Effect of chronic kidney disease on long-term survival in asymptomatic patients undergoing carotid endarterectomy

Objectives: This study evaluated the effect of chronic kidney disease (CKD), assessed by preoperative estimated glomerular filtration rate (eGFR) and serum creatinine (Cr), on postoperative outcomes and long-term survival in asymptomatic patients undergoing carotid endarterectomy (CEA). Methods: Data of 678 asymptomatic patients who underwent CEA between 2002 and 2014 were collected. We identified four groups depending on different eGFR values, estimated by the Modification of Diet in Renal Disease (MDRD) formula: group A ($90 mL/min/1.73 m2 ), group B (89-60mL/min/1.73 m2 ), group C (59-30 mL/min/1.73 m2 ), and group D (#29 mL/min/1.73 m2 ), and in two groups based on preoperative Cr values: group 1 (<1.5 mg/dL) and group 2 ($1.5 mg/dL). Primary outcomes were postoperative death, myocardial infarction (MI), and neurologic events (NE) within 30 days after surgery. The secondary outcome was long-term survival for each group. Odds ratios were calculated to evaluate multivariate hazards. Long-term survival of each group was assessed by Kaplan-Meier analysis. Results: One death (0.1%), 20 NEs (2.9%), and 4 MIs (0.6%) within 30 days after CEA were observed. Within this period, the Cr value was not a significant risk factor for morbility and mortality, to the contrary of eGFR value (OR, 1.02; confidence interval, 1.01-1.02; P < .0001). No significant differences in the 30-days outcomes were observed among eGFR and Cr groups. Median follow-up was 55 months (interquartile range, 27-84 months). The 5-year survival rates for groups A, B, C, and D were 98%6 0.02%, 91%6 0.02%, 80%6 0.03% and 58% 6 0.42%, respectively (P < .0001), and 88% 6 0.02% for group 1 and 66% 6 0.08% for group 2 (P < .0001).Conclusions: eGFR and Cr classes are not a reliable method in evaluating postoperative risk of MI and NE after CEA in asymptomatic patients, although preoperative eGFR value influences 30-day morbility and mortality. Both eGFR and Cr groups are reliable predictors of long-term survival.