The Use and Impact of Cilostazol on Patients Undergoing Endovascular Peripheral Interventions.

BACKGROUND: Cilostazol is used for the treatment of intermittent claudication. The impact of cilostazol on the outcomes of peripheral vascular interventions (PVIs) remains controversial. This study assesses the use and impact of cilostazol on patients undergoing PVI for peripheral arterial disease (PAD). METHODS: The Vascular Quality Initiative (VQI) database files for PVI were reviewed. Patients with PAD who underwent PVI for chronic limb threatening-ischemia or claudication were included and divided based on the use of cilostazol preoperatively. After propensity matching for patient demographics and comorbidities, the short-term and long-term outcomes of the 2 groups (preoperative cilostazol use versus no preoperative cilostazol use) were compared. The Kaplan-Meier method was used to determine outcomes. RESULTS: A total of 245,309 patients underwent PVI procedures and 6.6% (N = 16,366) were on cilostazol prior to intervention. Patients that received cilostazol were more likely to be male (62% vs 60%; P < 0.001), White (77% vs. 75%; P < 0.001), and smokers (83% vs. 77%; P < 0.001). They were less likely to have diabetes mellitus (50% vs. 56%; P < 0.001) and congestive heart failure (14% vs. 23%; P < 0.001). Patient on cilostazol were more likely to be treated for claudication (63% vs. 40%, P < 0.001), undergo prior lower extremity revascularization (55% vs. 51%, P < 0.001) and less likely to have undergone prior minor and major amputation (10% vs. 19%; P < 0.001) compared with patients who did not receive cilostazol. After 3:1 propensity matching, there were 50,265 patients included in the analysis with no differences in baseline characteristics. Patients on cilostazol were less likely to develop renal complications and more likely to be discharged home. Patients on cilostazol had significantly lower rates of long-term mortality (11.5% vs. 13.4%, P < 0.001 and major amputation (4.0% vs. 4.7%, P = 0.022). However, there were no significant differences in rates of reintervention, major adverse limb events, or patency after PVI. Amputation-free survival rates were significantly higher for patients on cilostazol, after 4 years of follow up (89% vs. 87%, P = 0.03). CONCLUSIONS: Cilostazol is underutilized in the VQI database and seems to be associated with improved amputation-free survival. Cilostazol therapy should be considered in all patients with PAD who can tolerate it prior to PVI.

Association of Renin-Angiotensin-Aldosterone System Inhibitor Usage Patterns with Midterm Amputation-Free Survival after Lower Extremity Bypass for Peripheral Arterial Disease.

BACKGROUND: Different renin-angiotensin-aldosterone system inhibitor (RAASI) usage patterns exist among patients undergoing lower extremity bypass (LEB) for peripheral arterial disease. We studied the association of RAASI usage patterns with LEB outcomes to determine which pattern is associated with improved survival after LEB. METHODS: We evaluated peripheral arterial disease patients who underwent LEB between January 2014 and December 2018 in the Vascular Quality Initiative-Medicare matched database. Study cohorts included no RAASI use, preoperative RAASI use only, postoperative RAASI use only, and continuous RAASI use both preoperatively and postoperatively. Logistic and Cox regression was used to adjust for potential confounders. Primary outcome was 2-year amputation-free survival (AFS). RESULTS: Of 19,012 patients included, 1,574 (8.3%) were on RAASIs preoperatively only, 1,051 (5.5%) postoperatively only, and 8,484 (45.2%) continuously. Compared to no RAASI use, isolated preoperative RAASI use was associated with 2.8-fold increased odds of 30-day mortality (adjusted Odds Ratio, 2.75; 95% confidence interval [CI], 2.15-3.51; P < 0.001) whereas continuous RAASI use had 56% lower odds of 30-day mortality (adjusted Odds Ratio, 0.44; 95% CI, 0.34-0.58; P < 0.001). Two-year AFS was 63.2% for no RAASI use and 60.4%, 66.2%, and 73.4% for preoperative, postoperative, and continuous RAASI use, respectively (P < 0.001). While no RAASI use and postoperative RAASI use had comparable adjusted risks of 2-year major amputation or death (adjusted Hazard Ratio [aHR], 0.94; 95% CI, 0.83-1.06; P = 0.312), this risk was 14% higher for preoperative RAASI use only (aHR, 1.14; 95% CI, 1.04-1.26; P = 0.006) and 23% lower for continuous RAASI use (aHR, 0.77; 95% CI, 0.72-0.82; P < 0.001). CONCLUSIONS: Isolated preoperative RAASI use was associated with worse 30-day mortality and 2-year AFS, while continuous RAASI use was associated with improved 30-day mortality and 2-year AFS. Optimum survival benefit may be derived from continuous RAAS inhibition in the preoperative and postoperative periods.

