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 €157 (−3292 to 4401) per life year gained and €179 (−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 €5000. 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. Registration number: ISRCTN65822028 (http://www.controlled-trials.com).

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.

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.

Systemic levels of plasmin–antiplasmin complexes are correlated with the expansion rate of small abdominal aortic aneurysms

Background

The cystatine proteolytic system, the serine proteolytic system and the metallodependent proteolytic system have all been reported to be involved in the matrix degradation of the aortic wall, causing abdominal aortic aneurysm (AAA). Plasmin is a common activator of all three systems and could theoretically be involved in the pathogenesis of AAA by activating all three systems. However, plasmin is immediately inactivated by antiplasmin, forming plasmin–antiplasmin (PAP) complexes when it reaches the circulation. This study was designed to assess whether the systemic levels of PAP complex in conservatively treated patients with AAA could be related to the natural history of AAA.

Methods

In 1994, 112 of 141 men with AAA (greater than 3 cm) diagnosed by population screening were interviewed, examined, and had blood samples taken and prepared for serum and ethylenediamine tetra-acetic acid plasma by a standard method. The serum and plasma were frozen at − 21°C until analysis. Of the 112 patients, 99 were followed with annual control scans and blood pressure measurements for 1–5 (mean 2·5) years, and were referred for operation if the AAA exceeded 5 cm in diameter. Of the 99 patients, a random sample of 70 had their level of PAP complexes determined (Dade Behring, Rødovre, Denmark). Furthermore, the level of serum elastin peptides (SEPs) was determined by enzyme-linked immunosorbent assay. Spearman's rank sum correlation test, multivariate linear regression analysis and receiver–operator characteristic (ROC) curve analysis were used for statistical analysis (SPSS 10.0; SPSS, Chicago, Illinois, USA).

Results

The level of PAP complex was positively correlated with annual expansion rate (r = 0·29, P = 0·01), but not with the initial AAA size (r = 0·17, P = 0·16) or SEP (r = 0·04, P = 0·77). The significant association to expansion persisted after adjustment for initial AAA size, SEP and smoking. Furthermore, the level of PAP complex was significantly predictive for AAAs expanding to operation recommendable size (area under ROC curve 65 per cent), with an optimal sensitivity and specificity of 65 and 67 per cent respectively. SEP level was also significantly predictive for AAAs expanding to operation recommendable size (area under ROC curve 56 per cent), with an optimal sensitivity and specificity of 56 and 57 per cent.

Conclusion

The progression of AAA seems to be caused by a general activation of the proteolytic systems involving plasmin and not by genetic or environmental factors causing increased activation of specific proteases or decreased activity of their specific inhibitors. Furthermore, the level of PAP complex in patients with an aneurysm seems to have a better and independently predictive value of the natural history of AAA, compared with the best serological predictor known to date, the serum level of elastin peptides.

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.

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.

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.

[What are the direct costs of an abdominal aortic aneurysm repair in a Danish hospital?]

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]

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.

Incident thromboembolism in the aorta and the renal, mesenteric, pelvic, and extremity arteries after discharge from the hospital with a diagnosis of atrial fibrillation

BACKGROUND

The impact of atrial fibrillation (AF) on risk of peripheral arterial thromboembolism is unknown.

METHODS

We analyzed the risk of thromboembolism (embolus and/or thrombosis) in the aorta and the renal, mesenteric, pelvic, and extremity arteries in a cohort of patients discharged from the hospital with an incident diagnosis of AF relative to the risk of thromboembolism in these vessels in the Danish population. In a random sample of half of the Danish population, 14 917 men and 14 945 women aged 50 to 89 years were identified in the Danish National Hospital Discharge Register with a diagnosis of AF from January 1, 1980, through December 31, 1993. Patients were followed up from diagnosis of AF in the Danish National Hospital Discharge Register and the Causes of Death Register until the first diagnosis of a thromboembolic event, death, or the end of 1993. Risk of a thromboembolic event relative to the risk in the Danish population was analyzed by means of Poisson regression modeling.

RESULTS

Patients with a hospital diagnosis of AF had an increased risk of thromboembolic events in the aorta and the renal, mesenteric, pelvic, and extremity arteries (relative risk, 4.0 [95% confidence interval, 3.5-4.6] in men; and relative risk, 5.7 [95% confidence interval, 5.1-6.3] in women) compared with the Danish population.

