Artificial Intelligence to Predict Quality-of-Life Outcomes for Vascular Intervention of the Leg.

BACKGROUND: Artificial intelligence (AI) tools created to enhance decision-making may have a significant impact on treatment algorithms for peripheral arterial disease (PAD). A Markov-based AI model was developed to predict optimal therapy based on maximization of calculated quality of life (cQoL), a patient-centered system of assessment designed to report outcomes directly linked to health-related quality of life. STUDY DESIGN: The AI model was prospectively interrogated immediately after individual interventions for PAD over a 12-year period to test predictive performance. Patient cQoL was determined at each patient follow-up visit. RESULTS: A total of 1,143 consecutive patients were evaluated, with a median follow-up of 18 months. Observed mean annualized cQoL was higher than predicted by the model (0.85 ± 0.38 vs 0.79 ± 0.18, p < 0.0001). Of 5 potential clinical outcomes, the AI model correctly predicted final status in 71.3% of patients, with insignificant model performance deterioration over time (-0.15% per month, r = -0.49, p = 0.063). The chance of having the condition predicted by the model was 0.57 ± 0.32, compared with a theoretical maximum of 0.70 ± 0.19 (p < 0.0001, mean ratio 0.79). The AI model performed better in patients with claudication than limb-threatening ischemia (75.5% vs 63.6%, p = 0.014) but equally well for open or endovascular intervention (69.8% vs 70.5%, p = 0.70). Graft or artery patency and amputation-free survival were better for patients with claudication and those treated with endovascular techniques. CONCLUSIONS: AI can successfully predict treatment for PAD that maximizes patient quality of life in most cases. Future application of AI incorporating better estimates of patient anatomic and physiological risk factors and refinement of model structure should further enhance performance.

Permanent inferior vena cava filters offer greater expected patient utility at lower predicted cost.

OBJECTIVE: Retrievable inferior vena cava (IVC) filters were first approved for use in the United States in 2003 to address the long-term complications of migration, thrombosis, fracture, and perforation observed with permanent IVC filter implantation. Although Food and Drug Administration approval of retrievable IVC filters includes permanent implantation, the incidence of complications from long-term implantation appears to be greater than that reported with existing permanent IVC filters. Also, only a small fraction of such retrievable IVC filters are ever retrieved. The purpose of the present study was to determine the threshold retrieval rate at which the use of retrievable IVC filters could be justified. METHODS: A Markov decision tree was constructed comparing retrievable and permanent IVC filters regarding their effectiveness and cost. A review of the reported data provided outcome probabilities, and the Tufts Medical Center Cost-Effectiveness Analysis Registry was the source of the utility values for the various potential outcomes. Medicare reimbursement rates served as a proxy for costs. A sensitivity analysis was performed for various parameters, primarily to determine the retrieval rate threshold at which the use of retrievable IVC filters would outperform the use of permanent IVC filters. RESULTS: Base case analysis demonstrated a greater predicted effectiveness for permanent compared with retrievable IVC filter implantation (5.41 quality-adjusted life-years [QALY] vs 5.33 QALY) at a lower cost ($2070 vs $4650). Monte Carlo simulation at 10,000 iterations confirmed the expected utility (5.4 ± 3.0 QALY vs 5.3 ± 3.0 QALY; P = .0002) and cost ($1900 ± $7400 vs $4800 ± 9900; P < .0001) to be statistically superior for permanent IVC filters. A sensitivity analysis for the filter retrieval rate demonstrated that the strategy of using a retrievable IVC filter was never preferable for utility or cost. The superiority of permanent IVC filter placement for effectiveness and cost persisted, regardless of anticipated patient-predicted annual mortality. A two-way sensitivity analysis for both IVC filter removal rate and annual patient mortality confirmed the superiority of permanent IVC filter placement at all levels. CONCLUSIONS: The predicted effectiveness of permanent IVC filters was greater and the predicted cost lower than those for retrievable IVC filters, regardless of the IVC filter retrieval rate. This interpretation of existing reported data using Markov decision analysis modeling supports the argument that unless the long-term complication rate of retrievable IVC filters can be significantly improved, their use should be abandoned in favor of currently available permanent IVC filters.

Occlusion of the Celiac Artery during Endovascular Thoracoabdominal Aortic Aneurysm Repair Is associated with Increased Perioperative Morbidity and Mortality.

