Trends in mortality and hospital admission rates for abdominal aortic aneurysm in England and Wales, 1979-1999

Economic instability, income, and unemployment effects on mortality: using SUR panel data in Iran

This study aims to investigate the effects of socioeconomic factors on mortality in Iran. To this end, this research examines how economic instability, income, and unemployment affect mortality using a seemingly unrelated regression (SUR) with panel data for 30 provinces in Iran from 2004 to 2019. The results indicate that unemployment and mortality have a countercyclical relationship among the working age-groups 20-59 but a procyclical pattern among old-age (60+), except for rural mortality. This result is harmonious between employment and age-group mortality. This finding implies that unemployment increases mortality in working age-groups due to psychological stress and poverty risk. In addition, the income level decreases mortality in all ages over 40 years due to the provision of higher access to health and medical services and social welfare. However, it increases mortality in rural areas and age-group 20-39 because of their hazardous, unsafe, and stressful work conditions. Therefore, policymakers should plan for an inclusive economic growth to reduce poverty and out-of-pocket payments and increase the quality and accessibility of public health services, especially for beneficiaries of lower social groups. Moreover, they should adopt strategies to alleviate the burden of premature, preventable, and treatable deaths.

An Epidemiologic Study of the Incidence and Mortality of Abdominal Aortic Aneurysms in Koreans Aged ≥50 Years from 2009 to 2018 Based on a National Database

Large-scale population studies of the incidence of and mortality from abdominal aortic aneurysm (AAA) are needed to develop healthcare policies and priorities. The aim of this study was to estimate the incidence of AAA and the all-cause mortality from it among Koreans aged ≥50 years from 2009 to 2018 using data from the Korean National Health Insurance System Database. The crude and standardized incidence and all-cause mortality of the disease among patients with unruptured AAA were calculated. A total of 73,933 AAA patients were identified. The overall incidence of AAA in adults ≥50 years during the study period was 37.5 per 100,000 population (49.7 per 100,000 in men and 26.8 per 100,000 in women), with an increase from 32.33 per 100,000 persons in 2009 to 46.85 per 100,000 in 2018. The crude all-cause mortality rate of patients with untreated AAA was 21.26/100 person-years in 2009 and 8.87/100 person-years in 2018, with decreasing trends observed both in men and women. This nationwide study showed that the incidence of AAA in Koreans aged ≥50 years in 2018 was 63.40 per 100,000 in men and 32.07 per 100,000 in women. The overall rates were 0.06% and 0.03%, respectively, with an increasing trend. Mortality has decreased in both treated and untreated patients. The observed increase in incidence suggests a rising burden of AAA in the Korean population, particularly among men. The decreasing mortality rates may indicate improvements in the management and treatment of AAA over the study period.

Abdominal Aortic Aneurysms (Etiology, Epidemiology, and Natural History)

Abdominal aortic aneurysm is a potentially lethal condition that is decreasing in frequency as tobacco use declines. The exact etiology remains unknown, but smoking and other perturbations seem to trigger an inflammatory state in the tunica media. Male sex and advanced age are clear demographic risk factors for the development of abdominal aortic aneurysms. The natural history of this disease varies, but screening remains vital as it is rarely diagnosed on physical examination, and elective repair (most commonly done endovascularly) offers significant morbidity and mortality advantages over emergent intervention for aortic rupture.

Global, regional, and national burden of aortic aneurysm, 1990-2017: a systematic analysis of the Global Burden of Disease Study 2017

AIMS

This study aimed at evaluating the age, sex, and country-income patterns in aortic aneurysm disease burden, analysing trends in mortality and years of life lost (YLLs), as well as their causal drivers and risk factors, using the 2017 Global Burden of Diseases, Injuries, and Risk Factors Study (GBD 2017).

METHODS AND RESULTS

We described the temporal, global, and regional (195 countries) patterns of aortic aneurysm (thoracic and abdominal) mortality, YLLs, their drivers [sociodemographic index (SDI), healthcare access and quality index (HAQ index)] and risk factors using the GBD 1990-2017. Correlation and mixed multilevel modelling between aortic aneurysm mortality, YLLs, HAQ index and other variables were applied. From 1990 to 2017, a global declining trend in age-standardized aortic aneurysm mortality was found [2.88 deaths/100 000 (95% uncertainty intervals, UI 2.79 to 3.03) in 1990 and 2.19 deaths/100 000 (95% UI 2.09 to 2.28) in 2017]. Among high-income countries (HICs) a consistent declining Spearman's correlation between age-standardised aortic aneurysm mortality, SDI (HICs; 1990 rho: 0.57, P ≤ 0.001; 2017 rho: 0.41, P = 0.001) and HAQ index was observed (HICs; 1990 rho: 0.50, P <0.001; 2016 rho: 0.35, P = 0.006); in comparison with low- and middle-income countries where correlation trends were weak and mixed. At a global level, higher HAQ index was related with lower aortic aneurysm mortality and YLLs [mortality, coef: -0.05, 95% confidence interval (CI): -0.06, -0.04; YLLs, coef: -0.94, 95% CI: -1.17, -0.71].

CONCLUSIONS

Age-standardized aortic aneurysm mortality declined globally between 1990 and 2017. Globally, age-standardized aortic aneurysm mortality and YLLs were related to changes in SDI and HAQ index levels, while country-level income-related variations were also observed.

Sex Differences in Outcomes Following Ruptured Abdominal Aortic Aneurysm Repair

IMPORTANCE

Sex differences in aortic surgery outcomes are commonly reported. However, data on ruptured abdominal aortic aneurysm (rAAA) repair outcomes in women vs men are limited.

