A Multivariate Analysis of a Modified Frailty Index on Perioperative Morbidity and Mortality Following Nonemergent Endovascular Aortic Aneurysm Repair

Background

Frailty has become an increasingly recognized perioperative risk stratification tool. While frailty has been strongly correlated with worsening surgical outcomes, the individual determinants of frailty have rarely been investigated in the setting of aortic disease. The aim of this study was to examine the determinants of an 11-factor modified Frailty Index (mFI-11) on mortality and postoperative complications in patients undergoing endovascular aortic aneurysm repair (EVAR).

Methods

Data from the National Surgical Quality Improvement Program database were queried for all patients undergoing nonemergent EVAR between 2005 and 2019. Univariate logistic regression was used to assess associations between mFI-11 variables and complications occurring within 30 days of surgery. Significant variables were then used for multivariate analysis. Variables included in mFI-11 scoring are diabetes, nonindependent functional status, chronic obstructive pulmonary disease, congestive heart failure, myocardial infarction (MI), previous percutaneous coronary intervention, cardiac surgery or angina, hypertension requiring medication, peripheral vascular disease, impaired sensorium, and previous transient ischemic attack or cerebrovascular accident. Overall complications included superficial surgical site infection, deep incisional surgical site infection, deep vein thrombosis, readmission, reintervention, bleeding requiring transfusions, major adverse events (MAEs), and mortality. MAEs included those classified as Clavien-Dindo grade IV, defined as life-threatening complications requiring intensive care unit–level management and single or multiple organ failure. Odds ratios (ORs) were calculated using SPSS 29.

Results

A total of 50,798 patients were identified, resulting in a cohort that was 81% male with an average age of 73.3 ± 8.5 years. Binary regression revealed a significant increase in 30-day mortality (OR = 1.49; 95% confidence interval [CI]: 1.34–1.66; P < 0.001), overall complications (OR = 1.30; 95% CI: 1.25–1.35; P < 0.001), MAEs (OR = 1.55; 95% CI: 1.45–1.65; P < 0.001), stroke (OR = 1.41; 95% CI: 1.15–1.72; P < 0.001), prolonged mechanical ventilation (OR = 1.63; 95% CI: 1.47–1.81; P < 0.001), acute kidney injury (OR = 1.37; 95% CI: 1.20–1.57; P < 0.001), cardiac arrest (OR = 1.71; 95% CI: 1.44–2.04; P < 0.001), and MI (OR = 1.54; 95% CI: 1.35–1.75; P < 0.001) per 1-point increase in mFI-11 score. Multivariate analysis demonstrated that functional dependency was highly associated with increased odds of all outcomes except stroke, cardiac arrest, and MI, and impaired sensorium was highly associated with 30-day mortality.

Conclusion

The mFI-11 is a strong predictor for postoperative complications and mortality in patients undergoing nonemergent EVAR. Measurement of frailty should be considered in the preoperative assessment of patients being evaluated for EVAR, with particular attention to the risk/benefit of aortic repair in those with dependent functional status or impaired sensorium.