Long-Term Impact of Vascular Surgery Stress on Frail Older Patients

Abstract

Frailty is a syndrome where the ability to cope with acute physiological stress is compromised, although it is unclear what impact this stress has on long-term outcomes. Vascular-Physiological and Operative Severity Score for enumeration of Mortality and Morbidity is a validated method for calculating levels of stress associated with vascular procedures. We designed this study to evaluate the long-term impact of different levels of surgical stress among frail older patients undergoing vascular surgery procedures. We identified all independently living patients who underwent prospective frailty assessment followed by an elective vascular surgery procedure captured in the Vascular Quality Initiative registry (endovascular abdominal aortic aneurysm [AAA] repair, thoracic endovascular aortic repair, suprainguinal and infrainguinal bypass, peripheral vascular intervention, carotid endarterectomy, and open AAA) at an academic institution between January 2016 and July 2018. Patient- and procedure-level data were obtained from our institutional data warehouse and Vascular Quality Initiative database, and used to calculate Vascular-Physiological and Operative Severity Score for enumeration of Mortality and Morbidity scores. The association between frailty and composite outcome of any major complications (surgical site infection; graft thrombectomy; major amputation; adverse cardiac, pulmonary, or neurologic event; acute renal insufficiency; and/or reoperation related to the index procedure), nonhome living status, or death within 1year after low-, medium-, and high-stress vascular procedures was evaluated using bivariate and logistic regression models. A total of 163 patients were identified (70% male, mean age 67.8years) who underwent open AAA repair (6%), endovascular AAA repair (21%), thoracic endovascular aortic repair (7%), suprainguinal bypass (5%), infrainguinal bypass (18%), carotid endarterectomy (18%), or peripheral vascular interventions (25%), which included 44 (27%) patients diagnosed with frailty before surgery. Overall, frail patients had significantly higher rates of the 1-year composite outcome (48% frail versus 27% nonfrail; P=0.012) when compared with nonfrail patients, with a significant dose-dependent effect as the level of stress increased. In comparison, increasing levels of surgical stress had a negligible effect on long-term outcomes among nonfrail patients. The interaction between frailty and high surgical stress was found in adjusted regression models to be a significant predictor of adverse outcomes within 1year after vascular surgery (odds ratio, 3.3; 95% confidence interval, 1.3-8.6; P<0.01). Frail patients who undergo high-stress vascular procedures have a significantly higher rate of complications leading to loss of functional independence and mortality within the year after their surgery. These data suggest that estimates of surgical stress should be incorporated into clinical decision making for frail older patients before and after surgery.