OBJECTIVE

To assess differences in perioperative and long-term mortality following rAAA repair in women vs men.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter, retrospective cohort study was conducted using the Vascular Quality Initiative database, which prospectively captures information on patients who undergo vascular surgery across 796 academic and community hospitals in North America. All patients who underwent endovascular or open rAAA repair between January 1, 2003, and December 31, 2019, were included. Outcomes were assessed up to January 1, 2020.

EXPOSURES

Patient sex.

MAIN OUTCOMES AND MEASURES

Demographic, clinical, and procedural characteristics were recorded, and differences between women vs men were assessed using independent t test and χ2 test. The primary outcomes were in-hospital and 8-year mortality. Associations between sex and outcomes were analyzed using univariable and multivariable logistic regression and Cox proportional hazards regression analysis.

RESULTS

A total of 1160 (21.9%) women and 4148 (78.1%) men underwent rAAA repair during the study period. There was a similar proportion of endovascular repairs in women and men (654 [56.4%] vs 2386 [57.5%]). Women were older (mean [SD] age, 75.8 [9.3] vs 71.7 [9.6] years), more likely to have chronic kidney disease (718 [61.9%] vs 2184 [52.7%]), and presented with ruptured aneurysms of smaller diameters (mean [SD] 68 [18.2] vs 78 [30.2] mm). In-hospital mortality was higher in women (34.4% vs 26.6%; odds ratio, 1.44; 95% CI, 1.25-1.66), which persisted after adjusting for demographic, clinical, and procedural characteristics (adjusted odds ratio, 1.36; 95% CI, 1.12-1.66; P = .002). Eight-year survival was lower in women (36.7% vs 49.5%; hazard ratio, 1.25; 95% CI, 1.04-1.50; P = .02), which persisted when stratified by endovascular and open repair. This survival difference existed in both the US and Canada. Variables associated with long-term mortality in women included older age and chronic kidney disease.

CONCLUSIONS AND RELEVANCE

Women who underwent rAAA repair had higher perioperative and 8-year mortality rates following both endovascular and open repair compared with men. Older age and higher rates of chronic kidney disease in women were associated with higher mortality rates. These findings suggest that future studies should assess the reasons for these disparities and whether opportunities exist to improve AAA care for women.

Nationwide Epidemiologic Study of Abdominal Aortic Aneurysms in Korea: A Cross-Sectional Study Using National Health Insurance Review and Assessment Service Data

Purpose

The prevalence and treatment patterns of abdominal aortic aneurysm (AAA) vary according to ethnicity and region. This study analyzed nationwide data on the epidemiology, practice patterns, and mortality rates of AAA in Korea.

Materials and Methods

Data from patients treated for AAA from 2012 to 2016 were extracted from the Korean Health Insurance Review and Assessment (HIRA) database.

Results

A total of 30,766 patients in Korea had treatment codes for AAA and 2,618 patients were treated for ruptured AAA. Of the 6,356 patients treated surgically, 1,849 and 4,507 underwent open surgical aneurysmal repairs (OSAR) or endovascular aneurysmal repairs (EVAR), respectively. The number of surgical treatments performed annually for AAA increased from 1,129 cases in 2012 to 1,501 cases in 2016. The number of EVAR cases increased from 753 to 1,109 during these five years, while the number of OSAR cases remained similar, at 376 and 392, respectively. The 30-day mortality rates after EVAR and OSAR were 4.2% and 10.6%, respectively. The mortality rates were significantly higher in patients with hypertension, dyslipidemia, chronic renal disease, diabetes mellitus, and congestive heart failure. There were significant differences in the prevalence, proportion of EVAR, and mortality rates according to the regional area.

Conclusion

The prevalence of AAA and the proportion of EVAR in Korea increased in the past 5 years, while the rupture rate and the proportion of OSAR remained similar. To minimize mortality and regional discrepancies, nationwide registry and treatment standardization are needed.

Epidemiology of fatal ruptured aortic aneurysms in the United States (1999-2016)

OBJECTIVE

Ruptured aortic aneurysms (rAAs) are associated with high mortality. The purpose of this study was to describe the trends of deaths due to rAA in the United States.

METHODS

A retrospective review of the national death certificate data from the U.S. National Vital Statistics System was done to identify deaths due to rAAs in the United States between 1999 and 2016. Patients aged 15 years or older with rAA as the underlying cause of death as defined by International Classification of Diseases, Tenth Revision codes I71.1 (ruptured thoracic aortic aneurysm [rTAA]), I71.3 (ruptured abdominal aortic aneurysm [rAAA]), I71.5 (ruptured thoracoabdominal aortic aneurysm), and I71.8 (rAA of unspecified site) were included and standardized to U.S. Census data.

RESULTS

A total of 104,458 deaths due to rAAs occurred during the study period. The overall age-adjusted incidence of fatal rAA was 23.3 per 1 million (rAAA, 15.1; rTAA, 3.1; thoracoabdominal, 0.4; and unspecified site, 4.8). The annual incidence of rAA decreased by 68% from 40.0 (1999) to 12.8 (2016) per 1 million (rTAA by -67% from 5.5 to 1.8 and rAAA by -70% from 26.3 to 7.89 per 1 million; P < .001 for all comparisons). These trends were consistent across age groups, sexes, and races. There was a significant seasonal variation in rAA mortality, with higher deaths in winter months compared with summer months. The incidence of rAA is highest in Midwest states (27.1 per 1 million), followed by Northeast (23.8 per 1 million) and West (14 per 1 million) states, and lowest in Southern states (13.6 per 1 million). Only 57% of rAAA deaths occurred in men ≥65 years.

CONCLUSIONS

The incidence of fatal rAA, rTAA, and rAAA drastically decreased in the United States between 1999 and 2016, a trend that was consistent across age groups, sexes, and races. A significant percentage of fatal rAAAs occurred in patients who are not eligible for the current screening program.

