Vascular Quality Initiative Database Research Articles

Variability in Short-term Mortality Following Repair of Ruptured Abdominal Aortic Aneurysms Across Centers and Physicians

Variation in the care management of repairs for ruptured infrarenal abdominal aortic aneurysms (rAAA) between centers and physicians, e.g., the procedural volumes may explain differences in mortality outcomes. First, we quantified the center and physician variability associated with 30- and 90-day mortality risk following open (rOSR) and endovascular (rEVAR) aneurysm repair. Second, we explored wheter part of this variability was attributable to procedural volume at the center and physician level. Two cohorts including rOSR and rEVAR procedures between 2013-2019 were analyzed from the Vascular Quality Initiative database. Thirty- and 90-day all-cause mortality was derived from linked Medicare claims data. The median odds ratio (MOR, median mortality risk from low- to high-risk cluster) and intraclass correlation (ICC, variability attributable to each cluster) for 30- and 90-day mortality risk associated with center and physician variability were derived using patient-level adjusted multilevel logistic regression models. Procedural volume was calculated at the center and physician levels and stratified by quartiles. The models were sequentially adjusted for volumes, and the difference in ICC (without vs. with accounting for volume) was calculated to describe the center and physician variability in mortality risk attributable to volumes. We included 450 rOSRs (mean age=74.5±7.6 years; 23.5% female) and 752 rEVARs (76.4±8.4 years; 26.1% female). Following rOSRs, the 30- and 90-day mortality rates were 32.9% and 38.7%. No variability across centers and physicians was noted (30- and 90-day MORs ≈ 1 and ICCs ≈ 0%). Neither center nor physician volume was associated with 30-day(P=.477 and P=.796) or 90-day mortality (P=.098 and P=.559). Following rEVAR, the 30- and 90-day mortality rate was 21.3% and 25.5%, respectively. Significant center variability (30-day MOR=1.82 95%CI 1.33-2.22 and ICC=11% 95%CI 2%-36%; 90-day MOR=1.76 95%CI 1.37-2.09 and ICC=10% 95%CI 3%-30%), but negligeable variability across physicians (30- and 90-day MORs≈1 and ICCs ≈ 0%) were noted. Neither center nor physician volume was associated with 30- (P=.076 and P=.336) nor 90-day mortality risk (P=.066 and P=.584). The center variability attributable to procedural volumes was negligeable (difference in ICCs: 1% for 30-day; 0% for 90-day mortality). Variability in practice from center-to-center was associated with short-term mortality outcomes in rEVAR, but not for rOSR. Physician variability was not associated with short-term mortality for rOSR or rEVAR. Annualized center and physician volumes did not significantly explain these associations. Further work is needed to identify center-level factors affecting the quality of care and outcomes for ruptured AAA.

Center-level outcomes following elective fenestrated endovascular aortic aneurysm repair in the Vascular Quality Initiative database

