Racial and ethnic differences in presentation severity and postoperative outcomes in vascular surgery

BACKGROUND

We assessed the effect of race and ethnicity on presentation severity and postoperative outcomes in those with abdominal aortic aneurysms (AAAs), carotid artery stenosis (CAS), peripheral arterial disease (PAD), and type B aortic dissection (TBAD).

METHODS

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception until December 2020. Two reviewers independently selected randomized controlled trials and observational studies reporting race and/or ethnicity and presentation severity and/or postoperative outcomes for adult patients who had undergone major vascular procedures. They independently extracted the study data and assessed the risk of bias using the Newcastle-Ottawa scale. The meta-analysis used random effects models to derive the odds ratios (ORs) and risk ratios (RRs) and their corresponding 95% confidence intervals (CIs). The primary outcome was presentation severity stratified by the proportion of patients with advanced disease, including ruptured vs nonruptured AAA, symptomatic vs asymptomatic CAS, chronic limb-threatening ischemia vs claudication, and complicated vs uncomplicated TBAD. The secondary outcomes included postoperative all-cause mortality and disease-specific outcomes.

RESULTS

A total of 81 studies met the inclusion criteria. Black (OR, 4.18; 95% CI, 1.31-13.26), Hispanic (OR, 2.01; 95% CI, 1.85-2.19), and Indigenous (OR, 1.97; 95% CI, 1.39-2.80) patients were more likely to present with ruptured AAAs than were White patients. Black and Hispanic patients had had higher symptomatic CAS (Black: OR, 1.20; 95% CI, 1.04-1.38; Hispanic: OR, 1.32; 95% CI, 1.20-1.45) and chronic limb-threatening ischemia (Black: OR, 1.67; 95% CI, 1.14-2.43; Hispanic: OR, 1.73; 95% CI 1.13-2.65) presentation rates. No study had evaluated the effect of race or ethnicity on complicated TBAD. All-cause mortality was higher for Black (RR, 1.23; 95% CI, 1.01-1.51), Hispanic (RR, 1.90; 95% CI, 1.57-2.31), and Indigenous (RR, 1.24; 95% CI, 1.12-1.37) patients after AAA repair. Postoperatively, Black (RR, 1.54; 95% CI, 1.19-2.00) and Hispanic (RR, 1.54; 95% CI, 1.31-1.81) patients were associated with stroke/transient ischemic attack after carotid revascularization and lower extremity amputation (RR, 1.90; 95% CI, 1.76-2.06; and RR, 1.69; 95% CI, 1.48-1.94, respectively).

CONCLUSIONS

Certain visible minorities were associated with higher morbidity and mortality across various vascular surgery presentations. Further research to understand the underpinnings is required.

Socioeconomic disparities in abdominal aortic aneurysm repair rates and survival

BACKGROUND

Abdominal aortic aneurysm (AAA) is more prevalent in socioeconomically disadvantaged areas. This study investigated socioeconomic disparities in AAA repair rates and survival.

METHODS

The study used ecological and cohort study designs, from 31 672 census areas in England (April 2006 to March 2018), the Index of Multiple Deprivation 2010 as the area-level deprivation indicator, and Poisson, logistic and Cox regression.

RESULTS

Some 77 606 patients (83.4 per cent men) in four age categories (55-64, 65-74, 75-84, 85 or more years) were admitted with AAA from a population aged at least 55 years of 14.7 million. Elective open and endovascular repair rates were 41 (95 per cent c.i. 23 to 61) and 60 (36 to 89) per cent higher respectively among men aged 55-64 years in the most versus least deprived areas by quintile. This differences diminished and appeared to reverse with increasing age, with 26 (-1 to 45) and 25 (13 to 35) per cent lower rates respectively in men aged 85 years or more in the most deprived areas. Men admitted from more deprived areas were more likely to die in hospital without aneurysm repair. Among those who had aneurysm repair, this was more likely to be for a ruptured aneurysm than among men from less deprived areas. For intact aneurysm repair, they were relatively more likely to have this during an emergency admission. The mortality rate after repair was higher for men from more deprived areas, although the hazard diminished with age. Patterns were unclear for women.