Abdominal Aortic Aneurysm: Evolving Controversies and Uncertainties

Abdominal aortic aneurysm (AAA) is defined as a permanent dilatation of the abdominal aorta that exceeds 3 cm. Most AAAs arise in the portion of abdominal aorta distal to the renal arteries and are defined as infrarenal. Most AAAs are totally asymptomatic until catastrophic rupture. The strongest predictor of AAA rupture is the diameter. Surgery is indicated to prevent rupture when the risk of rupture exceeds the risk of surgery. In this review, we aim to analyze this disease comprehensively, starting from an epidemiological perspective, exploring etiology and pathophysiology, and concluding with surgical controversies. We will pursue these goals by addressing eight specific questions regarding AAA: (1) Is the incidence of AAA increasing? (2) Are ultrasound screening programs for AAA effective? (3) What causes AAA: Genes versus environment? (4) Animal models: Are they really relevant? (5) What pathophysiology leads to AAA? (6) Indications for AAA surgery: Are surgeons over-eager to operate? (7) Elective AAA repair: Open or endovascular? (8) Emergency AAA repair: Open or endovascular?

Reparación Endovascular para Aneurisma de Aorta: Revisión Panorámica Sobre su Evidencia en el Mundo y su Aplicación en Latinoamérica

BACKGROUND

Aortic aneurysm (AA) is a pathology with high morbidity and mortality. The management can be expectant, surgical, or through endovascular repair (EVAR). In Latin America the incidence of AA has increased and the analysis of therapeutic options, especially if they are expensive, is fundamental.

OBJECTIVE

To analyze available evidence on the effectiveness, safety and coverage policies of the EVAR.

METHODOLOGY

Panoramic review in the main bibliographical bases (MEDLINE, LILACS, EMBASE, Cochrane Library, DARE) and generic internet searchers, main health technology assessment (HTA) agencies and health insurance companies. Systematic reviews (SR), clinical practice guidelines (CPG), HTA and coverage policies, followed by the identification of primary studies published after the SR search date were included. A search of studies published until November 2015 in English and Spanish was carried out.

RESULTS

311 references were recovered, from which seven SRs were selected, one clinical study and 15 CPGs, consensus or coverage policies and ETS.

CONCLUSIONS

For abdominal AA, high quality evidence showed no differences inlong-term survival with the use of EVAR compared to conventional surgery, but lower early mortality was observed (OR = 0.33, 95% CI 0.20 -0.55). EVAR was associated with a greater need for re-intervention. In the case of other types of AA, further evidence is still required to establish the benefit of EVAR. The CPGs, consensus, HTAs and coverage policies identified, mostly consider open surgery as the treatment of choice, reserving the EVAR for patients with high surgical risk for conventional surgery in the presence of favorable anatomy.

Mortality in endovascular and open abdominal aneurysm repair – trends in Germany

Abstract. Background: We analysed trends in mortality of endovascular (EVAR) and open aortic repair (OAR) in patients hospitalized for abdominal aortic aneurysms (AAA) in Germany from 2005 to 2015. Patients and methods: We used national statistics published by the Federal Statistical Office in Germany to calculate mortality rate of patients hospitalized with ruptured (rAAA, n = 2,448 in 2005, n = 2,180 in 2015) and non-ruptured (iAAA, n = 11,626 in 2005, n = 14,205 in 2015) AAA. Results: Considering only those who were treated with EVAR or OAR, treatment rates of iAAA with EVAR increased to 78.2 % in males and 72.6 % in females in 2015 and treatment rates of rAAA to 36.9 % and 40.7 %, respectively. In cases with iAAA, death rates associated with EVAR decreased in males from 2.1 to 1.1 % (p = 0.0005) in the period from 2005 to 2015 but not in females (1.8 % in 2005 and 2.3 % in 2015, p = 0.8511). Similar trends are seen in cases with rAAA (males 30.1 % and 24 %, p = 0.1034, females 36.4 to 37.3 %, p = 0.8511). Death rates associated with OAR increased in males from 4.7 % in 2005 to 5.7 % in 2015 (p = 0.0103) and tended to increase in females from 6.8 to 8.2 % (p = 0.1476). In cases of rAAA, there were no changes. EVAR treatment rates increased in cases with iAAA in both genders with age, as well as in males with rAAA, but not in females. OAR associated death rates increased with age in rAAA (from around 30 % in the sixth/seventh decade of life to almost 80 % in cases with patients over the age of 90) and in iAAA (from 1.1 to 20 %). Conclusions: The general increase in EVAR procedures in males and females hospitalized for rAAA and iAAA went along with a decrease in in-hospital mortality in males treated with EVAR for iAAA only and an increasing mortality in males treated with OAR for iAAA.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Reporting individual surgeon outcomes does not lead to risk aversion in abdominal aortic aneurysm surgery

INTRODUCTION Reporting surgeons' outcomes has recently been introduced in the UK. This has the potential to result in surgeons becoming risk averse. The aim of this study was to investigate whether reporting outcomes for abdominal aortic aneurysm (AAA) surgery impacts on the number and risk profile (level of fitness) of patients offered elective treatment. METHODS Publically available National Vascular Registry data were used to compare the number of AAAs treated in those centres across the UK that reported outcomes for the periods 2008-2012, 2009-2013 and 2010-2014. Furthermore, the number and characteristics of patients referred for consideration of elective AAA repair at a single tertiary unit were analysed yearly between 2010 and 2014. Clinic, casualty and theatre event codes were searched to obtain all AAAs treated. The results of cardiopulmonary exercise testing (CPET) were assessed. RESULTS For the 85 centres that reported outcomes in all three five-year periods, the median number of AAAs treated per unit increased between the periods 2008-2012 and 2010-2014 from 192 to 214 per year (p=0.006). In the single centre cohort study, the proportion of patients offered elective AAA repair increased from 74% in 2009-2010 to 81% in 2013-2014, with a maximum of 84% in 2012-2013. The age, aneurysm size and CPET results (anaerobic threshold levels) for those eventually offered elective treatment did not differ significantly between 2010 and 2014. CONCLUSIONS The results do not support the assumption that reporting individual surgeon outcomes is associated with a risk averse strategy regarding patient selection in aneurysm surgery at present.

