Insulin-like growth factor I - a novel biomarker of abdominal aortic aneurysms.

OBJECTIVE: The study aimed to test the potential role of insulin-like growth factor I (IGF-I) and IGF-II as biomarkers for abdominal aortic aneurysm (AAA). METHODS AND RESULTS: IGF-I and II levels were analysed in 115 patients with screening diagnosed AAA kept under annual surveillance for 10 years. Serum IGF-I correlated positively with AAA size and growth rate (r = 0.23, P = 0.016 and r = 0.27, P = 0.004), persisting after adjustment for potential confounders. Serum IGF-I level predicted cases needing later surgery (AOC: 0.63; 95% confidence interval: 0.52-0.73). CONCLUSIONS: In this prospective, long-term study, baseline serum IGF-I correlated positively with AAA size and growth rate and predicted future need for preventive surgery.

Atrial fibrillation and upper limb thromboembolectomy: a national cohort study.

BACKGROUND: The risk factors associated with, and the incidence of systemic embolism in patients with atrial fibrillation (AF) are poorly understood. OBJECTIVES: We studied the association between AF and upper limb thromboembolectomy involving brachial, ulnar or radial artery in a national cohort study that included all individuals aged 40-99 years with incident AF. METHODS: Data were retrieved from the Danish National Vascular Registry, the National Registry of Patients, the Danish Civil Registration System and Statistics Denmark. RESULTS: In total, 131,476 patients (68,042 men and 63,434 women) with AF without previous thromboembolectomy in the upper limb were registered. In the study cohort, 130 men underwent upper limb thromboembolectomy over 220,890 person-years of observation, whilst 275 women underwent thromboembolectomy over 197,777 patient-years. The incidence per 100,000 person-years was 58.9 (95% CI, 49.2-69.8) for men and 139.1 (95% CI, 123.1-156.5) for women. The relative risk of thromboembolectomy among patients with AF compared to the background population was 7.5 (95% CI, 6.3-8.9) for men, and 9.3 (95% CI, 8.3-10.5) for women. Women with AF had a relative thromboembolectomy risk of 1.8 (95% CI, 1.5-2.3) compared to men with AF. Among patients with AF, history of hypertension (HR 2.2-2.9), myocardial infarction (HR 2.9-3.9), heart failure (HR 1.6-1.9) and stroke (HR 2.2-3.8) were significantly associated with increased risk of thromboembolectomy in both men and women. CONCLUSIONS: AF substantially increases the risk of upper limb thromboembolectomy. This risk is higher with increasing age, female gender, and associated with hypertension, myocardial infarction, heart failure and stroke.

Upper-limb thrombo-embolectomy: national cohort study in Denmark.

OBJECTIVES: We investigated the incidence of thrombo-embolectomy in upper-limb and prognosis with respect to arm amputation, stroke and death. METHODS: We performed a national cohort study of individuals, aged 40-99 years, and undergoing first-time thrombo-embolectomy in the brachial, ulnar or radial artery in Denmark from 1990 to 2002. The data were retrieved from the National Vascular Registry and from the National Registry of Patients and the Civil Registration System. Patients were followed until 2006 to ascertain the occurrence of amputation and stroke and until 2007 with respect to death. RESULTS: In total, 1377 incident cases of thrombo-embolectomy were registered, comprising 504 (36.6%) males with a mean age of 72.0 (standard deviation (SD) 12.4) years and 873 (63.4%) females with a mean age of 77.2 (SD 11.7) years. Incidence was 3.3 (95% confidence interval (CI): 3.1-3.7) for males and 5.2 (95% CI: 4.9-5.6) for females per 100000 person-years. After thrombo-embolectomy, upper-limb amputation was performed in 11 (incidence 2.2%; 95% CI: 1.2-3.4) males and 31 (3.6%; 95% CI: 2.5-4.9) females. Age- and sex-specific risk of stroke was 2-16 times higher, and risk of death 3-11 times higher, than in the general population. CONCLUSIONS: Upper-limb thrombo-embolectomy is associated with an increased risk of limb amputation, stroke and death.

Long-term benefit and cost-effectiveness analysis of screening for abdominal aortic aneurysms from a randomized controlled trial.