CONCLUSION

There were clear socioeconomic disparities in operation rates, mode of presentation, and outcome for AAA surgery. Policies are needed to address these disparities.

AAA Revisited: A Comprehensive Review of Risk Factors, Management, and Hallmarks of Pathogenesis

Despite declining incidence and mortality rates in many countries, the abdominal aortic aneurysm (AAA) continues to represent a life-threatening cardiovascular condition with an overall prevalence of about 2-3% in the industrialized world. While the risk of AAA development is considerably higher for men of advanced age with a history of smoking, screening programs serve to detect the often asymptomatic condition and prevent aortic rupture with an associated death rate of up to 80%. This review summarizes the current knowledge on identified risk factors, the multifactorial process of pathogenesis, as well as the latest advances in medical treatment and surgical repair to provide a perspective for AAA management.

Cost-effectiveness of a population-based AAA screening program for men over 65 years old in Iran

BACKGROUND

Screening program tend to recognized patients in their early stage and consequently improve health outcomes. Cost-effectiveness of the abdominal aortic aneurysm (AAA) screening program has been scarcely studied in developing countries. We sought to evaluate the cost-effectiveness of a screening program for the abdominal aortic aneurysm (AAA) in men aged over 65 years in Iran.

METHODS

A Markov cohort model with 11 mutually exclusive health statuses was used to evaluate the cost-effectiveness of a population-based AAA screening program compared with a no-screening strategy. Transitions between the health statuses were simulated by using 3-month cycles. Data for disease transition probabilities and quality of life outcomes were obtained from published literature, and costs were calculated based on the price of medical services in Iran and the examination of the patients' medical records. The outcomes were life-years gained, the quality-adjusted life-year (QALY), costs, and the incremental cost-effectiveness ratio (ICER). The analysis was conducted for a lifetime horizon from the payer's perspective. Costs and effects were discounted at an annual rate of 3%. Uncertainty surrounding the model inputs was tested with deterministic and probabilistic sensitivity analyses.

RESULTS

The mean incremental cost of the AAA screening strategy compared with the no-screening strategy was $140 and the mean incremental QALY gain was 0.025 QALY, resulting in an ICER of $5566 ($14,656 PPP) per QALY gained. At a willingness-to-pay of 1 gross domestic product (GDP) per capita ($5628) per QALY gained, the probability of the cost-effectiveness of AAA screening was about 50%. However, at a willingness-to-pay of twice the GDP per capita per QALY gained, there was about a 95% probability for the AAA screening program to be cost-effective in Iran.

CONCLUSIONS

The results of this study showed that at a willingness-to-pay of 1 GDP per capita per QALY gained, a 1-time AAA screening program for men aged over 65 years could not be cost-effective. Nevertheless, at a willingness-to-pay of twice the GDP per capita per QALY gained, the AAA screening program could be cost-effective in Iran. Further, AAA screening in high-risk groups could be cost-effective at a willingness-to-pay of 1 GDP per capita per QALY gained.

Mesenteric vascular disease: A population-based cohort study

OBJECTIVES

Mesenteric vascular disease carries a high risk of mortality and morbidity; however, due to obscure clinical presentation, it can be under-recognized. Currently, epidemiology of mesenteric vascular disease remains poorly defined. The aim of this study is to analyze changes in Scottish mortality rates from mesenteric vascular disease overtime.

METHODS

This is a retrospective, longitudinal population-based cohort study using data extracted from death certificates and Scottish Index of Multiple Deprivation. All deaths related to a vascular disorder of the intestines recorded as an underlying cause of death between 1979 and 2014 were identified using International Classification of Disease-9 or International Classification of Disease-10 code groups. Data included demographics and location of death. The residence postcodes were used to classify socio-economic status using the Scottish Index of Multiple Deprivation.

