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.

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.

Regional variation in the cost of infrainguinal lower extremity bypass surgery in the United States.

BACKGROUND: Lower extremity bypass (LEB) remains the gold standard revascularization procedure in patients with peripheral arterial disease. The cost of LEB substantially varies based on patient's characteristics and comorbidities. The aim of this study was to assess regional variation in infrainguinal LEB cost and to identify the specific health care expenditures per service that are associated with the highest cost in each region. METHODS: We identified adult patients who underwent infrainguinal LEB in the Premier database between June 2009 and March 2015. Generalized linear regression models were used to report differences between regions in total in-hospital cost and service-specific cost adjusting for patient's demographics, clinical characteristics, and hospital factors. RESULTS: A total of 50,131 patients were identified. The median in-hospital cost was $13,259 (interquartile range, $9308-$19,590). The cost of LEB was significantly higher in West and Northeast regions with a median cost of nearly $16,000. The high cost in the Northeast region was driven by the fixed (indirect) cost, whereas the driver of the high cost in the West region was the variable (direct) cost. The adjusted total in-hospital cost was significantly higher in all regions compared with the South (mean difference, West, $3752 [95% confidence interval (CI), 3477-4027]; Northeast, $2959 [95% CI, 2703-3216]; Midwest, 1586 [95% CI, 1364-1808]). CONCLUSIONS: In this study, we show the marked regional variability in LEB costs. This disparity was independent from patient clinical condition and hospital factors. Cost inequality across the US represents a financial burden on both the patient and the health system.

Racial disparities after infrainguinal bypass surgery in hemodialysis patients.

BACKGROUND: Peripheral arterial disease poses a significant burden in the hemodialysis (HD)-dependent population. Race is a known modifier of outcomes after surgical treatment of peripheral arterial disease. A comprehensive evaluation of the effect of race on infrainguinal bypass surgery (IBS) outcomes in HD patients is lacking. In this study, we evaluated the effects of race on long-term IBS outcomes in a large, nationally representative cohort of HD patients. METHODS: We studied all HD patients who underwent IBS between January 2007 and December 2011 in the United States Renal Disease System-Medicare matched database. Univariate methods were used to compare patients' demographic and medical characteristics. Kaplan-Meier, univariate and multivariable logistic, and Cox regression analyses were used to evaluate long-term graft patency, limb salvage, and mortality. RESULTS: There were 9305 IBSs performed in 5188 white (56%), 3354 black (36%), and 763 Hispanic (8%) patients. Of these, 4531 (49%) were femoral-popliteal, 3173 (34%) were femoral-tibial, and 1601 (17%) were popliteal-tibial bypasses. Comparing whites vs blacks vs Hispanics, acute graft failure was 14% vs 16% vs 15% (P = .03), with no statistical difference on multivariate analyses. Primary patency was 52% vs 45% vs 48% at 1 year and 24% vs 21% vs 26% at 4 years (P < .001). Primary assisted patency was 56% vs 48% vs 53% at 1 year and 29% vs 25% vs 32% at 4 years (P < .001); secondary patency was 65% vs 56% vs 60% at 1 year and 40% vs 33% vs 40% at 4 years (P < .001). Limb salvage was 68% vs 60% vs 62% at 1 year and 45% vs 42% vs 40% at 4 years (P < .001). Black patients had higher long-term graft failure (adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 1.05-1.24; P = .001) and limb loss (aHR, 1.27; 95% CI, 1.15-1.40; P < .001) compared with white patients. No differences in graft failure (aHR, 0.99; 95% CI, 0.89-1.11; P = .89) and limb loss (aHR, 1.08; 95% CI, 0.94-1.23; P = .28) were found in Hispanics vs whites. All-cause mortality was lower among blacks (aHR, 0.65; 95% CI, 0.60-0.71; P < .001) and Hispanics (aHR, 0.67; 95% CI, 0.59-0.75; P < .001) compared with whites. CONCLUSIONS: This large study confirms the presence of multidirectional racial disparities in graft durability, limb salvage, and mortality after IBS in HD patients. Black patients had lower graft patency and higher limb loss than white and Hispanic patients, whereas perioperative and long-term mortality was higher in white patients. These results should inform further granular root cause analyses and subsequent action to eliminate these disparities.

