Impact of chronic renal insufficiency using serum creatinine vs glomerular filtration rate on perioperative clinical outcomes of carotid endarterectomy.

Background: Several studies have reported conflicting results after carotid endarterectomy in patients with chronic renal insufficiency (CRI). However, only a few used glomerular filtration rate (GFR) (Modification of Diet in Renal Disease) in their analysis.

Study Design: Nine hundred and forty carotid endarterectomies that had serum creatinine and GFR were analyzed. Patients were classified as normal (creatinine <1.5 mg/dL or GFR ≥60 mL/min/1.73 m(2)); moderate CRI (creatinine ≥1.5 to 2.9 mg/dL or GFR ≥30 to 59 mL/min/1.73 m(2)), and severe CRI (creatinine ≥3 mg/dL or GFR <30 mL/min/1.73 m(2)).

Results: Using creatinine, perioperative stroke and major adverse event rates for normal, moderate CRI, and severe CRI were 2%, 3.5%, and 11.1% (p = 0.091) and 2.4%, 4.4%, and 11.1% (p = 0.089) vs 1.1%, 3.7%, and 5.4% (p = 0.018) and 1.8%, 4%, and 5.4% (p = 0.086) using GFR. Univariate logistic regression analysis showed that creatinine ≥1.5 mg/dL had an odds ratio of 2.1 for having early stroke/death vs an odds ratio of 3.5 (p = 0.009) for GFR <60 mL/min/1.73 m(2). A multivariate analysis showed that GFR <60 mL/min/1.73 m(2) had an odds ratio for early stroke/death of 3.7 (p = 0.013). Using creatinine, perioperative stroke rates for symptomatic patients were 2.8%, 2.6%, and 0% and 1.6%, 4.1%, and 11.1% (p = 0.045) for asymptomatic patients with normal, moderate CRI, and severe CRI vs 1.6%, 4.7%, and 9.1% for symptomatic patients (p = 0.09) and 1%, 3.2%, and 3.9% for asymptomatic patients (p = 0.074) using GFR. Perioperative major adverse event rates for symptomatic patients using creatinine were 3.2%, 2.6%, and 0%, and for asymptomatic patients 2.1%, 5.4%, and 11.1% (p = 0.048) vs 2.1%, 4.7%, and 9.1% for symptomatic patients and 1.7%, 3.7%, and 7.7% (p = 0.193) for asymptomatic patients using GFR. Moderate/severe CRI also had more cardiac (5.7% vs 2.4%; p = 0.072) and respiratory complications (2.5% vs 0.2%; p = 0.018).

Conclusions: Glomerular filtration rate (Modification of Diet in Renal Disease) was more sensitive in detecting perioperative stroke/death after carotid endarterectomy in patients with CRI. Patients with moderate/severe CRI had more major adverse events than normal patients.