An Accumulated Deficits Model Predicts Perioperative and Long-term Adverse Events after Carotid Endarterectomy

Background: There is increasing recognition that decreased reserve in multiple organ systems, known as accumulated deficits (AD), may better stratify perioperative risk than traditional risk indices. We hypothesized that an AD model would predict both perioperative adverse events and long-term survival after carotid endarterectomy (CEA), particularly important in asymptomatic patients. Methods: Consecutive patients undergoing CEA between 1st January 2000 and 31st December 2010 were retrospectively identified. Seven of the deficit items from the Canadian Study of Health and Agingefrailty index (coronary disease, renal insufficiency, pulmonary disease, peripheral vascular disease, heart failure, hypertension, and diabetes) were tabulated for each patient. Predictors of perioperative and long-term outcomes were evaluated using regression analysis. Results: About 1,782 CEAs in 1,496 patients (mean age: 71.3 +/- 9.3 years, 56.3% male, 35.4% symptomatic) were included. The risk of major adverse events (stroke, death, or myocardial infarction) at 30 days for patients with <= 3 deficits was 2.53% vs. 8.81% for patients with >= 4 deficits (P < 0.001). For patients with >= 5 deficits, the risk was 15.18%. Each additional deficit increased the odds of a 30-day major adverse event and hospital stay >2 days by 1.64 (P < 0.001) and 1.15 (P < 0.001), respectively. In multivariate analysis, the presence of >= 4 deficits was more predictive of perioperative major adverse events (odds ratio [OR] = 3.62, P < 0.001) than symptomatology within 6 months (OR = 1.57, P = 0.08) or octogenarian status (OR = 2.00, P = 0.02). Kaplan-Meier analysis showed significantly decreased survival over time with accumulating deficits (P < 0.001). Patients with >= 4 deficits have a hazards ratio for death of 2.6 compared to patients with <= 3 deficits (P < 0.001). Overall survival is estimated at 79.5% (95% confidence interval [CI]: 0.77-0.82) at 5 years in patients with <= 3 deficits versus 52.4% (95% CI: 0.46-0.58) in patients with >= 4 deficits, respectively. In subgroup analysis of asymptomatic patients, 5-year survival for octogenarian male patients with >= 4 deficits was only 26.8%. For asymptomatic males aged 70-79 years with >= 4 deficits, 5-year survival was 59.9%. Conclusions: An AD model is more predictive of perioperative adverse events after CEA than age or symptomatic status. This model remains predictive of long-term survival. In asymptomatic male octogenarians with 4 or more AD, 5-year survival is severely limited.