Abdominal aortic aneurysm in women: prevalence, risk factors, and implications for screening

OBJECTIVE: Accurate data regarding the prevalence and associated risk factors for aneurysmal disease is essential when determining the appropriateness of screening for abdominal aortic aneurysms (AAA). Although women are poorly represented in most large studies of AAA prevalence, the US Preventative Services Task Force recently recommended against primary screening for AAA in women. The purpose of this analysis was to define the prevalence and risk factors associated with the development of AAA in women. METHODS: A free duplex ultrasound screening was offered to men and women with cardiovascular risk factors or a family history of AAA. Patients were recruited through advertising at local screening centers and screenings were performed between 2004 and 2006. Demographic information and cardiovascular and aneurysmal disease risk factors were obtained for each patient through a questionnaire. A total of 17,540 subjects were screened for AAA, including 10,012 women (mean age 69.6 years) and 7528 men (mean age 70.0 years). Univariate and multivariable logistic regression analysis was performed on the subset of women that were screened to determine risk factors for and prevalence of AAA. RESULTS: Seventy-four aneurysms were detected in women (including four aneurysms >5 cm diameter and 70 aneurysms 3 to 5 cm diameter) while 291 were detected in men, resulting in prevalence rates of 0.7% and 3.9%, respectively. Increasing age (odds ratio [OR]= 4.57, 95% confidence interval [CI] 1.98 to 10.54, P < .0001), history of tobacco use (OR = 3.29, 95% CI 1.86 to 5.80, P < .0001), and cardiovascular disease (OR= 3.57, 95% CI 2.19 to 5.84, P < .0001) were independently associated with AAA in women on univariate and multivariable analysis. Women with multiple atherosclerotic risk factors were more commonly found to have AAAs and had a prevalence rate of AAA as high as 6.4%. CONCLUSION: Although the medical literature suggests a low prevalence rate of AAA in women in the general population, specific risk factors are associated with the development of AAA, and subgroups of women can be identified that are at a substantially increased risk of aneurysmal disease. In particular, elevated rates of AAA were found among women of advanced age (> or =65 years) with a history of smoking or heart disease. These data support the notion that women with such risk factors should be considered for AAA screening.     

Genetic analysis of polymorphisms in biologically relevant candidate genes in patients with abdominal aortic aneurysms

BACKGROUND: Abdominal aortic aneurysms (AAAs) are characterized by histologic signs of chronic inflammation, destructive remodeling of extracellular matrix, and depletion of vascular smooth muscle cells. We investigated the process of extracellular matrix remodeling by performing a genetic association study with polymorphisms in the genes for matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and structural extracellular matrix molecules in AAA. Our hypothesis was that genetic variations in one or more of these genes contribute to greater or lesser activity of these gene products, and thereby contribute to susceptibility for developing AAAs. METHODS: DNA samples from 812 unrelated white subject (AAA, n = 387; controls, n = 425) were genotyped for 14 polymorphisms in 13 different candidate genes: MMP1(nt-1607), MMP2(nt-955), MMP3(nt-1612), MMP9(nt-1562), MMP10(nt+180), MMP12(nt-82), MMP13(nt-77), TIMP1(nt+434), TIMP1(rs2070584), TIMP2(rs2009196), TIMP3(nt-1296), TGFB1(nt-509), ELN(nt+422), and COL3A1(nt+581). Odds ratios and P values adjusted for gender and country of origin using logistic regression and stratified by family history of AAA were calculated to test for association between genotype and disease status. Haplotype analysis was carried out for the two TIMP1 polymorphisms in male subjects. RESULTS: Analyses with one polymorphism per test without interactions showed an association with the two TIMP1 gene polymorphisms (nt+434, P = .0047; rs2070584, P = .015) in male subjects without a family history of AAA. The association remained significant when analyzing TIMP1 haplotypes (chi 2 P = .014 and empirical P = .009). In addition, we found a significant interaction between the polymorphism and gender for MMP10 ( P = .037) in cases without a family history of AAA, as well as between the polymorphism and country of origin for ELN ( P = .0169) and TIMP3 ( P = .0023) in cases with a family history of AAA. CONCLUSIONS: These findings suggest that genetic variations in TIMP1, TIMP3, MMP10, and ELN genes may contribute to the pathogenesis of AAAs. Further work is needed to confirm the findings in an independent set of samples and to study the functional role of these variants in AAA. It is noteworthy that contrary to a previous study, we did not find an association between the MMP9 (nt-1562) polymorphism and AAA, suggesting genetic heterogeneity of the disease. CLINICAL RELEVANCE: Abdominal aortic aneurysms (AAAs) are an important cardiovascular disease, but the genetic and environmental risk factors, which contribute to individual's risk to develop an aneurysm, are poorly understood. Histologically, AAAs are characterized by signs of chronic inflammation, destructive remodeling of the extracellular matrix, and depletion of vascular smooth muscle cells. We hypothesized that genes involved in these events could harbor changes that make individuals more susceptible to developing aneurysms. This study identified significant genetic associations between DNA sequence changes in tissue inhibitor of metalloproteinase 1 (TIMP1), TIMP3, matrix metalloproteinase 10 (MMP10) and elastin (ELN) genes, and AAA. The results will require confirmation using an independent set of samples. After replication it is possible that these sequence changes in combination with other risk factors could be used in the future to identify individuals who are at increased risk for developing an AAA.     