Population-Based Study of Incidence of Acute Abdominal Aortic Aneurysms With Projected Impact of Screening Strategy

BACKGROUND

Current abdominal aortic aneurysm (AAA) screening in men age 65 might have limited impact on overall AAA death rates if incidence is moving to older ages. Up-to-date population-based studies of age-specific incidence, risk factors, and outcome of acute AAA are needed to inform screening policy.

METHODS AND RESULTS

In a prospective, population-based study (Oxfordshire, UK, 2002-2014), the incidence and outcome of acute AAA events were determined. Based on population projections and current incidence trends, the impact of screening strategies in the UK was estimated. Over the 12-year period, 103 incident acute AAA events occurred in the study population of 92 728. Incidence/100 000/year was 55 in men ages 65 to 74 years, but increased to 112 at 75 to 85 and 298 at ≥85, with 66.0% of all events occurring at age ≥75 years. Incidence at ages 65 to 74 was highest in male smokers (274), with 96.4% of events in men <75 years occurring in ever-smokers. Extrapolating rates to the UK population, using trial evidence of screening efficacy, the current UK screening program would prevent 5.6% of aneurysm-related deaths (315 200 scans/year: 1426/death prevented, 121/year-of-life saved). Screening only male smokers age 65 and then all men at age 75 would prevent 21.1% of deaths (247 900 scans/year; 297/death prevented, 34/year-of-life saved). By 2030, 91.0% of deaths will occur at age ≥75, 61.6% at ≥85, and 28.6% in women.

CONCLUSIONS

Given that two thirds of acute AAA occurred at ≥75 years of age, screening older age groups should be considered. Screening nonsmokers at age 65 is likely to have very little impact on AAA event rates.

Age-specific incidence, risk factors and outcome of acute abdominal aortic aneurysms in a defined population

BACKGROUND

Contemporary population-based data on age-specific incidence and outcome from acute abdominal aortic aneurysm (AAA) events are needed to understand the impact of risk factor modification and demographic change, and to inform AAA screening policy.

METHODS

In a prospective population-based study (Oxfordshire, UK, 2002-2014), event rates, incidence, early case fatality and long-term outcome from all acute AAA events were determined, both overall and in relation to the four main risk factors: smoking, hypertension, male sex and age.

RESULTS

Over the 12-year interval, 103 incident acute AAA events occurred in the study population of 92,728 (men 72·8 per cent; 59·2 per cent 30-day case fatality rate). The incidence per 100,000 population per year was 55 in men aged 65-74 years, but increased to 112 at age 75-84 years and to 298 at age 85 years or above. Some 66·0 per cent of all events occurred in those aged 75 years or more. The incidence at 65-74 years was highest in male smokers (274 per 100,000 population per year); 27 (96 per cent) of 28 events in men aged less than 75 years occurred in ever-smokers. Mean(s.d.) age at event was lowest in current smokers (72·2(7·2) years), compared with that in ex-smokers (81·2(7·0) years) and never-smokers (83·3(7·9) years) (P < 0·001). Hypertension was the predominant risk factor in women (diagnosed in 93 per cent), with 20 (71 per cent) of all 28 events in women occurring in those aged 75 years or above with hypertension. The 30-day case fatality rate increased from 40 per cent at age below 75 years to 69 per cent at age 75 years or more (P = 0·008).

CONCLUSION

Two-thirds of acute AAA events occurred at age 75 years or above, and more than 25 per cent of events were in women. Taken with the strong associations with smoking and hypertension, these findings could have implications for AAA screening.

Guilt by association: paradigm for detecting a silent killer (thoracic aortic aneurysm)

Recent studies have confirmed a close association between various medical conditions (intracranial aneurysm, abdominal aortic aneurysm, temporal arteritis, autoimmune disorder, renal cysts), certain aortic anatomic variants (bovine aortic arch, direct origin of left vertebral artery from aortic arch, bicuspid aortic valve), and family history of aneurysm disease with thoracic aortic aneurysm and dissection. This paper reviews these associations. We propose to capitalise on these associations as powerful and expanding opportunities to diagnose the virulent but silent disease of thoracic aortic aneurysm. This can be accomplished by recognition of this 'guilt by association' with the other conditions. Thus, patients with associated diseases and anatomic variants should be investigated for silent aortic aneurysms. Such a paradigm holds substantial potential for reducing death from the silent killer represented by thoracic aortic aneurysm disease.

Divergent Roles of Matrix Metalloproteinase 2 in Pathogenesis of Thoracic Aortic Aneurysm

Objective—

Aortic aneurysm, focal dilation of the aorta, results from impaired integrity of aortic extracellular matrix (ECM). Matrix metalloproteinases (MMPs) are traditionally known as ECM-degrading enzymes. MMP2 has been associated with aneurysm in patients and in animal models. We investigated the role of MMP2 in thoracic aortic aneurysm using 2 models of aortic remodeling and aneurysm.

