Age-based outcomes of autogenous fistulas for hemodialysis access.

BACKGROUND: Hemodialysis (HD) dependence and autogenous fistula use for HD span the spectrum of age. This study examines age-related outcomes of autogenous fistulas for HD access in a large population-based cohort of patients. METHODS: A retrospective cohort study of all patients who initiated HD in the United States Renal Database System (2007-2014). χ2 tests, t tests, Kaplan-Meier, log-rank tests, multivariable logistic, and Cox regression analyses were employed to evaluate access maturation, interventions, patency, and mortality. RESULTS: Of the 303,281 patients studied, 48,892 (16.1%) were younger than 50 years, 55,817 (18.4%) were 50 to 59 years, 79,138 (26.1%) were 60 to 69 years, 75,200 (24.8%) were 70 to 79 years, and 44,234 (14.6%) were 80 years or older. There was a decrease in autogenous fistula maturation with increasing age. Primary patency at 5 years comparing patients <50 vs 50 to 59 vs 60 to 69 vs 70 to 79 vs 80+ years was 24% vs 23% vs 21% vs 20% vs 18% (P < .001). Primary assisted patency at 5 years was 38% vs 40% vs 37% vs 35% vs 33% (P < .001). Secondary patency at 5 years was 48% vs 50% vs 47% vs 45% vs 42% (P < .001). The risk-adjusted analyses revealed a progressive decrease in primary, primary assisted, and secondary patency with increasing age. As expected, patient survival decreased with increasing age. CONCLUSIONS: In this population-based cohort of HD patients, there was a decrease in autogenous fistula maturation, primary patency, primary assisted patency, secondary patency, and patient survival with increasing age. Despite the relative decline in outcomes associated with older age, decisions about arteriovenous access creation in older patients should be individualized, taking overall clinical status and outcomes of alternatives modes of access into consideration.

Impact of Body Mass Index on Outcomes of Autogenous Fistulas for Hemodialysis Access.

BACKGROUND: The prevalence of obesity is increasing in the United States. The treatment of end-stage renal disease (ESRD) via hemodialysis spans the spectrum of body mass index (BMI). This study examines the impact of BMI on outcomes of autogenous fistulas for hemodialysis access in a large population-based cohort of patients. METHODS: A retrospective study of all patients in the prospectively maintained United States Renal Database System who initiated hemodialysis between 2007 and 2014 was performed. Chi-squared test, t-tests, Kaplan-Meier estimates, log-rank tests, multivariable logistic and Cox regression analysis were employed to evaluate access maturation, interventions, patency, and mortality. RESULTS: There were 300,778 patients studied. Of these, 9,394 (3.1%) were underweight, 87,351 (29.1%) were normal weight, 86,101 (28.6%) were overweight, 57,047 (19%) were obese class I, 31,077 (10.3%) were obese class II, and 29,808 (9.9%) were obese class III. There was no significant difference in maturation for patients who were underweight (adjusted hazard ratio [aHR] 0.97, 95% CI 0.89-1.06, P = 0.48), overweight (aHR 1.01, 95% CI 0.97-1.05, P = 0.66), obese class I (aHR 1.05, 95% CI 0.99-1.09, P = 0.22), or obese class II (aHR 1.01, 95% CI 0.94-1.05, P = 0.98 relative to normal weight. However, there was a 6% decrease in maturation for obese class III patients (aHR 0.94, 95% CI 0.89-0.99, P = 0.02) compared to normal weight patients. Primary (aHR 0.93, 95% CI 0.91-0.96, P < 0.001), primary assisted (aHR 0.90, 95% CI 0.88-0.93, P < 0.001), and secondary patency (aHR 0.89, 95% CI 0.86-0.92, P < 0.001) were lower for underweight compared to normal weight patients. There was 8%, 10%, and 7% decrease in primary (aHR 0.92, 95% CI 0.90-0.93, P < 0.001), primary assisted (aHR 0.90, 95% CI 0.88-0.92, P < 0.001), and secondary patency (aHR 0.93, 95% CI 0.91-0.94, P < 0.001) respectively for patients in obese class III compared to patients with normal weight. There was an increase in patient survival with increasing BMI. CONCLUSIONS: In this population-based cohort of hemodialysis-dependent patients, severe obesity was associated with a decrease in fistula maturation. Extremes of BMI were associated with lower patency, but higher BMI was associated with better patient survival. Obese patients nearing ESRD might require earlier referral for arteriovenous fistula (AVF) placement in order to allow for maturation and AVF use at incident hemodialysis.

Outcomes of autogenous fistulas and prosthetic grafts for hemodialysis access in diabetic and nondiabetic patients.