BACKGROUND: Some studies suggest that celiac artery coverage during elective endovascular thoracoabdominal aortic aneurysm (TAAA) repair is safe given sufficient collateralization of visceral organ perfusion from the superior mesenteric artery. However, there is concern that celiac artery coverage may lead to increased risk of foregut or spinal cord ischemia with an attendant increased risk of mortality. We sought to investigate rates of bowel ischemia, spinal cord ischemia, and 30-day mortality associated with celiac artery coverage during TEVAR and complex EVAR. METHODS: The Society for Vascular Surgery Vascular Quality Initiative database was queried for TEVAR and complex EVAR cases from 2012 to 2018. Inclusion criteria included TAAA pathology and endograft extension to aortic zone 6. Patients with aortic rupture, trauma, prior thoracic aortic surgery, known preoperative occlusion of the left subclavian superior mesenteric, or celiac arteries were excluded. Cases with intraoperative celiac artery occlusion (CAO) were compared retrospectively to cases with celiac artery preservation (CAP). Primary outcomes included 30-day mortality and a composite end point of 30-day mortality, spinal cord ischemia (transient or permanent lower extremity neurologic deficit), and bowel ischemia (colonoscopic evidence of ischemia, bloody stools in a patient who dies prior to colonoscopy or laparotomy, or other documented clinical diagnosis). Univariable comparisons were performed using chi-squared tests and Student's t-tests, as appropriate. Multivariable logistic regression analyses were employed to identify independent predictors of outcome. RESULTS: There were 628 cases identified for inclusion in the study. Patients undergoing CAO (n = 44) were more likely to be female or to have higher rates of preoperative spinal drain use, American Society of Anesthesiologists score ≥3, low preop hemoglobin, and/or symptomatic presentation, but fewer mean number of aortic zones covered. CAO was associated with higher 30-day mortality (5 of 44, 11%) compared to CAP (23 of 584, 4%), P = 0.039. The composite end point occurred at a significantly greater proportion for those who had CAO (10 of 44, 23%) compared to CAP (53 of 584, 9%, P = 0.008), driven by higher rates of 30-day mortality and bowel ischemia (9% vs. 2%, P = 0.026). By multivariate analysis, CAO was predictive of 30-day mortality (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 1.1-13.8, P = 0.04) and the composite endpoint (OR = 3.0, 95% CI = 1.1-8.5, P = 0.03). Increasing procedure time was also associated with 30-day mortality (OR = 1.4, 95% CI = 1.1-1.7, P < 0.001) and the composite end point (OR = 1.4, 95% CI = 1.1-1.6, P < 0.001). CONCLUSIONS: For those treated for TAAAs, CAO was independently predictive of increased 30-day mortality and a composite end point of perioperative mortality, spinal cord ischemia, and bowel ischemia. When treating patients with extensive aortic aneurysmal disease, physicians should attempt to preserve the celiac artery, by revascularization or avoiding ostium coverage, whenever feasible.

Real-world cost analysis of endovascular repair versus open repair in patients with nonruptured abdominal aortic aneurysms.

BACKGROUND: The aim of this study was to provide a nationwide, all-payer, real-world cost analysis of endovascular aortic aneurysm repair (EVAR) versus open aortic aneurysm repair (OAR) in patients with nonruptured abdominal aortic aneurysms (non-rAAA). METHODS: All non-rAAA patients registered between July 2009 and March 2015 in the Premier Healthcare Database were analyzed. The Student t-test and the χ2 test were used for continuous and categorical variables, respectively; median value comparisons were done with the Wilcoxon-Mann-Whitney rank-sum test. The in-hospital absolute mean total cost (sum of fixed cost and variable cost) and subcategories were analyzed after adjustment for inflation at July 2015. Fixed costs included all overhead costs while variables costs included in-hospital services including procedures, room and board, services provided by hospital staff, and pharmacy costs. Total cost was stratified based on admission type (emergency vs nonemergency), 75th percentile of length of hospital stay among individual procedures (expected vs extended stay), mortality, and complications. Student t-test and Fisher's analysis of variance were used for comparing mean cost. Year-wise comparison of mean cost was done with analysis of variance to look for a trend over time. RESULTS: Our study cohort included 38,809 non-rAAA patients (33,171 EVAR and 5638 OAR). The mean total cost of index admission was lower in EVAR in comparison with OAR ($32,052 vs $36,091; P < .001), with lower fixed costs ($11,309 vs $16,818; P < .001) and higher variable costs ($20,743 vs $19,272; P < .001). Cost of pharmacy, labor, operating room, room and board and other costs were significantly higher with OAR, whereas the supply cost was higher with EVAR. The expected hospital length of stay of patients who underwent EVAR was associated with a higher total cost ($27,271 vs $25,680; P < .001) and a higher variable cost ($18,186 vs $13,671; P < .001) than OAR patients. However, the extended hospital stay of patients who underwent EVAR had lower costs in all categories compared with the extended length of stay of those who underwent OAR. Mortality associated with EVAR was costlier than OAR associated mortality (mean $72,483 vs $59,804; P = .017). From 2009 to 2014, the mean total cost of EVAR increased significantly by 18.5% ($28,745 vs $34,049; P < .001) owing to a 7.8% increase in fixed costs ($10,931 vs $11,789; P < .001) and a 25.0% increase in variable costs ($17,804 vs $22,257; P < .001). The mean total cost OAR remained stable over time. CONCLUSIONS: Overall hospitalization costs associated with EVAR of non-rAAA was lower than the hospitalization cost of OAR. Interestingly, we found that, among patients who had an expected hospital length of stay, the hospitalization cost after OAR was significantly lower than after EVAR. The average hospitalization cost of OAR was stable during the 5 years study period, whereas the hospitalization cost of EVAR increased significantly over time. Further studies are required to identify reasons for increased costs associated with EVAR.