RESULTS

From 2,142,921 deaths over 36 years, 14,530 (0.7%) were due to mesenteric vascular disease with a median (interquartile range) age of 77 and a 2:1 female to male gender ratio. The mean ± standard deviation age significantly increased from 72.6 ± 12.1 in 1979 to 76.8 ± 11.1 in 2014 (p < 0.001, R² = 0.772). Males were consistently younger than females at the time of death. The two lowest Scottish Index of Multiple Deprivation categories accounted for half of the cohort, throughout the study period (p = 0.068). The adjusted death rate per 100,000 population increased from 7.6 in 1979 to 12.1 in 2014.

CONCLUSIONS

The reported death rates of mesenteric vascular disease in Scotland between 1979 and 2014 have nearly doubled. Mesenteric vascular disease affects twice as many women as men and is associated with social deprivation. The increased reporting of mesenteric vascular disease is likely due to increased recognition and incidence. These implications should be considered when planning healthcare provision in Scotland.

Editor's Choice - Inequalities in Abdominal Aortic Aneurysm Screening in England: Effects of Social Deprivation and Ethnicity

OBJECTIVE

Population screening for abdominal aortic aneurysm (AAA) in men is currently ongoing in several countries. The aim was to examine the effects of deprivation and ethnicity on uptake of screening for abdominal aortic aneurysm (AAA) and prevalence of AAA.

METHODS

This was a review of outcomes from a population screening programme using data collected contemporaneously on a bespoke national database. Men aged 65 in two annual cohorts (2013/14 and 2014/15) were invited for AAA screening. Attendance and prevalence of AAA (aortic diameter >2.9 cm) were recorded. Results were compared according to measures of social deprivation and recorded ethnicity.

RESULTS

Some 593,032 men were invited and 461,898 attended for ultrasound screening; uptake 77.9%. Uptake was related to social deprivation: 65.1% in the most deprived decile, 84.1% in the least deprived: OR for least deprived 2.84, 95% CI 2.76-2.92, p<.0001. Men in deprived areas were more likely to actively decline screening: 6% versus 3.8% in the least deprived decile. AAA were twice as common in the most deprived compared with the least deprived decile: OR 2.1, 95% CI 1.77-2.27, p<.0001. AAA were more common in white British men than in black (OR 0.46, 95% CI 0.31-0.71) or Asian (OR 0.18, 95% CI 0.13-0.26) men. There was considerable local variation in all findings.

CONCLUSIONS

Social deprivation affects uptake of AAA screening in 65 year old men. Local factors are the most important determinants of uptake, so solutions to improve uptake must be designed at local, not national level.

Influence of rurality, deprivation and distance from clinic on uptake in men invited for abdominal aortic aneurysm screening

BACKGROUND

Effective abdominal aortic aneurysm (AAA) screening requires high uptake. The aim was to assess the independent association of screening uptake with rurality, social deprivation, clinic type, distance to clinic and season.

METHODS

Screening across Grampian was undertaken by trained nurses in six community and three hospital clinics. Men aged 65 years were invited for screening by post (with 2 further reminders for non-responders). AAA screening data are stored on a national call-recall database. The Scottish postcode directory was used to allocate to all invited men a deprivation index (Scottish Index of Multiple Deprivation), a Scottish urban/rural category and distance to clinic. Multivariable analysis was undertaken.

RESULTS

The cohort included 5645 men invited for screening over 12 months (October 2012 to October 2013); 42·6 per cent lived in urban areas, 38·9 per cent in rural areas and 18·5 per cent in small towns (uptake 87·0, 89·3 and 90·8 per cent respectively). Overall uptake was 88·6 per cent with 76 new AAAs detected: 15·2 (95 per cent c.i. 11·8 to 18·6) per 1000 men screened. Aberdeen city (large urban area) had the lowest uptake (86·1 per cent). Uptake declined with increasing deprivation, with the steepest decline in urban areas. On multivariable analysis, a 1-point increase in deprivation deciles was associated with a 0·08 (95 per cent c.i. 0·06 to 0·11) reduction in the odds of being screened (P < 0·001). Clinic type (community versus hospital), distance to clinic and season were not associated independently with uptake.