ObjectiveHospital volume is associated with mortality after open aortic aneurysm repair. Fenestrated and branched endovascular aortic repair (B-FEVAR) has been increasingly used for repair of complex thoracoabdominal and juxtarenal aneurysms, but evidence of a center-volume relationship is limited. We aimed to measure the association of center volume with in-hospital mortality, postoperative outcomes, and 1-year survival following B-FEVAR. MethodsPatients undergoing elective endovascular thoracoabdominal and complex abdominal aneurysm repair with branch intervention (2014-2021) listed within the national Vascular Quality Initiative Thoracic Endovascular Aortic Repair/Complex EVAR database were analyzed. Centers were grouped into quartiles by mean annual procedure volume. Multivariable regression was used to evaluate the effect of center volume on in-hospital mortality adjusting for baseline and procedural characteristics. Kaplan-Meier estimation, log rank test, and mixed effects Cox regression were used to evaluate 1-year survival. ResultsA total of 4302 adult elective F-BEVAR procedures were identified at a total of 163 centers. In-hospital mortality did not differ by hospital volume (quartile [Q]1 = 35/1059 [3.3%]; Q2 = 30/1063 [2.8%]; Q3 = 33/1120 [2.9%]; and Q4 = 44/1060 [4.2%]; P = .308). The high volume group had a higher rate of major complication (Q1 = 14.9%; Q2 = 12.8%; Q3 = 13.3%; and Q4 = 20.1%; adjusted P < .001). Physician-modified grafts were more frequently employed in high-volume centers (Q1 = 4.5%; Q2 = 18.7%; Q3 = 11.3%; and Q4 = 19.2%; P < .001), with a decreased incidence of any endoleak noted at the end of the procedure (Q1 = 34.9%; Q2 = 32.8%; Q3 = 30.0%; and Q4 = 29.0%; P = .003). In the multivariable analysis, in-hospital mortality was not associated with center volume, comparing very low volume to medium- and high-volume centers (odds ratio [95% confidence interval] vs Q4: Q1 = 1.1 [0.6-1.9], Q2 = 0.6 [0.4-1.1], and Q3 = 0.9 [0.5-1.5]; all P > .05). No significant difference was found in 1-year survival between center volume groups. ConclusionsIn-hospital mortality is not associated with procedure volume within centers performing complex endovascular aortic repair. However, complication rates and endoleak may be associated with procedure volume. Long-term outcomes by annualized procedure volume, specifically graft durability and sac expansion, should be investigated.

Earned Outcomes Correlate with Reliability-Adjusted Surgical Mortality after Abdominal Aortic Aneurysm Repair and Predict Future Performance

Cumulative, probability-based metrics are regularly used to measure quality in professional sports, but these methods have not been applied to health care delivery. These techniques have the potential to be particularly useful in describing surgical quality, where case volume is variable and outcomes tend to be dominated by statistical "noise". The established statistical technique used to adjust for differences in case volume is reliability-adjustment which emphasizes statistical "signal"but has several limitations. We sought to validate a novel measure of surgical quality based on earned outcomes methods (deaths above average, DAA) against reliability-adjusted mortality rates, using abdominal aortic aneurysm (AAA) repair outcomes to illustrate the measure's performance. Earned outcomes methods were used to calculate the outcome of interest for each patient: deaths above average (DAA). Hospital-level DAA were calculated for non-ruptured open AAA repair and EVAR in the Vascular Quality Initiative (VQI) database from 2016-2019. DAA for each center is the sum of observed - predicted risk of death for each patient; predicted risk of death was calculated using established multivariable logistic regression modeling. Correlations of DAA with reliability-adjusted mortality rates and procedure volume were determined. Because an accurate quality metric should correlate with future results, outcomes from 2016-2017 were used to categorize hospital quality based on (1) risk-adjusted mortality, (2) risk- and reliability-adjusted mortality, and (3) DAA. The best performing quality metric was determined by comparing the ability of these categories to predict 2018-2019 risk-adjusted outcomes. During the study period, 3,734 patients underwent open repair (106 hospitals), and 20,680 patients underwent EVAR (183 hospitals). DAA was closely correlated with reliability-adjusted mortality rates for open repair (r=0.94, P<0.001) and EVAR (r=0.99, P<0.001). DAA also correlated with hospital case volume for open repair (r=-.54, P<0.001), but not EVAR (r=0.07, P=0.3). In 2016-2017, most hospitals had 0% mortality (55% open repair, 57% EVAR), making it impossible to evaluate these hospitals using traditional risk-adjusted mortality rates alone. Further, zero mortality hospitals in 2016-2017 did not demonstrate improved outcomes in 2018-2019 for open repair (3.8% vs 4.6%, P=0.5) or EVAR (0.8% vs 1.0%, P=0.2) compared to all other hospitals. In contrast to traditional risk-adjustment, 2016-2017 DAA evenly divided centers into quality quartiles which predicted 2018-2019 performance with increased mortality rate associated with each decrement in quality quartile (Q1 3.2%, Q2 4.0%, Q3 5.1%, Q4 6.0%). There was a significantly higher risk of mortality at worst quartile open repair hospitals compared to best quartile hospitals (OR 2.01, [95% CI 1.07-3.76], P=0.03). Using 2016-2019 DAA to define quality, highest quality quartile open repair hospitals had lower median DAA compared to lowest quality quartile hospitals (-1.18 DAA vs +1.32 DAA, P<0.001), correlating with lower median reliability-adjusted mortality rates (3.6% vs 5.1%, P<0.001). Adjustment for differences in hospital volume is essential when measuring hospital-level outcomes. Earned outcomes accurately categorize hospital quality and correlate with reliability-adjustment but are easier to calculate and interpret. From 2016-2019, highest quality open AAA repair hospitals prevented >40 perioperative deaths compared to the average hospital, and >80 perioperative deaths compared to lowest quality hospitals.