The impact of gender on presentation, therapy, and mortality of abdominal aortic aneurysm in the United States, 2001-2004

INTRODUCTION: The elective repair of abdominal aortic aneurysms (AAA) may decrease a patient's risk of rupture and confers a significantly lower in-hospital mortality rate than emergency repair. Previous works have shown that AAA rupture rates are higher in women compared to men, and that women have higher associated in-hospital mortality rates. This study was performed to evaluate, currently, to what extent patient gender influences presentation and treatment of AAA and the associated outcomes in the United States. METHODS: The Nationwide Inpatient Sample was used, with pertinent ICD-9 codes, to identify all patient-discharges that occurred with the primary diagnosis of intact (iAAA) or ruptured/dissecting (rAAA) abdominal aortic aneurysms between the years 2001 and 2004. Univariate and multiple logistic regression analyses of variables were performed. RESULTS: An estimated 220,403 AAA patient-discharges were identified during the study period. 37,016 (17%) patients presented with rAAA. A higher percentage of women with AAA presented with rupture compared to men (21% vs 16%; odds ratio [OR] 1.40, 95% confidence interval [CI], 1.27-1.54). This rupture rate did not significantly change from 2001 to 2004 (P = .85 for trend). For iAAA, women had higher odds of in-hospital mortality than men (OR 1.60; 95% CI, 1.24-2.07). Compared to men, in-hospital mortality rates for women with iAAA were higher for both endovascular (2.1% vs 0.83%, P < .0001) and open repairs (6.1% vs 4.0%, P < .0001). For iAAA, fewer women underwent endovascular repair (32.4% vs 46.7%, P < .0001; O.R. 0.59, 95% CI, 0.52-0.67). For patients who presented with rAAA, women were less likely to undergo surgical intervention compared to men (59% vs 70%, P < .0001). For those that underwent repair, women had higher in-hospital mortality rates than men (43% vs 36%, P < .0001; OR 1.49, 95% CI, 1.16-1.91). CONCLUSION: A higher percentage of women currently present with aneurysm rupture. They have higher in-hospital mortality rates for both iAAA and rAAA. This gender difference in the outcomes following repair of abdominal aortic aneurysm has persisted over time, the cause of which is not explained by these or previous data, a fact that warrants further investigation.     