BACKGROUND: The aim was to estimate long-term mortality benefits and cost-effectiveness of screening for abdominal aortic aneurysm (AAA) in men aged 64-73 years. METHODS: All men aged 64-73 years living in Viborg County were randomized to be controls (n = 6306) or invited for abdominal ultrasonography at a regional hospital (n = 6333). Mortality and AAA-related interventions were recorded in national databases. The cost of initial screening was based on actual costs of the programme. Incremental cost-effectiveness ratios (ICERs) were calculated on gains in life years and Quality Adjusted Life Years (QALY). Discounting (3 per cent) was applied to both costs and effects, and all costs were adjusted to euros at 2007 prices. RESULTS: The relative risk reduction of the screening programme in AAA-related mortality was 66 per cent (hazard ratio 0.34, 95 per cent confidence interval (c.i.) 0.20 to 0.57). The corresponding risk reduction in all-cause mortality was 2 per cent (hazard ratio 0.98, 95 per cent c.i. 0.93 to 1.03). The ICER was estimated at euro157 (-3292 to 4401) per life year gained and euro179 (-4083 to 4682) per QALY gained. Screening was found to be cost effective at a probability above 0.97 for a willingness-to-pay threshold of only euro5000. One-way sensitivity analysis demonstrated that this result was robust to various alternative assumptions, as the probability did not drop below 0.90 for any scenario. CONCLUSION: The mortality benefit of screening for AAA in men aged 64-73 years was maintained in the longer term and screening was cost effective.

Potential circulating biomarkers for abdominal aortic aneurysm expansion and rupture--a systematic review.

BACKGROUND: The maximal diameter of abdominal aortic aneurysms (AAAs) is the dominating indication for repair. However half of the AAAs repaired would never have ruptured if left unrepaired, although small AAAs occasionally rupture. Earlier surgery may be associated with a lower mortality. More precise indicators for surgery are warranted. This systematic review identifies potential systemic biomarkers for AAA rupture or expansion. METHODS: MEDLINE/PubMed and EMBASE (from 1985 trough May 2007) were searched with the medical subject heading abdominal aortic aneurysm and keywords "size", "progression" or "growth" or "expansion rate" or "rupture" on the basis of MESH tree and as a text search restricted to English, German, French and Italian. In addition, reference lists were studied and manual searches performed. Observational studies investigating the association of circulating biomarkers with AAA rupture, expansion or size were selected. DATA EXTRACTION: Two reviewers (SU and GU) independently extracted the following data: year of publication, study characteristics, duration of follow-up, circulating biomarker, AAA expansion rate or size or rupture. RESULTS: 699 papers were identified. After exclusion of thoracic aneurysms and cardiac studies (n=118), surgical or medical treatment studies (n=179), case reports and animal studies (n=87), as well as reviews or letters (n=66), 249 articles were selected. Also excluded were 230 papers that did not report AAA size, expansion rate or rupture. 39 papers were included. Several potential biomarkers were identified. The strongest association with AAA was obtained with serum elastin peptides (SEP) and plasmin-antiplasmin (PAP) complexes. Matrix-degrading metalloproteinase 9 (MMP9) and interferon-gamma (IFN-gamma) could have clinical potential while many putative biomarkers showed poor association. CONCLUSIONS: Several circulating agents in peripheral blood may predict AAA size, expansion rate or rupture. Few of them have clinical potential for future use. Confirmative studies and development of multivariate models are needed, together with continuing search for new biomarkers using the discovery based sciences within proteomics and/or genomics.

Doppler ultrasound compared with strain gauge for measurement of systolic ankle blood pressure.

This study assesses measurement variation in the measurement of ankle systolic blood pressure (ABP) when measured with Doppler ultrasound and with the strain gauge method. Ninety-seven patients were included. ABP was measured with Doppler ultrasound and with the strain gauge method. The methods were compared graphically by scatterplots and analyzed by paired t test, analysis of variance, and Pitman's paired variance ratio test. ABP was measured by strain gauge in all extremities, whereas no Doppler signal was obtainable in 7 limbs (4%). There was no systematic difference in measurements between the means of the two measurements. However, a substantial difference of more than 25 mm Hg was found in 15% of limbs and more than 20 mm Hg in 20%. In the majority of patients, measurements of ABP by Doppler ultrasound and the strain gauge method give similar results, but for a minority the discrepancy is substantial.