Previous thoracic aortic repair is not associated with adverse outcomes after thoracic endovascular aortic repair.

BACKGROUND: As many as 20% of patients who have undergone previous thoracic aortic repair will require reintervention, which could entail thoracic endovascular aortic repair (TEVAR). A paucity of data is available on mortality and the incidence of spinal cord ischemia (SCI) and other postoperative complications associated with TEVAR after previous aortic repairs exclusive to the thoracic aorta. The aim of the present study was to assess the effect of previous thoracic aortic repair on the 30-day mortality and SCI outcomes for patients after TEVAR. METHODS: The Society for Vascular Surgery Vascular Quality Initiative database was queried for all cases of TEVAR from 2012 to 2018. Patients were excluded if they had undergone previous abdominal aortic repair, the TEVAR had extended beyond aortic zone 5, or SCI data were missing. The 3 cohorts compared were TEVAR with previous ascending aortic or aortic arch repair (group 1), TEVAR with previous descending thoracic aortic repair (group 2), and TEVAR without previous repair (group 3). The primary outcomes of interest were 30-day mortality and SCI. The secondary outcomes included stroke, myocardial infarction, cardiac complications, respiratory complications, postoperative length of stay, and reintervention. The patient variables were compared using χ2 tests, analysis of variance, or Kruskal-Wallis tests, as appropriate. Logistic regression analysis was performed to identify the predictors of 30-day mortality and SCI. RESULTS: A total of 4010 patients met the inclusion criteria, with 470 in group 1, 132 in group 2, and 3408 in group 3. The 30-day mortality was 4% (19 of 470) in group 1, 6% (8 of 132) in group 2, and 6% (213 of 3408) in group 3 (P = .17). The incidence of SCI was 3% (14 of 470) in group 1, 3% (4 of 132) in group 2, and 3.8% (128 of 3408) in group 3 (P = .65). Stroke, reintervention, myocardial infarction, and cardiac complications were not significantly different among the 3 groups. The incidence of respiratory complications was greatest for group 3 (11%; 360 of 3408) compared with groups 1 (9%; 44 of 470) and 2 (4%; 5 of 132; P = .034). Similarly, the postoperative length of stay was longest for group 3 (9.6 ± 19.4 days vs 8.2 ± 18.3 days for group 1 and 5.9 ± 8.6 days for group 2; P = .038). The independent predictors of 30-day mortality for all TEVAR patients included units of packed red blood cells transfused intraoperatively, urgent or emergent repairs, older age, increasing serum creatinine level, inability to perform self-care, total procedure time, occlusion of the left subclavian artery intraoperatively, distal endograft landing zone 5, and diabetes. The predictors of SCI included the total procedure time, urgent and emergent repairs, and increasing serum creatinine level. CONCLUSIONS: TEVAR after previous thoracic aortic repair was not associated with an increased risk of SCI or 30-day mortality compared with TEVAR without previous aortic repair.

Errors in Reporting Significant Figures in Surgical and Medical Journals in 2017.

BACKGROUND: The present study was undertaken to ascertain the prevalence of published data with errors in the numerical significant figures in established surgical and medical journals in 2017. The frequency of errors was not only summarized but was also correlated to the published journal impact factor for the seven journals reviewed. METHODS: All original investigations and other analysis reporting quantitative statistical results published in seven surgical and medical journals in 2017 were electronically reviewed for errors in reporting significant figures of the published statistical findings. Errors in significant figures were placed into one of three author defined categories: calculated significant figure errors, interval precision errors, and P value reporting errors. Tests for intraobserver and interobserver reproducibility were conducted blindly to ensure validity and reproducibility between different readers. RESULTS: A total of 1675 articles published in 2017 were identified and reviewed. In total, 730 articles (44%) were reported to have an error in one category, with error rates ranging from 25% to 68% depending on publishing journal. The error rate for each journal were easily reproduced by different observers (κ coefficient range: 0.55-0.81) and correlated with its 2016 impact factor (r = 0.97, R2 = 0.95, P < 0.001). CONCLUSIONS: Published findings are frequently reported incorrectly in the surgical and medical literature and can be potentially misleading. The pervasiveness of errors correlates to fewer citations as measured by the lower impact factor.

Limitations of Vascular Quality Initiative-derived models to predict the outcomes of intervention for infrapopliteal limb-threatening ischemia.