Existence of abdominal aortic aneurysms in patients with thoracic aortic dissections

OBJECTIVE: The objective of this study was to determine the coexistence or later development of pararenal and infrarenal abdominal aortic aneurysms (AAAs) in patients with thoracic aortic dissections. METHODS: One hundred forty-five patients (95 men, 50 women) encountered from 1992 to 2001 with thoracic aortic dissections-excluding those associated with trauma, those with Marfan's syndrome, and those with thoracoabdominal aortic aneurysms-were studied. The most common risk factors included hypertension (59%) and a history of tobacco use (52%). Type III dissections affected 86 patients (59%), and type I dissections affected the remaining 59 patients (41%). Aortic computed tomography (CT) scans were obtained annually. Data were assessed by univariate and multivariate analyses. RESULTS: Five patients (3%) had a history of AAA repair prior to their thoracic aortic dissection diagnosis-3 were type III dissections and 2 were type I dissections. Twelve patient's (8%) AAAs were diagnosed with the initial CT study of their thoracic aortic dissection. Type III dissections accounted for all but one of these (11 of 12, 92%). Ten additional AAAs (7%) developed in the 128 patients with no initial evidence of an AAA being recognized from 1 to 48 months (average 16 months) after the thoracic aortic dissection was diagnosed. Type III dissections affected 8 of these 10 patients. Among the total 27 AAAs noted in this series, 74% (20 AAAs) were not continuous with the thoracic aortic dissection. In the univariate analysis, age (P =.0002), male gender (P =.044), history of smoking (P =.01), chronic obstructive pulmonary disease (P <.001), duration of dissection (P =.05), and presence of type III dissection (P =.009) were associated with the presence of an AAA. In the multivariate analysis, both chronic obstructive pulmonary disease (odds ratio 5.4, 95% CI, 1.3 to 22.3; P =.02) and age (OR 1.06, 95% CI, 1.02 to 1.11; P =.004) were significant predictors of the development of AAAs. CONCLUSION: This study documented that patients with thoracic aortic dissections are at risk to harbor or develop a later AAA. This finding supports the tenet that abdominal CTs or ultrasound scanning should be mandatory in the follow-up of patients with known thoracic aortic dissections.     

Influence of diagnostic criteria on the prevalence of abdominal aortic aneurysm

PURPOSE: We studied the prevalence of abdominal aortic aneurysm (AAA) in a population with high incidences of cardiovascular diseases and analyzed how the prevalence varies according to methodology and criteria. METHODS: All men and women aged 65 to 75 years who lived in the Norsj? municipality in northern Sweden were invited to undergo an ultrasound scanning (US) examination. Those with an aortic diameter of 28 mm or more or with poor visibility on US were examined with computed tomography scanning (CT). Various recommended AAA definitions, two diagnostic methods (US and CT), and two diameters (maximum and anteroposterior) were analyzed. RESULTS: Of 555 people invited to participate in the study, 504 accepted (248 men and 256 women; 91%). Eight subjects had undergone surgery for an AAA. Ninety-two subjects underwent CT. The mean maximum infrarenal aortic diameter was 24.6 mm (by means of US). Depending on diagnostic criteria, the AAA prevalence was 3.6% to 16.9% in men and 0.8% to 9.4% in women. Depending on which previous study was used as a comparison and the definition of AAA and diagnostic technique used, the prevalence in this study was 1.3 to 4.0 times higher for men and 2.0 to 5.8 times higher for women. CONCLUSION: In a region in which residents have a high risk for cardiovascular disease, we found the highest prevalence of AAA ever reported within a population. The prevalence highly depends on methodology and diagnostic criteria, with a 10-fold variation. Detailed defined criteria are necessary to permit comparisons between studies: the number of individuals who have undergone surgery for AAA and whether they are included, the prevalence in 5- and 10-year age intervals, attendance rate, visibility, which diameter(s) is measured, and the prevalences with as many as possible of the four described definitions of AAA. The etiology of the high prevalence of AAA in this population needs to be investigated further.     

Selective screening for abdominal aortic aneurysm among patients referred to the vascular laboratory.