BACKGROUND: This study evaluated the effect of diabetes on outcomes of autogenous fistulas and prosthetic grafts for hemodialysis access in a large population-based cohort of patients. METHODS: A retrospective cohort study was conducted of all patients who initiated hemodialysis in the United States Renal Database System (2007-2014). The χ2 test, Student t-test, Kaplan-Meier analysis, log-rank test, and multivariable logistic and Cox regression analyses were employed to evaluate maturation, interventions, patency, infection, and mortality. RESULTS: The study of 381,622 patients comprised 303,307 (79.5%) autogenous fistulas and 78,315 (20.5%) prosthetic grafts placed in 231,134 (60.6%) diabetic patients and 150,488 (39.4%) nondiabetic patients. There was decrease in maturation for diabetics compared to nondiabetics who received autogenous fistulas (adjusted hazard ratio [aHR], 0.86; 95% confidence interval [CI], 0.83-0.88; P < .001) and prosthetic grafts (aHR, 0.88; 95% CI, 0.83-0.93; P < .001). Comparing diabetics vs nondiabetics, primary patency at 5 years was 19.4% vs 23.5% (P < .001) for autogenous fistulas and 9.1% vs 11.2% (P < .001) for prosthetic grafts. Primary assisted patency at 5 years was 35.2% vs 38.7% (P < .001) for autogenous fistulas and 17.2% vs 19.2% (P = .015) for prosthetic grafts. Secondary patency at 5 years was 44.8% vs 48.6% (P < .001) for autogenous fistulas and 34.1% vs 36.8% (P = .002) for prosthetic grafts. There was 5% decrease in primary patency (aHR, 0.95; 95% CI, 0.94-0.96; P < .001) for diabetics compared to nondiabetics who received autogenous fistulas. There was no difference in primary assisted and secondary patency for autogenous fistulas as well as primary, primary assisted, and secondary patency for prosthetic grafts in comparing diabetic to nondiabetic patients. There was also no significant difference in severe prosthetic graft infection between the groups (aHR, 0.99; 95% CI, 0.92-1.08; P = .90). There was a 19% increase in patient mortality for diabetic relative to nondiabetic autogenous fistula recipients (aHR, 1.19; 95% CI, 1.17-1.20; P < .001) and 12% increase for prosthetic graft recipients (aHR, 1.12; 95% CI, 1.10-1.15; P < .001). CONCLUSIONS: In this population-based cohort of hemodialysis patients, diabetes mellitus was associated with a decrease in patient survival, access maturation, and primary fistula patency. In contrast, there was no association between diabetes and prosthetic graft patency and severe prosthetic graft infection warranting excision.

Racial differences in utilization and outcomes of hemodialysis access in the Unites States.

OBJECTIVE: To evaluate patterns of use and outcomes of arteriovenous fistulas and prosthetic grafts within racial categories in a large population based cohort of hemodialysis (HD) patients in the United States. METHODS: A retrospective analysis of white, black, and Hispanic patients in the prospectively maintained United States Renal Database System who had an autogenous fistula or prosthetic graft placed for HD access between January 2007 and December 2014 was performed. Analysis of variance, χ2, t-tests, Kaplan-Meier, log-rank tests, multivariable logistic, and Cox regression analyses were used to evaluate maturation, patency, infection, and mortality. RESULTS: This study of 359,942 patients, composed of 285,781 autogenous fistulas (79.4%) and 74,161 prosthetic grafts (20.6%) placed in 213,877 white (59.4%), 115,727 black (32.2%), and 30,338 Hispanic (8.4%) patients. There was a 11% increase in the risk-adjusted odds of HD catheter use as bridge to autogenous fistula placement in blacks (adjusted odds ratio, 1.11; 95% confidence interval [CI], 1.08-1.14; P < .001) and a 9% increase in Hispanics (adjusted odds ratio, 1.09; 95% CI, 1.05-1.14; P < .001) compared with whites. Fistula maturation for HD access for whites vs blacks vs Hispanics was 77.0% vs 76.3% vs 77.8% (P = .35). After adjusting for covariates, fistula maturation was higher for blacks (adjusted hazard ratio, 1.09; 95% CI, 1.06-1.13; P < .001) and Hispanics (adjusted hazard ratio, 1.13; 95% CI, 1.06-1.20; P < .001) compared with whites. There was no significant difference in prosthetic graft maturation for blacks and Hispanics compared with whites. Primary, primary-assisted, and secondary patency were highest for Hispanic and least for black autogenous fistula recipients. Primary, primary-assisted, and secondary patency was also highest for Hispanic patients who received prosthetic grafts. Prosthetic grafts were associated with a decrease in patency and patient survival compared with fistulas in all racial categories. Mortality was lower for blacks and Hispanics relative to white patients. Initiation of HD with a catheter and conversion to autogenous fistula was associated with decrease in patency and patient survival compared with initiation with a fistula in all racial groups. CONCLUSIONS: Autogenous fistulas are associated with better patency and patient survival compared with prosthetic grafts for all races studied. The use of HD catheter before fistula placement is more prevalent in Hispanic and black patients and is associated with worse patency and patient survival irrespective of race. Fistula and graft patency is highest for Hispanic patients. Patient survival is higher for Hispanic and black patients relative to whites. These associations suggest potential benefit with initiation of HD via autogenous fistula and minimizing temporizing catheter use, irrespective of race.

Hemodynamic events during carotid stenting are associated with significant periprocedural stroke and adverse events.