OBJECTIVE: The purpose of this study was to validate published Society for Vascular Surgery Vascular Quality Initiative (VQI) prediction models for patients with limb-threatening ischemia (LTI) undergoing open or endovascular revascularization for infrapopliteal occlusive disease. METHODS: We sought to validate our prior VQI LTI models for major adverse limb events (MALEs) and amputation-free survival (AFS) in a VQI new cohort undergoing open or percutaneous interventions from September 2014 through August 2016. Receiver operating characteristic curves were generated including the C statistic, and the predicted vs actual outcomes were correlated. The Hosmer-Lemeshow (HL) statistic was calculated to determine goodness of fit, and the Tjur R2 statistic was derived to demonstrate the degree to which the observed outcomes were accurately predicted by the models. RESULTS: Of 15,576 open infrainguinal and 34,679 percutaneous interventions collected in the VQI during the 24-month interval, 8852 and 17,124, respectively, were performed for LTI, among which 4410 and 5116 specifically targeted the infrapopliteal vessels. MALEs and AFS were identified for 400 of 927 (43.1%) and 576 of 982 (58.7%) open procedures and 197 of 855 (23.0%) and 658 of 1115 (59.0%) percutaneous procedures, respectively. For open operation, the predictive ability of the model was poor for MALEs (C = 0.59; HL = 107; R2 = 0.03) and only marginally better for AFS (C = 0.69; HL = 130; R2 = 0.10). Similarly, for endovascular intervention, the model performed poorly for MALEs (C = 0.62; HL = 183; R2 = 0.06) and slightly better for AFS (C = 0.68; HL = 68; R2 = 0.11). Breaking AFS into its component determinants, the predictive ability of the open operation model for patient survival (C = 0.77; HL = 70; R2 = 0.15) surpassed that for limb salvage (C = 0.64; HL = 54; R2 = 0.05). For endovascular interventions, the survival model (C = 0.71; HL = 94; R2 = 0.11) also outperformed the limb salvage model (C = 0.67; HL = 28; R2 = 0.07). For both types of intervention, the actual MALE rate was lower and AFS was higher than predicted by the models. CONCLUSIONS: The ability of reported VQI-derived models to accurately predict major outcomes for infrapopliteal LTI is limited and cannot be advocated for clinical decision-making at this time. Further study would be necessary to determine whether this is due to intraoperative and postoperative variables not accounted for in our models, absence of pertinent data points from the registry, or incomplete follow-up.

Outcomes for peripheral vascular intervention and lower extremity bypass in kidney transplant recipients are superior to outcomes of patients remaining on dialysis.

BACKGROUND: Improved survival is reported for patients with end-stage renal disease who are kidney transplant recipients (KTRs) compared with dialysis-dependent patients (DDPs). Whether amputation-free survival (AFS) and freedom from major adverse limb events (MALEs) after peripheral vascular intervention (PVI) or lower extremity bypass (LEB) are superior after renal transplantation remains incompletely defined. METHODS: A retrospective cohort study was undertaken of KTRs and DDPs undergoing infrainguinal PVI or LEB for symptoms of limb-threatening ischemia recorded in the Vascular Quality Initiative from 2003 to 2017. Primary outcomes were AFS and freedom from MALEs along with their components of assisted primary patency, limb salvage, and patient survival. The χ2 tests and independent samples t-tests were used to compare demographic variables. Kaplan-Meier survival analyses were used to estimate outcomes, and Cox regression analyses were used to confirm independent predictors of outcome. RESULTS: There were 2707 PVI (351 KTRs and 2356 DDPs) and 1444 LEB (198 KTRs and 1246 DDPs) procedures performed for limb-threatening ischemia. Chronic obstructive pulmonary disease, congestive heart failure, female patients, and African Americans were more common among the DDP group, as were lower preoperative hemoglobin values and older age. After PVI, KTRs had better AFS than DDPs (42% vs 66% at 1 year, 15% vs 26% at 2 years; hazard ratio [HR], 1.91; 95% confidence interval [CI], 1.38-2.64; P < .001) and fewer MALEs (53% vs 64% at 1 year, 35% vs 49% at 18 months; HR, 1.71; 95% CI, 1.25-2.34; P = .001). PVI outcomes, AFS, and freedom from MALEs were driven primarily by differences in limb salvage and patient survival but not assisted primary patency. After LEB, KTRs also displayed improved AFS compared with DDPs (44% vs 65% at 1 year, 10% vs 36% at 3 years; HR, 2.32; 95% CI, 1.41-3.81; P = .001), driven by patient survival but not limb salvage, whereas differences in freedom from MALEs did not attain statistical significance (67% vs 58%; P = .08). CONCLUSIONS: For patients with end-stage renal disease, subsequent kidney transplantation was associated with better AFS and freedom from MALEs after PVI but only improved AFS after LEB. Open or endovascular revascularization can be advocated in patients with limb-threatening ischemia who have received kidney transplantation to a greater degree than in those who remain dialysis dependent.

The impact of current smoking on outcomes after infrainguinal bypass for claudication.