High-risk and low-risk screening for abdominal aortic aneurysm both reduce aneurysm-related mortality. A stratified analysis from a single-centre randomised screening trial.

BACKGROUND: Cardiovascular diseases and chronic obstructive pulmonary disease (COPD) are both associated with abdominal aortic aneurysms (AAA). The aim of this study was therefore to analyse whether screening for AAA could be restricted to men with such diseases (high risk group). METHODS: Before the date of randomisation of a population screening trial of 12,639 64-73-year-old males, all discharge diagnoses from the National Patient Registry concerning AAA-related diseases were merged with the screening results on attendance, AAA prevalence, and AAA-related mortality and overall mortality. Differences in proportions were compared by Chi square tests and differences in mortality by Cox regression analyses. RESULTS: The attendance rate was 78.8% and 6.7% had an AAA in the high risk group compared to 75.8% attendance (P<0.001) and 2.9% (P<0.001) in the remaining population. Cumulatively, screening of only high risk men with would have required 72.9% (95% C.I.: 72.3-74.5%) fewer screening invitations, would have discovered 46.1% (95% C.I.: 38.9-53.4%) of the AAA cases diagnosed and prevented 46.7% (95% C.I.: 28.3-65.7%) of the AAA-related deaths. However, screening decreased AAA-related mortality both among men with and without known COPD or cardiovascular diseases: mortality ratio: 0.22 (95% C.I.: 0.08-0.65), P=0.006, and 0.24 (95% C.I: 0.09-0.63, P=0.004, respectively. CONCLUSION: High-risk population screening would prevent less than half of AAA-related deaths. Therefore, restricting screening to such high-risk groups does not seem justified, but cost effectiveness analyses are needed to reach a firm conclusion.

Preliminary ten year results from a randomised single centre mass screening trial for abdominal aortic aneurysm.

BACKGROUND: At present, several regions and countries are considering screening for abdominal aortic aneurysm (AAA). However, The Chichester Aneurysms Screening Trial has reported poor long term benefit of screening for AAA. We therefore supplement previously published data with a preliminary analysis of the ten-year mortality from AAA, based upon population-based data until 2002 (7 years) and incomplete hospital-based information on deaths until 2005 (10 years). METHODS AND MATERIAL: In 1994 we started a randomised screening trial of 12,639 64-73 year-old males; 6,306 were controls, and 6,333 were invited to an abdominal ultrasound scan at their district hospital. Information on all deaths until 15.3.2005 was obtained from the Office of Civil Registration. Information on AAA related deaths was obtained from the national registry of Causes of Deaths from 1.4.1994 to 31.12.2001, and supplemented with AAA deaths known to the Danish National Patient Registry until 15.3.2005. Operations were obtained from the Danish National Vascular Registry from 1.4.1994 to 15.3.2005. Death certificates and medical records were reviewed by two independent assessors. The analyses were based on "intention to treat" from the date of randomisation. RESULTS: The attendance rate was 76.6% and 191 (4.0%) had an AAA. The median observation time was 9.58 years. In the invited group 13 subjects were acutely operated on compared to 40 in the control group (Risk ratio: 0.32 (95% C.I. 0.17-0.60, P<0.001)), and 14 died due to AAA compared to 51 in the control group (Hazard ratio: 0.27 (95% C.I.: 0.15-0.49, P<0.001). CONCLUSION: Over ten years, screening reduced mortality from AAA by 73%, and the frequency of emergency operations by 68%.

Cost-effectiveness analysis of screening for abdominal aortic aneurysms based on five year results from a randomised hospital based mass screening trial.