Contemporary outcomes of concomitant suprainguinal bypass with infrainguinal revascularization procedures in patients with chronic limb-threatening ischemia.

OBJECTIVE: Combined suprainguinal and infrainguinal revascularization is sometimes necessary in the treatment of patients with chronic limb-threatening ischemia (CLTI). However, data on outcomes of concomitant revascularization procedures are lacking. We studied the outcomes of patients with CLTI who underwent suprainguinal bypass (SIB) alone, SIB with concomitant infrainguinal bypass (IIB), and SIB with concomitant infrainguinal peripheral endovascular intervention (IIPVI). METHODS: We reviewed all patients in the Vascular Quality Initiative with CLTI who underwent SIB from January 2010 to June 2020. Logistic regression, Kaplan-Meier survival estimates, log-rank tests, and Cox regression were used to analyze outcomes. Outcomes were 30-day mortality, perioperative myocardial infarction, perioperative major amputation, 1-year amputation-free survival, and 5-year survival. RESULTS: Of 8037 patients included, 81.3% (n = 6537) underwent SIB alone, 9.7% (n = 783) underwent SIB+IIB, and 8.9% (n = 717) underwent SIB+IIPVI. The indication for surgery was rest pain in 5040 (62.5%) and tissue loss in 3031 (37.6%). There were no significant differences in 30-day mortality and perioperative myocardial infarction rates. However, there was 2.8-fold increased odds of perioperative major amputation in both SIB+IIPVI (odds ratio [OR], 2.76; 95% confidence interval [CI], 1.30-5.88; P = .008) and SIB+IIB (OR, 2.79; 95% CI, 1.38-5.54; P = .004) among patients with rest pain as compared with SIB alone. Comparing SIB+IIPVI with SIB alone, there were no significant differences in 1-year freedom from amputation and amputation-free survival. SIB+IIPVI was associated with a 27% increased risk of 5-year mortality (hazard ratio [HR], 1.27; 95% CI, 1.03-1.55; P = .035). Compared with SIB alone, SIB+IIB was associated with 97% increased risk of 1-year major amputation among patients with rest pain (HR, 1.97; 95% CI, 1.06-3.69; P = .033), but a 47% decreased risk of 1-year major amputation or death for patients with tissue loss (HR, 0.53; 95% CI, 0.37-0.78; P = .001). SIB+IIPVI, compared with SIB+IIB, was associated with a two-fold increased risk of 1-year major amputation or death (HR, 2.04; 95% CI, 1.04-2.23), P = .003) and a 52% increased risk of 5-year mortality (HR,1.52; 95% CI, 1.04-2.24; P = .032) among patients with tissue loss. CONCLUSIONS: This study shows that SIB with concomitant infrainguinal revascularization in patients with rest pain is associated with an increased risk of amputation, whereas SIB+IIB in patients with tissue loss is associated with decreased risk of amputation or death. SIB+IIB outperformed SIB+IIPVI in patients with tissue loss. SIB with infrainguinal revascularization should be limited in patients with rest pain in line with current guidelines, but SIB+IIB may be preferred in patients with tissue loss.

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 impaired ambulatory capacity on the outcomes of peripheral vascular interventions among patients with chronic limb-threating ischemia.