OBJECTIVE: Although smoking cessation is a benchmark of medical management of intermittent claudication, many patients require further revascularization. Currently, revascularization among smokers is a controversial topic, and practice patterns differ institutionally, regionally, and nationally. Patients who smoke at the time of revascularization are thought to have a poor prognosis, but data on this topic are limited. The purpose of this study was to evaluate the impact of smoking on outcomes after infrainguinal bypass for claudication. METHODS: Data from the national Vascular Quality Initiative from 2004 to 2014 were used to identify infrainguinal bypasses performed for claudication. Patients were categorized as former smokers (quit >1 year before intervention) and current smokers (smoking within 1 year of intervention). Demographic and comorbid differences of categorical variables were assessed. Significant predictors were included in adjusted Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) by smoking status for outcomes of major adverse limb event (MALE), amputation-free survival, limb loss, death, and MALE or death. Cumulative incidence curves were created using competing risks modeling. RESULTS: We identified 2913 patients (25% female, 9% black) undergoing incident infrainguinal bypass grafting for claudication. There were 1437 current smokers and 1476 former smokers in our study. Current smoking status was a significant predictor of MALE (HR, 1.27; 95% CI, 1.00-1.60; P = .048) and MALE or death (HR, 1.22; 95% CI, 1.03-1.44; P = .02). Other factors found to be independently associated with poor outcomes in adjusted models included black race, below-knee bypass grafting, use of prosthetic conduit, and dialysis dependence. CONCLUSIONS: Current smokers undergoing an infrainguinal bypass procedure for claudication experienced more MALEs than former smokers did. Future studies with longer term follow-up should address limitations of this study by identifying a data source with long-term follow-up examining the relationship of smoking exposure (pack history and duration) with outcomes.

Perioperative psoas to lumbar vertebral index does not successfully predict amputation-free survival after lower extremity revascularization.

BACKGROUND: Accurate and convenient methods for assessing a patient's risk of postoperative morbidity and mortality comprise important tools in clinical decision-making. Whereas some aspects of the patient's fitness for surgery can be easily quantified, measurement of the patient's frailty is often difficult or time-consuming. Previous research in the context of multiple types of major surgical procedures has reported psoas-L4 vertebral index (PLVI) to be a useful predictor of postoperative morbidity and mortality. METHODS: This retrospective cohort study assessed the hypothesis that PLVI can predict amputation-free survival (AFS) in patients undergoing open or endovascular lower extremity revascularization. The records of all lower extremity revascularization patients with preoperative computed tomography arteriography before revascularization during a recent 6-year period were reviewed for demographic information and outcomes. With use of embedded computed tomography software, the cross-sectional area of the bilateral psoas muscles and vertebral body at the L4 level were measured and used to calculate the PLVI. Univariate, multivariate logistic regression, and Cox proportional hazards analyses were performed for the primary outcome of AFS. RESULTS: During a 6-year period, 188 patents had preoperative scanning, qualifying for inclusion in the study; 52% received open surgical bypass and 48% received a percutaneous endovascular procedure, with a median duration of follow-up of 12 months (interquartile range [IQR], 3-24 months). Median bilateral psoas cross-sectional area was 24.9 cm2 (IQR, 20.5-29.7 cm2), and mean PLVI was 1.74 (IQR, 1.39-2.05). Cox proportional hazards analysis identified age (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.01-1.14; P = .026), congestive heart failure (HR, 4.7; 95% CI, 1.29-16.9; P = .019), and dyslipidemia (HR, 0.34; 95% CI, 0.12-0.99; P = .049) as independent predictors of AFS loss, whereas PLVI was not (HR, 2.6; 95% CI, 0.83-8.39; P = .099). Kaplan-Meier life-table analysis demonstrated no significant differences in survival between the highest and lowest PLVI cohorts of patients. Hazard analysis showed concomitant congestive heart failure (HR, 15; 95% CI, 1.1-210; P = .042) and serum albumin concentration (HR, 0.16; 95% CI, 0.05-0.52; P = .0026) to be independent predictors of limb loss, whereas advanced age (HR, 1.20; 95% CI, 1.07-1.35; P = .0026), bypass procedure (HR, 4.6; 95% CI, 1.04-21; P = .045), non-African American race (HR, 9.09; 95% CI, 1.02-100; P = .048), and higher PLVI (HR, 10.9; 95% CI, 1.7-72; P = .013) predicted increased risk of mortality. CONCLUSIONS: PLVI did not predict AFS after intervention for peripheral arterial occlusive disease. This is contrary to the ability of PLVI to predict perioperative and midterm survival after abdominal aortic aneurysm repair and other major abdominal surgery.

