O-127 - AAA PATIENTS HAVE A HIGH EXCESS MORTALITY AFTER SUCCESSFUL REPAIR, WHICH ASSOCIATES WITH A CLEAR SEX-DISPARITY BUT NO AGE-DISPARITY IN BOTH MORTALITY RATES AND CARDIOVASCULAR RISK.

TOPIC:
Abdominal Aortic Aneurysms
AUTHORS:
Bulder R. (Vascular Surgery, Leiden University Medical Center ~ Leiden ~ Netherlands) , Hamming J. (Vascular Surgery, Leiden University Medical Center ~ Leiden ~ Netherlands) , Van Der Vorst J. (Vascular Surgery, Leiden University Medical Center ~ Leiden ~ Netherlands) , Bedene A. (Clinical Epidemiology, Leiden University Medical Center ~ Leiden ~ Netherlands) , Lijfering W. (Clinical Epidemiology, Leiden University Medical Center ~ Leiden ~ Netherlands) , Bastiaannet E. (Epidemiology, biostatistics, and prevention institute, University of Zurich ~ Zurich ~ Switzerland) , Lindeman J. (Vascular Surgery, Leiden University Medical Center ~ Leiden ~ Netherlands)
Introduction:
A previous study on National Swedish data signals a high excess mortality in patients after successful elective abdominal aortic aneurysm (AAA) repair.(1) This excess mortality persists over time, despite improvements in surgical care and intensification of cardiovascular risk management (CVRM). In this, a clear sex-disparity, with higher mortality rates for women, stands out. Although the persistent excess mortality could possibly be explained by more frail patients being considered for treatment in the endovascular era, it is generally attributed to the high cardiovascular risk that accompanies AAA disease.(2) Whether observations from the Swedish population also apply to other populations is still unknown. Furthermore, little is known about potential underlying mechanisms. The aim of this study was to I) quantify the age- and sex-specific excess mortality of AAA patients in the Dutch population and II): estimate the share of cardiovascular death on the excess mortality after elective AAA repair. To that end, a large nationwide dataset, allowing for data stratification, was used with data over 25 years, including patient specific data on cardiovascular risk medication
Methods:
This study was conducted using data from the Dutch National Central Bureau of Statistics, and includes 40730 patients (87% male) who underwent primary elective AAA repair between 1995-2017. Three timeframes were defined for comparison. These included: a period of predominantly open repair with low levels of CVRM (1995-2000, n=11096), a transition period (2001-2011, n=18731), and a period of mainly endovascular aneurysm repair and intensified CVRM (2012-2017, n=10903). Relative survival analyses (1, 3, 5 and 10 years) were applied to evaluate survival between electively treated AAA patients, and a sex- and age-matched general population. This tool allows for quantification of disease specific mortality, whilst adjusting for sex, age, and time-dependent differences in life-expectancy. The contribution of cardiovascular death to overall mortality, and possible changes in the risk of dying from cardiovascular (CV) causes, versus non-cardiovascular (non-CV) causes were evaluated by competitive death analyses (Fine and Grey method). All analyses were stratified by sex and age (<65, 65-69, 70-74, 75-79, >80 years) to address possible sex- and age dependent differences.
Results:
The data show clear improvements in short term (1-year) survival for men in all age categories, but no improvements for women (Figure 1). Long-term survival rates remained steadily compromised for both men and women, and women had an overall lower survival in all age categories (Figure 1). Analysis stratified by age showed an equally compromised survival for younger and older patients (Figure 1). This study is hallmarked by progressive implementation of CVRM. Competitive death analysis showed no shift in the risk of CV versus non-CV death over time for both men and women, nor for different age categories. Women had a significant higher risk of CV death in all age categories (e.g. 3-years cumulative incidence of CV death for period 1, 2, and 3 for women (70-74 years) was 12.60, 12.45, 12.47, versus men (70-74 years) 9.49, 9.48, 9.82 respectively). The risk of CV related death, compared to other causes of death, was higher in men during the first 3.5 years after surgery, whereas for women, this risk persisted up to 6.5 years after surgery (Figure 2).
Conclusion:
This study confirms the high excess mortality of AAA patients after successful elective repair. Although improvements in surgical care resulted in significant lower short-term mortality rates in men but not in women, overall life-expectancy has not improved over time. A particular concern remains the high short- and long-term excess mortality in women, as well as their increased risk of cardiovascular death, existing a longer time after surgery compared to men. The progressive implementation of CVRM did not improve life-expectancy, nor did it affect the proportion of cardiovascular death in overall mortality. This might reflect undertreatment and/or limited efficacy of CVRM in the AAA population. As this is an observational study, it cannot be excluded that observations are influenced by confounders, in particular lowering the of intervention threshold with more frail patients in the more recent years. Yet this study found no differences in mortality between younger and older patients. Future studies should focus on elaborating the basis of the high excess mortality, and best strategies to reduce cardiovascular risk in these patients.
References:
1. Bulder RMA, Talvitie M, Bastiaannet E, Hamming JF, Hultgren R, Lindeman JHN. Long-term Prognosis After Elective Abdominal Aortic Aneurysm Repair is Poor in Women and Men: The Challenges Remain. Ann Surg. 2020; 272:773-778. 2. Kaasenbrood L, Boekholdt SM, van der Graaf Y, Ray KK, Peters RJ, Kastelein JJ, et al. Distribution of Estimated 10-Year Risk of Recurrent Vascular Events and Residual Risk in a Secondary Prevention Population. Circulation 2016; 134:1419-1429.
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