BACKGROUND: There are limited data on the impact of carotid angioplasty and stenting (CAS)-related changes in blood pressure, heart rate, and preprocedural medications on periprocedural stroke in contemporary, real-world practice. This study evaluates the risk attributable to the CAS-related hemodynamic events and the impact preprocedural medications have on mitigating this risk in a large, population-based cohort. METHODS: We studied all patients in the Vascular Quality Initiative who underwent CAS between January 2006 and December 2016. Kaplan-Meier, multivariable logistic, and Cox regression analyses were used to evaluate the impact of periprocedural hypertension, hypotension, bradycardia, and medication use on immediate periprocedural stroke (IPPS), 30-day, and 1-year stroke. RESULTS: Of the 13,698 CAS procedures studied, 1239 (9.1%), 1824 (13.3%), and 1333 (9.7%) patients experienced periprocedural hypertension, hypotension, and bradycardia, respectively. IPPS was 3.2% vs 2.1% vs 0.65% (P < .001), comparing patients with periprocedural hypertension vs hypotension vs normotension and 1.4 vs 1.0% (P = .19) for bradycardic vs nonbradycardic patients. Periprocedural hypertension was associated with a four-fold increase in IPPS (adjusted odd ratio [aOR], 3.97; 95% confidence interval [CI], 2.63-5.99; P < .001). periprocedural hypotension and bradycardia were associated with 5.5-fold (aOR, 5.56; 95% CI, 3.24-9.52; P < .001) and 2.3-fold (aOR, 2.31; 95% CI, 1.26-4.25; P = .007) increases in IPPS among patients with carotid symptoms. There was 76% decrease in IPPS for patients who did not experience a periprocedural hemodynamic event (aOR, 0.24; 95% CI, 0.16-0.35; P < .001). Unlike preprocedural beta-blockers and angiotensin-converting enzyme inhibitors, prophylactic antibradyarrhythmic agents conferred a 58% reduction in IPPS among patients with carotid symptoms (aOR, 0.42; 95% CI, 0.23-0.78; P = .006). The periprocedural hemodynamic events were also associated with 7.7-fold increase in myocardial infarction (aOR, 7.70; 95% CI, 4.77-12.45; P < .001), a 2.2-fold increase in 30-day mortality (aOR, 2.24; 95% CI, 1.61-3.12; P < .001), and a 16% increase in length of stay (aOR, 1.16; 95% CI, 0.04-2.28; P = .042). The occurrence of these hemodynamic events is higher in patients with prior cardiac disease and the difference in periprocedural outcomes extended to 1 year. CONCLUSIONS: Periprocedural hemodynamic events are associated with an increase in periprocedural stroke, myocardial infarction, death, and length of stay. Periprocedural hypertension in all patients; hypotension and bradycardia in patients with symptomatic carotid disease are associated with significant increase in IPPS. Prophylactic antibradyarrhythmic agents are associated with decrease in bradycardia and IPPS. These results heighten the need to anticipate and promptly address these CAS-related hemodynamic events, especially in susceptible patients.

Age-related outcomes of arteriovenous grafts for hemodialysis access.

BACKGROUND: The prevalence of end-stage renal disease spans the spectrum of age. Arteriovenous grafts are viable alternatives for hemodialysis access in patients whose anatomy precludes placement of an arteriovenous fistula. This report describes the age-related outcomes after arteriovenous graft placement in a population-based cohort. METHODS: A retrospective cohort study was conducted of all patients who initiated hemodialysis in the U.S. Renal Data System (2007-2014). The χ2 test, t-test, Kaplan-Meier analysis, log-rank test, and multivariable logistic and Cox regression analyses were employed to evaluate access maturation, interventions, patency, and mortality. RESULTS: Of the 78,341 patients studied, 10,150 (13%) were younger than 50 years, 13,167 (16.8%) were 50 to 59 years, 19,975 (25.5%) were 60 to 69 years, 20,307 (25.9%) were 70 to 79 years, and 14,742 (18.8%) were 80+ years. There was no significant difference in access maturation time for patients in the older age categories compared to patients younger than 50 years. Primary patency at 5 years comparing <50 years vs 50 to 59 years vs 60 to 69 years vs 70 to 79 years vs 80+ years was 12% vs 12% vs 9% vs 9% vs 8% (P < .001). Primary assisted patency at 5 years was 20% vs 21% vs 18% vs 17% vs 14% (P < .001). Secondary patency at 5 years was 36% vs 39% vs 36% vs 30% vs 31% (P < .001). There was no significant difference in primary patency (adjusted hazard ratio [aHR], 1.00; 95% confidence interval [CI], 1.00-1.00; P < .001), primary assisted patency (aHR, 1.00; 95% CI, 1.00-1.00; P < .001), and secondary patency (aHR, 1.00; 95% CI, 1.00-1.00; P = .029) with increasing age. However, there was a decrease in severe prosthetic graft infection requiring graft excision (aHR, 0.99; 95% CI, 0.99-0.99; P < .001) and increase in mortality (aHR, 1.03; 95% CI, 1.03-1.03; P < .001) for the older age categories compared with the younger patients. CONCLUSIONS: In this population-based cohort of hemodialysis patients, there was no significant association between older age and prosthetic graft maturation or patency. However, older age was associated with a decrease in severe graft infection and the expected increase in mortality.

Gender-Based Utilization and Outcomes of Autogenous Fistulas and Prosthetic Grafts for Hemodialysis Access.

BACKGROUND: To evaluate gender-based patterns of utilization and outcomes of arteriovenous fistulas (AVFs) and grafts (AVGs) in a population-based cohort of hemodialysis (HD) patients. METHODS: A retrospective analysis of all patients in the United States Renal Data System who had an AVF or AVG placed for HD access (January 2007 to December 2014). Outcomes were access maturation, conduit patency, infection, and mortality. Chi-square, Student's t, Kaplan-Meier, and multivariable Cox regression analyses were employed accordingly. RESULTS: There were 456,693 (57%) males and 341,571 (43%) females who initiated HD via AVF (16%), AVG (4%) and HD catheter (80%). There was a 30% decrease in odds of initiating HD with AVF in females compared with males (adjusted odds ratio [aOR]: 0.70; 95% confidence interval [CI]: 0.69-0.71, P < 0.001). The use of HD catheter as a bridge to AVF was 36% higher in females compared with males (aOR: 1.36; 95% CI: 1.33-1.39, P < 0.001). Preemptive AVF maturation was 78% for males and 76% for females (P < 0.001). The risk-adjusted analyses showed a 7% decrease in AVF maturation comparing females with males (adjusted hazard ratio [aHR]: 0.93; 95% CI: 0.92-0.95, P < 0.001) but no difference in AVG maturation (aHR: 0.99; 95% CI: 0.97-1.01, P = 0.46) After risk adjustment, primary (AVF: aHR-0.87; AVG: aHR-0.96), primary-assisted (AVF: aHR-0.84; AVG: aHR-0.97), and secondary (AVF: aHR-0.85; AVG: aHR-0.98) patency were lower for females compared with males (all P < 0.05). Initiation of HD with a catheter and conversion to AVF was associated with lower patency in males (aHR: 0.29; 95% CI: 0.28-0.29; P < 0.001) and females (aHR: 0.31; 95% CI: 0.30-0.31; P < 0.001) compared with AVF initiates. Patient survival was higher for females compared with males who received AVF (aHR: 1.08; 95% CI: 1.07-1.09; P < 0.001) and AVG (aHR: 1.13; 95% CI: 1.11-1.15; P < 0.001). Initiation with HD catheter and subsequent conversion to AVF was associated with an increase in mortality for males (aHR: 1.45; 95% CI: 1.43-1.47; P < 0.001) and females (aHR: 1.44; 95% CI: 1.44-1.52; P < 0.001) compared with initiation via AVF. There was no significant difference in severe AVG infection comparing females with males (aHR: 1.05; 95% CI: 0.98-1.13; P = 0.16). CONCLUSIONS: Female gender is associated with a lower prevalence of preemptive AVF's, higher utilization of catheters as a bridge to AVF, and lower patency compared with males. There was no difference in access maturation but patient survival was higher for females compared with males.