BACKGROUND: The aim of this study was to estimate the cost effectiveness of screening for abdominal aortic aneurysm (AAA). MATERIAL AND METHODS: All 12,639 men born in the years 1921-1933 (aged 64-73) living in Viborg County, Denmark, were randomly allocated either to receive an invitation to abdominal ultrasound scanning for AAA or to be controls. Costs for screening and surveillance were assessed prospectively. Diagnosis Related Group (DRG) costs from 1999 were used concerning admissions with uncomplicated and complicated operations. Admissions for AAA surgery were retrospectively classified according to complications in patient records. RESULTS: Mean follow-up time was 52 months. 76.6% of invited men attended screening, and 191 (4.0%) had an AAA. As previously reported, the cumulative 5-year AAA-specific mortality in the invited group was significantly reduced by 67% compared to the control group (P = 0.003). The costs were estimated to be Euro 11.23 per scan. The costs per life-year saved were Euro 9057 (Euro 5872-20,063) after 5 years, and were expected to decrease to Euro 2708 (Euro 1758-6031) after 10 years and to Euro 1825 (Euro 1185-4063) after 15 years. CONCLUSION: Screening of 64-73 years old males in Denmark seems cost effective.

Systemic levels of cotinine and elastase, but not pulmonary function, are associated with the progression of small abdominal aortic aneurysms.

OBJECTIVE: to study whether smoking and impaired pulmonary function are associated with the expansion of abdominal aortic aneurysms (AAA). METHODS AND MATERIAL: seventy-nine men with small (3-5 cm), screen-detected AAA underwent a simple 5-step smoking history, measurement of the forced first second expiratory volume (FEV1), venepuncture and annual ultrasound scan for mean follow-up period of 3.5 years. RESULTS: all but one patient had a significantly reduced FEV1 (p<0.05, Mann-Whitney). The FEV1/expected FEV1 ratio (rFEV1) was not related to AAA expansion but was negatively correlated with P-elastase-alpha1-antitrypsin-complexes (P-Elastase). P-Elastase was positively correlated with smoking and S-cotinine. Smoking, S-cotinine, and P-elastase were positively correlated with the mean annual AAA expansion rate but not rFEV1. CONCLUSION: in general, patients with AAA have impaired pulmonary function. A simple five step smoking classification is as predictive of AAA-expansion as S-cotinine. Smoking may cause elastase secretion leading to pulmonary and aortic elastin degradation but the lack of association between AAA-expansion and rFEV1 suggest that other mechanisms are important.

Relationships between activators and inhibitors of plasminogen, and the progression of small abdominal aortic aneurysms.

OBJECTIVE: plasmin is a common activator of the known proteolytic systems involved in the aneurysmal degradation, and is reported to be associated with the expansion of abdominal aortic aneurysms (AAA). The aim of this study was to study the activating pathways of plasminogen as predictors of the progression of AAA. MATERIALS AND METHODS: one hundred and twelve of 122 male patients with a small AAA (def.: +3cm) were interviewed, examined, had blood samples taken at diagnosis, and scanned annually for 1-5 years (mean 3.5 years), and referred for surgery if the AAA exceeded 5cm in diameter.A random sample of 70 of the 112 cases had plasma levels of urokinase-like-plasminogen activator (uPA), tissue-type-plasminogen activator (tPA), plasminogen-activator-inhibitor-1 (PAI-1), macrophage inhibiting factor (MIF), tumour-growth-factor-beta1 (TGF-beta1), homocysteine, and serum levels of IgA-antibodies against Chlamydia pneumoniae (IgA-CP) and Cotinine (a nicotine metabolite) measured. Spearmans correlation analysis was used for statistics. RESULTS: the annual expansion rate correlated positively with tPA, IgA-CP and S-Cotinine; r =0.37 (p=0.002), 0.29 (p=0.006) and 0.24 (p=0.038), while PAI1, uPA, TGF-beta1, homocysteine, and MIF did not. S-Cotinine did also correlate positively with tPA, r=0.24 (p=0.049). CONCLUSION: the aortic matrix degradation in AAA may be partly caused by an activation of plasminogen by tPA, but apparently not by uPA, which usually dominates matrix degradation. Smoking seems to be a factor for this pathway, while the pathways of IgA-CP and MIF, a new marker of aneurysmal progression, seem different. The latter observations suggest that other proteolytic pathways are involved in the aortic wall degradation in AAA.

Immunoblotting analysis of abdominal aortic aneurysms using antibodies against Chlamydia pneumoniae recombinant MOMP.

