Dual antiplatelet therapy is not associated with target vessel occlusion or bleeding complications following fenestrated and branched aortic repair.

Abstract

Delphi consensus guidelines recommend utilization of dual antiplatelet therapy (DAPT) following fenestrated and branched aortic repair (F/BEVAR) for target vessel (TV) patency. Limited data supports this recommendation with little known about the impact on bleeding events and optimal treatment duration. This study assesses TV occlusion and bleeding complications based on antithrombotic regimens following F/BEVAR. Patients who underwent F/BEVAR for treatment of thoracoabdominal aortic aneurysms (TAAA) at a single institution from 2012-2024 were assessed. Discharge regimens were maintained for 3-months, long-term regimens were assessed at 6-months and included single antiplatelet therapy (SAPT), DAPT, and anticoagulation (AC)+SAPT. TV occlusion and bleeding events within 3-months were assessed with univariate analysis. Long-term outcomes including TV occlusion, bleeding events, reintervention, and survival were compared with Kaplan-Meier analysis. Multivariate Cox regression analysis was performed for TV occlusion, bleeding events, and survival. 235 patients were included; 53% were discharged on SAPT, 28% on DAPT, and 19% on AC+SAPT. During the study period, there were 35 TV occlusions (3.8%) - including 31 branches (6.1%), 4 fenestrations (1.0%), 29 renal (6.4%), and 5 mesenteric targets (1.1%). In total, nine TV occlusions (26%) occurred in the setting of documented cessation and/or non-compliance with prescribed antiplatelet medication regimens. TV occlusion within 3-months did not differ by discharge regimen. In time-to-event analysis, TV occlusions were similar based on discharge (p=0.30) and long-term regimens (p=0.62). At 1-year, 3.4%, 2.5% and 0% of patients discharged on SAPT, DAPT, and AC+SAPT had TV occlusions. In subgroup analysis, there were differences in TV occlusion by type of SAPT prescribed at discharge; 1-year (ASA: 2.1% vs. Plavix: 17.1%, p<0.001). In adjusted analysis, renal targets (HR 7.5, 95% CI 2.9-19.3) and branch configurations (HR 8.3, 95% CI 2.9-23.9) were associated with increased risk for TV occlusion, but medication regimens were not. In total, 41 patients (17%) experienced 51 bleeding events. The majority of bleeding events were minor (73%) and gastrointestinal bleeds (57%). Bleeding events by long-term regimen did not differ in time-to-event analysis (p=0.07). However, in adjusted analysis, long-term AC+SAPT was associated with increased risk of bleeding complications (HR 3.1, 95% CI 1.3-7.6) and decreased long-term survival (HR 2.2, 95% CI 1.1-4.3) compared to SAPT, while DAPT was not. DAPT was not associated with a significant reduction in TV occlusion following F/BEVAR. However, complete cessation of antithrombotic medications increases risk for TV occlusion, highlighting the critical importance of continued adherence to antiplatelet therapy. Bleeding complications are more common with long-term AC+SAPT, but not DAPT. Randomized control trials are needed to further delineate optimal antithrombotic medication regimens given the high-risk comorbidity profile of patients treated and associated impact of TV occlusion and bleeding events on patient outcomes.