First Population-Based Screening of Abdominal Aortic Aneurysm in Portugal

Editor's Choice - Vascular Registries Contributing to VASCUNET Collaborative Abdominal Aortic Aneurysm Outcome Projects: A Scoping Review

OBJECTIVE

Vascular surgery registries report on procedures and outcomes to promote patient safety and drive quality improvement. International registries have contributed significantly to the VASCUNET collaborative abdominal aortic aneurysm (AAA) outcome projects. This scoping review aimed to outline the national registries in vascular surgery that currently participate in the VASCUNET collaborative AAA projects.

METHODS

A scoping review of all published VASCUNET AAA studies and validation reports between 1997 and 2024 was undertaken. A survey was conducted among representatives of the international vascular registries contributing to VASCUNET collaborative AAA projects.

RESULTS

Currently, vascular registries from 10 countries (Australia, Denmark, Finland, Hungary, Iceland, New Zealand, Norway, Sweden, Switzerland, and the UK) contribute to the current VASCUNET collaborative AAA project, of which eight have national coverage. In the past, three countries (Germany, Malta, and Italy) have participated in previous VASCUNET AAA projects, and a further three countries (Serbia, Greece, and Portugal) have planned participation in future projects. External validity is high for all current registries, with most reporting rates of > 90%. The majority have internal validation processes to assess data accuracy. VASCUNET mediated validation has also been performed by the consortium for five countries to date (Hungary, Sweden, Denmark, Malta, and Switzerland), for which a high degree of external and internal validity was identified. Most registries have established mechanisms for data linkage with national administrative datasets or insurance claims datasets and contribute to quality improvement through regular reporting to participating centres.

CONCLUSION

National vascular registries from nations participating in the VASCUNET collaborative AAA projects are largely comprehensive, with high case ascertainment rates and good quality data with internal quality assurance. This provides a template for new registries wishing to join the VASCUNET collaboration and a benchmark for future research.

Cost-Effectiveness of the CNIC-Polypill Strategy Compared With Separate Monocomponents in Secondary Prevention of Cardiovascular and Cerebrovascular Disease in Portugal: The MERCURY Study

Background: Cardiovascular (CV) diseases remain a leading and costly cause of death globally. Patients with previous CV events are at high risk of recurrence. Secondary prevention therapies improve CV risk factor control and reduce disease costs. Objectives: To assess the cost-effectiveness of a CV polypill strategy (CNIC-Polypill) compared with the loose combination of monocomponents to improve the control of CV risk factors in patients with previous coronary heart disease or stroke. Methods: A Markov model cost-utility analysis was developed using 4 health states, SMART risk equation, and 3-month cycles for year 1 and annual cycles thereafter, over a lifetime horizon from the perspective of the National Health System in Portugal (base case). The NEPTUNO study, Portuguese registries, mortality tables, official reports, and the literature were consulted to define effectiveness, epidemiological costs, and utility data. Outcomes were costs (estimated in 2020 euros) per life-year (LY) and quality-adjusted LY (QALY) gained. A 4% discount rate was applied. Alternative scenarios and one-way and probabilistic sensitivity analyses tested the consistency and robustness of results. Results: The CNIC-Polypill strategy in secondary prevention provides more LY and QALY, at a higher cost, than monocomponents. The incremental cost-utility ratio is €1557/QALY gained. Assuming a willingness-to-pay threshold of €30 000/QALY gained, there is a 79.7% and a 44.4% probability of the CNIC-Polypill being cost-effective and cost-saving, respectively, compared with the loose combination of monocomponents. Results remain consistent in the alternative scenarios and robust in the sensitivity analyses. Discussion: The model reflects increments in the number of years patients would live and in quality of life with the CNIC-Polypill. The clinical effectiveness of the CNIC-Polypill strategy initially demonstrated in the NEPTUNO study has been recently corroborated in the SECURE trial. The incremental cost of the CNIC-Polypill strategy emerges slightly above the comparator, but willingness-to-pay estimates and sensitivity analyses indicate that the CNIC-Polypill strategy is consistently cost-effective compared with monocomponents and remains within acceptable affordability margins. Conclusion: The CNIC-Polypill is a cost-effective secondary prevention strategy. In patients with histories of coronary heart disease or stroke, the CNIC-Polypill more effectively controls CV risk factors compared with monocomponents.

Editor's Choice - Systematic Review and Meta-Analysis of Normal Infrarenal Aortic Diameter in the General Worldwide Population and Changes in Recent Decades

OBJECTIVE

To analyse the characteristics of normal infrarenal aortic diameter (AD) in the general worldwide population, to examine changes over time, and to investigate geographical differences.

DATA SOURCES

PubMed, Cochrane Library, and Web of Science.