Fixed and variable cost of carotid endarterectomy and stenting in the United States: A comparative study.

OBJECTIVE: Despite multiple landmark clinical trials, little data exists on real-world cost of carotid artery stenting (CAS) and carotid endarterectomy (CEA) to the United States healthcare system. We aim to study differences in actual hospitalization cost between patients who underwent CAS vs CEA in a nationally representative database. METHODS: We studied hospital discharge and billing records of all patients, in the Premier Perspective Database, who underwent CEA or CAS between the third quarter of 2009 and the first quarter of 2015. Nearest-neighbor 1:1 propensity score matching was performed, to account for differences in patient and hospital characteristics as well as clinical comorbidities of patients who underwent both procedures, for both symptomatic and asymptomatic cohorts using 32 variables. Pearson χ2, Student t-test, and nonparametric K-sample equality-of-medians tests were used to analyze the data, as appropriate. The primary outcome was total in-hospital cost, including fixed (administrative, capital and utilities) and variable costs (labor and supply). Cost data were presented as medians, inflation-adjusted for 2015 U.S. dollar and rounded to the nearest dollar. RESULTS: A total of 115,548 procedures were identified. The mean age was 71 and 69 years; 58% and 57% were male patients; and 81% and 77% were white among asymptomatic and symptomatic patients, respectively. After propensity score matching, 25,812 asymptomatic (12,906 CEA and 12,906 CAS) and 3864 symptomatic (1932 CEA and 1932 CAS) patients were included. Total hospitalization cost per CAS was 40% ($11,814 vs $8378; P < .001) and 37% ($19,426 vs $14,190; P < .001) higher than CEA among asymptomatic and symptomatic patients, respectively. Patients who underwent CAS incurred significantly higher total hospitalization cost despite stratifying by type of cost (fixed and variable), U.S. census regions and symptomatic status. Moreover, asymptomatic patients who underwent CAS performed by any surgical specialty incurred an average of $2717 to $4918 higher total hospitalization cost compared with patients who underwent CEA (all P < 001). Among symptomatic patients, those who underwent CAS performed by vascular, cardiac, and neurologic surgeons, incurred $2108 ($16,114 vs $14,006; P = .006), $7055 ($17,351 vs $10,296; P = .023) and $6479 ($27,290 vs $20,811; P = .002) higher total hospitalization cost compared with patients who underwent CEA, respectively. CONCLUSIONS: The total hospitalization cost incurred by patients who underwent CAS was significantly higher than for those who underwent CEA, despite matching cohort based on patient and hospital characteristics, and stratifying by symptomatic status, type of cost, hospital region, and surgeon specialty. Our findings could provide additional important information giving the ongoing controversy regarding the appropriate indication for CAS.

Comprehensive Assessment of Factors Associated With In-Hospital Mortality After Elective Abdominal Aortic Aneurysm Repair.