CONCLUSION

A hospital diagnosis of AF is an important risk factor for peripheral arterial thromboembolic complications.

Smoking, but not lipids, lipoprotein(a) and antibodies against oxidised LDL, is correlated to the expansion of abdominal aortic aneurysms

OBJECTIVES

to study the role of smoking, lipids, lipoprotein (a), and autoantibodies against oxidised low density lipoprotein (Ab-oxLDL) in the expansion of small abdominal aortic aneurysms (AAA). To study the role of Ab-oxLDL and lp(a) in the progression of lower limb atherosclerosis.

METHODS AND MATERIALS

one hundred and thirty-eight male patients with AAA were interviewed, examined, and their serum lipids and S-Ab-oxLDL determined. Of these, 117 were followed annually with ultrasound and underwent control scans and blood pressure measurements for a mean of 2.5 (range 1-5) years.

RESULTS

initial AAA size, smoking and level of triglycerides were positively correlated to increased aneurysmal expansion, while beta-blocker medication was associated with decreased expansion. Besides initial AAA size, only smoking had persisting significance after adjustment of the other significant variables. Initial ankle brachial pressure index (ABI) and Lp(A) but not ab-oxLDL were significantly correlated to ABI change.

CONCLUSION

smoking cessation may inhibit aneurysmal expansion. Lipids seem to play a minor role in the progression of AAA.

Optimal interval screening and surveillance of abdominal aortic aneurysms

OBJECTIVES

to determine safe and optimal intervals of rescreening and surveillance for AAA.

METHODS

hospital-based mass screening of 6339 65-73-year-old men from 1994-98. 76.4% attended. One hundred and ninety-one (4%) had AAA53 cm. Twenty-four (0.5%) were initially >5 cm and referred for surgery, while the rest were offered annual control scans to check for expansion. Later, all 348 (7.5%) men who 3 to 5 years ago had an ectatic aorta (infrarenal aortic diameter of 25-29 mm or distal/renal aortic diameter ratio >1.2) were offered rescreening. Of these, 62 (18%) died before rescanning, while 248 of the survivors attended rescreening (87%). Furthermore, a random sample of 380 of those with non-ectatic aortas were offered rescreening. Of these, 49 (13%) died before rescreening (p=0.06), while 275 (83%) of the survivors attended re-screening.

RESULTS

none of the controls had developed AAA. Of those who initially had an 25-29 mm aorta, 29% had developed AAA (size range 30-48 mm) with expansion rates varying from 1.0 to 4.7 mm/year. Only 3.5% with a ratio >1.2 developed AAA (size range: 30-34 mm) with expansion rates from 1.3 to 2.4 mm/year. During the fourth year of surveillance some AAA initially sized below 3.5 cm expanded to above 5 cm, while some sized 3.5-3.9 cm did so during the second year, >4 cm did so during the first year of surveillance.

CONCLUSION

rescreening for AAA can be restricted to initially ectatic aortas sized 25-29 mm at 5-year intervals. Surveillance of small AAA can be restricted to 1-4 year intervals.

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.

[Iliac aneurysm compared with abdominal aorta aneurysm]

The aim of the study was to compare the epidemiology, risk factors and manifestations of iliac and abdominal aortic aneurysm (AAA). Two studies were used: 1. Five thousand four hundred and seventy 65-73 year old men invited to screening for AAA. 2. Review of all 350 patients operated for central aneurysms in the county of Viborg in Denmark 1989-1997. Four thousand one hundred and seventy-six attended screening. One hundred and seventy (4.0%) had an AAA. Twenty-one (0.56%) required operation, while the prevalence of operation-requiring iliac aneurysm (IA) was 0.17%. The operative incidence of IA was 18.4 per mill. per year, and 92.4 per mill. per year were operated for AAA. Patients with IA had lower cholesterol-levels, and urological symptoms were present in 42% of cases with isolated IA, and 25% of combined aneurysms compared to 8% of isolated AAA (p < 0.05). Fifty-eight percent of the isolated IAs were ruptured, while only 27% of AAAs were ruptured (p < 0.05). The per- and postoperative mortality was 57% in ruptured isolated IA, 47% in ruptured combined aneurysms, and 31% in ruptured isolated AAA (p < 0.05). IA seems to be more under-diagnosed than AAA, and are often diagnosed because of clinical manifestations, especially urological or rupture. They seem more lethal in ruptured cases.