BACKGROUND: Patients examined for peripheral arterial disease at the vascular laboratory, Uppsala University Hospital, are since 1993 screened for abdominal aortic aneurysm (AAA). The objective of this study was to study the prevalence of AAA found at this selective high-risk screening. METHODS: All files in the vascular laboratory were retrospectively reviewed. Of 9296 persons examined with arterial duplex between 1993 and October 2005, 5924 were screened for AAA. The primary target vessel was the carotid arteries in 3772 subjects, the renal arteries in 1529 subjects and the lower extremity arteries in 1457 subjects. An AAA was defined as an infrarenal aortic diameter >/=30mm. RESULTS: 179 subjects were found to have an AAA. In a logistic regression model male gender, age and duplex-verified arterial stenosis were independently associated with AAA (odds ratio 3.2, 2.0/20 years and 2.0, respectively, p<0.001). In men <60 years the AAA prevalence was 0.9% (95% confidence interval 0.2-1.6%) when arterial stenosis was absent and 1.5% (0.0-3.2%) when present. In men >/=60 years the AAA prevalence was 4.0% (3.0-5.1%) when no arterial stenosis was found and 7.3% (5.7-8.9%) when found. The corresponding prevalences in women were 0%, 0%, 1.2% (0.5-1.8%), and 3.1% (1.9-4.3%), respectively. CONCLUSIONS: Men >/=60 years referred for arterial examination have a significant risk of having an AAA while only women >/=65 years with a duplex verified arterial stenosis have a sufficient risk of having an AAA. Studies to evaluate the benefit of selective high-risk screening are warranted.     

Is there an association between chronic lung disease and abdominal aortic aneurysm expansion?

Background: Although there is evidence demonstrating an association between chronic obstructive pulmonary disease (COPD) and abdominal aortic aneurysm (AAA), it is not clear whether COPD predicts greater rates of expansion of established aneurysms. We sought such an association in a cohort of men with aneurysms detected in a population‐based study of screening for aneurysms. Methods: In addition to regular aortic ultrasound scans, 179 men with AAA underwent full lung function testing in order to identify the presence of COPD and its subgroups, emphysema and other obstructive ventilatory defects (OVD). The rate of expansion of each aneurysm was calculated and the men were divided into ‘rapid expanders’ (3 mm or more per year) and ‘slow expanders’ (less than 3 mm per year). Any association with the presence of COPD or smoking was tested using a multivariate model. Results: Over a median follow‐up period of 36 months the mean rate of aortic expansion for the cohort of 179 men was 2.1 mm/year. There was no significant difference in prevalence of COPD (68% overall) or having ever been a smoker (87% overall) between the rapid expanders and the slow expanders. Conclusions: Although there was a high prevalence of COPD among men with an AAA, there was no association between the rate of expansion of AAA and the presence of any form of this disease.     

LDL Cholesterol is Associated with Small Abdominal Aortic Aneurysms

OBJECTIVE: To examine the relationship between serum lipids and abdominal aortic aneurysms (AAA). METHODS: Two hundred and six males (>50 years) with AAA (> or =30 mm) detected in a population based screening programme were compared with 252 age-matched male controls in a nested case-control study. Smoking status, previous medical and family histories, height, weight, blood pressure, ankle brachial pressure index (ABPI) and non-fasting lipid profile were recorded. RESULTS: Cases were found to have significantly higher LDL cholesterol than controls. LDL cholesterol was an independent predictor of the risk for aneurysms in a logistic regression model adjusting for smoking status, family history of AAA, history of ischaemic heart disease, presence of peripheral vascular disease, use of lipid lowering medication and treatment for hypertension. There was a linear effect with increased levels of LDL cholesterol increasing the risk of having a small aneurysm (test for trend p=0.03). CONCLUSION: The highly significant association between LDL cholesterol and small aneurysms suggests that LDL, possibly acting via inflammatory mediated matrix degeneration, could be an initiating factor in the development of AAA. The ability of statin therapy to prevent AAA formation requires further investigation.     