IMPORTANCE: Patient- and hospital-level factors affecting outcomes after open and endovascular abdominal aortic aneurysm (AAA) repair are each well described separately, but not together. OBJECTIVE: To describe the association of patient- and hospital-level factors with in-hospital mortality after elective AAA repair. DESIGN, SETTING, AND PARTICIPANTS: Retrospective review of the Nationwide Inpatient Sample database (January 2007-December 2011). The review included all patients undergoing elective open AAA repair (OAR) or endovascular AAA repair (EVAR) and was conducted between December 2014 and January 2015. MAIN OUTCOMES AND MEASURES: Factors associated with in-hospital mortality were analyzed for OAR and EVAR using multivariable analyses, adjusting for previously defined patient- and hospital-level risk factors. RESULTS: Of the 166 443 surgeries (131 908 EVARs and 34 535 OARs) that were performed at 1207 hospitals, 133 407 patients (80.2%) were men, 123 522 patients (89.6%) were white, and the mean (SD) age was 73 (0.04) years. Overall in-hospital mortality was 0.7% for EVAR and 3.8% for OAR. Mortality after EVAR was significantly higher among hospitals with high general surgery mortality (mortality quartile ≥ 50%; odds ratio [OR], 1.37; 95% CI, 1.01-1.86; P = .04) and there was no difference in mortality among hospitals meeting the Leapfrog criteria for AAA repair (OR, 0.64; 95% CI, 0.38-1.09; P = .09). Mortality after OAR was significantly lower among hospitals performing at least 25% of AAA repairs using open techniques (OR, 0.68; 95% CI, 0.52-0.88; P = .004). Neither hospital bed size nor teaching status was significantly associated with mortality after either EVAR or OAR. Overall, OAR (OR, 6.07; 95% CI, 4.92-7.49) and intrinsic patient risk (Medicare score; OR, 4.81; 95% CI, 3.45-6.72) were most likely associated with in-hospital mortality after AAA repair, although hospitals with poor general surgery performance (OR, 1.31; 95% CI, 1.06-1.63) and those with at least a 25% proportion of open cases (OR, 1.39; 95% CI, 1.10-1.75) were also significantly associated with mortality (all P < .002). Notably, the proportion of institutions performing at least 25% open cases fell from 41% in 2007 to 18% in 2011 (P < .001). CONCLUSIONS AND RELEVANCE: Patient-level factors were associated with in-hospital mortality outcomes after elective AAA repair. Hospital case volume and practice patterns were also associated. This demonstrates the importance of adequate institutional experience with OAR techniques, which appear to be critically declining. Based on these data, appropriate patient selection and medical optimization appear to be the most important means by which we can improve outcomes following elective AAA repair, although patient referral to high-volume aortic centers of excellence should be a secondary consideration.

Racial disparities after vascular trauma are age-dependent.

OBJECTIVE: Different racial disparities exist between white and black all-cause trauma patients depending on their age group; however, the effects of race and age on outcomes after vascular trauma are unknown. We assessed whether the previously described age-dependent racial disparities after all-cause trauma persist in the vascular trauma population. METHODS: Vascular trauma patients were identified from the Nationwide Inpatient Sample (January 2005 to December 2012) using International Classification of Diseases-Ninth Edition codes. Univariable and multivariable analyses were used to compare in-hospital mortality and amputation for blacks vs whites for younger (16-64 years) and older (≥65 years) age groups. RESULTS: Black patients (n = 937) were younger, more frequently male, without insurance, and suffered from more penetrating and nonaccidental injuries than white patients (n = 1486; P < .001). On univariable analysis, blacks had a significantly higher risk of death (odds ratio, [OR], 1.78; 95% confidence interval [CI], 1.16-2.74) and a significantly lower risk of amputation (OR, 0.54; 95% CI, 0.38-0.77), but these differences were not sustained after adjusting for baseline differences between groups. When stratified by age, there were significant racial disparities in mortality and amputation on univariable analysis. After risk adjustment, these differences persisted in the older group (mortality: OR, 5.95; 95% CI, 1.42-25.0; amputation: OR, 4.21; 95% CI, 1.28-13.6; P < .001) but not the younger group (mortality: OR, 1.31; 95% CI, 0.71-2.42; amputation: OR, 0.92; 95% CI, 0.58-1.46; P = not significant). Differences in survival and amputation after vascular trauma appear to be related to a higher prevalence of nonaccidental penetrating injuries in the younger black population. Race was the single greatest predictor of poor outcomes in the older population (P ≤ .008). CONCLUSIONS: Older black patients are nearly five-times more likely to experience death or amputation after vascular trauma than their white counterparts. Contrary to reports suggesting that younger white patients have better outcomes after all-cause trauma than younger black patients, racial disparities among patients with traumatic vascular injuries appear to be confined to the older age group after risk adjustment.

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.

Mortality variability after endovascular versus open abdominal aortic aneurysm repair in a large tertiary vascular center using a Medicare-derived risk prediction model.

