were included. The primary outcome was mean reduction in log-transformed AAA volume growth rate (%) measured with magnetic resonance imaging (MRI) at 12?months compared with baseline. Secondary outcomes include AAA-diameter growth rate and intraluminal thrombus (ILT) volume enlargement rate. A total of 144 patients from eight Swedish centres were randomized (72 in each group). MRI AAA volume increase was 9.1% for the ticagrelor group and 7.5% for the placebo group (P?=?0.205) based on intention-to-treat analysis, and 8.5% vs. 7.4% in a per-protocol analysis (P?=?0.372). MRI diameter change was 2.5?mm vs. 1.8?mm (P?=?0.113), US diameter change 2.3?mm vs. 2.2?mm (P?=?0.778), and ILT volume change 12.9% vs. 10.4% (P?=?0.590).
In this RCT, platelet inhibition with ticagrelor did not reduce growth of small AAAs. Whether the ILT has an important pathophysiological role for AAA growth cannot be determined based on this study due to the observed lack of thrombus modulating effect of ticagrelor.
The TicAAA trial is registered at the US National Institutes of Health (ClinicalTrials.gov) #NCT02070653.
Department of Vascular Surgery, St. Olavs Hospital, Trondheim, Norway; Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: firstname.lastname@example.org.
The delayed development of abdominal aortic aneurysm (AAA) in women compared with men might be secondary to a protective effect from endogenous estrogens. The role of postmenopausal hormone therapy remains unclear. The aim of the present study was to evaluate the effect of female sex hormones compared with other risk factors associated with AAA through a long-term study of a large female cohort.
The present prospective cohort study included 20,024 postmenopausal women from the Norwegian Nord-Trøndelag Health Study. A total of 201 cases of AAA were identified during a median follow-up period of 18 years (295,554 person-years; 1995-2014). The data were recorded from questionnaires, physical measurements, medical records, blood sample test results, and the Norwegian Cause of Death Registry. The effect of risk factors was evaluated in a multiple Cox regression analysis. Multiple imputation was performed for missing data (n = 50 data sets). The serum estradiol concentrations in women with and without incidental AAAs were compared. The median interval from blood sample collection to the AAA diagnosis was 7 years.
Current smokers had >10-fold increased risk of incident AAA during the follow-up period (hazard ratio [HR], 10.9; 95% confidence interval [CI], 7.4-16.1). Positive associations were found for hypertension (HR, 2.0; 95% CI, 1.4-3.0) and coronary heart disease (HR, 2.2; 95% CI, 1.6-3.2). The HR associated with the current use of postmenopausal hormone therapy was 0.58 (95% CI, 0.6-1.5). No substantial difference in estradiol concentrations was found between women with and without AAA (P = .075).
The effect of female sex hormones on the risk of incident AAAs in women, as evaluated by the serum concentrations of estradiol and the use of postmenopausal hormone therapy, is clinically less important than the strong associations found with smoking, hypertension, and coronary heart disease.
BACKGROUND: The contribution of hereditary and environmental factors to the development of abdominal aortic aneurysms (AAAs) is still partly unknown. The aim of this study was to analyze the role of these factors in a large population-based sample of twins. METHODS: The Swedish Twin Registry, containing data on twins born in the country since 1886, was cross-linked with the Inpatient Registry, providing national coverage of discharge diagnoses coded according to the International Classification of Diseases (ICD). All twins with an infrarenal AAA were identified. Concordance rates and tetrachoric correlations were calculated for monozygotic (MZ) and dizygotic (DZ) twins. Tetrachoric correlations were calculated assuming an underlying normal distribution of liability, with multiple factors contributing additively and a threshold value that discriminates between AAA and no AAA. Higher concordance rates and correlations of liability in MZ twins than in DZ twins suggest that genetic factors influence disease development. Structural equation modeling techniques, Mx-analyses, were used to estimate the contributions of genetic effects as well as shared and nonshared environmental factors for development of AAA. RESULTS: There were 172,890 twins registered at the time of the study including 265 twins (81% men; mean age 72 years; range, 48-94) with AAA. There were 7 MZ and 5 DZ concordant pairs as well as 44 MZ and 197 DZ discordant pairs with AAA. The probandwise concordance rates for MZ and DZ pairs were 24% and 4.8%, respectively. The tetrachoric correlations were 0.71 in MZ pairs and 0.31 in DZ pairs. The odds ratio (OR) was 71 (95% confidence interval [CI] 27-183) for MZ twins and 7.6 (95% CI 3.0-19) for DZ twins. In the structural equation models, genetic effects accounted for 70% (95% CI 0.33-0.83), shared environmental effects for 0% (95% CI 0-0.27), and nonshared environmental effects for 30% (95% CI 0.17-0.46) of the phenotypic variance among twins. CONCLUSION: These data provide robust epidemiologic evidence that heritability contributes to aneurysm formation. Concordances and correlations were higher in MZ compared with DZ twins, indicating genetic effects. There was a 24% probability that an MZ twin of a person with AAA will have the disease. The twin of an MZ twin with AAA had a risk of AAA that was 71 times that of the MZ twin of a person without AAA. A heritability of 70% of the total trait variance was estimated. The remaining variance was explained by nonshared environmental factors with no support for a role of shared environmental influences.