OBJECTIVES: antibodies against Chlamydia pneumoniae have been associated with atherosclerosis and with expansion of abdominal aortic aneurysms (AAA). C. pneumoniae has been demonstrated in coronary arteries, AAA and the carotid arteries by use of polymerase chain reactions (PCR), immunohistochemical procedures and electron microscopy. However, the correlation between demonstrating C. pneumoniae DNA or antigen in tissue from plaque material or aneurysms and the antibody titres in serum is controversial. The specificity of immunohistochemical procedures is unknown. The aim of this study was to assess the possibility of potential non-specific findings for methods based on immunostaining. MATERIALS AND METHODS: twenty patients undergoing infrarenal AAA repair were studied. Full AAA thickness tissue was collected from the anterior wall of the aneurysm. Analysis was performed using polyacrylamide gelelectrophoresis, immunoblotting and mass spectrometric protein identification. RESULTS: C. pneumoniae antigen was not demonstrated in any of the AAA samples, whereas a major cross-reacting protein was present in all AAA samples. The protein was identified as the human haemoglobin beta chain. CONCLUSION: we were not able to find C. pneumoniae antigens reacting with an anti C. pneumoniae major outer membrane protein (MOMP). Direct detection of C. pneumoniae by immunohistostaining procedures should be interpreted with caution due to potential crossreaction with non chlamydial proteins.

Hospital costs and benefits of screening for abdominal aortic aneurysms. Results from a randomised population screening trial.

OBJECTIVES: to analyse the hospital costs and benefits of screening older males for abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: in 1994 a hospital-based screening trial of 12 658 65-73-year-old males was started. AAA >5 cm were referred for surgery. The remaining AAA were offered annual scans. Those with aortic ectasia were rescreened at 5 yearly intervals. AAA-operations and hospital AAA-related deaths were researched. The costs of screening, surveillance, and treatment were also registered. RESULTS: the attendance rate was 76%; of whom 191 (4.0%) had AAA. Mean observation time was 5.13 years. Sixty in the screened and 41 in the control group were operated (p=0.06), of which 7 and 27 respectively were operated as an emergency (p<0.001), and 6 and 19 respectively died due to AAA (p=0.009). The costs per scan were 83.50 DKK, 81 400 DKK per emergency operation (71 485 DKK after screening), and 117 000 DKK per emergency operation. The cost per prevented hospital death was 67 855 DKK, equivalent to approximately life year saved approx. 7540 DKK (GBP1=12 DKK). CONCLUSION: screening appears to reduce hospital AAA mortality and to be cost-effective.

Plasma levels of plasmin-antiplasmin-complexes are predictive for small abdominal aortic aneurysms expanding to operation-recommendable sizes.

OBJECTIVE: Three proteolytic systems seem involved in the aneurysmal degradation of the aortic wall. Plasmin is a common activator of the systems and could thus be predictive for the progression of abdominal aortic aneurysms (AAAs). METHODS AND MATERIALS: In 1994, 112 of 141 male patients with AAA diagnosed through population screening (defined as 3 cm or more) were interviewed and examined and had blood samples taken. One hundred twelve cases were scanned annually for 1 to 5 years (mean, 2.5 years) and referred for surgery if the AAA exceeded 5 cm in diameter. A random sample of 70 of the 112 cases had P-plasmin-antiplasmin-complexes (PAPs), P-plasminogen, and S-elastin-peptides (SEPs). RESULTS: PAP was positively correlated with annual expansion rate (r = 0.39, 0.16-0.56), persisting after adjustment for initial AAA size, SEP, age, and smoking. However, PAP levels did not correlate with the initial AAA size or SEP. Furthermore, PAP levels were significantly predictive for cases expanding to operation-recommendable AAA sizes. Combined with the initial AAA size, both optimal sensitivity and specificity were 82%, increasing to 95% and 96%, respectively, excluding those lost to follow-up and accepting 2 mm of interobserver variation. CONCLUSION: The progression of AAA is correlated with the PAP level, which seems to have a predictive value similar to the best serologic predictor known, serum-elastin-peptides.

Cystatin C deficiency is associated with the progression of small abdominal aortic aneurysms.