OBJECTIVE: Despite prior literature recommending against limb salvage in patients with poor functional status such as nonambulatory patients with chronic limb-threatening ischemia (CLTI), peripheral endovascular interventions continue to be carried out in this group of patients. Clinical outcomes following these interventions are, however, not well-characterized. METHODS: A retrospective review was conducted on all patients treated for CLTI in the Vascular Quality Initiative from September 2016 to December 2019. Logistic regression, Kaplan-Meier survival estimates, log-rank tests, and Cox regression analyses were used as appropriate to study outcomes. The primary outcomes were 30-day mortality and 1-year amputation-free survival. The secondary outcomes were in-hospital death, postoperative complications, 1-year freedom from major amputation, and 2-year survival. RESULTS: Of the 49,807 patients studied, 28,469 (57.2%) were ambulatory, 15,148 (31.0%) were ambulatory with assistance, 5395 (10.8%) were wheelchair bound, and 525 (1.1%) were bedridden. There was a 2-fold increase in the odds of 30-day death in patients who were ambulatory with assistance (odds ratio [OR], 2.03; 95% confidence interval [CI], 1.77-2.34; P < .001) and wheelchair-bound patients (OR, 2.09; 95% CI, 1.74-2.51; P < .001), and a more than 6-fold increase in bedridden patients (OR, 6.28; 95% CI, 4.55-8.65; P < .001) compared with ambulatory patients. There was a significantly higher odds of postoperative complications in patients who were ambulatory with assistance or bedridden, but no difference with wheelchair-bound patients. Among ambulatory patients, the risks of major amputation and death within 1 year were only 10% and 12%, respectively, whereas that of bedridden patients were as high as 30% and 38%, respectively. A stepwise decrease in amputation-free survival from 81% with full ambulatory capacity to less than 50% (47.7%) in bedridden patients was observed. The risk of major amputation or death within 1 year was 35% higher for ambulatory with assistance (hazard ratio [HR], 1.35; 95% CI, 1.26-1.44; P < .001), 65% higher for wheelchair-bound (HR, 1.65; 95% CI, 1.51-1.79; P < .001) and 2.6-fold higher for bedridden (HR, 2.64; 95% CI, 2.17-3.21; P < .001) compared with ambulatory. A similar association was seen for 1-year freedom from major amputation and 2-year survival. CONCLUSIONS: Ambulatory impairment in patients with CLTI is associated with a significant increase in 30-day mortality and significant decrease in amputation-free survival after peripheral endovascular intervention. Bedridden patients had a 6-fold increase in the 30-day death rate, whereas their amputation-free survival dropped to less than 50% at 1 year. These risks should be considered during shared decision-making regarding management options for nonambulatory patients with CLTI.

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.

Safety of carotid artery revascularization procedures in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (Afib) is a major contributor to cerebrovascular events. Coexisting carotid artery disease is not uncommon in Afib patients, yet they have been excluded from major randomized clinical trials. Therefore, the aim of this study was to evaluate the safety of carotid endarterectomy (CEA) and carotid artery stenting (CAS) in Afib patients. METHODS: The Premier Healthcare Database was queried (2009-2015). Patients who underwent CEA or CAS were captured by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Multivariable logistic modeling was implemented to examine the outcomes: in-hospital stroke, intracerebral hemorrhage (ICH), mortality, and stroke/death. RESULTS: There were 86,778 patients included. The majority were asymptomatic (n = 82,128 [94.6%]). Afib was reported in 6743 patients (7.8%). In terms of absolute outcomes in both asymptomatic and symptomatic patients, Afib patients (vs non-Afib patients) had higher mortality and stroke/death (asymptomatic: mortality, 0.4% vs 0.2%; stroke/death, 1.7% vs 1.2%; symptomatic: mortality, 6.9% vs 2.1%; stroke/death, 10.6% vs 4.5%; all P < .05). Adjusted analysis yielded higher odds of ICH (adjusted odds ratio [aOR], 1.29; 95% confidence interval [CI], 1.00-1.67), mortality (aOR, 1.59; 95% CI, 1.11-2.26), and stroke/death (aOR, 1.30; 95% CI, 1.08-1.58) in Afib patients. Although univariable analysis found Afib to be a statistically significant predictor of ischemic stroke, similar results could not be elucidated in the multivariable analysis (aOR, 1.17; 95% CI, 0.93-1.47). In Afib patients, important predictors of stroke/death included CAS (aOR, 1.80; 95% CI, 1.21-2.68) and symptomatic presentation (aOR, 5.00; 95% CI, 3.20-7.83). Other important predictors were type of preoperative medication use, age, and hospital size. CONCLUSIONS: Afib was associated with worse postoperative outcomes in patients with carotid artery disease. Symptomatic status in Afib patients is associated with a stroke/death risk that is higher than in recommended guidelines for CEA and particularly for CAS. Overall, CEA was associated with lower periprocedural ICH, mortality, and stroke/death in Afib patients compared with CAS.

