Survival and Long-Term Cardiovascular Outcomes after Carotid Endarterectomy in Patients with Chronic Renal Insufficiency

Abstract

Multiple studies have evaluated the perioperative outcomes of patients with chronic renal insufficiency (CRI) undergoing carotid endarterectomy (CEA), generally indicating worse survival and cardiovascular (CV) outcomes, although not consistently and with a paucity of long-term data. The present study addresses the perioperative and long-term impact of CRI on CV events and survival after CEA. A cohort of consecutive patients treated with CEA between January 1, 2000, and December 31, 2008, was analyzed based on medical records and Social Security Death Index. Estimated glomerular filtration rate (GFR) was assessed at baseline. Renal function was used to divide patients into 3 groups: normal (GFR ≥ 60 mL/min/1.73 m(2)), moderate CRI (GFR, 30-59), and severe CRI (GFR <30). The end points were major coronary events, major cerebrovascular events (any stroke), noncardiac vascular interventions (aortic disease, carotid disease, and critical limb ischemia), and mortality. Subgroup analysis based on the presence of preoperative neurologic symptoms was also performed. Survival analysis and Cox regression models were used to assess the effect of baseline predictors. A total of 1,342 CEAs (mean age, 71.2 ± 9.2 years; 55.6% male; 35.3% symptomatic) were performed during the study period with a mean clinical follow-up of 57 months (median, 55; range, 0-155 months). Eight hundred sixty-eight (65%) patients had normal renal function, 414 (31%) had moderate CRI, and 60 (4%) had severe CRI (24 on dialysis). The combined 30-day stroke/death rates for the symptomatic and asymptomatic groups were 3.2% and 1.4% (normal renal function), 5.7% and 2.6% (moderate CRI), and 14.3% and 10.3% (severe CRI), respectively, with the differences being significant only for the severe-CRI group. At 5 years, the severe-CRI group experienced significantly more coronary events (36.9% vs. 16.3%, P < 0.001), more cerebrovascular events (21.6% vs. 6.3%, P < 0.001), and deaths (70.0% vs. 20.3%, P < 0.001), whereas the moderate-CRI group had no significantly different outcomes compared with the normal group, except for mortality (29.8% vs. 20.3%, P < 0.001). After adjusting for all risk factors, severe CRI remained predictive of coronary events (hazard ratio [HR], 2.21; 95% confidence interval [CI], 1.25-3.90; P = 0.007), cerebrovascular events (HR, 3.11; 95% CI, 1.44-6.74; P = 0.004), and mortality (HR, 4.36; 95% CI, 3.00-6.34; P < 0.001). Symptomatology at baseline was predictive of 5-year mortality (HR, 1.43; 95% CI, 1.14-1.81; P = 0.002). The need for noncardiac vascular interventions was equally distributed among all the groups. Severe but not moderate CRI is associated with poor perioperative outcomes and is an independent predictor of CV events and death at 5 years after CEA. The decision to perform CEA in symptomatic and asymptomatic patients with severe CRI should be individualized given the poor reported outcomes.