Perioperative and long-term impact of chronic kidney disease on carotid artery interventions

Abstract

Objective: Chronic kidney disease (CKD) increases morbidity and mortality after vascular procedures and adversely affects late survival of patients. The presence of CKD also confers increased risk of stroke in patients with asymptomatic carotid stenosis. Patients undergoing carotid intervention in the Vascular Study Group of New England database were stratified by CKD status referable to periprocedural and late outcomes.

Methods: All carotid artery stenting and carotid endarterectomies (CEAs) performed from 2003 to 2013 were stratified by CKD severity as mild (estimated glomerular filtration rate [eGFR] >60 mL/min/1.73 m²), moderate (eGFR 30-59), and severe (eGFR <30). The impact of CKD on outcomes of carotid procedures was evaluated using univariate and multivariate methods.

Results: Of 12,568 patients identified, 11,746 (93%) underwent CEA and 822 (7%) underwent carotid artery stenting. Procedures were performed for symptomatic disease in 40%. CKD severity was mild in 58%, moderate in 35%, and severe in 7%. The 30-day stroke rate was very low across all CKD groups (1.76% mild vs 1.84% moderate and 1.34% severe; P = .009). The 30-day mortality increased with worsening renal function (0.4% mild vs 0.9% moderate and 0.9% severe; P = .01). Independent predictors of 30-day stroke or death included American Society of Anesthesiologists (ASA) class 4 or 5 (odds ratio, 2.3; 95% confidence interval [CI], 1.5-3.4; P = .0001). Multivariable Cox hazards regression showed that severe CKD (hazard ratio [HR], 1.8; 95% CI, 1.3-2.6), ASA class 4 or 5 (HR, 1.7; 95% CI, 1.3-2.2), preoperative cortical symptoms (HR, 1.5; 95% CI, 1.2-1.8), history of diabetes (HR, 1.4; 95% CI, 1.1-1.7), and age (HR, 1.03/y; 95% CI, 1.02-1.04) independently (all P < .01) predicted neurologic events or death at median follow-up of 12.7 months (interquartile range, 10.3-15.2 months). CKD did not increase the risk of neurologic events at 1-year follow-up. Predictors (P < .05) of late death included moderate CKD (HR, 1.3; 95% CI, 1.01-1.7), severe CKD (HR, 2.2; 95% CI, 1.6-2.9), ASA class 4 or 5 (HR, 1.6; 95% CI, 1.2-2.0), history of diabetes (HR, 1.4; 95% CI, 1.2-1.7), chronic obstructive pulmonary disease (HR, 1.4; 95% CI, 1.1-1.8), and cortical symptoms (HR, 1.3; 95% CI, 1.05-1.6). The 1-, 5-, and 10-year survival rates decreased with worsening renal function (log-rank test, P < .001), but patients with severe CKD maintained a 71% survival at 5 years.

Conclusions: CKD severity increases risk of perioperative mortality as well as late mortality. Patients with CKD benefit from stroke-free survival especially after CEA. Unlike patients with peripheral arterial occlusive disease, for whom severe CKD reduces median survival to ∼2.5 years, patients with CKD and carotid disease exhibit much longer survival. This suggests that carotid interventions have utility in carefully selected patients with moderate and severe CKD, particularly in symptomatic disease.