Temporal trends in abdominal aortic aneurysms: a population-based national cohort study

Introduction: Abdominal Aortic Aneurysm (AAA) is associated with high morbidity and mortality(1). While aneurysm related mortality has declined over time, all-cause mortality remains significant, likely driven by a high prevalence of cardiovascular comorbidity, and not the aneurysmatic disease itself(2). However, there is a scarcity of updated data on comorbidity profile among patients with AAA. Such data are imperative in order to understand the complexity of these patients to optimize treatment of both AAA and individual comorbidities. Therefore, this nationwide cohort study aims to provide up-to-date knowledge on temporal trends in comorbidity burden among patients with AAA.
Methods: Through three national population-based medical registries with comprehensive data on patient demographics and diagnoses, we identified all patients aged 50 years and older with an incident diagnosis of AAA from 2000 through 2018. To ensure lookback for diagnoses, we excluded patients who immigrated within the last year. We then examined changes in demographics and comorbidity profile by time periods (2000–2004, 2005–2009, 2010-2014 and 2015–2018) using descriptive statistics.
Results: We identified 39,547 patients with a diagnosis of AAA from 2000 through 2018. The number of patients increased from 7,212 in 2000-2004 to 11,737 in 2010-2015 (last period was shorter). Mean age at diagnosis ranged from 72.6 to 73.2, and between 25.7 to 27.3% were females (see Table). The proportion of AAA patients with at least one comorbid condition was substantial, and increased from 69.8% in 2000-2004 to 79.0% in 2015-2019; 45.4-50.3% had concomitant disease in other vascular beds. In particular, the proportion of patients with hypertension (23.1 to 44.7%), hypercholesterolemia (5.7 to 20.5%), prior myocardial infarction (10.6% to 14.6%), diabetes (6.4% to 10.2%) and atrial fibrillation (12.0% to 17.0%) increased over time, whereas the proportion with known peripheral arterial disease decreased (17.6% to 12.7%).
Conclusion: This nationwide study revealed an increasing number of patients with AAA over a 19 year period. AAA predominantly affected older patients with a substantial and increasing burden of comorbidity. More than two thirds of patients had at least one other underlying disease and about half had vascular comorbidity. These changes in patient vulnerability emphasize the importance of optimizing prophylactic medical treatment according to international guidelines in order to achieve better outcomes.