Psychological consequences of screening for abdominal aortic aneurysm and conservative treatment of small abdominal aortic aneurysms

OBJECTIVE

To describe the potential psychological consequences of screening for abdominal aortic aneurysms (AAAs).

METHODS

The participants were prospectively and randomly sampled from a randomised screening trial for AAA and asked to complete a validated generic and global anonymous quality of life (QL) questionnaire by self-assessment (ScreenQL). Material case-control study: ScreenQL was completed once by 168 (48%) of 350 non-responders to screening, 271 (81%) of 335 attenders before screening, 286 (85%) of 335 attenders after screening, 127 (85%) of 149 with a small AAA diagnosed at screening, and 231 (66%) of 350 who were randomised not to be offered screening for AAA (controls). Prospective study (paired data): 127 men having a small AAA diagnosed. Twenty-nine (81%) of 36 men operated after initial conservative treatment.

RESULTS

Initially, the QL score was 5% lower among men with a small AAA compared to the controls (p<0.05), mainly because of poorer health perception. The QL score declined significantly further to 7% below control values during the period of conservative treatment. This impairment was mainly due to a 21% and 15% reduction in scores relating to health perception and psychosomatic distress, respectively. However, all scores improved to control levels in patients operated on. The QL of attending men for screening was significantly lower than that of the controls and the attenders after the screening. No differences were noticed concerning the non-attenders.

CONCLUSION

The offer of screening causes transient psychological stress in subjects found not to have AAA. However, diagnosis of an AAA seems to impair QL permanently and progressively in conservatively treated cases. This impairment seems reversible by operation. Nevertheless, the impairment seems considerable, and must be considered in the management of AAA and in the final evaluation of screening for AAA.

A comparative study of iliac and abdominal aortic aneurysms

BACKGROUND

The aim of the paper is to compare the epidemiology, risk factors and manifestations of iliac and abdominal aortic aneurysms.

METHODS

Two studies were used: 1. 5,470 65-73-year-old men invited for screening for abdominal aortic aneurysms. 2. Review of all 350 patients operated on for central aneurysms in the county of Viborg, Denmark from 1989-1997.

RESULTS

4,176 attended for screening. One hundred and seventy (4.0%) had an abdominal aortic aneurysm. Twenty-one (0.56%) needed operation. The proportion of patients with common iliac aneurysms requiring surgery was 0.17%. The operative incidence of iliac aneurysm was 18.4 per million per year, and 92.4 per million per year were operated on for abdominal aortic aneurysm. The mean serum cholesterol level for isolated iliac aneurysm and combined aneurysms was significantly lower compared to isolated abdominal aortic aneurysm (p<0.05). Urological symptoms were present in 42% of cases with isolated iliac aneurysm, and 25% of combined aneurysms compared to 8% of isolated abdominal aortic aneurysms. Fifty-eight percent of the isolated iliac aneurysms were ruptured, as against 27% of the abdominal aortic aneurysms. The peri- and postoperative mortality was 57% in ruptured isolated iliac aneurysms, 47% in ruptured combined aneurysms, and 31% in ruptured isolated aortic aneurysms.

CONCLUSIONS

Iliac aneurysms seem to be more underdiagnosed than abdominal aortic aneurysms, and are often diagnosed because of clinical manifestations, especially urological, or rupture. Iliac aneurysms seem more lethal than those of the abdominal aorta in cases of rupture.

Apolipoprotein E genotype is associated with differential expansion rates of small abdominal aortic aneurysms

BACKGROUND

The common polymorphism of the apolipoprotein E (APOE) gene is associated with differential risk of atherosclerosis; the gene could be a candidate gene in abdominal aortic aneurysms (AAA).

METHODS

APOE genotypes were determined in 57 men aged 65-73 years with a small AAA (30-50 mm). The patients were included in a population ultrasonographic screening programme and were followed with at least two examinations during an interval of 2-4.5 years. The AAA expansion rates in patients with four different APOE genotypes were studied, with adjustment for initial AAA size and smoking.

RESULTS

APOE genotype was a significant determinant of AAA expansion rate (P = 0.001). The adjusted mean (95 per cent confidence interval) rate was 2.1 (1.7-2.6) mm/year in 31 men with genotype E3E3, 1.3 (0.7-1.9) mm/year in 17 men with E3E4, 3.1 (2.0-4. 1) mm/year in six men with E2E3 and 4.2 (2.7-5.6) mm/year in three men with E2E4. The mean expansion rate was 2.2 (1.5-2.8) mm/year in non-smokers and 3.0 (2.5-3.6) mm/year in smokers (P = 0.014).

