Racial disparities after infrainguinal bypass surgery in hemodialysis patients

Peripheral arterial disease poses a significant burden in the hemodialysis (HD)-dependent population. Race is a known modifier of outcomes after surgical treatment of peripheral arterial disease. A comprehensive evaluation of the effect of race on infrainguinal bypass surgery (IBS) outcomes in HD patients is lacking. In this study, we evaluated the effects of race on long-term IBS outcomes in a large, nationally representative cohort of HD patients.

We studied all HD patients who underwent IBS between January 2007 and December 2011 in the United States Renal Disease System-Medicare matched database. Univariate methods were used to compare patients' demographic and medical characteristics. Kaplan-Meier, univariate and multivariable logistic, and Cox regression analyses were used to evaluate long-term graft patency, limb salvage, and mortality.

There were 9305 IBSs performed in 5188 white (56%), 3354 black (36%), and 763 Hispanic (8%) patients. Of these, 4531 (49%) were femoral-popliteal, 3173 (34%) were femoral-tibial, and 1601 (17%) were popliteal-tibial bypasses. Comparing whites vs blacks vs Hispanics, acute graft failure was 14% vs 16% vs 15% (P = .03), with no statistical difference on multivariate analyses. Primary patency was 52% vs 45% vs 48% at 1 year and 24% vs 21% vs 26% at 4 years (P < .001). Primary assisted patency was 56% vs 48% vs 53% at 1 year and 29% vs 25% vs 32% at 4 years (P < .001); secondary patency was 65% vs 56% vs 60% at 1 year and 40% vs 33% vs 40% at 4 years (P < .001). Limb salvage was 68% vs 60% vs 62% at 1 year and 45% vs 42% vs 40% at 4 years (P < .001). Black patients had higher long-term graft failure (adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 1.05-1.24; P = .001) and limb loss (aHR, 1.27; 95% CI, 1.15-1.40; P < .001) compared with white patients. No differences in graft failure (aHR, 0.99; 95% CI, 0.89-1.11; P = .89) and limb loss (aHR, 1.08; 95% CI, 0.94-1.23; P = .28) were found in Hispanics vs whites. All-cause mortality was lower among blacks (aHR, 0.65; 95% CI, 0.60-0.71; P < .001) and Hispanics (aHR, 0.67; 95% CI, 0.59-0.75; P < .001) compared with whites.

This large study confirms the presence of multidirectional racial disparities in graft durability, limb salvage, and mortality after IBS in HD patients. Black patients had lower graft patency and higher limb loss than white and Hispanic patients, whereas perioperative and long-term mortality was higher in white patients. These results should inform further granular root cause analyses and subsequent action to eliminate these disparities.