Approach and Results—

Male 10-week-old MMP2-deficient (MMP2 −/− ) and wild-type mice received angiotensin II (Ang II, 1.5 mg/kg/day) or saline (Alzet pump) for 4 weeks. Although both genotypes exhibited dilation of the ascending aorta after Ang II infusion, MMP2 −/− mice showed more severe dilation of the thoracic aorta and thoracic aortic aneurysm. The Ang II–induced increase in elastin and collagen (mRNA and protein) was markedly suppressed in MMP2 −/− thoracic aorta and smooth muscle cells, whereas only mRNA levels were reduced in MMP2 −/− -Ang II abdominal aorta. Consistent with the absence of MMP2, proteolytic activities were lower in MMP2 −/− -Ang II compared with wild-type-Ang II thoracic and abdominal aorta. MMP2-deficiency suppressed the activation of latent transforming growth factor-β and the Smad2/3 pathway in vivo and in vitro. Intriguingly, MMP2 −/− mice were protected against CaCl 2 -induced thoracic aortic aneurysm, which triggered ECM degradation but not synthesis.

Conclusions—

This study reveals the dual role of MMP2 in ECM degradation, as well as ECM synthesis. Moreover, the greater susceptibility of the thoracic aorta to impaired ECM synthesis, compared with vulnerability of the abdominal aorta to aberrant ECM degradation, provides an insight into the regional susceptibility of the aorta to aneurysm development.

Ruptured abdominal aortic aneurysms: decreasing incidence may reduce the impact of a Scottish screening programme

Objectives

The aim of this study was to determine whether there has been a change in annual ruptured abdominal aortic aneurysm admissions and elective abdominal aortic aneurysm repairs in a tertiary vascular surgery department.

Methods

All patients admitted with ruptured abdominal aortic aneurysm from 1987 to 2009 and all undergoing elective abdominal aortic aneurysm repair from 1995 to 2009 were identified from the local surgical audit database. Annual ruptured abdominal aortic aneurysm admissions were calculated and compared in the first and second halves of the study period.

Results

During a 23-year period, 888 patients (male 728, female 158, gender was not documented for two patients) were identified with a ruptured abdominal aortic aneurysm. The annual number of admissions remained relatively constant from 1987 to 1997, with a mean of 44 (95% CI 39.91–48.09). There was a significant decrease to a mean of 33.67 per annum (95% CI 28.53–38.8) in the period 1998–2009, p = 0.006. The mean mortality was 39.8% and showed no significant decrease. There was no increase in the number of elective abdominal aortic aneurysm repairs during the study period.

Conclusions

This study suggests that the incidence of ruptured abdominal aortic aneurysms is decreasing, mirroring the trend seen in other cardiovascular disease. As such, further analysis as to the cost-effectiveness of a Scottish screening programme is merited.

Presence of Renal Simple Cysts Is Associated With Increased Risk of Abdominal Aortic Aneurysms

We compared the incidence of renal simple cysts in 271 patients with abdominal aortic aneurysm (AAA) and 1387 patients without AAA (controls) using computed tomography (CT) angiography and abdominal CT, as a health screening program. The AAA group had significantly higher prevalence of renal simple cysts (55% vs 19%, P = .001) and chronic obstructive pulmonary disease (COPD; 12% vs 1%, P = .011) than the controls. After propensity score matching (n = 164), the prevalence of renal simple cysts was still significantly higher in the AAA group. In multivariate analysis, independent predictors of AAA were age, male gender, smoking history, hypertension, high-sensitivity C-reactive protein, creatinine, COPD, and renal simple cysts. The structural weakness predisposing for renal simple cysts may be associated with the initiation of AAA formation. More studies are needed to determine whether the presence of renal simple cysts can be considered as a risk factor for AAA.

Endovascular treatment of abdominal aortic aneurysms

Patients with abdominal aortic aneurysms (AAAs) are usually treated with endovascular aneurysm repair (EVAR), which has become the standard of care in many hospitals for patients with suitable anatomy. Clinical evidence indicates that EVAR is associated with superior perioperative outcomes and similar long-term survival compared with open repair. Since the randomized, controlled trials that provided this evidence were conducted, however, the stent graft technology for infrarenal AAA has been further developed. Improvements include profile downsizing, optimization of sealing and fixation, and the use of low porosity fabrics. In addition, imaging techniques have improved, enabling better preoperative planning, stent graft placement, and postoperative surveillance. Also in the past few years, fenestrated and branched stent grafts have increasingly been used to manage anatomically challenging aneurysms, and experiments with off-label use of stent grafts have been performed to treat patients deemed unfit or unsuitable for other treatment strategies. Overall, the indications for endovascular management of AAA are expanding to include increasingly complex and anatomically challenging aneurysms. Ongoing studies and optimization of imaging, in addition to technological refinement of stent grafts, will hopefully continue to broaden the utilization of EVAR.

Aneurysm global epidemiology study: public health measures can further reduce abdominal aortic aneurysm mortality

BACKGROUND

Contemporary data from Western populations suggest steep declines in abdominal aortic aneurysm (AAA) mortality; however, international trends are unclear. This study aimed to investigate global AAA mortality trends and to analyze any association with common cardiovascular risk factors.

METHODS AND RESULTS

AAA mortality (1994-2010) using International Classification of Diseases codes were extracted from the World Health Organization mortality database and age standardized. The World Health Organization InfoBase and International Mortality and Smoking Statistics provided risk factor data. Nineteen World Health Organization member states were included (Europe, 14; Australasia, 2; North America, 2; Asia, 1). Regression analysis of temporal trends in cardiovascular risk factors (1946-2010) was done independently for correlations to AAA mortality trends. Global AAA mortality trends show substantial heterogeneity, with the United States and United Kingdom recording the greatest national decline, whereas internationally, male individuals and those <75 years of age demonstrated the greatest reductions. AAA mortality has increased in Hungary, Romania, Austria, and Denmark; therefore, the mortality decline is not universal. A positive linear relationship exists between global trends in systolic blood pressure (P≤0.03), cholesterol (P≤0.03), and smoking prevalence (P≤0.02) in males and females. Body mass index demonstrated a negative linear association with AAA mortality (P≤0.007), whereas fasting blood glucose showed no association.