Hemodialysis and peritoneal dialysis access related outcomes in the pediatric and adolescent population.

BACKGROUND: There is paucity of comparative data on the objective performance of arteriovenous fistulas (AVF), grafts (AVG), hemodialysis (HD) catheter and peritoneal dialysis (PD) catheter in the pediatric population. METHODS: A retrospective analysis of all patients <21 years in the United States Renal Database System who had an AVF, AVG, HD catheter or PD catheter placed for dialysis access between 1/2007 and 12/2014 was performed. Multivariable cox regression was used to evaluate mortality, patency (primary, primary-assisted and secondary), maturation and catheter survival. RESULTS: The 11,575 patients studied comprised of 9445 (82%) HD, 1435 (12%) PD, 528 (4.6%) HD to PD and 167 (1.4%) PD to HD patients. The HD subcohort comprised of 1296 (13.7%) AVF initiates, 199 (2.1%) AVG initiates, 1347 (14.3%) AVF converts after initial HD catheter use, 292 (3.1%) AVG converts and 6311 (67%) patients who persistently utilized HD catheters. There was no difference between PD and HD in patients 0-5 (aHR: 1.36; 95% CI: 0.89-2.07; P = 0.15) and 6-12 years (aHR: 1.05; 95% CI: 0.72-1.52; P = 0.8). However, PD was associated with 73% and 76% increase in mortality relative to HD among patients in the 13-17 (aHR: 1.73; 95% CI: 1.35-2.21; P < 0.001) and 18-20 (aHR: 1.76; 95% CI: 1.38-2.24; P < 0.001) age categories. AVG was associated with 78% increase in mortality compared to AVF (aHR: 1.78; 95% CI: 1.41-2.25; P < 0.001). Persistent use of HD catheters was associated with 29% increase in mortality (aHR: 1.29; 95% CI: 1.07-1.57; P = 0.009) compared to initiation and persistent use of AVF. Conversion from HD catheter to AVF was associated with 66% decrease in mortality compared to persistent HD catheter use (aHR: 0.34; 95% CI: 0.28-0.40; P < 0.001). Primary, primary assisted and secondary patency were higher for AVF compared to AVG. CONCLUSION: There was no difference in risk adjusted mortality between HD and PD in children less than 13 years. PD is associated with higher mortality compared to HD in adolescents. Initiation of HD with AVF is associated with better patency and patient survival relative to AVG and persistent use of HD catheters in pediatric patients irrespective of transplant potential. Conversion from HD catheter to AVF or AVG in patients who inevitably initiate HD with a catheter is associated with better survival compared to persistent HD catheter use. TYPE OF STUDY: Retrospective cohort study. LEVEL OF EVIDENCE: Level II.

Vascular access for hemodialysis in the elderly.

OBJECTIVE: The objective of this study was to compare the outcomes of arteriovenous fistulas (AVFs) with arteriovenous grafts (AVGs) in a large population-based cohort of elderly patients in the United States. METHODS: A retrospective analysis was performed of all patients ≥75 years old in the prospectively maintained United States Renal Database System who had an AVF or AVG placed for hemodialysis (HD) access between January 2007 and December 2011. Outcomes were mortality, conduit patency, maturation, time to catheter-free dialysis, and infection. A χ2 test, Student t-test, Kaplan-Meier analysis, and multivariable Cox regression analysis were employed. RESULTS: Of the 124,421 patients studied, there were 19,173 (15%) AVF initiates, 4480 (4%) AVG initiates, 29,872 (24%) AVF converts, 10,712 (9%) AVG converts, and 59,824 (48%) patients who persisted on HD catheters. Compared with AVF initiates, relative mortality was significantly higher for AVG initiates (adjusted hazard ratio [aHR], 1.24; P < .001), AVF converts (aHR, 1.36; P < .001), AVG converts (aHR, 1.62; P < .001), and catheter-persistent patients (aHR, 2.23; P < .001). Primary patency (aHR, 1.21; P < .001) and primary assisted patency (aHR, 1.31; P < .001) were higher for AVF. Secondary patency was higher for AVGs within the first 4 months (aHR, 1.12; P < .001) but higher for AVFs beyond that time point (aHR, 1.25; P < .001). Maturation rate and median time to maturation were 80% vs 84% (P < .001) and 46 vs 26 days (P < .001) for AVF vs AVG. CONCLUSIONS: Pre-emptive AVF remains the best mode of HD in elderly patients who can tolerate surgery. Patients who cannot tolerate pre-emptive surgery or have to initiate HD on an urgent basis with a catheter should convert to AVF when it is feasible if life expectancy is >4 months. If life expectancy is <4 months, surgical risk and quality of life should be considered in making the decision to persistently dialyze through HD catheter or to convert to AVG.