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.

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.

Arteriovenous Access superficialization: A New Technique and Review of Options.

BACKGROUND: Up to 30% of autogenous cephalic vein arteriovenous fistulas (AVFs) are too deep for reliable cannulation. Techniques to superficialize these AVFs have been described previously. This study describes a new surgical technique for AVF superficialization and provides a review of the alternative techniques. METHODS: The path of the fistula is marked using ultrasound, and transverse incisions are made along this path. The underlying tissue is separated from the dermis over this area to expose the fistula outflow vein. The mobilized vein is then elevated and "trapped" directly under the dermis by closing the superficial fascia and adipose tissue beneath it. RESULTS: Between March 2016 and February 2019, 23 patients underwent superficialization using this technique at two centers. The mean time between AVF creation and superficialization was 6.3 months, and the time to first use for hemodialysis after superficialization was 38.8 ± 27.9 days. The average presuperficialization depth was 7.1 ± 2.4 mm and average postsuperficialization depth was 3.7 ± 2.7 mm (P = 0.002). Sixteen fistulas were successfully accessed for a cannulation rate of 89%. 94.7% of fistulas remained patent at last visit, with only one thrombosed 8-10 weeks after superficialization. CONCLUSIONS: This technique appears to be both safe and effective, and results in a vein that is immediately subdermal without major contour deformity. Early outcomes are comparable to those alternative methods described in the literature.

Outcomes of Infrainguinal Lower Extremity Bypass Are Superior in Kidney Transplant Recipients Than Patients with Dialysis.

Patients with end-stage renal disease (ESRD) whether on dialysis therapy (DT) or who received a kidney transplant (KT) have previously shown unfavorable surgical outcomes. Little is known about the comparative efficacy and durability of lower extremity bypass (LEB) in those patients. The Vascular Quality Initiative database was explored to identify DT or KT recipients (2003-2016) who had LEB. We included 1,714 bypass procedures; DT: 1,512 (88.2%). Primary patency (PP) at 2 year was comparable between KT and DT groups (PP [95% confidence interval {CI}]: 77.0% [69.7%-82.8%] vs. 80.5% [77.8%-82.9%]; P = 0.212), and the risk-adjusted hazard was similar (adjusted hazard ratio [aHR] [95% CI]: 0.89 [0.61-1.30]; P = 0.540). Amputation-free survival (AFS) at 2 year was more favorable in KT group (AFS [95% CI]: 73.1% [66.3%-78.8%] vs. 48.0% [45.4%-50.6%]; P < 0.001), (aHR [95% CI]: 2.29 [1.62-3.23]; P < 0.001). Patients on DT exhibited a higher risk of mortality than KT recipients (aHR [95% CI]: 2.94 [2.07-4.17]; P < 0.001). This study demonstrated superior limb outcomes in KT recipients than patients on DT after LEB. Despite the comparable PP, the risk of amputation or death was doubled in patients on DT compared with KT recipients. Because both groups were similar in several baseline characteristics, the difference in outcome is likely driven by the positive effect of KT on the physiological milieu of these patients.

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.

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.

Survival after major lower extremity amputation in patients with end-stage renal disease.