Strategies to reduce rates of severe endothermal heat-induced thrombosis following radiofrequency ablation

ObjectiveEndothermal heat-induced thrombosis (EHIT) is a potential complication of radiofrequency ablation (RFA). Data on effective prophylaxis of EHIT are limited. In 2018, a high-volume, single institution implemented strategies to decrease the incidence of EHIT, including a single periprocedural prophylactic dose of low-molecular-weight heparin to patients with a great saphenous vein (GSV) diameter of ≥8 mm or saphenofemoral junction (SFJ) diameter of ≥10 mm and limiting treatment to one vein per procedure. The size threshold was derived from existing literature. The study objective was to evaluate the effects of these institutional changes on thrombotic complication rates after RFA. MethodsA retrospective cohort control study was conducted using the Vascular Quality Initiative database. Data were collected for patients who underwent RFA with a GSV diameter of ≥8 mm or SFJ diameter of ≥10 mm from January 2015 to July 2022. The clinical end points were thrombotic complications (ie, thrombophlebitis, EHIT, deep vein thrombosis) and bleeding complications. Patient demographic and procedural variables were included in the analysis, and significant variables after univariable logistic regression were included in a multivariable logistic regression. ResultsAfter the policy change, the overall vein center EHIT rate decreased from 2.6% to 1.5%, with a trend toward significance (P = .096). The inclusion criterion of a GSV diameter of ≥8 mm or an SFJ diameter of ≥10 mm yielded 845 patients, of whom 298 were treated before the policy change and 547 after. There was a significant reduction in the rate of EHIT classified as class ≥III (2.34 vs 0.366; P = .020) after the institutional changes. Treatment of two or more veins and an increased vein diameter were associated with an increased risk of EHIT (P = .049 and P < .001, respectively). No significant association was found between periprocedural anticoagulation and all-cause thrombotic complications or EHIT (P = .563 and P = .885, respectively). ConclusionsThe institutional policy changes have led to lower rates of EHIT, with a reduction in severe EHIT rates in patients with an ≥8-mm diameter GSV or a ≥10-mm diameter SFJ treated with RFA. Of the changes implemented, restricting treatment to one vein was associated with a reduction in severe EHIT. No association was found with periprocedural low-molecular-weight heparin, although a type 2 error might have occurred. Alternative strategies to prevent thrombotic complications should be explored, such as increasing the dosage and duration of periprocedural anticoagulation, antiplatelet use, and nonpharmacologic strategies.

Obese patients with CEAP (clinical, etiology, anatomy, pathophysiology) C2 and C3 disease show enhanced symptom improvement after endovenous thermal ablation