Utilization, patency, and complications associated with vascular access for hemodialysis in the United States.

BACKGROUND: This study examines the utilization and outcomes of vascular access for long-term hemodialysis in the United States and describes the impact of temporizing catheter use on outcomes. We aimed to evaluate the prevalence, patency, and associated patient survival for pre-emptively placed autogenous fistulas and prosthetic grafts; for autogenous fistulas and prosthetic grafts placed after a temporizing catheter; and for hemodialysis catheters that remained in use. METHODS: We performed a retrospective study of all patients who initiated hemodialysis in the United States during a 5-year period (2007-2011). The United States Renal Data System-Medicare matched national database was used to compare outcomes after pre-emptive autogenous fistulas, preemptive prosthetic grafts, autogenous fistula after temporizing catheter, prosthetic graft after temporizing catheter, and persistent catheter use. Outcomes were primary patency, primary assisted patency, secondary patency, maturation, catheter-free dialysis, severe access infection, and mortality. RESULTS: There were 73,884 (16%) patients who initiated hemodialysis with autogenous fistula, 16,533 (3%) who initiated hemodialysis with prosthetic grafts, 106,797 (22%) who temporized with hemodialysis catheter prior to autogenous fistula use, 32,890 (7%) who temporized with catheter prior to prosthetic graft use, and 246,822 (52%) patients who remained on the catheter. Maturation rate and median time to maturation were 79% vs 84% and 47 days vs 29 days for pre-emptively placed autogenous fistulas vs prosthetic grafts. Primary patency (adjusted hazard ratio [aHR], 1.26; 95% confidence interval [CI], 1.25-1.28; P < .001) and primary assisted patency (aHR, 1.36; 95% CI, 1.35-1.38; P < .001) were significantly higher for autogenous fistula compared with prosthetic grafts. Secondary patency was higher for autogenous fistulas beyond 2 months (aHR, 1.36; 95% CI, 1.32-1.40; P < .001). Severe infection (aHR, 9.6; 95% CI, 8.86-10.36; P < .001) and mortality (aHR, 1.29; 95% CI, 1.27-1.31; P < .001) were higher for prosthetic grafts compared with autogenous fistulas. Temporizing with a catheter was associated with a 51% increase in mortality (aHR, 1.51; 95% CI, 1.48-1.53; P < .001), 69% decrease in primary patency (aHR, 0.31; 95% CI, 0.31-0.32; P < .001), and 130% increase in severe infection (aHR, 2.3; 95% CI, 2.2-2.5; P < .001) compared to initiation with autogenous fistulas or prosthetic grafts. Mortality was 2.2 times higher for patients who remained on catheters compared to those who initiated hemodialysis with autogenous fistulas (aHR, 2.25; 95% CI, 2.21-2.28; P < .001). CONCLUSIONS: Temporizing catheter use was associated with higher mortality, higher infection, and lower patency, thus undermining the highly prevalent approach of electively using catheters as a bridge to permanent access. Autogenous fistulas are associated with longer time to catheter-free dialysis but better patency, lower infection risk, and lower mortality compared with prosthetic grafts in the general population.

Outcomes of Primary and Secondary Carotid Artery Stenting.

BACKGROUND AND PURPOSE: Little is known of the excess risk attributable to secondary carotid angioplasty and stenting (CAS). This study evaluates outcomes of redo-CAS and CAS after prior ipsilateral carotid endarterectomy (CASAPICEA) relative to primary-CAS. METHODS: We studied all patients in the Vascular Quality Initiative, who underwent primary-CAS, CASAPICEA, or redo-CAS (2003-2016). Kaplan-Meier, multivariable logistic and Cox regression analyses were used to evaluate outcomes within 30 days and up to 1 year and identify their predictors. RESULTS: There were 11 742 CAS procedures performed: 8519 (72%) primary-, 2645 (23%) CASAPICEA, and 578 (5%) redo-CAS. Comparing primary-CAS versus CASAPICEA versus redo-CAS, 30-day stroke/death was 2.5% versus 2.0% versus 1.3% for asymptomatic patients (P=0.23) and 5.2% versus 2.6% versus 5.0% for symptomatic patients (P=0.003). CASAPICEA was associated with significantly lower 30-day stroke/death (odds ratio: 0.60; 95% confidence interval: 0.37-0.98; P=0.04) compared with primary-CAS among symptomatic patients. The odds of bradycardia were lower following CASAPICEA (odds ratio: 0.32; 95% confidence interval: 0.26-0.39; P<0.001) and redo-CAS (odds ratio: 0.55; 95% confidence interval: 0.39-0.78; P=0.001) compared with primary-CAS. Similarly, the odds of hypotension were significantly lower in both groups compared with primary-CAS (CASAPICEA: 0.41 [0.35-0.48], P<0.001; redo-CAS: 0.66 [0.50-0.86] P=0.003). There were no significant differences in the hazards of stroke/death at 1 year for CASAPICEA and redo-CAS compared with primary-CAS. CONCLUSIONS: CASAPICEA is associated with significantly lower odds of periprocedural stroke/death compared with primary-CAS among symptomatic patients. CASAPICEA and redo-CAS are associated with significantly lower odds of periprocedural hypotension and bradycardia but higher odds of hypertension compared with primary-CAS.

Perioperative Outcomes of Open versus Endovascular Repair for Ruptured Thoracoabdominal Aneurysms.