CONCLUSION

Both urban residence and social deprivation were associated independently with uptake among men invited for AAA screening.

Smoking, sex, risk factors and abdominal aortic aneurysms: a prospective study of 18 782 persons aged above 65 years in the Southern Community Cohort Study

BACKGROUND

Abdominal aortic aneurysm (AAA) is a leading cause of death in the USA. We evaluated the incidence and predictors of AAA in a prospectively followed cohort.

METHODS

We calculated age-adjusted AAA incidence rates (IR) among 18 782 participants aged ≥65 years in the Southern Community Cohort Study who received Medicare coverage from 1999-2012, and assessed predictors of AAA using multivariable Cox proportional hazards models, overall and stratified by sex, adjusting for demographic, lifestyle, socioeconomic, medical and other factors. HRs and 95% CIs were calculated for AAA in relation to factors ascertained at enrolment.

RESULTS

Over a median follow-up of 4.94 years, 281 cases were identified. Annual IR was 153/100,000, 401, 354 and 174 among blacks, whites, men and women, respectively. AAA risk was lower among women (HR 0.48, 95% CI 0.36 to 0.65) and blacks (HR 0.51, 95% CI 0.37 to 0.69). Smoking was the strongest risk factor (former: HR 1.91, 95% CI 1.27 to 2.87; current: HR 5.55, 95% CI 3.67 to 8.40), and pronounced in women (former: HR 3.4, 95% CI 1.83 to 6.31; current: HR 9.17, 95% CI 4.95 to 17). A history of hypertension (HR 1.44, 95% CI 1.04 to 2.01) and myocardial infarction or coronary artery bypass surgery (HR 1.9, 95% CI 1.37 to 2.63) was negatively associated, whereas a body mass index ≥25 kg/m(2) (HR 0.72; 95% CI 0.53 to 0.98) was protective. College education (HR 0.6, 95% CI 0.37 to 0.97) and black race (HR 0.44, 95% CI 0.28 to 0.67) were protective among men.

CONCLUSIONS

Smoking is a major risk factor for incident AAA, with a strong and similar association between men and women. Further studies are needed to evaluate benefits of ultrasound screening for AAA among women smokers.

Population risk factor estimates for abdominal aortic aneurysm from electronic medical records: a case control study

BACKGROUND

Using abdominal aortic aneurysm (AAA) as a model, this case-control study used electronic medical record (EMR) data to assess known risk factors and identify new associations.

METHODS

The study population consisted of cases with AAA (n =888) and controls (n =10,523) from the Geisinger Health System EMR in Central and Northeastern Pennsylvania. We extracted all clinical and diagnostic data for these patients from January 2004 to December 2009 from the EMR. From this sample set, bootstrap replication procedures were used to randomly generate 2,500 iterations of data sets, each with 500 cases and 2000 controls. Estimates of risk factor effect sizes were obtained by stepwise logistic regression followed by bootstrap aggregation. Variables were ranked using the number of inclusions in iterations and P values.

RESULTS

The benign neoplasm diagnosis was negatively associated with AAA, a novel finding. Similarly, type 2 diabetes, diastolic blood pressure, weight and myelogenous neoplasms were negatively associated with AAA. Peripheral artery disease, smoking, age, coronary stenosis, systolic blood pressure, age, height, male sex, pulmonary disease and hypertension were associated with an increased risk for AAA.

CONCLUSIONS

This study utilized EMR data, retrospectively, for risk factor assessment of a complex disease. Known risk factors for AAA were replicated in magnitude and direction. A novel negative association of benign neoplasms was identified. EMRs allow researchers to rapidly and inexpensively use clinical data to expand cohort size and derive better risk estimates for AAA as well as other complex diseases.

Socioeconomic deprivation and the incidence of 12 cardiovascular diseases in 1.9 million women and men: implications for risk prediction and prevention

Background

Recent experimental evidence suggests that socioeconomic characteristics of neighbourhoods influence cardiovascular health, but observational studies which examine deprivation across a wide range of cardiovascular diseases (CVDs) are lacking.

