Using the Risk Analysis Index to Assess Frailty in Veteran Cohort Undergoing Endovascular Aortic Aneurysm Repair

Abstract

Surgical frailty is strongly associated with increased perioperative morbidity and mortality. The Risk Analysis Index (RAI) is a validated frailty score system that has been shown to predict short-term outcomes and long-term mortality in various surgical subspecialties. This study applies the frailty score to the veteran aneurysm population. After obtaining institutional review board approval, Veteran Affairs Surgical Quality Improvement Program data were queried for endovascular repair of intrarenal abdominal aortic aneurysm or dissection Current Procedural Terminology codes (34800, 34803, and 34805). Preoperative variables were used to calculate a RAI score. Patients were placed into three cohorts based on RAI score (nonfrail: ≤20, frail: 21-34, very frail: ≥35). The χ2 test and analysis of variance tests were used compare cohorts. Forward logistic regression modeling was used to determine risks of each cohort. Between 2001 and 2018, 5878 patients underwent endovascular repair of intrarenal abdominal aortic aneurysm or dissection. Of these patients, 99.5% were male with an average age of 71 ± 8 years. The cohorts contained 36.2% (n = 2129), 56.0% (n = 3294), and 7.7% (n = 455) for the nonfrail (RAI of ≤24), frail (RAI = 25-34), and very frail (RAI of ≥35), respectively. Frailty was associated with increased rates of cardiac, pulmonary, renal, and overall complications, death, and increased length of stay (Table I). When risk adjusted, frailty was associated with up to 3.2 times as likely to have any complication and up to 7.3 times as likely to perish within 30 days (Table II). Emergent surgery was associated with an odds ratio for mortality of 14.2 (95% confidence interval, 7.9-25.7; P < .001) and a complication odds ratio of 4.1 (95% confidence interval, 2.8-5.9; P <.001). Frailty as determined by the RAI was associated with postoperative outcomes in a dose-dependent manner. Frailty was associated with higher rates of major cardiac (myocardial infarction, cardiac arrest), pulmonary (pneumonia, failure to wean vent, reintubation), renal (renal insufficiency, renal failure), overall complications, and death. We recommend the use of this frailty index as a screening tool to guide discussions with patients undergoing endovascular aortic aneurysm repair.Table IPostoperative complications based on organ system after endovascular aneurysm repair differentiating into three groups based on Risk Analysis Index (RAI) frailty assessmentNonfrail RAI ≤ 24 (n = 2129)Frail RAI 25-34 (n = 3294)Very Frail RAI ≥ 35 (n = 455)Total (n = 5878)P valueaCardiac (%)10 (0.5)41 (1.2)19 (4.2)70 (1.2)<.001Pulmonary (%)45 (2.1)106 (3.2)42 (9.2)193 (3.3)<.001Renal (%)12 (0.6)50 (1.5)11 (2.4)73 (1.2).004LOS (±SD), days3.6 ± 5.44.8 ± 10.011.4 ± 36.64.9 ± 13.3<.001Complication (%)148 (7.0)327 (7.0)96 (9.9)571 (9.7)<.001Death (%)11 (0.5)38 (1.2)23 (5.1)72 (1.2)<.001LOS, Length of stay; SD, standard deviation.aBased on analysis of variance. Open table in a new tab Table IIOdds ratios for outcomes after endovascular aneurysm repair in the Veteran Affairs Surgical Quality Improvement Program by Risk Analysis Index (RAI)Nonfrail RAI ≤ 24Frail RAI 25-34Very frail RAI ≥ 35OR (95% CI)P valueOR (95% CI)P valueDeathRef2.1 (1.0-4.1)0.037.3 (3.4-15.4)<.001ComplicationRef1.4 (1.1-1.7)0.0023.2 (2.4-4.3)<.001CI, confidence interval; OR, odds ratio; Ref, reference.Odds ratios determined by forward binary logistic regression with covariates of emergency surgery, diabetes, operative time, RAI, steroid use, and smoking. Open table in a new tab