CONCLUSION

APOE genotype seems to influence AAA expansion rate, but the effects of the individual genotypes, in particular E3E3 and E3E4, are contradictory when compared with the effects of the genotypes on risk of atherosclerosis.

The progression of lower limb atherosclerosis is associated with IgA antibodies against Chlamydia pneumoniae

OBJECTIVE

to study the influence of serologically diagnosed chronic infection with Chlamydia pneumoniae on the progression of lower limb atherosclerosis in a group of disposed men.

MATERIAL AND METHODS

the highest systolic brachial and lowest systolic ankle blood pressures were followed for an average of 2.7 years in 129 men aged 65-73 years with conservatively treated small abdominal aortic aneurysms. Blood samples were taken to measure low-density lipoprotein and IgA and IgG titres of antibodies against C. pneumoniae by a microimmunofluorescence test.

RESULTS

the prevalences of seropositivity varied from 43 to 83% depending on the definition. The ankle-brachial blood pressure index of the IgA-seropositive [corrected] men decreases by 11%, while it decreased by 4.8% among IgA-seronegative men (p<0.05). The significant difference persisted in a multiple-regression analysis adjusting for age, smoking, initial systolic ankle BP, and initial brachial systolic or diastolic BP, but disappeared after adjusting for the level of low-density lipoprotein.

CONCLUSIONS

C. pneumoniae infection is associated with the progression of atherosclerosis.

[Surgery for ruptured abdominal aneurysm assisted by vascular unit team at the primary receiving hospital]

The objective of the study was to compare emergency operations for ruptured abdominal aortic aneurysm (RAAA) by a mobile operation team, with operation for RAAA carried out at our vascular unit. During a five year period (1993-1998), 18 emergency operations were carried out for abdominal aortic aneurysm (AAA) with rupture at the primary receiving hospital with assistance from a mobile operation team. In the same period 82 aneurysms with rupture were resected at our vascular surgical unit. Preoperatively, patients operated at the primary receiving hospitals had significantly lower blood pressure (P < 0.05) and an intraoperative higher blood loss (P < 0.05). Furthermore, postoperative complications tended to be higher among patients operated at hospitals without a vascular unit. consequently, the mortality was 67% compared to 47% in the department. However, 1/3 of the patients operated by the mobile operation team survived. Consequently, haemodynamically unstable non-transportable patients with an RAAA should be considered for surgery by a mobile operation team.

[Natural history of abdominal aortic aneurysm with and without concomitant chronic obstructive pulmonary disease]

The relationship between abdominal aortic aneurysms (AAA) and chronical obstructive pulmonary disease (COPD), and in particular the suggested common elastin degradation caused by elastase and smoking was analysed by a cross sectional population mass screening study for AAA, and a prospective cohort study of small AAA. All previous computer-hospital-recorded diagnoses were received concerning 4,404 men invited to screening for AAA. One hundred and forty-one had AAA (4.2%). They were asked for an interview, a clinical examination, and a blood sample. Men with an AAA of 3-5 cm were offered annual control-scans to check for expansion. Of COPD-patients, 7.7% had AAA (crude OR = 2.05), however the adjusted OR was only 1.53 after adjusting for other co-existing diseases (p = 0.13). The mean annual expansion was 2.74 mm per year in COPD patients and 2.72 in non-COPD patients, and 4.7 mm in oral steroid-users compared to 2.6 in non-steroid-users (p < 0.05). S-elastin-peptides (SEP) and P-elastase-alpha1-antitrypsin-complexes (PEAC) were negatively correlated to FEV1 in COPD-patients. However, SEP, beta-agonist-treatment, and FEV1 was positively correlated to expansion by multivariate regression analysis, while PEAC and S-alpha1-antitrypsin did not influence expansion, suggesting elastase plays a major role in the pathogenesis of COPD but not in AAA. The high prevalence of AAA among patients with COPD is more likely to be caused by medication and coexisting diseases rather than a common pathway of pathogenesis.

The validity of ultrasonographic scanning as screening method for abdominal aortic aneurysm

OBJECTIVE

the sensitivity and specificity of screening for abdominal aortic aneurysms (AAAs) with ultrasonographic scanning (US) is unknown. The aim of the study was to validate US as screening test for AAAs.