Methods

Record-linkage cohort study of 1.93 million people to examine the association between small-area socioeconomic deprivation and 12 CVDs. Health records covered primary care, hospital admissions, a myocardial infarction registry and cause-specific mortality in England (CALIBER). Patients were aged ≥30 years and were initially free of CVD. Cox proportional hazard models stratified by general practice were used.

Findings

During a median follow-up of 5.5 years 114,859 people had one of 12 initial CVD presentations. In women the hazards of all CVDs except abdominal aortic aneurysm increased linearly with higher small-area socioeconomic deprivation (adjusted HR for most vs. least deprived ranged from 1.05, 95%CI 0.83–1.32 for abdominal aortic aneurysm to 1.55, 95%CI 1.42–1.70 for heart failure; I² = 81.9%, τ² = 0.01). In men heterogeneity was higher (HR ranged from 0.89, 95%CI 0.75–1.06 for cardiac arrest to 1.85, 95%CI 1.67–2.04 for peripheral arterial disease; I² = 96.0%, τ² = 0.06) and no association was observed with stable angina, sudden cardiac death, subarachnoid haemorrhage, transient ischaemic attack and abdominal aortic aneurysm. Lifetime risk difference between least and most deprived quintiles was most marked for peripheral arterial disease in women (4.3% least deprived, 5.8% most deprived) and men (4.6% least deprived, 7.8% in most deprived); but it was small or negligible for sudden cardiac death, transient ischaemic attack, abdominal aortic aneurysm and ischaemic and intracerebral haemorrhage, in both women and men.

Conclusions

Associations of small-area socioeconomic deprivation with 12 types of CVDs were heterogeneous, and in men absent for several diseases. Findings suggest that policies to reduce deprivation may impact more strongly on heart failure and peripheral arterial disease, and might be more effective in women.

Evaluation of the accuracy of aorta scan BVI 9600 in screening for abdominal aortic aneurysm

OBJECTIVES

Despite a decreasing incidence of abdominal aortic aneurysm (AAA), the cost-effectiveness of AAA ultrasound screening can be improved by reducing the screening costs and increasing the uptake rates. The BVI 9600 (BVI) is a promising tool for this purpose as it is inexpensive and can detect AAA without a trained operator. This study aims to investigate whether the BVI can be used to detect AAA for the purpose of a low-cost outreach screening approach.

METHODS

A total of 142 subjects had their abdominal aortae measured by five sonographers using the BVI and a conventional ultrasound machine. The examination included four anterior-posterior measurements at four equally spaced scanning locations from the xiphisternum to the umbilicus. The measurements produced by each machine were compared using Bland-Altman plots, followed by an analysis of the AAA detection performance.

RESULTS

The BVI measured the aortic diameter to within 0.88-1.56 cm of the true diameter, exceeding the 0.5 cm "clinically acceptable difference" (CAD). Its accuracy was poorer when measuring the aneurysmal aortae (mean difference -0.56 cm, variability 1.72 cm) than normal aortae (mean difference 0.02 cm, variability 0.76 cm). Nine out of 52 aneurysms were not detected due to undersizing measurement and non-visualization of the aortae.

CONCLUSIONS

At present, the BVI is not sufficiently accurate to detect AAA for screening purposes. A number of technical features require improvement.

Neighbourhood deprivation and hospitalization for atrial fibrillation in Sweden

AIMS

Several cardiovascular disorders (CVDs) are strongly associated with socioeconomic disparities and neighbourhood deprivation. However, no study has determined whether neighbourhood deprivation is associated with atrial fibrillation (AF). We aimed to determine whether there is an association between neighbourhood deprivation and hospitalization for AF.