BACKGROUND: The cysteine protease inhibitor cystatin C may play a role in the development and progression of abdominal aortic aneurysms (AAAs). METHODS: From a mass screening trial of men aged 65-73 years, 151 small AAAs were followed for a mean of 2.9 years. Of these patients, 142 had serum samples taken to determine the levels of cystatin C, creatinine and C-reactive protein (CRP). RESULTS: Serum cystatin C concentration correlated negatively with AAA size (r = - 0.22 (95 per cent confidence interval (c.i.) - 0.59 to - 0.02)) and annual expansion rate (r = - 0.24 (95 per cent c.i. - 0.75 to - 0.05)), persisting after adjustment for renal function, smoking, diastolic blood pressure, CRP, age and AAA size. Creatinine clearance and CRP did not correlate with size or expansion rate. Thirty-one AAAs had expanded to over 50 mm, when operation was recommended. The serum level of cystatin C was a significant predictor of this occurrence, with a sensitivity and specificity of 61 and 57 per cent respectively. However, initial AAA size had the optimal sensitivity and specificity (both 81 per cent) in this regard. CONCLUSION: Deficiency of cystatin C was associated with increased aneurysm size and expansion rate, possibly due to lack of inhibition of cysteine proteases.

[What are the direct costs of an abdominal aortic aneurysm repair in a Danish hospital?]. / Hvad koster en indlaeggelse til operation for et abdominalt aortaaneurisme på et dansk sygehus?

INTRODUCTION: The aim of the study was to estimate the direct cost of an abdominal aortic aneurysm (AAA) repair and to validate it against the national Diagnostic Related Group (DRG) costs. MATERIAL: Over a three-year period, between January 1996 and December 1998, a total of 100 men were selected at random from a series of 197 patients treated with open surgery for (AAA) at the Department of Vascular Surgery, Viborg Hospital. RESULTS: The total cost of an AAA operation without complications was estimated to be 70,000 DKK, compared to the DRG price of 79,000 DKK. Complications were significantly more frequent after emergency repair (odds ratio = 4.3 (95% CI; 1.9-10.1)). A statistically significant difference was seen in the cost of AAA repair between elective and emergency operations with rupture (p < 0.05), mainly because of the longer stay in hospital. DISCUSSION: The estimated cost is sufficiently reliable to be used in analysis of cost-effectiveness.

[Optimal interval screening and observation of abdominal aortic aneurysms]. / Optimal intervalscreening og observation af abdominale aortaaneurismer.

INTRODUCTION: Screening and observation of abdominal aortic aneurysms (AAA) produce psychological stress. Consequently, safe and optimal intervals of rescreening and observation must be developed. METHOD: In a randomised, mass screening trial of 6,339 men aged, 65-73 years from 1994 to 1998, 76% attended, and 191 (4%) had AAA > or = 3 cm. Twenty-four (0.5%) had AAA above 5 cm in diameter and were referred for surgery, while the rest were offered annual control. Later, all 348 (7.5%) men who, 3 to 5 years before, had had an ectatic aorta (an infrarenal aortic diameter of 25-29 mm or a distal/renal aortic diameter ratio of > 1.2) were offered rescreening, together with a control group of 380 men. RESULTS: None of the controls had developed AAA. Of those who initially had an aortic diameter of 25-29 mm aorta, 28.5% had developed AAA (size range 30-48 mm), whereas only 3.5% with a ratio > 1.2 developed AAA (size range 30-34 mm). During the fourth year of surveillance some AAA initially sized below 3.5 cm expanded to above 5 cm, whereas this occurred in some sized 3.5-3.9 cm during the second year and in most above 4 cm did during the first year of observation. CONCLUSION: Rescreening for AAA can be restricted to initially ectatic aortas sized 25-29 mm at five-year intervals. Observation of small AAA can be restricted to 1-4 year intervals.

Randomized double-blind controlled trial of roxithromycin for prevention of abdominal aortic aneurysm expansion.