BACKGROUND: Open aneurysm repair (OAR) remains the gold standard for treating ruptured thoracoabdominal aortic aneurysms (TAAAs). The aim of our study is to compare the 30-day postoperative outcomes among patients with ruptured TAAA undergoing OAR versus endovascular aneurysm repair. METHODS: Using the National Surgical Quality Improvement Program database (2006-2015), we identified patients who underwent OAR and endovascular repair for a ruptured TAAA. Postoperative outcomes of interest included mortality, renal failure, stroke, and cardiopulmonary complications. The independent impact of repair type on each of the aforementioned outcomes was examined after robust risk adjustment. RESULTS: A total of 206 ruptured TAAA repairs were performed [OAR 144 (70%) versus endovascular 62 (30%)]. The majority of patients were male (53 %) and white (77%). The comorbidities were similar between the 2 groups. On average, the operative time of OAR was approximately 3 hr longer than endovascular repair (P < 0.001). The mortality was similar between the 2 groups (OAR 38% versus endovascular 26%, P = 0.09). Compared with endovascular repair, OAR was associated with higher rates of renal and pulmonary complications (32% vs. 13%, P = 0.004; 58% vs. 37%, P = 0.007, respectively). After adjusting for high-risk patient characteristics, endovascular repair, in comparison with OAR, was associated with a 66% reduction of pulmonary injury and 70% reduction in renal failure (odds ratio [OR] 0.34, 95% CI 0.16-0.73, P = 0.005; OR 0.30, 95% CI 0.11-0.82, P = 0.02). CONCLUSIONS: Our study reflects the contemporary outcomes following the repair of ruptured TAAA. Despite similar mortality, the endovascular approach was associated with a significant reduction in the risk of renal failure and pulmonary injury.

Endarterectomy versus stenting in patients with prior ipsilateral carotid artery stenting.

OBJECTIVE: In-stent restenosis is a recognized complication of carotid angioplasty and stenting (CAS), and it is associated with an increased risk of stroke. Few case series have reported outcomes separately following carotid endarterectomy (CEA) and CAS for the treatment of in-stent restenosis. In this study, we perform an evaluation of redo-CAS vs CEA in a large contemporary cohort of patients who underwent prior ipsilateral CAS. METHODS: We studied all patients in the Vascular Quality Initiative (VQI) database, who underwent CEA or CAS between January 1, 2003, and April 30, 2016, after prior ipsilateral CAS. Univariate methods (χ2, t-test), Kaplan-Meier, logistic, and Cox regression analyses adjusting for patient characteristics were employed to evaluate stroke, death, myocardial infarction (MI), stroke/death, and stroke/death/MI within 30 days and up to 1 year following the procedure. RESULTS: There were 645 carotid interventions (CEA, 134 [21%] and redo-CAS, 511 [79%]) performed in this cohort of patients with prior ipsilateral CAS. Postoperative stroke within 30 days comparing CEA vs CAS was 0% vs 0.3% (P = .61) for asymptomatic patients and 4.4% vs 3.5% (P = .79) for symptomatic patients for an overall stroke rate of 1.5% vs 1.4%. MI was 2.3% vs 1.2% (P = .35), 30-day mortality was 3.7% vs 0.9% (P = .02) following CEA vs CAS, whereas the composite of perioperative stroke/death was 4.5% vs 1.9% (P = .09). Freedom from stroke/death at 1 year was 91% for CEA and 92% for redo-CAS (P = .76). After risk adjustment, there was no significant difference in 30-day stroke (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.15-4.48; P = .82), mortality (OR, 2.21; 95% CI, 0.54-9.11; P = .27), or stroke/death (OR, 0.99; 95% CI, 0.26-3.84; P = .99) as well as 1-year stroke (hazard ratio [HR], 0.60; 95% CI, 0.13-2.85; P = .52), mortality (HR, 0.83; 95% CI, 0.42-1.65; P = .60), or stroke/death (HR, 0.80; 95% CI, 0.43-1.49; P = .48) comparing CEA with CAS. The significant predictors of perioperative stroke/death were older age, diabetes, active smoking, and preoperative American Society of Anesthesiologists class IV status (all P < .05). CONCLUSIONS: We have reported adverse event rates for CEA and CAS after prior CAS and shown no significant difference in perioperative and 1-year outcomes between both groups. However, CEA is offered to patients who are more severely ill than redo-CAS, resulting in significantly higher absolute mortality. We recommend avoidance of CEA especially in asymptomatic patients with serious systemic disease. Tight management of diabetes and smoking cessation remain potent targets for outcomes improvement in redo-CAS patients.

Perioperative and Long-term Outcomes After Carotid Endarterectomy in Hemodialysis Patients.