Thoracoabdominal aortic aneurysm repair after prior aortic surgery

PURPOSE: The purpose of this study was to determine whether the morbidity and mortality of surgery for thoracoabdominal aortic aneurysm (TAAA) in patients with prior aortic surgery are increased. METHODS: The results for all patients undergoing operation for TAAA at a single institution were reviewed. RESULTS: Over a 10-year interval, 279 patients (136 women and 143 men) underwent aortic replacement for TAAA. The mean patient age was 68 years (range, 34-90). The extent of aortic replacement was relatively evenly distributed: type I (91), type II (54), type III (78), or type IV (56). Of these 279 patients, 76 (27%) had undergone prior aortic surgery. Prior infrarenal AAA was the most common prior procedure (56, 20%). Reoperation for prior failed TAAA repair was performed in 20 (7%) patients. A history of Marfan syndrome was highly associated with the need for remedial TAAA procedures (P <.0001). Overall 30-day mortality was 11.4% (32). Mortality was independent of prior aortic surgery (P =.98), prior AAA (P =.84), prior TAAA (P =.61), and gender (P =.18). Postoperative complications were seen in 67 (24%) patients and were more likely in patients who had undergone prior AAA surgery (P =.008). TAAA repair in patients with recurrent TAAA was not associated with higher morbidity (P =.33). Paraplegia (10) occurred in type I (3), type II (2), and type III (5) aneurysms but not in type IV (0), and its development was associated with higher mortality (P =.01). Prior aortic surgery was not found to be predictive of paraplegia (P =.90), although 30% of patients who developed paraplegia had a history of prior AAA repair. CONCLUSIONS: Aortic reoperation for TAAA is required in a significant number of patients, particularly those with Marfan syndrome. Therefore, ongoing surveillance of the residual aorta is mandatory. Postoperative complications are more likely to occur in patients after prior infrarenal aortic replacement, but mortality is not significantly increased. Special technical considerations exist for remedial procedures after failed TAAA repair to provide protection for the spinal cord, kidneys, and viscera. Patients with failed TAAA procedures or progression of aneurysmal extent should be offered reoperation when indicated.     

Negative association between infra-renal aortic diameter and glycaemia: the Health in Men Study.

OBJECTIVE: There is evidence of a negative association between diabetes and abdominal aortic aneurysm (AAA). The aim of this study was to assess whether there is a similar relationship between both diabetes and glucose level, and infra-renal aortic diameter throughout its range. DESIGN AND METHODS: Infra-renal aortic diameter was measured using ultrasound in 12,203 men aged 65-83 years as part of a trial of screening for AAA. A range of cardiovascular risk factors were also assessed. In a follow-up study, fasting serum glucose was measured in 2,859 non-diabetic men. Aortic diameter was logarithmically transformed and treated as both a continuous and categorical variable in stepwise multivariate linear and logistic models. RESULTS: The median aortic diameter was slightly smaller in the diabetic men (21.3+/-3.9 vs 21.6+/-3.8, P<0.0001). There was an independent negative association between diabetes and AAA (OR 0.79, 95% CI: 0.63,0.98), and an inverse correlation (Coefficient: -0.0064, p=0.0024) between fasting glucose and aortic diameter in non-diabetic men. CONCLUSIONS: Diabetes is inversely associated with both AAA and aortic diameter in men over 65 years. This association is independent of other risk factors for AAA. Aortic diameter also has an inverse relationship with fasting glucose concentrations in men without diabetes.     

Influence of gender on outcome from ruptured abdominal aortic aneurysm

BACKGROUND: The aim of the present study was to compare outcomes following ruptured abdominal aortic aneurysm (AAA) in men and women. METHODS: Overall mortality from ruptured AAA was compared in men and women using the Western Australia Health Services Research Database. The linked chains of de-identified hospital morbidity and death records were selected using the ICD-9-CM (International Classification of Diseases - Clinical Modification) diagnostic and procedure codes pertaining to AAA. Cases were divided into three groups for analysis: patients who died without admission to hospital, those admitted to hospital with a ruptured AAA but who did not undergo operation, and patients who underwent operation for ruptured AAA. RESULTS: Ruptured AAA occurred in 648 men and 225 women over the age of 55 years during the decade 1985-1994. Only 50 per cent of women, compared with 59 per cent of men, were admitted to hospital. Of those admitted to hospital only 37 per cent of women underwent operation, compared with 63 per cent of men. The overall mortality rate from ruptured AAA was 90 per cent in women and 76 per cent in men (chi2 = 50.34, 1 d.f., P < 0.0001). Although women were, on average, 6 years older than men, this unfavourable pattern occurred across all age groups. CONCLUSION: Women with a ruptured AAA are more likely to die than men. More research is required to identify the causes of this sex difference.     