BACKGROUND: Macrolide treatment has been reported to lower the risk of recurrent ischaemic heart disease. The influence of macrolides on the expansion rate of abdominal aortic aneurysms (AAAs) remains unknown. The aim was to investigate the effect of roxithromycin on the expansion rate of small AAAs. METHODS: A total of 92 subjects with a small AAA were recruited from two populations. One population consisted of 6339 men aged 65-73 years who were offered a hospital-based mass screening programme for AAA. From this population 66 subjects were recruited. The remaining 26 men were recruited from among 49 subjects diagnosed at interval screening for an initial aortic diameter between 25 and 29 mm. Subjects were randomized to receive either oral roxithromycin 300 mg once daily for 28 days or matching placebo, and followed for a mean of 1.5 years. RESULTS: During the first year the mean annual expansion rate of AAAs was reduced by 44 [corrected] per cent in the intervention group (1.56 mm per year), compared with 2.80 mm per year following placebo (P = 0.02). During the second year the difference was only 5 per cent [corrected]. Multiple linear regression analysis showed that roxithromycin treatment and initial AAA size were significantly related to AAA expansion when adjusted for smoking, diastolic blood pressure and immunoglobulin A level of 20 or more [corrected]. Logistic regression analysis confirmed a significant difference in expansion rates above 2 mm annually between the intervention and placebo groups: odds ratio = 0.09 (95 per cent confidence interval 0.01-0.83) [corrected]. CONCLUSION: In comparison to placebo, roxithromycin 300 mg daily for 4 weeks reduced the expansion rate of AAAs.

Antibodies against Chlamydia pneumoniae predict the need for elective surgical intervention on small abdominal aortic aneurysms.

OBJECTIVE: to compare the ability of two independent Chlamydia pneumoniae antibody tests to predict need for small abdominal aortic aneurysm (AAA) repair. PATIENTS AND METHODS: annual scans were offered to 149 screening diagnosed small AAA (<5 cm). Serum samples were collected for measuring IgA and IgG-antibodies to C. pneumoniae by microimmunofluorescence (MIF) test and the new ELISA (Labsystems). RESULTS: a significant concordance was found between MIF and ELISA titres with Kappa values of 0.29 for S-IgA and 0.42 for S-IgG. IgG antibodies measured by ELISA were most predictive for cases expanding operation recommendable sizes with a sensitivity and specificity of 80% and 66%, respectively. CONCLUSION: the simpler EIA has a high correlation with the MIF test and both were predictive for the natural history of AAA. Chlamydia antibody test may be used to identify individuals who might benefit from follow-up and anti-chlamydia treatment.

Five-year results of elastin and collagen markers as predictive tools in the management of small abdominal aortic aneurysms.

OBJECTIVE: small abdominal aortic aneurysms (AAAs) do rupture and only half of AAAs above 5 cm would have ruptured unoperated. Furthermore, conservative treatment of AAAs may cause psychological side effects and impaired quality of life. To optimise the indication and time for operation for AAAs, we analysed whether serum elastin peptides (EP), procollagen-IIIN-terminal propeptide (PIIINP), and the initial AAA size could predict operation for AAAs in initially conservatively treated AAA. MATERIAL AND METHODS: in 1994, 4404 65-73 year old males were invited to hospital-based screening for AAAs by ultrasonography. Seventy-six percent attended. One hundred and forty-one (4.2%) had AAAs (def: +30 mm). Nineteen were offered operation (AAA +50 mm), and 112 were followed with annual control scans for 1-5 years (mean 2.5 years). Of these, 99 had their EP (ng/ml) and PIIINP (ng/ml) determined using ELISA and RIA techniques. Two observers and one scanner were used. RESULTS: the mean expansion rate was 2.7 mm/year. The initial AAA size (r =0.46; 0.26-0.61), EP ( r =0.31; 0.11-0.49), and NPIIIP ( r =0.24; 0.02-0.44) was independently significant associated to expansion rate in a multiple linear regression analysis including the three mentioned variables. The multivariate formula could by ROC curve analysis predict cases reaching 5 cm in diameter within 5 years with a sensitivity and specificity of 91% and 87%, respectively, increasing to 91% and 94%, respectively, by accepting a 2 mm variation in those measurements. Twenty-three were lost to follow up, 21 of these due to death or severe illness. Of these, seven would have been predicted to reach an AAA size recommendable for surgery. If all 23 were included in the analysis, the sensitivity and specificity would have been 87% and 85%, respectively. CONCLUSION: a predictive model using EP, PIIINP, and initial AAA size seems capable of predicting nine out of 10 AAAs that will be operated on within 5 years. However, a larger sample size is needed for clinical recommendations.