Importance: Early landmark trials excluding dialysis patients showed carotid endarterectomy (CEA) decreased stroke risk compared with medical management. Dialysis dependence has been associated with poor outcomes after CEA in small studies, but, to our knowledge, there are no large studies evaluating outcomes of CEA in this patient group. Objective: To delineate perioperative and long-term outcomes after CEA in dialysis-dependent patients in a large national database. Design, Setting, and Participants: A retrospective review of all patients who underwent CEA in the US Renal Disease System-Medicare-matched database between January 1, 2006, and December 31, 2011, was performed in June 2015. The median follow-up time was 2.5 years. Logistic and Cox regression analyses were used to evaluate perioperative and long-term outcomes. Main Outcomes and Measures: The primary outcomes of interest were perioperative stroke, myocardial infarction and mortality, and long-term stroke and mortality. Results: A total of 5142 patients were studied; 83% of whom were asymptomatic. The mean (SD) age was 68.9 (9.6) years for asymptomatic patients and 70.0 (9.1) years for symptomatic patients. The 30-day stroke rate, myocardial infarction, and mortality for the asymptomatic and symptomatic groups were 2.7% vs 5.2% (P = .001), 4.6% vs 5.0% (P = .69), and 2.6% vs 2.9% (P = .61), respectively. Predictors of perioperative stroke were symptomatic status (odds ratio [OR], 2.01; 95% CI, 1.18-3.42; P = .01), black race (OR, 2.30; 95% CI, 1.24-4.25; P = .008), and Hispanic ethnicity (OR, 2.28; 95% CI, 1.17-4.42; P = .02). Freedom from stroke and overall survival were lower in symptomatic compared with asymptomatic patients at 1, 2, 3, 4, and 5 years (in asymptomatic vs symptomatic patients, freedom from stroke rates were 92% vs 87% at 1 year, 88% vs 83% at 2 years, 84% vs 78% at 3 years, 80% vs 73% at 4 years, and 79% vs 69% at 5 years, respectively, and overall survival rates were 78% vs 73% at 1 year, 60% vs 57% at 2 years, 46% vs 42% at 3 years, 37% vs 32% at 4 years, and 33% vs 29% at 5 years; P < .05). Predictors of long-term stroke were preoperative symptoms (hazard ratio, 1.67; 95% CI, 1.24-2.24; P < .001), female sex (hazard ratio, 1.34; 95% CI, 1.03-1.73; P = .04), and inability to ambulate (hazard ratio, 1.81; 95% CI, 1.25-2.62; P = .002). Predictors of long-term mortality were increasing age (OR, 1.02; 95% CI, 1.01-1.03; P < .01), active smoking (OR, 1.22; 95% CI, 1.00-1.48; P = .045), history of congestive heart failure (OR, 1.25; 95% CI, 1.12-1.39; P < .001), and chronic obstructive pulmonary disease (OR, 1.26; 95% CI, 1.09-1.45; P = .002). Conclusions and Relevance: To our knowledge, this is the largest study to date of dialysis patients who have undergone CEA. We have shown that the risks of CEA in asymptomatic patients is high and may outweigh the benefits. The risk of CEA in symptomatic patients is also high, and it should only be offered to a small carefully selected cohort of symptomatic patients.

Outcomes after carotid artery stenting in hemodialysis patients.

BACKGROUND: Patients who require hemodialysis are historically excluded from randomized studies of carotid artery stenting (CAS) due to perceived poor outcomes. Observational studies of outcomes after CAS in hemodialysis patients are mostly limited to small, single-institution series. OBJECTIVE: This study evaluated long-term outcomes after CAS in a large nationally representative cohort of hemodialysis patients. METHODS: We studied all patients who underwent CAS in the United States Renal Disease System database between January 2006 and December 2011. Patient outcomes were determined by matching with the Medicare database. Univariable and multivariable logistic and Cox regression were used to compare perioperative (stroke, death, myocardial infarction) and long-term (stroke, death) outcomes after CAS. RESULTS: The cohort included 1109 patients who underwent CAS. Median follow-up was 2.5 years (interquartile range, 1.30-3.71; maximum, 4.97 years). Mean age was 67 (standard deviation, 9.9) years, and 61% of patients were male, 75% were white, and 83% were asymptomatic. Overall, 30-day perioperative stroke, myocardial infarction, and death rates were 5.5%, 5.5%, and 3.1%, respectively. Long-term freedom from stroke was 90% at 1 year, 85% at 2 years, and 76% at 4 years. Patient survival was 73% at 1 year and 29% at 4 years. Symptomatic status was the only significant predictor of stroke in a long-term period of 4 years (hazard ratio, 1.92; 95% confidence interval, 1.12-3.29; P < .05). CONCLUSIONS: This study, which is the largest population-based study of outcomes after CAS in hemodialysis patients, demonstrates relatively poor long-term survival and prohibitive operative stroke and death risk. We recommend avoidance of CAS in asymptomatic dialysis patients and cautious consideration when planning CAS in symptomatic patients.

Contemporary Outcomes for Open Infrainguinal Bypass in the Endovascular Era.

BACKGROUND: The role of infrainguinal bypasses in this era of increasing endovascular interventions remains the subject of significant debate. In this study, we evaluate contemporary long-term outcomes of lower-extremity open revascularization for peripheral arterial disease (PAD). METHODS: We evaluated all patients who underwent infrainguinal bypass with autogenous vein conduits for claudication or critical limb ischemia in our institution between January 1st, 2007 and July 31st, 2014. Kaplan-Meier and Cox regression analyses were used to evaluate graft failure and identify its predictors. Outcomes were defined per the Society for Vascular Surgery standards. RESULTS: There were 428 autogenous vein grafts (femoro-popliteal: 32%, femoro-tibial: 39%, popliteo-tibial: 27%, and tibio-tibial: 2%) placed in 368 patients (mean age of 67 ± 11.4 years). Most patients were male (59%), white (73%), and presented with critical limb ischemia (81%). Sixty-five cases (15%) were redo bypasses. Arm veins and spliced vein conduits were used in 15% and 14% of cases, respectively. Primary patency at 1, 3, and 5 years was 66%, 59%, and 55%, respectively. Primary-assisted patency was 78%, 69%, and 64% at 1, 3, and 5 years, respectively. Secondary patency was 88%, 84%, and 82% at 1, 3, and 5 years, respectively. Patency was higher for grafts harvested from the lower versus upper extremities and for proximal versus distal bypass (all P < 0.05). Limb salvage rate was 88% after a mean follow-up of 2 ± 1.8 years. Significant predictors of graft failure were younger age, diabetes mellitus, and hyperlipidemia (all P < 0.05). CONCLUSIONS: In this contemporary cohort of patients, we have demonstrated that infrainguinal bypass for lower-extremity revascularization has good long-term outcomes in patients with symptomatic PAD. Patency and limb salvage rates are optimized with careful selection of autogenous conduits, close monitoring of high-risk groups and management of comorbidities.

Vascular access modifies the protective effect of obesity on survival in hemodialysis patients.