ObjectiveEndovenous thermal ablation (EVTA) is a prevalent treatment option for patients with severe venous disease. However, the decision to intervene for patients with less severe disease (CEAP [clinical, etiology, anatomy, pathophysiology] C2 and C3) is less clear and becomes further complicated for patients with obesity, a pathology known to increase venous disease symptom severity. Therefore, the objective of this study was to use the Society for Vascular Surgery Vascular Quality Initiative database to evaluate outcomes after EVTA in obese patients with CEAP C2 and C3 venous insufficiency. MethodsUsing the Society for Vascular Surgery Vascular Quality Initiative database, we retrospectively analyzed the initial procedure of all patients with a CEAP clinical class of C2 or C3 who underwent EVTA from January 2015 to December 2021. Patients were grouped by obesity, defined as a body mass index of ≥30 kg/m2. The primary outcome was the change in venous clinical severity score (VCSS) from the procedure to the patient's initial follow-up. The secondary outcomes included the change in patient-reported outcomes at follow-up via the HASTI (heaviness, achiness, swelling, throbbing, itching) score, incidence of follow-up complications, and recanalization of treated veins. The change in the VCSS and HASTI score were analyzed using Student t tests, and complications and recanalization were assessed using the Fisher exact test. Significant outcomes were confirmed by multiple variable logistic regression. The remaining significant variables were then analyzed, with obesity categorized using the World Health Organization classification system to analyze how increasing obesity levels affect outcomes. ResultsThere were 8146 limbs that met the inclusion criteria, of which 5183 (63.6%) were classified as nonobese and 2963 (36.4%) as obese. Obesity showed no impact on improvement in the VCSS (−3.29 vs −3.35; P = .408). Obesity was found to be associated with a larger improvement in overall symptoms, as evidence by a greater improvement in the HASTI score (−7.24 vs −6.62; P < .001). Obese limbs showed a higher incidence of superficial phlebitis (1.5% vs 0.7%; P = .001), but no difference was found in recanalization or any other complication. ConclusionsThese data suggest that obese patients with CEAP clinical class C2 or C3 experience greater improvement in their perceived symptoms after EVTA with little difference in clinical improvement and complications compared with nonobese patients. Although obesity has been associated with increased severity of venous disease symptoms, obese patients are able to derive significant relief after treatment during the short term and may experience greater relief of symptoms than nonobese patients when treated at more mild disease presentations.

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

ObjectivesCilostazol is used for the treatment of intermittent claudication. The impact of cilostazol on the outcomes of peripheral vascular interventions (PVI) remains controversial. This study assesses the use and impact of cilostazol on patients undergoing PVI for peripheral arterial disease (PAD). MethodsThe Vascular Quality Initiative (VQI) database files for PVI were reviewed. Patients with PAD who underwent PVI for CLTI 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 two groups (preoperative cilostazol use versus no pre-operative cilostazol use) were compared. The Kaplan-Meier method was used to determine outcomes. ResultsA 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 < .001), White (77% vs 75%; P < .001), and smokers (83% vs 77%; P < .001). They were less likely to have diabetes mellitus (50% vs 56%; P < .001) and congestive heart failure (14% vs 23%; P < .001). Patient on cilostazol were more likely to be treated for claudication (63% vs 40%, P < .001), undergo prior lower extremity revascularization (55% vs 51%, P<.001) and less likely to have undergone prior minor and major amputation (10% vs 19%; P < .001) compared to 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 <.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 four years of follow-up (89% vs 87%, P=0.03). ConclusionCilostazol 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.

Temporal trends in hemodialysis access creation during the fistula first era

ObjectiveAlthough forearm arteriovenous fistulas (AVFs) are the preferred initial vascular access for hemodialysis based on national guidelines, there are no population-level studies evaluating trends in creation of forearm vs upper arm AVFs and arteriovenous grafts (AVGs). The purpose of this study was to report temporal trends in first-time permanent hemodialysis access type, and to assess the effect of national initiatives on rates of AVF placement. MethodsRetrospective cross-sectional study (2012-2022) utilizing the Vascular Quality Initiative database. All patients older than 18 years with creation of first-time upper extremity surgical hemodialysis access were included. Anatomic location of the AVF or AVG (forearm vs upper arm) was defined based on inflow artery, outflow vein, and presumed cannulation zone. Primary analysis examined temporal trends in rates of forearm vs upper arm AVFs and AVGs using time series analyses (modified Mann-Kendall test). Subgroup analyses examined rates of access configuration stratified by age, sex, race, dialysis, and socioeconomic status. Interrupted time series analysis was performed to assess the effect of the 2015 Fistula First Catheter Last initiative on rates of AVFs. ResultsOf the 52,170 accesses, 57.9% were upper arm AVFs, 25.2% were forearm AVFs, 15.4% were upper arm AVGs, and 1.5% were forearm AVGs. From 2012 to 2022, there was no significant change in overall rates of forearm or upper arm AVFs. There was a numerical increase in upper arm AVGs (13.9 to 18.2 per 100; P = .09), whereas forearm AVGs significantly declined (1.8 to 0.7 per 100; P = .02). In subgroup analyses, we observed a decrease in forearm AVFs among men (33.1 to 28.7 per 100; P = .04) and disadvantaged (Area Deprivation Index percentile ≥50) patients (29.0 to 20.7 per 100; P = .04), whereas female (17.2 to 23.1 per 100; P = .03), Black (15.6 to 24.5 per 100; P < .01), elderly (age ≥80 years) (18.7 to 32.5 per 100; P < .01), and disadvantaged (13.6 to 20.5 per 100; P < .01) patients had a significant increase in upper arm AVGs. The Fistula First Catheter Last initiative had no effect on the rate of AVF placement (83.2 to 83.7 per 100; P=.37). ConclusionsDespite national initiatives to promote autogenous vascular access, the rates of first-time AVFs have remained relatively constant, with forearm AVFs only representing one-quarter of all permanent surgical accesses. Furthermore, elderly, Black, female, and disadvantaged patients saw an increase in upper arm AVGs. Further efforts to elucidate factors associated with forearm AVF placement, as well as potential physician, center, and regional variation is warranted.