Influence of sex on the results of abdominal aortic aneurysm repair

Purpose: The purpose of this study is to determine the effect of sex on the survival rate and complications after repair of nonruptured and ruptured abdominal aortic aneurysms (AAA).Methods: The Canadian Society for Vascular Surgery Aneurysm Registry formed the database for analysis and provided current, ongoing follow-up of the patients. Statistical methods included t tests, chi-squared analysis, Kaplan-Meier analysis, and Cox regression analysis.Results: Of the 679 patients undergoing repair of a nonruptured AAA, 19.7% were women and 82.3% men. The following risk factors were significantly different (p < 0.05) in women and men: women were older; more had never smoked; more had a positive family history of AAA; fewer had an electrocardiogram showing evidence of an old myocardial infarction; more had coexisting aortoiliac occlusive disease; fewer had popliteal or femoral aneurysms; and the average size of the AAA was smaller. In spite of potential differences in risk, the in-hospital mortality rates were not affected by sex: 5.2% mortality rate for women and 4.4% for men. Early and late vascular complications occurred with a similar prevalence. The late survival rates were not different in women and men: for women, the 1-, 3-, and 5-year cumulative survival rates were 93.0%, 74.2%, and 63.3%, respectively, and for men 90.3%, 82.8%, and 68.9%. To control for the potential effects of other confounding variables on survival, the Cox proportional hazards method was used. When sex was included in a model along with other significant predictive variables of late survival, sex was not found to be a significant predictor of late results. Of the 146 patients with a ruptured AAA, 13.7% were women and 83.3% men. The in-hospital mortality rates were not significantly different: 55.0% for women and 49.2% for men. There was no difference between the cumulative survival rates: the 3- and 5-year survival rates for women were 36.0% and 9.0%, respectively, and for men 33.9% and 26.9%.Conclusions: Sex was not found to have an effect on the early or late results after repair of nonruptured or ruptured AAA. However, a literature review suggests the possibility of a gender bias in the diagnosis and/or selection of patients for surgical treatment because the proportion of women in surgical series is generally less than the proportion determined from autopsy studies, ultrasound studies, hospital discharge data, and national mortality information. (J VASC SURG 1994;20:914-26.)     

The plasma level of matrix metalloproteinase 9 may predict the natural history of small abdominal aortic aneurysms. A preliminary study.

OBJECTIVES: increased levels of various proteinases have been detected in abdominal aortic aneurysms (AAA) and are assumed to cause the degradation of the aortic wall. To determine whether systemic measurement of these proteinases and their inhibitors may predict the natural cause of AAA. METHODS AND MATERIAL: serum (S) and plasma (P) samples were obtained from 121 men following the diagnosis of a small AAA (3-5 cm) at population screening. Annual control scans were performed to check for expansion. Circulating levels of elastase-alpha 1 antitrypsin-complexes, alpha 1 antitrypsin, matrix metalloproteinase (MMP) 2 & 9, tissue-inhibitor-matrixproteinase 1 & 2, procollagen III-N-terminal-propeptide, and elastin-peptides were measured in a random group of 36 men. RESULTS: alpha 1 antitrypsin was significantly and positively associated with expansion. Similarly, P-MMP9 levels were significantly associated with size and expansion. There was a difference between median serum and plasma values, probably because of secretion from platelets. CONCLUSION: P-MMP9 and P-alpha 1 antitrypsin may predict the natural history of AAA.     

The methylenetetrahydrofolate reductase C677T polymorphism does not associate with susceptibility to abdominal aortic aneurysm.

OBJECTIVES: To test whether the T variant of the C677T polymorphism in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) would associate with three distinct forms of vascular disease, abdominal aortic aneurysm (AAA), coronary artery disease (CAD) and peripheral vascular disease (PVD). BACKGROUND: Increases in homocysteine induce elastolytic activity in the arterial wall, a condition which may favour vascular pathogenesis including aneurysm formation. Homozygosity of the common T variant of the C677T polymorphism in the gene for MTHFR has been shown to associate with increased levels of homocysteine. Thus, this functional polymorphism may lead to an increased propensity to develop cardiovascular disease and, in particular, AAA. METHODS: An association study was conducted across 1207 subjects; 428 patients with AAA, 271 CAD patients, 226 PVD patients and 282 controls being genotyped for the C667T variants of MTHFR. RESULTS: There were no significant differences in the frequency of the MTHFR C677T variant between any of the groups examined. AAA patients who were homozygotes for the 677T allele did, however, appear to have significantly larger aneurysms than C allele carriers. CONCLUSION: This study provides no evidence that the T variant of MTHFR is associated with susceptibility to AAA, CAD or PVD. It may, however, be a contributory factor in AAA severity as indicated by aneurysm size.     