CONCLUSIONS

AAA mortality has not declined globally, and this study reveals that differences between nations can be explained by variations in traditional cardiovascular risk factors. Declines in smoking prevalence correlate most closely with declines in AAA mortality, and a novel obesity paradox has been identified that requires further investigation. Public health measures could therefore further reduce global AAA mortality, with greatest benefits in the younger age group.

Population-based study of incidence and outcome of acute aortic dissection and premorbid risk factor control: 10-year results from the Oxford Vascular Study

BACKGROUND

Acute aortic dissection is a preventable life-threatening condition. However, there have been no prospective population-based studies of incidence or outcome to inform an understanding of risk factors, strategies for prevention, or projections for future clinical service provision.

METHODS AND RESULTS

We prospectively determined incidence and outcomes of all acute aortic dissections in a population of 92 728 in Oxfordshire, United Kingdom, from 2002 to 2012. Among 155 patients with 174 acute aortic events, 54 patients had 59 thoracoabdominal aortic dissections (52 incident events: 6/100 000, 95% confidence interval, 4-7; 37 Stanford type A, 15 Stanford type B; 31 men, mean age=72.0 years). Among patients with type A incident events, 18 (48.6%) died before hospital assessment (61.1% women). The 30-day fatality rate was 47.4% for patients with type A dissections who survived to hospital admission and 13.3% for patients with type B dissections, although subsequent 5-year survival rates were high (85.7% for type A; 83.3% for type B). Even though 67.3% of patients were on antihypertensive drugs, 46.0% of all patients had at least 1 systolic BP ≥180 mm Hg in their primary care records over the preceding 5 years, and the proportion of blood pressures in the hypertensive range (>140/90 mm Hg) averaged 56.0%. Premorbid blood pressure was higher in patients with type A dissections that were immediately fatal than in those who survived to admission (mean/standard deviation pre-event systolic blood pressure=151.2/19.3 versus 137.9/17.9; P<0.001).

CONCLUSIONS

Uncontrolled hypertension remains the most significant treatable risk factor for acute aortic dissection. Prospective population-based ascertainment showed that hospital-based registries will underestimate not only incidence and case fatality, but also the association with premorbid hypertension.

Trends in aortic aneurysm- and dissection-related mortality in the state of São Paulo, Brazil, 1985-2009: multiple-cause-of-death analysis

BACKGROUND

Aortic aneurysm and dissection are important causes of death in older people. Ruptured aneurysms show catastrophic fatality rates reaching near 80%. Few population-based mortality studies have been published in the world and none in Brazil. The objective of the present study was to use multiple-cause-of-death methodology in the analysis of mortality trends related to aortic aneurysm and dissection in the state of Sao Paulo, between 1985 and 2009.

METHODS

We analyzed mortality data from the Sao Paulo State Data Analysis System, selecting all death certificates on which aortic aneurysm and dissection were listed as a cause-of-death. The variables sex, age, season of the year, and underlying, associated or total mentions of causes of death were studied using standardized mortality rates, proportions and historical trends. Statistical analyses were performed by chi-square goodness-of-fit and H Kruskal-Wallis tests, and variance analysis. The joinpoint regression model was used to evaluate changes in age-standardized rates trends. A p value less than 0.05 was regarded as significant.

RESULTS

Over a 25-year period, there were 42,615 deaths related to aortic aneurysm and dissection, of which 36,088 (84.7%) were identified as underlying cause and 6,527 (15.3%) as an associated cause-of-death. Dissection and ruptured aneurysms were considered as an underlying cause of death in 93% of the deaths. For the entire period, a significant increased trend of age-standardized death rates was observed in men and women, while certain non-significant decreases occurred from 1996/2004 until 2009. Abdominal aortic aneurysms and aortic dissections prevailed among men and aortic dissections and aortic aneurysms of unspecified site among women. In 1985 and 2009 death rates ratios of men to women were respectively 2.86 and 2.19, corresponding to a difference decrease between rates of 23.4%. For aortic dissection, ruptured and non-ruptured aneurysms, the overall mean ages at death were, respectively, 63.2, 68.4 and 71.6 years; while, as the underlying cause, the main associated causes of death were as follows: hemorrhages (in 43.8%/40.5%/13.9%); hypertensive diseases (in 49.2%/22.43%/24.5%) and atherosclerosis (in 14.8%/25.5%/15.3%); and, as associated causes, their principal overall underlying causes of death were diseases of the circulatory (55.7%), and respiratory (13.8%) systems and neoplasms (7.8%). A significant seasonal variation, with highest frequency in winter, occurred in deaths identified as underlying cause for aortic dissection, ruptured and non-ruptured aneurysms.

CONCLUSIONS

This study introduces the methodology of multiple-causes-of-death to enhance epidemiologic knowledge of aortic aneurysm and dissection in São Paulo, Brazil. The results presented confer light to the importance of mortality statistics and the need for epidemiologic studies to understand unique trends in our own population.

Explaining the decrease in mortality from abdominal aortic aneurysm rupture

BACKGROUND

A steady rise in mortality from abdominal aortic aneurysm (AAA) was reported in the 1980s and 1990 s, although this is now declining rapidly. Reasons for the recent decline in mortality from AAA rupture are investigated here.

METHODS

Routine statistics for mortality, hospital admissions and procedures in England and Wales were investigated. All data were age-standardized. Trends in smoking, hypertension and treatment for hypercholesterolaemia (statins), together with regression coefficients for mortality, were available from public sources for those aged at least 65 years. Deaths from ruptured AAA avoided in this age group were estimated by using the IMPACT equation: deaths avoided = (deaths in index year) × (risk factor decline) × β-coefficient.

