Advertisement
Advertisement
June 2, 2021
Population-Based Analysis Shows Continued Decline in AAA Mortality
June 2, 2021—In a population-based analysis involving multiple countries, Png et al found that abdominal aortic aneurysm (AAA) mortality continued to decrease in association with reductions in smoking and hypertension. The study was published online in European Journal of Vascular and Endovascular Surgery.
Key Findings
- In both males and females, AAA mortality continued to decline in the second decade of the 21st century (2011-2015) at a faster rate than previous time periods (2001-2005 and 2006-2010).
- AAA-related mortality decreased regardless of age group, and there was no evidence to suggest a shift in AAA burden to the older age group.
- There was a statistically significant correlation between smoking prevalence and hypertension and decreases in AAA mortality.
- There was a significant inverse relationship between obesity and AAA mortality and a trend toward an inverse relationship between diabetes and AAA mortality, but this was not statistically significant.
Previous reports noted declines in AAA mortality in the early 21st century, and the investigators sought to determine whether these declines continued into the second decade of the 21st century, evaluate the rate of the decline, and whether there was any difference in AAA mortality by age group (< 65 and > 65 years).
Mortality data were obtained from the World Health Organization (WHO) database based on ICD-10 codes. Population data by country, gender, and year were extracted from the World Development Indicators database. Risk factors analyzed were smoking prevalence and cardiovascular risk factors, specifically hypertension, diabetes, and obesity. Smoking prevalence data were obtained from the Global Burden of Disease Study data set, and data on cardiovascular risk factors were extracted from the WHO’s Global InfoBase. Gross domestic product data from the World Bank’s International Comparison Program were used as a proxy for health and socioeconomic systems.
Countries were included for analysis if they had < 30% data missing and ≥ 10 annual AAA-related deaths. Seventeen countries in four regions met inclusion criteria: Australasia (Australia and New Zealand); Europe (Austria, Denmark, France, Germany, Hungary, Netherlands, Norway, Romania, Spain, Sweden, United Kingdom); North America (Canada, United States); and Asia (Israel, Japan).
Males and females were analyzed separately. Independent regression analysis was performed to assess temporal trends in cardiovascular risk factors and correlations with AAA mortality trends, reported as annual percentage change. Statistical significance was assessed with t statistics.
Decreases in male AAA mortality were seen in 13 of the 17 countries between 2001 and 2015, whereas 11 countries had decreases in female AAA mortality. The United States (–5.24%), the United Kingdom (–4.52%), and the Netherlands (–4.27%) had the largest average annual decrease in male AAA mortality, while four countries (Hungary, Israel, Japan, Romania) had increasing overall male AAA mortality. For female AAA mortality, the largest annual declines were seen in the United Kingdom (–4.65%), the United States (–4.04%), and Australia (–3.02%), while increased mortality was seen in Austria, Denmark, Hungary, Romania, Japan, and Spain. When weighted by population per year, the average change in male and female AAA mortality was –2.84% and –1.64%, respectively.
No significant difference in mortality was seen between younger (< 65 years) and older (> 65 years) patients, with similar results seen when using age 75 years as a cutoff. In both male and female populations, AAA-related mortality strongly correlated with smoking prevalence (males, P = .03X; females, P = .001) and hypertension (males, P = .001; females, P = .01X), whereas it negatively correlated with obesity (males, P = .001; females, P = .001). There was no significant correlation with diabetes; to verify this finding, multiple regression was performed including prevalence of diabetes and obesity, which found that increased male diabetes prevalence was associated with decreased AAA mortality (P = .01X) and female diabetes prevalence remained not statistically significant (P = .27).
The relationship between diabetes, obesity, and AAA outcomes would be better explained by large-scale, longitudinal, population-based studies, and future AAA-related health strategies would benefit from a greater understanding of population-level epidemiology and risk factors, noted the investigators.
ENDOVASCULAR TODAY ASKS…
Investigator Edward Choke, MD, with Sengkang General Hospital in Singapore, was asked to elaborate on the study results:
Smoking and hypertension were found to be strongly associated with AAA mortality. What are the implications of these results in terms of future public health strategies?
The first thing to say is that these were just associations and they do not imply causality. Nevertheless, the associations were significant, biologically plausible, and consistent across the different countries analyzed. In other words, countries with the largest reductions in smoking and hypertension demonstrated the largest reductions in AAA mortality. Public health policies to reduce smoking and hypertension in order to reduce cardiovascular deaths are already in place in many parts of the world. Our findings further affirmed the known links between smoking and hypertension to AAA and provide a strong argument that effective public health strategies against smoking and hypertension will probably reduce AAA mortality in addition to other cardiovascular deaths. This is particularly pertinent for countries with rising trends of AAA mortality that are contrary to the overall global trend. Also, it may be possible that AAA screening programs may achieve better yield if they target populations with a high prevalence of smoking and hypertension.
What does this mean for aortic specialists?
Our findings showed that there has been a continuous—and perhaps even an accelerated—decrease in AAA mortality in most countries in the second decade of the 21st century. Despite this, a small number of countries bucked this trend and in fact showed an increase in AAA mortality. The implications are therefore slightly different for aortic specialists depending on the trend in their countries.
The general trend is encouraging, but there is still a long way to go in efforts to eradicate AAA mortality. For example, in country-level analyses, previous investigators in Finland reported that decreased AAA mortality can be attributed to decreased AAA prevalence, a decreased incidence of AAA rupture, and a shift from open to endovascular aneurysm repair (EVAR) in the treatment of intact AAA, leading to lower 30-day mortality.1 Aortic specialists, with their respective vascular bodies or societies, should be aware of the trends in their countries and, based on these findings, target their policies to modifiable factors to further reduce their countries’ AAA mortality. For example, public health policies targeted at reducing smoking will be useful in countries with high smoking and high AAA prevalence. If AAA prevalence has decreased but the incidence of AAA rupture remains high, then screening for AAA may be the solution. By reducing perioperative mortality of AAA repair, EVAR may also contribute to reducing trends of AAA mortality, and aortic specialists play a key role in offering the best available treatments for their patients with AAAs. There may also be geographic variations in trends within each country, and aortic specialists should therefore be aware of the trends in their particular region so that health care can be efficiently organized in accordance with geographic requirements.
1. Laine MT, Laukontaus SJ, Sund R, et al. A population-based study of abdominal aortic aneurysm treatment in Finland 2000 to 2014. Circulation. 2017;136:1726-1734. doi: 10.1161/CIRCULATIONAHA.117.028259
Advertisement
Advertisement
Find more Literature Highlights.
Browse additional literature summaries, key findings, and investigator commentaries across the vascular interventional field.
Read More