Indicators of infection with Chlamydia pneumoniae are associated with expansion of abdominal aortic aneurysms

PURPOSE: Chlamydia Pneumoniae has been shown to be associated with atherosclerosis, myocardial infarction, and abdominal aortic aneurysms (AAAs). The possible association between AAA expansion and C pneumoniae infection was therefore assessed. METHODS: Blood samples were taken from patients with an AAA that was considered for surgical repair after having been diagnosed by means of the Chichester aneurysm screening program (UK) as having an initially infrarenal aortic diameter of 3.0 to 5.9 cm. The patients were examined prospectively for as long as 11.5 years (mean, 4.1 years) with ultrasound scanning. Of 110 patients considered for surgery, 90 men and 10 women had blood samples taken. Their IgG and IgA antibodies against C pneumoniae were measured by means of a microimmunofluorescence test. Unpaired t tests, multiple linear regression analyses, and logistic regression analyses were used for statistical analysis. RESULTS: A total of 44% (95% CI, 31%-55%) of the men with an AAA had an IgA titer of 64 or more, an IgG titer of 128 or more, or both, compared with 10% of the women with an AAA (OR = 7.2; 95% CI, 1.05-160.8). A titer of IgG of 128 or more was significantly associated with higher expansion (5.3 vs 2.6 mm per year), even after adjustment for initial AAA size and age. A significant positive correlation between both IgA and IgG titers and mean annual expansion was observed (r = 0.28; 95% CI, 0.05-0.49; and r = 0.45; 95% CI, 0.24-0.62, respectively), persisting after adjusting for initial AAA size and age. An IgG titer of 128 or more was present significantly more often in cases with an expansion greater than 1 cm annually (adjusted OR = 12.6; 95% CI, 1.37-293). CONCLUSION: A high proportion of men with an AAA has signs of infection with C pneumoniae. The progression of their AAAs was positively correlated with the presence of indicators of C pneumoniae infection.     

French women from multiplex abdominal aortic aneurysm families should be screened

BACKGROUND: Multiplex abdominal aortic aneurysm families (MAAAFs) (> or =1 subject plus the proband) represent 1% to 34% of abdominal aortic aneurysm (AAA), but the percentage in France is unknown. METHOD: The MAAAF rate was retrospectively defined by analysis of 3 groups: 72 of 104 consecutive individuals undergoing AAA surgery during 1994, 24 of 53 women and 35 of 76 men with giant (> or =9 cm) AAA operated on during 1986 to 1994. MAAAF characteristics were determined based on 10 families issued from these 3 groups and 34 others identified nationwide. Data were obtained from a standardized questionnaire for probands and relatives, detailed pedigrees of each family, and computed tomography (CT) scans without contrast medium of the aorta and lower limb arteries for first-degree relatives > or =40-year-of age. RESULTS: The MAAAF rate was 4.2% for the consecutive-surgery patients (proband M/F ratio, 17:1; mean age at surgery, 68.5 +/- 8.5 years). CT detected no additional AAA among them (screened individuals M/F ratio, 0.63; mean age, 54.0 +/- 11.2 years). MAAAF rates were 8.3% and 14.3% for the women's and giant-AAA groups with CT screening, respectively. Characteristics were investigated in 104 affected subjects from 44 MAAAFs: female relatives were more often affected than probands (P < 0.025). Compared with men, affected female relatives were significantly older at diagnosis and surgery (P < 0.05 and P < 0.02, respectively), as were affected women (P < 0.02 and P < 0.01, respectively). CT scan screening identified significantly more AAA and abdominal aortic dilatations among the 44 MAAAFs than the consecutive-surgery group (5 and 4, respectively; P < 0.001). CONCLUSION: Although the MAAAF rate seems low in France, women from MAAAF were affected more often and later, suggesting that they should be screened.     