REVIEW METHODS

This was a systematic review and meta-analysis of studies published up to October 2020 describing infrarenal AD measured by ultrasound in the general adult population. The study was conducted in accordance with the PRISMA statement and placed no restrictions on geographical location or year of publication. Studies of individuals pre-selected for certain diseases or risk factors and opportunistic screening were excluded. A random effects model was used to estimate pooled mean AD, and meta-regression analysis was used to study the effects of determinants of AD.

RESULTS

Thirty-two studies were included, reporting data for 941 144 individuals (98% were men). The pooled mean AD was 19.4 mm (95% confidence interval [CI] 18.8 - 20.1), being 20.1 mm (95% CI 19.4 - 20.8) in men and 17.8 mm (95% CI 16.5 - 19.1) in women (p < .001). Outer edge to outer edge (OTO) caliper placement method (p = .015) and body surface area (BSA; p = .010) were significantly associated with larger AD. In men, the largest mean AD was observed in Oceania (p < .001) and the smallest in Asia (p < .020). As none of the studies collected data between 2002 and 2007, the studies were divided into two periods: 2001 and before, and 2008 and after. All recent studies were European, with the diameters being significantly smaller (p = .003) in the latter period (18.3 mm [95% CI 17.5 - 19.1] vs. 20.7 mm [95% CI 19.1 - 22.3]). In the meta-regression models, the reduction in AD over time remained significant after adjustment for potential effect modifiers such as sex, age, geographical area, body size, cardiovascular risk factors, and ultrasound method.

CONCLUSION

Mean infrarenal AD in older European adults has decreased significantly in recent decades. Male sex, BSA, and OTO ultrasound measurement method are associated with larger AD, and geographical differences were observed in men.

Incidental abdominal aortic aneurysms are largely undocumented and unmonitored

BACKGROUND

In countries without organized population screening, incidental detection remains the major form of abdominal aortic aneurysm (AAA) diagnosis. Despite the presumed homogeneity in AAA prevalence, its rate of repair is highly variable, with Portugal treating 2 to 6 times fewer AAA per habitant than other western countries.

OBJECTIVES

To evaluate the detection rate and monitoring of incidental AAA in a multicentre cohort from Portuguese hospitals.

METHODS

All abdominal CT scans performed in men ≥ 65 years old in three major Portuguese hospitals between January and June 2018 were selected for review. CT scans prescribed by the Vascular Surgery or Emergency Departments were excluded. Patients with previously known AAA were also excluded. Subjects with newly detected aneurysms were assessed for the two primary outcomes: the description of the finding by the radiologist in the written report; the effective follow-up recommendations by the prescriber of the CT or by the general practitioner (GP). Patients with newly found AAA that met criteria for monitoring or treatment and failed to be given guidance were contacted and included in surveillance programs.

RESULTS

Overall, 3292 abdominal CT scans were selected for review. A total of 133 newly found aneurysms were detected (4.2% prevalence in the cohort). Of those, 48 cases (36%) were not described by the radiologist in the written report. Further 42 patients (32%) were not successfully oriented by the ordering physician or GP, despite having had their AAA mentioned. Overall, only 32% (n = 42) of the newly diagnosed AAA were correctly identified and referred to monitoring.

CONCLUSIONS

Incidental AAA is a common occurrence in in-hospital abdominal CTs. A significant number is not documented by the radiologist and the vast majority is not referred to monitoring. This could be a major reason for the low elective treatment rate of AAA in Portugal.

Feasibility and Efficiency Study of a Population-Based Abdominal Aortic Aneurysm Screening Program in Men and Women in Spain

BACKGROUND

Based on current evidence, one-time screening for abdominal aortic aneurysm (AAA) in men using ultrasound evaluation reduces mortality related to AAA rupture and is considered cost-effective, although all-cause mortality reduction still remains in question. In Spain, there is no population screening program for AAA, so the aim of our study was to perform a pilot population screening program in our area to assess feasibility and efficiency of an AAA screening program for men and women.

METHODS

A population AAA screening pilot program was performed in a Barcelona area, including 400,000 inhabitants. According to inclusion criteria, 4,730 individuals aged 65 years at the moment of the trial were invited for screening (2,089 men and 2,641 women). Primary care doctors, trained in duplex ultrasound abdominal evaluations, performed an abdominal aortic measurement. Individuals with a previous diagnosis of AAA, limited life expectancy, or wrong contact data were excluded. Participation data, aortic diameters, AAA prevalence, and related cardiovascular risk factors were analyzed. The results were used in a cost-utility model to assess the efficiency of the screening program.

RESULTS

Participation was 50.3% in men and 44% in women. Eleven patients were excluded because of previously diagnosed AAA. Five new asymptomatic AAA were detected in 65-year-old men (0.5% prevalence), all being active smokers. When considering patients excluded for previous AAA diagnosis, the prevalence in 65-year-old men reached 1.4%. Global AAA prevalence in smoking men reached 2.67%. No AAA was detected in women. Subaneurysmal aorta prevalence in men was 2.9% (n = 29), and in women, it was 0.08% (n = 2). A cost-utility analysis model on screening versus no screening retrieved 13,664€ per quality-adjusted life years at a 10-year horizon and 39,455€ per quality-adjusted life years at a 30-year horizon.