Better survival for African and Hispanic/Latino Americans after infrainguinal revascularization in the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: Inferior survival outcomes have historically been reported for African Americans with cardiovascular disease, and poorer outcomes have been presumed for peripheral arterial disease (PAD) as well. The current study evaluates the effect of race and ethnicity on survival of patients undergoing open or endovascular interventions for lower extremity PAD. METHODS: Data of patients from the Society for Vascular Surgery Vascular Quality Initiative database were obtained for patients undergoing open infrainguinal (INFRA) or suprainguinal (SUPRA) bypass, peripheral vascular intervention (PVI), and amputation (AMP). Patients were further stratified as suprainguinal (SupraPVI) if any of the first three interventions listed included the aorta or iliac vessels or infrainguinal (InfraPVI) if not. The primary outcome was the patient's death (overall mortality) as recorded in the database or determined by cross-reference with the Social Security Death Index (SSDI). The secondary outcome consisted of perioperative mortality during the index hospitalization. Generalized linear modeling provided multivariate analysis, with entry of variables dependent on results of univariate analysis. RESULTS: From January 2003 through September 2015, a total of 24,241 INFRA bypass, 8028 SUPRA bypass, 48,048 InfraPVI, 21,196 SupraPVI, and 3423 AMP patients met criteria for analysis, with a median follow-up of 18 (interquartile range, 8-33) months. Combining all procedures, overall mortality was lower among African Americans than among white Americans (12.4% vs 14.2%; P < .0001) but not death in the periprocedural period (1.1% vs 1.2%; P = .26). To account for differences in length of follow-up, Cox proportional hazards analysis confirmed that the African American race was independently associated with a significantly lower occurrence of overall mortality after INFRA bypass (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.70-0.88; P < .0009), InfraPVI (HR, 0.72; 95% CI, 0.67-0.78; P < .0001), and SupraPVI (HR, 0.77; 95% CI, 0.66-0.90; P = .0009) interventions but not after SUPRA bypass or AMP. Similarly, by Cox proportional hazards, Hispanic/Latino ethnicity was also independently associated with lower overall mortality after INFRA bypass (HR, 0.75; 95% CI, 0.62-0.91; P = .0030), InfraPVI (HR, 0.69; 95% CI, 0.62-0.78; P < .0001), and SupraPVI (HR, 0.68; 95% CI, 0.52-0.89; P = .0045) but not after SUPRA bypass or AMP. CONCLUSIONS: Contrary to the published data for other forms of cardiovascular disease, African American patients as well as patients identified with Hispanic/Latino ethnicity with PAD included in the Society for Vascular Surgery Vascular Quality Initiative undergoing INFRA revascularization for lower extremity PAD experienced better overall survival compared with white Americans.

Revascularization of smokers with claudication is not predicted to limit quality of life despite a higher risk of late failure.

OBJECTIVE: Tobacco smoking after lower extremity revascularization for claudication has repeatedly been shown to increase the risk of adverse events, such that many vascular specialists consider that refusal to abstain from smoking constitutes a major contraindication to open surgical bypass or endovascular intervention. METHODS: A Markov decision analysis (DA) model was used to compare the options of direct revascularization vs medical therapy only in smokers with claudication. The primary outcome was calculated quality of life (cQoL), determined for each patient at follow-up based on the outcomes of the treatment received. Markov DA software was used to predict the QoL for each treatment option preoperatively based on smoking status. RESULTS: Among patients referred during a recent 64-month period with vasculogenic claudication, 94 were actively smoking compared with 217 who were not. The DA model predicted that if the patients who smoked were to discontinue smoking, the best therapy would be bypass surgery for 77% and endovascular intervention for 17%. However, despite at least doubling the risks with intervention in the patients who continue to smoke, the DA model still predicted that 78% and 9% would fare better with open surgical or endovascular intervention, respectively. Among actively smoking patients, open surgical (3%) or endovascular (4%) therapies were initially performed in few patients, whereas 93% were offered only medical therapy. Among initial nonsmokers, revascularization was performed by open (27%) or endovascular (42%) means. At 3 years, the median (interquartile range [IQR]) cQoL was lower in initial smokers than in nonsmokers (0.73 [IQR, 0.73-0.77] vs 0.82 [IQR, 0.75-0.86]; P < .0001), primarily because of a lack of revascularization for smokers. Among initial smokers who did undergo revascularization initially, because of progression of symptoms, or after smoking cessation, cQoL was similar to initial nonsmokers (0.77 [IQR, 0.73-0.84] vs 0.73 [IQR, 0.73-0.73]; P = .37). Although 26% of initial smokers had stopped by the time of their last follow-up, 10% of initially nonsmoking patients were smoking at follow-up. However, among all patients undergoing intervention, the cQoL of patients smoking at the time of last their follow-up was similar to nonsmokers (0.82 [IQR, 0.82-0.86] vs 0.83 [IQR, 0.73-0.86]; P = .99). CONCLUSIONS: Patients with claudication who smoke may be denied the symptom improvement associated with revascularization, yet recidivism for smoking also occurs among patients who have stopped smoking in order to receive revascularization. The strategy not to directly revascularize patients with claudication who continue to smoke does not appear to maximize patient midterm QoL.