BACKGROUND: The protective effect of obesity on the survival of patients undergoing hemodialysis (HD) for end-stage renal disease (ESRD), described as the obesity paradox, has been established previously. Survival benefits also have been ascribed to permanent modes of HD access (fistula/graft) compared with catheter at first HD. The purpose of this study is to evaluate the impact of incident HD access type on the obesity paradox. METHODS: A retrospective study of all patients with ESRD in the US Renal Database System who initiated HD between 2006 and 2010 was carried out. Multivariate logistic, Cox regression, and propensity score matched analyses were used to evaluate the association between body mass index (BMI), modes of HD access (fistula/graft vs catheter), and mortality. RESULTS: There were 501,920 dialysis initiates studied; 83% via catheter, 14% via fistula, and 3% via grafts. Mortality was lesser for patients initiating hemodialysis with permanent forms of access compared with catheter (adjusted odds ratio 0.68, 95% confidence interval 0.67-0.69, P < .001). High body mass index (BMI) was associated with lower mortality. Patients with high BMI were more likely to initiate hemodialysis via permanent modes of access compared with patients with normal BMI. CONCLUSION: The highly popularized protective effect of increased BMI on survival in HD patients is significantly influenced by the method of hemodialysis access. There is greater use of permanent access among patients with high BMI compared with patients with normal BMI. There remains a critical need to increase permanent access utilization at incident hemodialysis so as to improve survival irrespective of BMI status.

The age effect in increasing operative mortality following delay in elective abdominal aortic aneurysm repair.

BACKGROUND: Elective repair of large abdominal aortic aneurysms (AAAs) is associated with the risk of significant perioperative mortality. When abdominal aneurysm repair is delayed, patients with asymptomatic large AAAs face the risk of death from rupture. In addition to the risk of rupture, the advancing age of the patients adds a future operative risk. This risk has been historically documented in age groups. However, a more accurate representation of the increasing operative risk with age is needed. METHODS: We analyzed all patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent endovascular or open repair for asymptomatic infrarenal AAA between 2005 and 2012. Multivariable logistic regression was used to evaluate the effect of increasing age and operative delay on 30-day postoperative mortality. RESULTS: There were 27,576 patients who underwent AAA repair during the study period (mean age 73.5 years, standard deviation 8.6, 80% male, 24% open repair). There was a linear relative increase of 5% (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.04-1.06, P < 0.001) in the odds of operative death after AAA repair with each year of operative delay irrespective of treatment approach. There was a linear relative increase of 4% for endovascular aneurysm repair (OR 1.04, 95% CI 1.02-1.05, P < 0.001) and 6% for open repair (OR 1.06, 95% CI 1.04-1.08, P < 0.001) with each year of delay in repair. CONCLUSIONS: Because of increasing age, delay in surgery is associated with uniform increase in the risk of perioperative mortality in asymptomatic patients who meet criteria for AAA repair. It is important for surgeons to incorporate this more accurate estimation of operative risk into discussions with patients who qualify for treatment yet decide to forgo surgery for the repair of their AAA.

Racial/Ethnic Disparities Associated With Initial Hemodialysis Access.

IMPORTANCE: Superior outcomes have been established with the use of an arteriovenous fistula (AVF) at first hemodialysis. However, considering the influence of comorbidities, medical insurance, and specialist care, racial/ethnic differences in the patterns of utilization of AVFs are unknown and deserve evaluation. OBJECTIVE: To assess national trends in initial hemodialysis access with respect to race/ethnicity stratified by comorbid disease, nephrology care, and medical insurance status within the US Renal Data System. DESIGN, SETTING, AND PARTICIPANTS: A retrospective analysis of all patients with end-stage renal disease in the US Renal Data System who initiated hemodialysis between January 1, 2006, and December 31, 2010. Univariable statistics (χ² test and analysis of variance) and logistic regression were used to compare racial/ethnic groups (white vs black vs Hispanic). Multivariable logistic regression and propensity score-matching techniques were used to evaluate hemodialysis access rates between patients of different races/ethnicities with comparable characteristics. MAIN OUTCOMES AND MEASURES: Utilization rates of AVF, arteriovenous graft, and intravascular hemodialysis catheter. RESULTS: In this cohort of 396,075 patients, more white patients initiated hemodialysis with an AVF than black patients or Hispanic patients (18.3% vs 15.5% and 14.6%, respectively; P < .001). Black patients and Hispanic patients initiated hemodialysis with an AVF less frequently despite being younger and having less coronary artery disease, chronic obstructive pulmonary disease, and cancer than white patients with an AVF. When stratified by medical insurance status, black patients (odds ratios, 0.90 [95% CI, 0.82-0.98] for uninsured and 0.85 [95% CI, 0.84-0.87] for insured) and Hispanic patients (odds ratios, 0.72 [95% CI, 0.65-0.81] for uninsured and 0.81 [95% CI, 0.79-0.84] for insured) persistently initiated hemodialysis with an AVF less frequently than white patients (P < .05 for all). Arteriovenous fistula utilization at initial hemodialysis was lower among black patients (odds ratio, 0.81 [95% CI, 0.78-0.84]) and Hispanic patients (odds ratio, 0.86 [95% CI, 0.82-0.90]) compared with white patients within the category of patients who had nephrology care for longer than 1 year (P < .001 for all). CONCLUSIONS AND RELEVANCE: Black patients and Hispanic patients tend to initiate hemodialysis with an AVF less frequently than white patients despite being younger and having fewer comorbidities. These disparities persisted independent of factors that drive health access for fistula placement, such as medical insurance status and nephrology care. The sociocultural underpinnings of these disparities deserve investigation and redress to maximize the benefits of initiating hemodialysis via fistula in patients with end-stage renal disease irrespective of race/ethnicity.