OBJECTIVE: Previous reports have documented better outcomes after open abdominal aortic aneurysm (AAA) repair in tertiary centers compared with lower-volume hospitals, but outcome variability for endovascular AAA repair (EVAR) vs open AAA repairs in a large tertiary center using a Medicare-derived mortality risk prediction model has not been previously reported. In the current study, we compared the observed vs predicted mortality after EVAR and open AAA repair in a single large tertiary vascular center. METHODS: We retrospectively analyzed all patients who underwent repair of a nonruptured infrarenal AAA in our center from 2003 to 2012. Univariable and multivariable logistic regression were used to evaluate 30-day mortality. Patients were stratified into low-risk, medium-risk, and high-risk groups, and mortality was predicted for each patient based on demographics and comorbidities according to the Medicare risk prediction model. RESULTS: We analyzed 297 patients (EVAR, 72%; open AAA repair, 28%; symptomatic, 25%). Most of our patients were of high and moderate risk (48% and 28%, respectively). The observed 30-day mortality was 1.9% after EVAR vs 2.4% after open repair (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.14-4.29; P = .67). There was no difference in mortality with EVAR vs open repair after adjusting for predefined patient characteristics (OR, 0.92; 95% CI, 0.16-7.43; P = .93); only preoperative renal disease was predictive of 30-day mortality after AAA repair in our cohort (OR, 8.39; 95% CI, 1.41-67.0). The observed mortality within our study was significantly lower than the Medicare-derived expected mortality for each treatment group within patients stratified as high risk or medium risk (P ≤ .0002 for all). CONCLUSIONS: Despite treating patients with high preoperative risk status, we report a 10-fold decrease in operative mortality for EVAR and open AAA repair in a tertiary vascular center compared with national Medicare-derived predictions. High-risk patients should be considered for aneurysm management in dedicated aortic centers, regardless of approach.

Progress toward elimination of malaria in Nigeria: uptake of artemisinin-based combination therapies for the treatment of malaria in households in Benin City.

BACKGROUND: The Roll Back Malaria (RBM) Partnership converged in Abuja in 2000. In 2005, Nigeria adopted artemisinin-based combination therapies (ACTs) as first-line therapy for uncomplicated malaria. It was determined that by 2010, 80% of persons with malaria would be effectively treated. OBJECTIVES: To describe household practices for malaria treatment in Benin City; to explore demographic characteristics that may influence use of ACTs. MATERIALS AND METHODS: Multistage sampling technique was used to select households from each of the three local government areas in Benin City. Adult respondents were interviewed. Household reference persons (HRPs) were defined by International Labour Organization categories. Data were collected between December 2009 and February 2010 and were analyzed using Statistical Package for the Social Sciences Version 16.0, at a significance level of P < 0.05 (2-tailed). RESULTS: Of the 240 households selected, 217 were accessible, and respondents from 90% of these recalled the most recent episode (s) of malaria. One-third of malaria episodes had occurred in children younger than 5 years. ACTs were used in 4.9% of households; sulfadoxine-pyrimethamine was the chief non-ACT antimalarial, followed by artemisinin monotherapies. Patent medicine stores were the most common sources of antimalarial medicines (38.2%), followed by private hospitals (20.3%) and private pharmacies (10.6%). Only 8.3% of households got their medicines from government hospitals. Having a HRP in managerial or professional categories was associated with a 6 times higher odds of using ACTs, compared to other occupational categories [odds ratio (OR) 5.8; confidence interval (CI) 1.470-20.758, P = 0.016]. Fathers' tertiary or higher education was significantly associated with ACT use, but not mothers' (OR 0.054, CI 0.006-0.510; P = 0.011 and OR 0.905, CI 0.195-4.198; P = 0.898, respectively). CONCLUSION: Ten years after the historic Abuja meeting, only 5% of households in Benin City used ACTs for the treatment of malaria, sourcing medicines chiefly from patent medicine stores and private hospitals. Fathers' level of education was significantly associated with ACT use. Interventions to eliminate malaria from Nigeria should mainstream the men folk and health care providers outside government hospitals, in line with the Nigerian reality.