Predicting outcomes for infrapopliteal limb-threatening ischemia using the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: The outcomes of open surgical or endovascular intervention for limb-threatening ischemia (LTI) involving the infrapopliteal vessels are dependent on complex anatomic, demographic, and disease factors. To assist in decision-making, we used the Vascular Quality Initiative (VQI) to derive a model using only preoperatively available factors to predict important outcomes for open or endovascular revascularization. METHODS: National VQI data for the infrainguinal bypass and peripheral vascular intervention (PVI) modules were reviewed in a blinded fashion for patients who underwent intervention for LTI of the infrapopliteal vessels. Primary outcomes consisted of major adverse limb event (MALE) and amputation-free survival (AFS). Generalized linear modeling was used for the multivariate analyses, with entry of variables dependent on results of univariate analysis. RESULTS: From January 2003 through August 2014 a total of 19,053 infrainguinal open bypass and 48,739 PVI procedures were identified, among which 5264 and 5252, respectively, represented infrapopliteal (tibial-peroneal-pedal) revascularization for LTI. From these, 3036 infrapopliteal open bypass patients and 1319 infrapopliteal PVI patients had sufficient follow-up data for study inclusion. For open surgery, the reduced generalized linear model revealed that American Society of Anesthesiologists class 4 or 5, previous major amputation, living at home, and female sex had the greatest adverse effect on MALE, and dialysis dependence, low body mass index, and lack of great saphenous vein as a conduit had the greatest negative effect on AFS. For PVI, lesion length from 10 to 15 cm, treatment of three or more arteries, and classification other than A on the Trans-Atlantic Inter-Society Consensus demonstrated the largest adverse effects on MALE, and dialysis dependence, low body mass index, and congestive heart failure most negatively affected AFS. CONCLUSIONS: This study on a cross-section of patients selected for intervention in academic and community hospitals offers a "real world" glimpse of factors predictive of outcome. The VQI can be used to derive models that predict the outcomes of open surgical bypass or PVI for LTI involving the infrapopliteal vessels.

Contemporary results of carotid endarterectomy in "normal-risk" patients from the Society for Vascular Surgery Vascular Registry.

OBJECTIVE: Acceptable complication rates after carotid endarterectomy (CEA) are drawn from decades-old data. The recent Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) demonstrated improved stroke and mortality outcomes after CEA compared with carotid artery stenting, with 30-day periprocedural CEA stroke rates of 3.2% and 1.4% for symptomatic (SX) and asymptomatic (ASX) patients, respectively. It is unclear whether these target rates can be attained in "normal-risk" (NR) patients experienced outside of the trial. This study was done to determine the contemporary results of CEA from a broader selection of NR patients. METHODS: The Society for Vascular Surgery (SVS) Vascular Registry was examined to determine in-hospital and 30-day event rates for NR, SX, and ASX patients undergoing CEA. NR was defined as patients without anatomic or physiologic risk factors as defined by SVS Carotid Practice Guidelines. Raw data and risk-adjusted rates of death, stroke, and myocardial infarction (MI) were compared between the ASX and SX cohorts. RESULTS: There were 3977 patients (1456 SX, 2521 ASX) available for comparison. The SX group consisted of more men (61.7% vs 57.0%; P = .0045) but reflected a lower proportion of white patients (91.3% vs 94.4%; P = .0002), with lower prevalence of coronary artery disease (P < .0001), prior MI (P < .0001), peripheral vascular disease (P = .0017), and hypertension (P = .029), although New York Heart Association grade >3 congestive heart failure was equally present in both groups (P = .30). Baseline stenosis >80% on duplex imaging was less prevalent among SX patients (54.2% vs 67.8%; P < .0001). Perioperative stroke rates were higher for SX patients in the hospital (2.8% vs 0.8%; P < .0001) and at 30 days (3.4% vs 1.0%; P < .0001), which contributed to the higher composite death, stroke, and MI rates in the hospital (3.6% vs 1.8; P = .0003) and at 30 days (4.5% vs 2.2%; P < .0001) observed in SX patients. After risk adjustment, the rate of stroke/death was greater among SX patients in the hospital (odds ratio, 2.05; 95% confidence interval, 1.18-3.58) although not at 30 days (odds ratio, 1.36; 95% confidence interval, 0.85-2.17). No in-hospital or 30-day differences were observed for death or MI by symptom status. CONCLUSIONS: The SVS Vascular Registry results for CEA in NR patients are similar by symptom status to those reported for CREST and may serve as a benchmark for comparing results of alternative therapies for treatment of carotid stenosis in NR patients outside of monitored clinical trials. The contemporary perioperative risk of stroke after CEA in NR patients continues to be higher for SX than for ASX patients.

Standard duplex criteria overestimate the degree of stenosis after eversion carotid endarterectomy.