OBJECTIVE: This study evaluates survival of patients with end-stage renal disease (ESRD) after major lower extremity amputation (MLEA), given the burden of peripheral arterial disease in patients with ESRD, the hindrance posed by cardiovascular disease on their survival, and the national investment in ESRD-related care. METHODS: A retrospective review of all hemodialysis patients (HD) and renal transplant (RT) recipients who underwent MLEA between January 2007 and December 2011 in the United States Renal Data System was performed. Univariable, Kaplan-Meier, multivariable logistic, and Cox regression analyses were used to evaluate patient survival among HD patients and RT recipients overall; and within strata of amputation level, gender, and race. RESULTS: There were 32,540 MLEAs (HD, 92%; RT, 8%). Among HD patients, the median survival was 6 months for above knee amputation (AKA) and 16 months for below knee amputation (BKA). The risk-adjusted mortality was higher for AKA compared with BKA (adjusted hazard ratio [aHR], 1.48; 95% confidence interval [CI], 1.44-1.52; P < .001), females compared with males (aHR, 1.04; 95% CI, 1.01-1.08; P = .004), but lower for blacks (aHR, 0.78 95% CI, 0.76-0.81; P < .001) and Hispanics (aHR, 0.74; 95% CI, 0.70-0.79; P < .001) compared with white HD patients. Among RT recipients, the median survival was 16 months for AKA and 47 months for BKA. Mortality was significantly higher for above knee amputees compared with below knee amputees (aHR, 1.83; 95% CI, 1.60-2.10; P < .001). However, there was no difference in mortality between the gender and racial categories of RT recipients. There was a twofold increase in the 30-day mortality (adjusted odd ratio, 1.94; 95% CI, 1.66-2.25; P < .001) and long-term mortality (aHR, 2.18; 95% CI, 2.05-2.32; P < .001) for HD patients relative to RT recipients. CONCLUSIONS: Survival after MLEA is limited in patients with ESRD. It is relatively better for RT recipients compared with HD patients. Mortality was higher for females compared with males, but lower for blacks and Hispanics compared with white HD patients. There were no gender- or race-specific difference in mortality among RT recipients. These estimates of life expectancy should guide the informed decision- making process for patients and their healthcare providers when the need for intervention arises after MLEA in these unique categories of patients.

Infrainguinal bypass surgery outcomes are worse in hemodialysis patients compared with patients with renal transplants.

OBJECTIVE: Studies of infrainguinal bypass surgery (IBS) in patients with end-stage renal disease have focused on hemodialysis (HD) patients. Little is known of the applicability of their outcomes to patients with renal transplants (RTs). In this study, we sought to compare perioperative and long-term outcomes of IBS in a large population-based cohort of HD and RT patients. METHODS: A retrospective review of all HD and RT patients who underwent IBS between January 2007 and December 2011 in the U.S. Renal Data System was performed. Univariable, Kaplan-Meier, multivariable logistic, and Cox regression analyses were employed to evaluate 30-day postoperative (graft failure, limb loss, conduit infection, death) and long-term (primary patency [PP], primary assisted patency [PAP], secondary patency [SP], limb salvage, mortality) outcomes. RESULTS: There were 10,787 IBSs performed in 9739 (90%) HD patients and 1048 (10%) RT patients who presented predominantly with critical limb ischemia (72%). Bypass configurations were femoral-popliteal (48%), femoral-tibial (34%), and popliteal-tibial (18%). Comparing HD vs RT patients, PP, PAP, and SP were 18% vs 33%, 23% vs 38%, and 30% vs 48%, respectively, at 5 years among autogenous conduit recipients (all P < .001) and 20% vs 28% (P = .02), 23% vs 31% (P = .02), and 33% vs 53% (P < .001) among prosthetic conduit recipients. Limb salvage and patient survival were 39% vs 56% and 19% vs 48%, respectively, at 5 years (all P < .001). Risk-adjusted analyses demonstrated higher PP (adjusted hazard ratio [aHR], 1.32; 95% confidence interval [CI], 1.20-1.45; P < .001), PAP (aHR, 1.32; 95% CI, 1.19-1.45; P < .001), SP (aHR, 1.47; 95% CI, 1.31-1.65; P < .001), limb salvage (aHR, 1.48; 95% CI, 1.30-1.67; P < .001), and patient survival (aHR, 2.42; 95% CI, 2.17-2.71; P < .001) for RT compared with HD patients. CONCLUSIONS: The HD-dependent state is associated with elevated bypass and patient-level risks after IBS compared with patients with RTs. These results show that the benefits of renal transplantation likely extend to infrainguinal bypass-specific outcomes. The estimates of risk reported herein should inform the patient's and provider's expectations at the point of care.