RESULTS

From 1997, deaths from ruptured AAA have decreased sharply, almost twofold in men. Hospital admissions for elective AAA repair have increased modestly (from 40 to 45 per 100,000 population), attributable entirely to more procedures in those aged 75 years and over (P < 0.001). Admissions for ruptured AAA have declined from 18.6 to 13.5 per 100,000 population, across all ages, with the proportion offered and surviving emergency repair unchanged. From 1997, mortality from ruptured aneurysm in those aged at least 65 years has fallen from 65.9 to 44.6 per 100,000 population. An estimated 8-11 deaths per 100,000 population were avoided by a reduced prevalence of smoking and a similar number from an increase in the number of elective AAA repairs. Estimates for the effects of blood pressure and lipid control are uncertain.

CONCLUSION

The reduction in incidence of ruptured AAA since 1997 is attributable largely to changes in smoking prevalence and increases in elective AAA repair in those aged 75 years and over.

Neuropsychiatric symptoms in patients with aortic aneurysms

Background

Emerging evidence suggests that vascular disease confers vulnerability to a late-onset of depressive illness and the impairment of specific cognitive functions, most notably in the domains of memory storage and retrieval. Lower limb athero-thrombosis and abdominal aortic aneurysm (AAA) have both been previously associated with neuropsychiatric symptoms possibly due to associated intracerebral vascular disease or systemic inflammation, hence suggesting that these illnesses may be regarded as models to investigate the vascular genesis of neuropsychiatric symptoms. The aim of this study was to compare neuropsychiatric symptoms such as depression, anxiety and a variety of cognitive domains in patients who had symptoms of peripheral athero-thrombosis (intermittent claudication) and those who had an asymptomatic abdominal aortic aneurysm AAA.

Methodology/Principal Findings

In a cross-sectional study, 26 participants with either intermittent claudication or AAA were assessed using a detailed neuropsychiatric assessment battery for various cognitive domains and depression and anxiety symptoms (Hamilton Depression and Anxiety Scales). Student t test and linear regression analyses were applied to compare neuropsychiatric symptoms between patient groups. AAA participants showed greater levels of cognitive impairment in the domains of immediate and delayed memory as compared to patients who had intermittent claudication. Cognitive dysfunction was best predicted by increasing aortic diameter. CRP was positively related to AAA diameter, but not to cognitive function. AAA and aortic diameter in particular were associated with cognitive dysfunction in this study.

Conclusions/Significance

AAA patients are at a higher risk for cognitive impairment than intermittent claudication patients. Validation of this finding is required in a larger study, but if confirmed could suggest that systemic factors peculiar to AAA may impact on cognitive function.

Trends in incidence and mortality from abdominal aortic aneurysm in New Zealand

BACKGROUND

This study examined trends in abdominal aortic aneurysm (AAA) incidence and mortality in New Zealand (NZ) and compared these with mortality rates from England and Wales.

METHODS

Cause-specific death data were obtained from the NZ Ministry of Health, UK Office for National Statistics and National Archives (for England and Wales). The NZ National Minimum Data Set provided hospital discharge data from July 1994 to June 2009.

RESULTS

In 2005-2007 the age-standardized AAA mortality rate for men was 33·3 per cent less in NZ than in England and Wales (5·21 versus 7·81 per 100 000), whereas for women it was 9·8 per cent less (2·12 versus 2·35 per 100 000). Standardized mortality rates in NZ fell by 53·0 per cent for men and 34·1 per cent for women from 1991 to 2007. Between 1991-1992 and 2005-2007 the probability of a 65-year-old dying from an AAA fell by 28·2 per cent (from 1·872 to 1·344 per cent) in men, and by 6·3 per cent (from 0·837 to 0·784 per cent) in women. New AAA admission and hospital death rates in NZ peaked in 1999 for men, and in 2001 for women, and have since declined sharply. Hospital mortality ratios have also fallen, except for women with a ruptured aneurysm.

CONCLUSION

The burden of AAA disease has been falling since at least 1991 in NZ, and since 1995 in England and Wales. Although survival appears to be improving, most of the reduction is due to lower disease incidence.

Falling rates of hospitalization and mortality from abdominal aortic aneurysms in Australia

BACKGROUND

Studies of the population trends for abdominal aortic aneurysms (AAAs) in the period 1970 to 2000 all indicated that the incidence of AAAs was increasing. It is not known whether this increase has continued. We hypothesized that the incidence of AAAs has begun to fall in Australia.

METHODS

Age-standardized national trends in mortality from AAAs were estimated for the period 1999 to 2006, and hospital separations (deaths or discharges) for AAAs were estimated for the period 1999 to 2008. Poisson regression models were constructed to estimate the relative change over time.

RESULTS

The age-standardized mortality rate from AAAs fell by an average of 6.0% (95% confidence interval [CI], 4.7-7.3) per annum in men and 2.9% (95% CI, 1.0-4.7) in women. After adjusting for age, hospital separations for men decreased by an average of 2.3% (95% CI, 1.4-2.7) per annum for nonruptured AAAs, and 5.9% (95% CI, 5.0-6.6) for ruptured AAAs and for women decreased by an average of 2.2% (95% CI, 1.4-3.0) per annum for nonruptured AAAs, and 5.1% (95% CI, 3.7-6.5) for ruptured AAAs. Ruptured, compared with nonruptured, AAAs were proportionally more common in women compared with men. The age-specific trends in separations from hospital were all downward apart from nonruptured AAAs in individuals aged 80 years and over.

CONCLUSIONS

The rates of separation from hospital and mortality for AAAs in Australia have fallen since 1999. This suggests a true fall in incidence of AAAs. Although the reasons for this are unknown, it has implications for policy decisions about screening.

The management of abdominal aortic aneurysms

Abdominal aortic aneurysms cause about 6000 deaths per year in England and Wales, predominantly from rupture. Significant progress has been made in recent years in developing minimally invasive, endovascular methods of treatment. This review evaluates the current management options for abdominal aortic aneurysm.