The strange relationship between diabetes and abdominal aortic aneurysm

In a 1997 report of a large abdominal aortic aneurysm (AAA) screening study, we observed a negative association between diabetes and AAA. Although this was not previously described and negative associations between diseases are rare, the credibility of the finding was supported by consistent results in several previous studies and by the absence of an obvious artifactual explanation. Since that time, a variety of studies of AAA diagnosis, both by screening and prospective clinical follow-up, have confirmed the finding. Other studies have reported slower aneurysm enlargement and fewer repairs for rupture in diabetics. The seeming protective effect of diabetes for AAA contrasts with its causal role in occlusive vascular disease and so provides a strong challenge to the traditional view of AAA as a manifestation of atherosclerosis. Research focused on a protective effect of diabetes has already increased our understanding of the etiology of AAA, and might eventually pave the way for new therapies to slow AAA progression.     

Should abdominal aortic aneurysm be managed differently in women?

Although abdominal aortic aneurysm (AAA) is 4 to 6 times more common in men than in women, more than a third of all AAA deaths occur in women. In several reports from the UK Small Aneurysm Trial group, the rupture rate for women was 3-4 times that seen in men. A joint council of several vascular societies responded to these observations with the recommendation that AAA should be repaired earlier in women, at 4.5 cm to 5.0 cm rather than the 5.5 cm established in randomized trials for men. However, this recommendation does not appear to reflect a full consideration of the evidence. For example, population-based studies have reported mortality following AAA repair to be 40-60% higher in women than in men. Also, in the UK Small Aneurysm Trial itself, there was no trend toward a benefit from early repair in women. The totality of evidence available at present provides no good reason to alter for women the 5.5 cm threshold for elective repair established for men by the small AAA trials.     

Gender differences in abdominal aortic aneurysm prevalence,treatment, and outcome

Purpose: The purpose of this study was to investigate gender differences in the management of and outcome of surgery for abdominal aortic aneurysms (AAA).Methods: Hospital discharge data from all acute care hospitals in Michigan, as compiled in the Michigan Inpatient Data Base, were retrospectively analyzed to assess sex differences in regard to AAA prevalence, treatment, and surgical outcome from 1980 to 1990. This population database included 11,512 women and 29,846 men 50 years of age and older with diagnoses of intact or ruptured AAA.Results: Hospitalizations for intact or ruptured AAA were approximately five times more common among men compared with women. After controlling for age and year of surgery, men were 1.8 times as likely as women to have an intact AAA treated surgically and 1.4 times as likely to have a ruptured AAA treated surgically (95% confidence intervals, 1.7 to 1.9 and 1.2 to 1.7, respectively). Women who had operations for intact AAA had a 1.4 times greater risk of dying compared with men, and women who had operations for ruptured AAA had a 1.45 times greater risk of dying, after controlling for other predictors of death (95% confidence intervals, 1.14 to 1.73 and 1.10 to 1.90, respectively).Conclusions: In a population-based statewide experience, women who had intact or ruptured AAA were less likely than men to undergo aortic reconstruction and, when they did, were less likely than men to survive to discharge. (J Vasc Surg 1997;25:561-8.)     

Screening for AAA in the USA

The United States (U.S.) was home to both the first and the largest reported abdominal aortic aneurysm (AAA) screening programs to date. Influenced by the results of four randomized trials conducted outside the U.S., the U.S. Preventive Services Task Force (USPSTF) recommended one-time AAA screening with ultrasound for men 65-75 years old who have ever smoked. After the USPSTF report, the U.S. Congress added a Medicare benefit for free, one-time AAA screening with ultrasound for men who have smoked and for men and women with a family history of AAA. Screening may be underutilized in this target population, but recommendations by American vascular societies for much broader use of screening and repair than can be justified by the available evidence are influencing practice and threaten the effectiveness and cost-effectiveness of AAA screening in the U.S.