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.

Aggressive infrainguinal revascularization in renal transplant patients is justifiable.

While studies demonstrate poor outcomes of lower extremity revascularization in patients with end-stage renal disease, little is known about results in renal transplant patients. We analyzed 2-year primary patency and limb salvage outcomes and associated risk factors of transplant (n = 202) and nontransplant patients (n = 25 274) in the Vascular Quality Initiative database undergoing infrainguinal bypass from 2003 to 2016. Multivariable Cox regression analysis and coarsened exact matching with many-to-one were used. Transplant patients were more likely to have critical limb ischemia and revascularization of more distal arteries and to receive vein conduits. Primary patency was similar between transplant and nontransplant patients at 1 year (80.8% vs 77.5%) and 2 years (67.9% vs 63.7%, P = .079). Amputation-free survival was higher for nontransplant patients (1 year: 82.4% vs 75.3%, 2 years: 68.8% vs 58.2%, P = .0060), although overall survival was equivalent (2 years: 84.6% vs 87.2%, 4 years: 75.9% vs 79.6%, P = .35). Risk factors for primary patency loss included being female, critical limb ischemia, prior bypass, and distal bypass. Age, diabetes, prior contralateral amputation, critical limb ischemia, prosthetic conduit, and more distal bypass were associated with limb loss. This is the largest series of infrainguinal revascularization in transplant patients. Outcomes for transplant patients are not inferior, and aggressive approaches at limb salvage are justifiable in appropriately selected patients.

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.

Comparing the efficacy of shunting approaches and cerebral monitoring during carotid endarterectomy using a national database.

OBJECTIVE: Carotid endarterectomy practice patterns, including the use of shunts and cerebral monitoring techniques, are typically surgeon-dependent and differ greatly on a national level. Prior literature evaluating these techniques is often underpowered for detecting variations in low-frequency outcomes. The purpose of this study was to evaluate current carotid endarterectomy practice patterns and to allow comparison across surgical approaches using a large national database. METHODS: We divided carotid cases entered into the Vascular Quality Initiative database between October 2012 and April 2015 into routine shunting, selective shunting, and never shunting cohorts, excluding endarterectomies performed with concomitant procedures and those with incomplete information on the use of a shunt. The selective group was subdivided into cases with awake, electroencephalography, and stump pressure monitoring. We evaluated differences in practice patterns and compared rates of stroke, death, return to the operating room, reperfusion injury, and re-exploration after closure across these groups. Multivariate logistic regression models adjusting for risk factors were used to identify predictors of each outcome. RESULTS: Between October 2012 and April 2015, there were a total of 28,457 endarterectomies included in our analysis, of which 14,128 involved routine shunting, 1740 involved never shunting, and 12,489 involved selective shunting. Of the selective cases, 6144 involved electroencephalography monitoring, 2310 involved stump pressure monitoring, and 2052 involved awake monitoring. Unadjusted rates of in-hospital death and stroke were 0.30% (95% confidence interval [CI], 0.21-0.39) and 0.78% (95% CI, 0.64-0.93) for routine shunting and 0.22% (95% CI, 0.14-0.31) and 0.91% (95% CI, 0.75-1.08) for selective shunting, respectively. The unadjusted rate of in-hospital death was lower in the awake monitoring group than in the routine shunting group (0.05% vs 0.30%; P = .037). After adjustment for patient risk factors, the multivariate models showed no difference in rates of any primary outcomes among the groups, although there was a shorter postoperative length of stay for the awake monitoring group compared with the routine shunting group (1.55 days vs 2.00 days, respectively; P < .01). CONCLUSIONS: Analysis of the Vascular Quality Initiative registry shows equivalent unadjusted rates of in-hospital death and stroke across different approaches to shunting and cerebral monitoring with the exception of the awake monitoring group, which has lower unadjusted mortality compared with the routine shunting group. In the risk-adjusted analysis, however, there are no differences across any of the groups. Given the clinical equivalence of approaches to shunting and cerebral monitoring, further work should evaluate the relative cost of these techniques.