METHODS AND MATERIAL

4176 (76.3%) of 5470 men aged 65-73 attended hospital-based US screening for an AAA at their local hospital. Two observers and one scanner were used. The maximal anterior-posterior (AP) of the dilated aorta, or 2 cm above the bifurcation, and at the crossing of left renal vein was recorded. In 50 cases, blinded measurements were carried out by two observers. An AAA was defined as an AP diameter greater than 29 mm.

RESULTS

the standard deviation (s.d.) of the interobserver variability of the distal AP diameter was 0.84. The mean distal AP diameter was 17. 9 mm (s.d. 2.92). Combining these data, the estimated diagnostic sensitivity was 98.9%, the estimated diagnostic specificity was 99. 9%. The interobserver s.d. of the proximal AP diameter was 1.76. The mean proximal AP diameter was 18.4 mm (s.d. 2.45). Combining these data, the estimated diagnostic sensitivity was 87.4%, the estimated diagnostic specificity was 99.9%.

CONCLUSION

US seems to be a valid screening method for AAA. Screening for proximal infrarenal aorta aneurysm remains acceptable because the majority of aortic diameters in this segment are so much smaller than the diameters that define an AAA.

Vascular surgical society of great britain and ireland: immunoglobulin A antibodies against chlamydia pneumoniae are associated with expansion of small abdominal aortic aneurysms and declining ankle blood pressure

BACKGROUND: The potential correlation between chronic infection with Chlamydia pneumoniae and the progression of small abdominal aortic aneurysms (AAAs) and lower limb atherosclerosis was studied. METHODS: Mass screening for AAA was carried out in outdoor clinics at all hospitals in the county. Some 139 men (aged 65-73 years) with a 3.0-4.9-cm AAA were followed prospectively for 1-3 (mean 2.7) years. Initially, an interview and examination was performed, and blood samples were taken. RESULTS: Some 62 per cent (53-71 per cent) had an immunoglobulin (Ig) A level of 40 or more, or an IgG level of 64 or above. Some 83 per cent (74-93 per cent) had an IgA level of 20 or more, or an IgG level of 32 or more. Men with an IgA level of 20 or more had 51 per cent greater AAA expansion and men with an IgA level of 40 or above had 24 per cent more expansion. An IgA level of 20 or more, or IgA of 40 or greater, were significant independent predictors of AAA expansion adjusted for age, smoking, initial AAA size, steroid treatment, diastolic blood pressure, pulmonary function and other plasma factors. The ankle blood pressure index (ABI) of the IgA-seropositive men decreased 11 per cent, while the ABI decreased by 5 per cent among IgA-seronegative men (P < 0.05). The significant difference persisted after adjusting for age, smoking, initial systolic ankle blood pressure, initial brachial systolic or diastolic blood pressure, but disappeared after adjusting for low-density lipoprotein (LDL) levels. CONCLUSION: A high proportion of men with a small AAA have signs of chronic C. pneumoniae infection. The progression of AAAs and lower limb atherosclerosis seems to be correlated to chronic infection with C. pneumoniae.

Immunoglobulin A antibodies against Chlamydia pneumoniae are associated with expansion of abdominal aortic aneurysm

BACKGROUND

The aim of this study was to examine the possible association between the progression of small abdominal aortic aneurysm (AAA) and chronic infection with Chlamydia pneumoniae.

METHODS

Patients from a hospital-based mass screening programme for AAA with annual follow-up (mean 2.7 years) were included. After initial interview, 139 men aged 65-73 years with a small AAA underwent examination and blood sampling. Immunoglobulin (Ig) G and IgA titres against C. pneumoniae were measured by a microimmunofluorescence test.

RESULTS

Some 83 (95 per cent confidence interval 74-93) per cent of the men had an IgA titre of 20 or more, or an IgG titre of 32 or more. Men with an IgA titre of 20 or more had a 48 per cent higher AAA expansion rate than those with a titre of less than 20 (3.1 versus 2.1 mm/year; P < 0.05). Multiple linear and logistic regression analyses showed that an IgA titre of 20 or more was a significant independent predictor of increased AAA expansion, adjusted for known risk factors of expansion. Initial AAA size and serum total cholesterol level were also predictors of expansion.

CONCLUSION

A high proportion of men with a small AAA had signs of chronic infection with C. pneumoniae. Aneurysm progression correlated with evidence of chronic C. pneumoniae infection.