METHODS AND RESULTS

The entire Swedish population aged 25-74 years was followed from 1 January 2000 until hospitalization for AF, death, emigration, or the end of the study period (31 December 2008). Data were analysed by multilevel logistic regression, with individual-level characteristics (age, marital status, family income, educational attainment, migration status, urban/rural status, mobility, and comorbidity) at the first level and level of neighbourhood deprivation at the second level. Neighbourhood deprivation was significantly associated with AF hospitalization rate in women [odds ratio (OR) = 1.40, 95% confidence interval (CI) 1.35-1.47], but not men (OR = 1.01, 95% CI 0.97-1.04). The odds of AF in women living in the most deprived neighbourhoods remained significant after adjustment for age and individual-level socioeconomic characteristics (OR = 1.12, 95% 1.08-1.16). However, in the full model, which took account of age, individual-level socioeconomic characteristics, and comorbidities (chronic lower respiratory diseases, OR = 1.30; type 2 diabetes, OR = 1.32; alcoholism and alcohol-related liver disease, OR = 1.57; hypertension, OR = 2.84; obesity, OR = 1.80; heart failure, OR = 7.40; coronary heart disease, OR = 1.81; and hyperthyroidism, OR = 6.79), the odds of AF did not remain significant in women in the most deprived neighbourhoods (OR = 1.03, 95% CI 0.99-1.07).

CONCLUSION

Neighbourhood deprivation and socioeconomic disparities are not independently associated with hospitalized AF in contrast to many other CVDs.

Implications of attendance patterns in Northern Ireland for abdominal aortic aneurysm screening

INTRODUCTION

Evidence supports the introduction of an abdominal aortic aneurysm (AAA) screening programme. The aims of this study were to estimate future disease patterns and to determine the effect of the proportion attending on the programme's cost-effectiveness.

PATIENTS AND METHODS

The results of the local AAA screening programme were reviewed. Ultrasonic infrarenal aortic diameter of 30 mm was considered aneurysmal. Projected population numbers from the Department of Health and current disease prevalence were used to estimate future number of potential patients. The Multi-centre Aneurysm Screening Study (MASS) Markov model was used to calculate an incremental cost-effectiveness ratio (ICER) and 95% uncertainty intervals (UI), using a 30-year time horizon and 3.5% per annum discount, to determine the effect of attendance.

RESULTS

Men were recruited from August 2004 to May 2010. 13316 were invited for a scan and 5931 (44.5%) attended. 321 AAA were diagnosed, giving a prevalence of 5.4%, while 27 large AAA (0.46%) were repaired. The annual incidence of AAA until 2021 will range from 441 to 526, with an incidence of 40-48 large AAA, with both showing a gradual increase with time. Using this attendance rate, the ICER was calculated at £2350 per life-year gained (95% UI: £1620-£4290), or £3020 per quality-adjusted life-year gained (95% UI: £2080-£5500).

CONCLUSIONS

The prevalence of disease in this local AAA screening was similar to other studies. The low attendance will result in many AAA being missed, but will not impact greatly on the long-term cost-effectiveness.

Pathophysiology and epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are found in up to 8% of men aged >65 years, yet usually remain asymptomatic until they rupture. Rupture of an AAA and its associated catastrophic physiological insult carries overall mortality in excess of 80%, and 2% of all deaths are AAA-related. Pathologically, AAAs are associated with inflammation, smooth muscle cell apoptosis, and matrix degradation. Once thought to be a consequence of advanced atherosclerosis, accruing evidence indicates that AAAs are a focal representation of a systemic disease of the vasculature. Risk factors for AAAs include increasing age, male sex, smoking, and low HDL-cholesterol levels. Familial associations exist and although susceptibility genes have been described on the basis of candidate-gene studies, robust genetic studies have failed to discover causative gene mutations. The surgical management of AAAs has been revolutionized by minimally invasive endovascular repair. Ongoing randomized trials will establish whether endovascular repair confers a survival advantage over open surgery for patients with a ruptured AAA. In many countries, centralization of vascular surgical services has largely been driven by the improved outcomes of elective aneurysm surgery in specialized centers, the widespread adoption of endovascular techniques, and the introduction of screening programs.

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.