Preliminary results of a prospective randomized trial of restrictive versus standard fluid regime in elective open abdominal aortic aneurysm repair

BACKGROUND

Open abdominal aortic aneurysm (AAA) repair is associated with a significant morbidity (primarily respiratory and cardiac complications) and an overall mortality rate of 4% to 10%. We tested the hypothesis that perioperative fluid restriction would reduce complications and improve outcome after elective open AAA repair.

METHODS

In a prospective randomized control trial, patients undergoing elective open infra-renal AAA repair were randomized to a "standard" or "restricted" perioperative fluid administration group. Primary outcome measure was rate of major complications (MC) after AAA repair and secondary outcome measures included: Sequential Organ Failure Assessment Score; FiO2/PO2 ratio; Urinary Albumin/Creatinine Ratio; Length-of-stay in, intensive care unit, high dependency unit, in-hospital. This prospective Randomized Controlled Trial was registered in a publicly accessible database and has the following ID number ISRCTN27753612.

RESULTS

Overall 22 patients were randomized, 1 was excluded on a priori criteria, leaving standard group (11) and restricted group (10) for analysis. No significant difference was noted between groups in respect to age, gender, American Society Anesthesiology class, Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity scores, operation time, and operation blood loss. There were no in-hospital deaths and no 30-day mortality. The cumulative fluid balance on day 5 postoperative was for standard group, 8242 +/- 714 mL, compared with restricted group, 2570 +/- 977 mL, P < 0.01. MC were significantly reduced in the restricted group (n = 10), 1 MC, compared with standard group (n = 11), 14 MC, P < 0.024. Total and postoperative length-of-stay in-hospital was significantly reduced in the restricted group, 9 +/- 1 and 8 +/- 1 days, compared with standard group, 18 +/- 5 and 16 +/- 5 days, P < 0.01 and P < 0.025, respectively.

CONCLUSIONS

Serious complications are common after elective open AAA repair, and we have shown for the first time that a restricted perioperative fluid regimen can prevent MC and significantly reduce overall hospital stay.

Epidemiology, aetiology, risk of rupture and treatment of abdominal aortic aneurysms: does sex matter?

OBJECTIVES

To unravel the extent to which gender plays a role in the epidemiology, aetiology, risk of rupture and treatment of abdominal aortic aneurysms (AAAs) and to give an overview of these factors.

DESIGN, MATERIALS AND METHODS

A literature review was performed in the Medline database and Cochrane Library for gender-specific articles on epidemiology, aetiology, risk of rupture and treatment of AAAs.

RESULTS

Our literature review suggests that the prevalence of AAA in women is underestimated. Regarding aetiology, an oestrogen-mediated reduction in macrophage MMP-9 production seems to be an important mechanism causing gender-related differences in AAA development. We found consensus in the literature that women run a greater risk of rupture compared to men under the current management rules for AAAs. Their treatment mortality also seems to be higher for both elective and ruptured repair.

CONCLUSIONS

Gender-specific guidelines should be put into place for the management of AAAs and awareness for this disease should be increased, both in women themselves and in their doctors.

More patients are treated for nonruptured abdominal aortic aneurysms, but the proportion of women remains unchanged

BACKGROUND

Large variations in the intervention rates for ruptured and nonruptured abdominal aortic aneurysm (AAA) over time have been reported, both decreasing and increasing numbers. Women have been reported to constitute an increasing proportion of patients treated for several manifestations of cardiovascular disease; whether a similar trend is true for AAA is not well understood. This study investigated recent temporal trends in a complete national register regarding the number and type of procedure performed for AAA, and outcome, with special emphasis on gender differences.

METHODS

Data for all individuals treated for nonruptured or ruptured AAA in Sweden (1990 to 2005) were obtained from the Swedish National Board of Health and Welfare (NBHW). A total of 14369 individuals were identified; 2327 (16%) were women. Date and type of intervention, date and cause of death, age, and sex were included in the statistical model.

RESULTS

There was a relative annual increase in interventions for nonruptured AAA; 4% for women (P < .0001) and 2% for men (P < .0001). No significant trends were observed for interventions for rupture during the observation period. No significant increase in the proportion of women was recorded for nonrupture (17%) or rupture (15%). Women had higher crude 30-day mortality rate than men after treatment for both nonruptured (5.7% vs 4.9%) and ruptured (41.9% vs 36.8%) AAA. In a logistic regression model, survival improved over time after intervention for nonrupture (P < .0001) and rupture (P < .0001). Increasing age (P < .0001 for both nonrupture and rupture) but not sex (P = .49 for non rupture and P = .42 for rupture) had a negative influence on mortality.

CONCLUSION

Interventions for nonruptured but not for ruptured AAA increased over time, with an expected rapid increase of endovascular repair in the nonruptured group. The unchanged fraction of women over time possibly reflects the true distribution of AAA between the sexes. The outcome after treatment for both nonruptured and ruptured AAA improved, as anticipated, over time. No increase in mortality among women was recorded after adjustment for age.

The Place of Screening in the Management of Abdominal Aortic Aneurysm

The present method of management of Abdominal Aortic Aneurysms (AAA) is ineffective in preventing AAA rupture. 5000 people still die of AAA in the UK each year. Improvements in surgery can only reduce the mortality in the minority who reach hospital following chance detection, and then only by a few percent.

Screening, with detection in the community and planned treatment can reduce the mortality of the disease by 58%. Screening programmes for AAA have recently been approved for men aged 65 years, in both the UK and the USA. The proposed UK National Screening Programme is outlined briefly

Conclusion:

If the aim of treatment is to reduce the mortality of the disease as a whole, resources would be better spent on screening programmes for AAA, rather than developing increasingly sophisticated operative techniques that could only reduce the overall death from AAA by a few percent.