A review of Chlamydia pneumoniae and atherosclerosis

Chlamydia pneumoniae is a Gram-negative obligate intracellular bacterium that causes acute upper and lower respiratory infections. Its distribution is worldwide. Seroepidemiological studies have shown an association between C. pneumoniae and atherosclerosis, and the risk of acute myocardial infarction. Several studies had detected C. pneumoniae in atherosclerotic lesions from coronary and carotid arteries, in abdominal aortic aneurysms (AAA), and in sclerotic aortic valves. One study consistently succeeded in culturing C. pneumoniae from an atherosclerotic lesion, indicating the presence of viable organisms. However, the pathogenicity is unknown, and the significance of detecting the organism is unresolved. In two minor controlled clinical trials, patients with ischaemic heart disease were randomised into antibiotic-treated and placebo groups. Both trials showed a significant reduction in serious endpoints in patients receiving macrolide. Macrolide therapy thus seems to improve the outcome of severe ischaemic heart disease. It is not known whether this is caused by eradicating C. pneumoniae organisms, or by the macrolide's non-specific anti-inflammatory effect. Since both C. pneumoniae and inflammation are found in the AAA wall, it may be considered that macrolide would also improve the outcome of AAA and other diseases related to vascular surgery. In order to confirm this, randomised trials with macrolide therapy are needed, as well as diagnostic methods that can differentiate between individuals who are or are not infected with C. pneumoniae. The latter are needed in order to clarify the impact of the presence of C. pneumoniae and to avoid indiscriminate use of antimicrobials.

Impaired results of a randomised double blinded clinical trial of propranolol versus placebo on the expansion rate of small abdominal aortic aneurysms

BACKGROUND

To study the propranolol treatment of small abdominal aortic aneurysms (AAA) concerning intention to treat, side effects, and inhibition of expansion.

METHODS

DESIGN

Two-year lasting prospective randomised double-blinded intervention trial.

SETTING

Hospital-based mass screening for AAA with annual ambulatory control of small AAA.

PARTICIPANTS

Of 122 screening-diagnosed small AAA, 51 (42%) were excluded because of contraindications or present beta-blockage, and 17 refused participation. Thus, 54 (44.3%) were included.

INTERVENTION

Participants were randomised to 40 mg propranolol twice a day or placebo.

MEASURES

The same observed was used to follow-up AAA-expansion, side effects, quality of life (QL), branchial and ankle blood pressure (ABI), and pulmonary function (FEV1 and FVC).

RESULTS

Sixty percent in the propranolol group, and 25% in the placebo group dropped out, mainly caused by dyspnoea in the propranolol group (RR=1.74, 95% C.I.: 1.06-2.86). Five (16.7%) died in the propranolol group, while 1 (4.2%) died in the placebo group (RR=1.6 (1.02-2.51)). Furthermore, decreased pulmonary function, ABI, and QL was noticed in the propranolol group. Consequently, the trial was stopped after two years. Ninety-five percent of the measurements of the AAA were measured within 2 mm variation. If expansion was defined as above 2 mm annually, the relative risk of expansion in the placebo group was 1.17 (0.74-1.85), and 2.44 (0.88-6.77) among the non-drop-outs.

CONCLUSIONS

Only 22% of small screenings-diagnosed AAA were treatable with propranolol for two years. Consequently, only large scale studies are capable of showing potential minor inhibition of expansion by propranolol. However, whether such treatment ever becomes ethically acceptable is debatable.

Natural history of abdominal aortic aneurysm with and without coexisting chronic obstructive pulmonary disease

PURPOSE

To study the relation between abdominal aortic aneurysms and chronical obstructive pulmonary disease (COPD), in particular the suggested common elastin degradation caused by elastase and smoking.

METHODS

A cross-sectional population study and a prospective cohort study of small abdominal aortic aneurysms was performed in a community setting. All previous diagnoses recorded in a hospital computer database were received for 4404 men 65 to 73 years of age who had been invited to a population screening for abdominal aortic aneurysm. One hundred forty-one men had AAA (4.2%). They were asked to participate in an interview, a clinical examination, and collection of blood sample. Men with an abdominal aortic aneurysm 3 to 5 cm in diameter were offered annual ultrasound scans to check for expansion.