CONCLUSIONS

AAA population-based screening by ultrasound evaluation in primary care is logistically feasible in our area. Despite that, AAA prevalence is lower than expected in men, and null in women. Cost-utility model results indicate that a local AAA screening program is only efficient in a 30 years' time horizon. Such inefficient results for a population screening make it necessary to consider other strategies such as opportunistic or subgroup screening in our area.

Nationwide Analysis of Ruptured Abdominal Aortic Aneurysm in Portugal (2000-2015)

OBJECTIVE

Ruptured abdominal aortic aneurysm (rAAA) is a lethal condition that requires acute repair to prevent death. This analysis aims to assess the nationwide trends in rAAA admission, repair and mortality in a country, Portugal, without national screening for AAA.

METHODS

rAAA registered in the hospital administrative database of the National Health Service and all nationally registered deaths due to rAAA based on death certificate data were analysed. Three time periods (2000-2004, 2005-2009, and 2010-2015) were compared in patients ≥ 50 years old to assess the variations over time.

RESULTS

A total of 2 275 patients ≥50 years old with rAAA were identified in the two databases from 2000 to 2015. The age standardised incidence of rAAA was 2.78 ± 0.24/100 000/year in 2000-2004, 3.17 ± 0.39/100 000/year in 2005-2009 and 3.21 ± 0.28/100 000/year in 2010-2015 (p < .001). When comparing the time periods 2000-2004 to 2005-2009, the age standardised rate of admission (n = 1460) increased from 1.57 ± 0.25/100 000/year to 2.24 ± 0.32/100 000/year (p < .001). The operative mortality rates decreased during this time period (from 55.3 ± 4.7% to 48.8 ± 4.7%, p < .001). In 2010-2015, the age standardised rate of admissions due to rAAA decreased (1.98 ± 0.22/100 000/year). Operative mortality remained stable (48.9 ± 6.2%). The rate of patient deaths outside the hospital decreased from the first to the second period (1.21 ± 0.10/100 000/year and 0.93 ± 0.29/100 000/year, respectively) but later increased (1.14 ± 0.22/100 000/year). This resulted in a higher overall rAAA related mortality in Portugal in the third period (2.20 ± 0.18/100 000/year, 2.21 ± 0.27/100 000/year and 2.26 ± 0.26/100 000/year in 2000-2004, 2005-2009, and 2010-2015, respectively, p < .001).

CONCLUSION

Overall, the incidence of rAAA in Portugal has been stable over the past 10 years. The rates of admission, repair, and death due to rAAA repair seem to have reached an inflection point and are now decreasing. Mortality outside the hospital remains a matter of concern, warranting further planning of streamlined transfer networks and vascular surgical departments.

Disparities in Contemporary Treatment Rates of Abdominal Aortic Aneurysms Across Western Countries

OBJECTIVE/BACKGROUND

Several abdominal aortic aneurysm (AAA) screening programs have demonstrated a similar prevalence of this disease in Westerns countries, ranging from 1.2% to 2.8%. However, the annual rate of AAA repair is significantly less even, and its relationship to AAA prevalence is not clear. The objective was to perform a systematic review, describing an international overview in the yearly rate of AAA repairs.

METHODS

The number of elective and emergency AAA repairs was obtained via thorough review of publications indexed in PubMed and Scopus from 2010 to October 2018. Portuguese data were obtained from the national administrative database of health care. Data from the UK were extracted from the National Vascular Registry's 2015 annual report. Each country's population was assessed from published national censuses, thus allowing estimation of the number of AAAs treated per 100,000 habitants.

RESULTS

Data from 14 countries were obtained. The yearly number of elective operations per 100,000 habitants was 2.2 in Hungary, 3.8 in Portugal, 5.3 in Spain, 5.9 in Iceland, 6.5 in Finland, 7.0 in New Zealand, 7.8 in the UK, 10.0 in Denmark, 10.2 in Sweden, 13.3 in the USA, 14.8 in Norway, 15.3 in the Netherlands, 15.6 in Italy, and 17.3 in Germany. The yearly rate of ruptured repairs was 0.5 in Hungary, 1.5 in Portugal, 1.8 in Spain, 1.7 in Iceland, 1.7 in Finland, 1.3 in New Zealand, 1.8 in the UK, 3.3 in Denmark (2013), 2.7 in Sweden (2013), 1.7 in the USA, 2.1 in Norway, 3.1 in the Netherlands, 2.3 in Italy, and 2.7 in Germany.

CONCLUSION

The rate of AAA treatment is highly variable, with a nearly eightfold variance between the countries with the highest and lowest rates of elective repair. Correlation between elective and ruptured repairs was not clear. A deeper understanding of the reasons for the disparities in AAA treatment among Western countries is of the utmost importance.