Pre-operative platelet reactivity is a strong, independent predictor of bleeding complications after branched endovascular thoracoabdominal aortic aneurysm repair

Antiplatelet Therapy, Abdominal Aortic Aneurysm Progression, and Clinical Outcomes

Importance

Preclinical studies suggest a potential role for aspirin in slowing abdominal aortic aneurysm (AAA) progression and preventing rupture. Evidence on the clinical benefit of aspirin in AAA from human studies is lacking.

Objective

To investigate the association of aspirin use with aneurysm progression and long-term clinical outcomes in patients with AAA.

Design, Setting, and Participants

This was a retrospective, single-center cohort study. Adult patients with at least 2 available vascular ultrasounds at the Cleveland Clinic were included, and patients with history of aneurysm repair, dissection, or rupture were excluded. All patients were followed up for 10 years. Data were analyzed from May 2022 to July 2023.

Main Outcomes and Measures

Clinical outcomes were time-to-first occurrence of all-cause mortality, major bleeding, or composite of dissection, rupture, and repair. Multivariable-adjusted Cox proportional-hazard regression was used to estimate hazard ratios (HR) for all-cause mortality, and subhazard ratios competing-risk regression using Fine and Gray proportional subhazards regression was used for major bleeding and composite outcome. Aneurysm progression was assessed by comparing the mean annualized change of aneurysm diameter using multivariable-adjusted linear regression and comparing the odds of having rapid progression (annual diameter change >0.5 cm per year) using logistic regression.

Results

A total of 3435 patients (mean [SD] age 73.7 [9.0] years; 2672 male patients [77.5%]; 120 Asian, Hispanic, American Indian, or Pacific Islander patients [3.4%]; 255 Black patients [7.4%]; 3060 White patients [89.0%]; and median [IQR] follow-up, 4.9 [2.5-7.5] years) were included in the final analyses, of which 2150 (63%) were verified to be taking aspirin by prescription. Patients taking aspirin had a slower mean (SD) annualized change in aneurysm diameter (2.8 [3.0] vs 3.8 [4.2] mm per year; P = .001) and lower odds of having rapid aneurysm progression compared with patients not taking aspirin (adjusted odds ratio, 0.64; 95% CI, 0.49-0.89; P = .002). Aspirin use was not associated with risk of all-cause mortality (adjusted HR [aHR], 0.92; 95% CI, 0.79-1.07; P = .32), nor was aspirin use associated with major bleeding (aHR, 0.88; 95% CI, 0.76-1.03; P = .12), or composite outcome (aHR, 1.16; 95% CI, 0.93-1.45; P = .09) at 10 years.

Conclusions

In this retrospective study of a clinical cohort of 3435 patients with objectively measured changes in aortic aneurysm growth, aspirin use was significantly associated with slower progression of AAA with a favorable safety profile.

Platelet function changes in patients undergoing endovascular aortic aneurysm repair: Review of the literature

Patients with abdominal aortic aneurysm (AAA) have a higher risk of cardiovascular (CV) events, which seems to be associated with disturbed platelet (PLT) function. Endovascular aneurysm repair (EVAR) is an emerging, less-invasive treatment alternative to surgical AAA repair. Both platelet function abnormalities in patients with AAA and the effect of EVAR on platelet function are poorly understood. In this review, we aim to fill the gap regarding the effect of EVAR on PLT function in AAA patients by discussing PLT function disturbances in patients with AAA, PLT function changes after EVAR, evidence from clinical studies regarding PLT function before and after EVAR, and antiplatelet or and antithrombotic treatment in patients undergoing EVAR. The goal of our review is to summarize the contemporary knowledge and initiate further studies to better understand PLT function changes in patients undergoing EVAR, optimize the pharmacotherapy before and after EVAR and further improve outcomes in this group of patients.