RESULTS

Among patients with COPD 7.7% had abdominal aortic aneurysms (crude odds ratio=2.05). The adjusted odds ratio, however, was only 1.59 after adjustment for coexisting diseases associated with abdominal aortic aneurysm (P=.13). The mean annual expansion was 2.74 mm per year among patients with COPD, 2.72 among patients without COPD, and 4.7 mm among patients who used oral steroids compared with 2.6 among patients who did not use steroids (P < .05). Concentration of serum elastin peptide and plasma elastase-alpha1-antitrypsin complexes correlated negatively with forced expiratory volume in the first second (FEV1) among patients with COPD. However, multivariate regression analysis showed that concentration of serum elastin peptide, therapy with beta-agonists, and FEV1 correlated positively with degree of expansion but that concentration of plasma elastase-alpha1-antitrypsin complexes and serum alpha1-antitrypsin did not influence expansion, suggesting that elastase plays an important role in the pathogenesis of COPD but not of abdominal aortic aneurysm.

CONCLUSION

The high prevalence of abdominal aortic aneurysm among patients with COPD is more likely to be caused by medication and coexisting diseases rather than a common pathway of pathogenesis.

Is screening for abdominal aortic aneurysm acceptable to the population? Selection and recruitment to hospital-based mass screening for abdominal aortic aneurysm

BACKGROUND

The aim of the study was to analyse whether the selection and recruitment for hospital-based mass screening for abdominal aortic aneurysms (AAA) is acceptable for the population according to the criteria from the Council of Europe.

METHODS

A random sample of 4404 65-73-year-old males were invited to hospital-based mass screening for AAA. As methods of secondary recruitment, they could change their time of appointment, and non-responders were reinvited once.

RESULTS

The attendance rate was 76 per cent; 4.2 per cent had AAA. Men with cardiopulmonary and vascular diseases had higher attendance rate (80.5 per cent), and prevalence of AAA (9.1 per cent). Men with potentially mobility-disabling diseases also had a higher attendance rate (80.4 per cent). However, possible unfavourable social selection was noticed in the group of retired men with no information of former occupation. They had 68.5 per cent attendance, and 7.6 per cent AAA. If true, this selection decreases the number of potentially diagnosed AAA by only 2 per cent. Opportunity of revised appointment and reinvitation of non-responders increased the primary attendance of 65 per cent to 76 per cent. More AAA were found at secondary scans (6.3 per cent compared with 3.9 per cent).

CONCLUSION

The attendance rate fell markedly with age, but the recruitment was high even at the age of 73, and travel distance and social class did not markedly influence uptake. A positive morbidity selection to screening for AAA was observed for cardiovascular or pulmonary diseases and potentially mobility-disabling diseases. Furthermore, higher prevalence of AAA was found for initial nonattenders. Thus, screening for AAA seems acceptable to the population, and extra efforts to increase the attendance are beneficial without increased costs per diagnosed AAA. Finally, if mass-screening proves to be cost-ineffective, selective screening of patients with hypertension or ischaemic heart disease might be beneficial.

Failure to demonstrate Chlamydia pneumoniae in symptomatic abdominal aortic aneurysms by a nested polymerase chain reaction (PCR)

OBJECTIVE

To investigate whether Chlamydia pneumoniae is present in symptomatic abdominal aortic aneurysms (AAA).

METHOD AND MATERIALS

After optimisation of DNA extraction procedures an inhibitor-controlled nested polymerase chain reaction (PCR) amplifying fragments of the gene encoding the C. pneumoniae specific major outer membrane protein was performed on 124 wall-specimens from 20 patients with symptomatic AAA.

RESULTS

None of the specimens contained C. pneumoniae-specific DNA. Minor inhibition of the PCR was noticed especially in media specimens.

CONCLUSION

Using a sensitive and specific nested PCR, we were not able to detect C. pneumoniae in symptomatic AAA. The failure to detect C. pneumoniae in symptomatic AAA, combined with previously reported positive findings in atherosclerotic lesions, supports the hypothesis that AAA and atherosclerosis might be two different disease entities.

Serum-elastin-peptides as a predictor of expansion of small abdominal aortic aneurysms

OBJECTIVE

To optimise the indication and time for operation for abdominal aortic aneurysm (AAA), we analysed whether or not serum-elastin-peptides (SEP) could be a potential predictor for expansion.