OBJECTIVE: The eversion technique for carotid endarterectomy (eCEA) offers an alternative to longitudinal arteriotomy and patch closure (pCEA) for open carotid revascularization. In some reports, eCEA has been associated with a higher rate of >50% restenosis of the internal carotid when it is defined as peak systolic velocity (PSV) >125 cm/s by duplex imaging. Because the conformation of the carotid bifurcation may differ after eCEA compared with native carotid arteries, it was hypothesized that standard duplex criteria might not accurately reflect the presence of restenosis after eCEA. METHODS: In a case-control study, the outcomes of all patients undergoing carotid endarterectomy by one surgeon during the last 10 years were analyzed retrospectively, with a primary end point of PSV >125 cm/s. Duplex flow velocities were compared with luminal diameter measurements for any carotid computed tomography arteriography or magnetic resonance angiography study obtained within 2 months of duplex imaging, with the degree of stenosis calculated by the methodology used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) as well as cross-sectional area (CSA) reduction. Simulations were generated and analyzed by computational model simulations of the eCEA and pCEA arteries. RESULTS: Eversion and longitudinal arteriotomy with patch techniques were used in 118 and 177 carotid arteries, respectively. Duplex follow-up was available in 90 eCEA arteries at a median of 16 (range, 2-136) months and in 150 pCEA arteries at a median of 41 (range, 3-115) months postoperatively. PSV >125 cm/s was present at some time during follow-up in 31% of eCEA and pCEA carotid arteries, each, and in the most recent duplex examination in 7% after eCEA and 21% after pCEA (P = .003), with no eCEA and two pCEA arteries occluding completely during follow-up (P = .29). In 19 carotid arteries with PSV >125 cm/s after angle correction (median, 160 cm/s; interquartile range, 146-432 cm/s) after eCEA that were subsequently examined by axial imaging, the mean percentage stenosis was 8% ± 11% by NASCET, 11% ± 5% by ECST, and 20% ± 9% by CSA criteria. For eight pCEA arteries with PSV >125 cm/s (median velocity, 148 cm/s; interquartile range, 139-242 cm/s), the corresponding NASCET, ECST, and CSA stenoses were 8% ± 35%, 26% ± 32%, and 25% ± 33%, respectively. NASCET internal carotid diameter reduction of at least 50% was noted by axial imaging after two of the eight pCEAs, and the PSV exceeded 200 cm/s in each case. CONCLUSIONS: The presence of hemodynamically significant carotid artery restenosis may be overestimated by standard duplex criteria after eCEA and perhaps after pCEA. Insufficient information currently exists to determine what PSV does correspond to hemodynamically significant restenosis.

Failure of patients with peripheral arterial disease to accept the recommended treatment results in worse outcomes.

BACKGROUND: Strategies available to facilitate decision making for patients with peripheral arterial disease (PAD) include a Markov-based decision analysis (DA) model and the Lower Extremity Grading System (LEGS) score. Both have suggested inferior outcomes when the actual treatment received (ATX) differs from that predicted. This study focuses on patient outcomes when such discordance exists. METHODS: All patients referred for symptomatic lower extremity PAD over a 3-year period were evaluated using the DA model and the LEGS score. Calculated quality of life (cQOL) values were assigned before treatment based on patient symptom, perfusion, and amputation status and at follow-up (range 1.000 [perfect health] to .000 [death]). The primary outcome of cQOL was compared according to whether the ATX matched that proposed by the surgeon or predicted by the DA model or LEGS score. Secondary outcomes for revascularized patients included major adverse limb event with perioperative death (MALE + POD) and amputation-free survival (AFS). RESULTS: Among 375 procedures in 345 consecutive patients, the greatest improvement in cQOL at last follow-up (median 16 months) was observed with endovascular (0.23 ± 0.16, n = 93) or open (0.21 ± 0.17, n = 137) revascularization compared with primary amputation (0.10 ± 0.07, n = 23) or medical therapy (0.04 ± 0.09, n = 122). Multivariate regression showed discordance with the surgeon's recommendation (P < 0.05) and/or the DA model (P < 0.05) to be independent predictors of improvement failure. ATX did not always agree with that proposed by the surgeon (89% agree, κ = 0.84), the DA model (68% agree, κ = 0.53), or the LEGS score (53% agree, κ = 0.32). Improvement in cQOL was greatest when ATX was concordant with treatment proposed by the surgeon (0.18 vs. 0.08, P < 0.01), the DA model (0.19 vs. 0.13, P < 0.01), or the LEGS score (0.23 vs. 0.10, P < 0.01). Patient refusal to follow the surgeon's recommendations and continued smoking were associated with minimal improvement (cQOL ranges 0.05-0.07 and 0.00-0.02, respectively), while pursuing a less morbid procedure was associated with greater improvement (cQOL range 0.28-0.38). Among revascularized patients, MALE + POD was lower at 36 months after endovascular than open surgery (21% ± 5% vs. 36% ± 4%, P < 0.05), while AFS was not significantly different. Only discordance with the surgeon's recommendation was an independent predictor of MALE + POD, possibly because of limitations in sample subset size. CONCLUSIONS: Mean cQOL improved most with direct revascularization, especially when the treatment received matched that predicted by the models or proposed by the surgeon. Type of treatment received was an independent predictor of agreement of treatment with recommendations. Patient refusal to follow the recommended treatment as well as the strategy not to revascularize claudicants who persist in smoking were associated with much less patient benefit from treatment.