A Frailty-Based Risk Score Predicts Morbidity and Mortality After Elective Endovascular Repair of Descending Thoracic Aortic Aneurysms.

Background: Thoracic endovascular aortic repair (TEVAR) has expanded access to descending thoracic aortic aneurysm (DTAA) repair particularly for elderly and frail patients. This high-risk population has limited long-term overall survival, such that appropriate patient selection is required to optimize patient benefit and resource utilization. Our objective is to develop and validate a frailty-based, procedure-specific risk score for patients undergoing elective TEVAR for DTAA.

Methods: Patients undergoing nonemergent TEVAR for DTAA during 2005-2016 were identified in the National Surgical Quality Improvement Program database. Those with concurrent cardiac or open aortic surgery, abdominal visceral intervention, or Zone 0 deployment were excluded. Patients were randomly divided between derivation and validation samples. The primary outcome was 30-day major adverse events (MAE), including mortality and major systemic complications. Using the derivation cohort, variables associated with MAE were identified by univariable analyses. Those with P < 0.05 were included in multivariable logistic regression analysis. Independent procedure-specific and frailty-related risk factors for MAE were used to develop a pragmatic score to assess risk for TEVAR.

Results: Overall, 1,784 patients were included. 14% of the derivation patients had MAE (14% major complications, 4% mortality). Independent risk factors for MAE were primarily associated with markers of frailty and TEVAR extent and complexity and included functional dependence (OR 2.9, 95% CI 1.6-5.4), pulmonary disease (1.6, 1.1-2.4), thoracoabdominal extent (2.2 (1.4-3.4), need for iliac access (2.1, 1.1-3.8), and Zone I or II deployment (OR 1.7, 1.1-2.5). According to their respective beta coefficients, each variable was assigned a single point. Based on total points, patients were stratified as low- (0 points), intermediate- (1 point), or high-risk (≥2 points), with stepwise increases in mortality (0%, 4%, and 9%) and major complications (7%, 11%, and 23%) between strata. Validation patients had similar characteristics, risk strata distribution, and outcomes as the derivation patients, and the risk model had similar performance in both groups.

Conclusions: Markers of frailty and procedure complexity strongly predict MAE after TEVAR for DTAA and can improve patient selection by enabling patient and procedure-specific risk stratification. While TEVAR is safe in low-risk patients, intermediate-risk patients warrant careful discussion of the risks and benefits of aortic intervention; under certain circumstances, high-risk patients may not benefit. Further study is required to define the association between frailty and long-term outcomes.