MATERIALS AND METHODS

Four thousand, four hundred and four 65-73-year-old males were invited for screening to detect an AAA. Three thousand, three hundred and thirty-four attended (76%). One hundred and forty-one had AAA, and 19 > 5 cm in diameter were referred for immediate operation. The remaining 122 AAA were offered an annual follow-up. Ninety-nine were later asked for a blood-sample, 83 attended. SEP was determined using an ELISA-technique. The observer was blinded to the SEP result.

RESULTS

The average expansion was 2.6 mm/year, and 10 (8.1) were referred for operation because of a diameter of > 5 cm. SEP were positively correlated to expansion (R = 0.4, F = 14.65). In multiple regression analyses, AAA size, SEP, beta-agonist-treatment, and FEV1, but not beta-blockers, were predictors of expansion. SEP remained a relatively strong predictor (F = 13.13).

CONCLUSIONS

Serum-elastin-peptides seem to predict expansion, but a larger, longer study is needed to establish clinical recommendations.

[Screening for abdominal aortic aneurysm]

In spite of increasing number of elective resections of abdominal aortic aneurysms (AAA) the mortality or ruptured AAA is increasing. The advantages of elective operations are obvious; the lethality is 2-6% while the lethality of ruptured AAA is 75-95%. However, AAA seldom causes symptoms before rupture. Ultrasonographic screening for AAA takes 10 minutes per scan, and the sensitivity and specificity are high. Ultrasonographic screening for AAA is a reliable, safe and inexpensive method for screening, and screening for AAA is discussed worldwide. One point four percent of deaths among men from 65 to 80 year of age are caused by ruptured AAA. Screening men over 65 for AAA can theoretically prevent a substantial number of deaths. Our calculations predict one prevented AAA-death per 200-300 scans for a cost of about 4000 DKK per saved year of life. However, cost-benefit analyses are based on uncertain assumptions concerning prevalence, incidence and risk of rupture. Therefore a randomized trial screening of 65-73 year old males is taking place in the County of Viborg in Denmark.

[Preliminary results of screening for abdominal aortic aneurysm in the ounty of Viborg]

The incidence of abdominal aortic aneurysms (AAA) and ruptured AAA is increasing. One to three percent of deaths among 65-80 year-old males are caused by AAA. Sixty-six to ninety-five percent of ruptured AAA are lethal, while elective resection has a 3-6% operative mortality. Most AAA's are asymptomatic before rupture. Ultrasonographic scanning of the aorta takes below ten minutes with close to 100% sensitivity and specificity. The County of Viborg has started a randomized screening trial including 13,500 65-73 year-old males. Half of these are invited to the nearest hospital over a period of three years. In 1994-1995 4938 were invited and 3748 were scanned, resulting in an acceptance rate of 76%. The aorta was visible in 99.7%, and the total time consumption was 9.7 minutes per scan. The costs were 83.75 DKK per scan. One hundred and fifty-three (4.1%) had an AAA defined as an aortic diameter above 29 mm. Twenty were above 49 mm and were offered operation, i.e. 5.3 per thousand scans or 13% of the diagnosed AAA.

Mass or high-risk screening for abdominal aortic aneurysm

BACKGROUND

Abdominal aortic aneurysm (AAA) is known to be associated with various diseases, especially hypertension, acute myocardial infarction (AMI), chronic obstructive airway disease (COAD), and intermittent claudication. These associations have led to a debate about whether screening of older men for AAA should be restricted to those with an associated disease.

METHODS

To compare mass screening of men for AAA with screening of men with AAA-associated diseases, all previous computerized hospital-recorded AAA-associated diseases were merged with the results of mass screening of 4404 men aged 65-73 years.

RESULTS

Of hypertensives, 82.6 per cent attended screening of whom 17.8 per cent had AAA. For previous AMI the equivalent values were 82.3 and 9.3 per cent; for COAD 74.3 and 7.7 per cent; for angina pectoris 83.8 and 7.5 per cent; for lower limb arteriosclerosis 81.1 and 6.1 per cent; and for stroke or transient cerebral ischaemia 75.0 and 6.2 per cent. Screening of these six high-risk groups alone would have required 78.5 per cent fewer scans and 51.1 per cent of the AAAs diagnosed at mass screening would have been recognized. The attendance rate would have been 80.4 per cent, of whom 9.5 per cent would have had an aneurysm. The attendance rate among non-high-risk men was 74.7 per cent and 2.7 per cent had an aneurysm.

CONCLUSION

If screening for AAA is desirable, the authors recommend mass rather than high-risk screening.