Population-based screening for abdominal aortic aneurysms (AAAs) in elderly men is organized in many regions and countries in the Western world, and the prevalence of disease is reported to decline. Whether the prevalence among those with a family history also is declining is unknown. The primary purpose of this study was to assess the prevalence of AAAs among siblings of persons with AAAs and to investigate the proportion of siblings already diagnosed by opportunistic screening.
Patients treated for AAAs from January 2008 through December 2010 (n = 412) in Stockholm, Sweden, were screened for siblings. Seven hundred seventy-nine siblings were identified. All siblings 65 (odds ratio, 10.8; 95% confidence interval, 1.3-86.4; P = .03). Ever smoking was not statistically significant as a risk.
A strikingly high prevalence of AAAs in siblings was found as compared to the reported declining aneurysm prevalence in elderly men in the Western world. Systematic improvements regarding screening of first-degree relatives is mandated and selective screening of siblings is an underused tool to prevent death from aneurysm disease, both among men and women.
This study assessed the proportion of previously known abdominal aortic aneurysm (AAA) in patients presenting with a ruptured AAA (rAAA) and analyzed the reasons for nontreatment at the time of the initial AAA diagnosis.
This retrospective, observational study included all patients with rAAA admitted to a hospital in the counties of Stockholm and Gotland during 2009 to 2013. The patients' records were retrospectively reviewed, with extraction of data on previously detected AAA, demographics, and mortality at 30 and 90 days.
We identified 283 patients (76% men) with a mean age of 78.7 years. An AAA had been previously detected in 85 (30%). The overall mortality was higher (68% vs 53%; P = .018) and the intervention rate was lower in patients with a previously detected AAA (59% vs 82%, P
In a recent publication in The Lancet Johansson and colleagues claim no effect on aneurysm mortality among men participating in the Swedish AAA screening program, and question its justification. The study is, however, limited by a corrupt study design and incorrect data, making the publication misleading. On the contrary, several RCTs and contemporary nationwide data with sufficient follow-up clearly show that AAA screening saves lives and is highly cost-effective. The program has so far identified about 6000 men with an AAA, of whom 1500 have been operated on to prevent rupture. Thus, more than 750 men have experienced a longer life (by a mean of 8 years) as a result of the program. Continuous evaluation of the program is important but requires a scientifically sound methodology.
CommentOn: Lancet. 2018 Jun 16;391(10138):2441-2447 PMID 29916384
Patients with abdominal aortic aneurysms (AAA) are more prone to develop popliteal artery aneurysms (PAA), but the prevalence is not well known. Our aim was to investigate the prevalence of PAA in patients with AAA, and to determine whether a certain risk factor profile is more commonly found in patients with concurrent aneurysms. All AAA patients (ICD code I71.3, I71.4) attending the outpatient clinic at the Karolinska University Hospital between 2011 and 2013 were included in the study cohort (n=465); 48% (225) had been subjected to an ultrasound or computed tomography scan of their popliteal arteries. In these patients, three definitions of PAA were considered (? 10.5, ? 12, ? 15 mm), although the overall analysis is based on PAA ? 12 mm. The mean age was 70.7 years (SD 7.5), 89% were men, and the mean AAA diameter was 47 mm (SD 14). The prevalence of PAA was 19% (n=43) by definition ? 12 mm, and 11% (n=25) with 15 mm. Claudication was more frequently found in AAA patients with PAA than patients without PAA. Sensitivity between clinical examination and radiology was 26%, and the specificity for clinical examination was 90%. In conclusion, owing to the high prevalence of PAA in AAA patients, described by us and others, the low cost and risks associated with ultrasound and the poor sensitivity at clinical examination, all women and men with AAA should undergo one radiological examination of their popliteal arteries.