Local Anesthesia for Endovascular Repair of Abdominal Aortic Aneurysm Allows for Accurate Graft Deployment with Durable Results

ObjectiveLocal anesthesia (LA) is sparsely used in endovascular aneurysm repair (EVAR) despite short term benefit, likely secondary to concerns over patient movement preventing accurate endograft deployment. The objective of this study is to examine the association between anesthesia type and endoleak, sac regression, reintervention, and mortality. MethodsThe Vascular Quality Initiative database was queried for all EVAR cases from 2014-2022. Patients were included if they underwent percutaneous elective EVAR with anatomical criteria within instructions for use of commercially approved endografts. Multivariable logistic regression with propensity score weighting lysis was used to determine the association between anesthesia type on the risk of any endoleak noted by intra-operative completion angiogram and sac regression. Multivariable survival analysis with propensity score weighting was used to determine the association between anesthesia type and endoleak at 1 year, long-term reintervention and mortality. Results13932 EVARs met inclusion criteria: 1075 (8%) LA and 12857 (92%) general anesthesia (GA). On completion angiogram, LA was associated with fewer rates of any endoleaks overall (16% vs 24%, p<0.001). On multivariable analysis with propensity score weighting, LA was associated with similar adjusted odds of any endoleak on intra-operative completion angiogram (OR 0.56, 95%CI 0.47-0.68) as well as combined type 1a and type 1b endoleaks (OR 0.72, 05%CI 0.47-1.09). Follow-up computed tomography imaging at 1 year was available for 4892 patients, 377 (8%) LA and 4515 (92%) GA. At 1 year, LA was associated similar rate of freedom from any endoleaks compared to GA (0.66 (95%CI 0.63-0.69) vs 0.71 (95%CI 0.70-0.72), p=0.663) and increased rates of sac regression (50% vs 45% p=0.040). On multivariable analysis with propensity score weighting, LA and GA were associated with similar adjusted odds of sac regression (OR 1.22, 05%CI 0.97-1.55). LA and GA had similar rates endoleak at 1 year (HR 0.14, 95%CI 0.63-1.07), however LA was associated with decreased hazards of combined type 1a and 1b endoleaks at 1 year (HR 0.87, 95%CI 0.80-0.96). LA and GA had similar adjusted long-term reintervention rate (HR 0.77, 95%CI 0.44-1.38) and long-term mortality (HR 1.100, 95%CI 079-1.25). ConclusionLA is not associated with increased adjusted rates of any endoleak on completion angiogram or at 1-year follow-up compared to GA. LA is associated with decreased adjusted rates of yype 1a and type1b endoleak at 1 year, but similar rates of sac regression, long term reintervention and mortality. Concerns for accurate graft deployment should not preclude use of LA and LA should be increasingly considered when deciding on anesthetic type for standard elective EVAR.

Developing machine learning algorithms to predict outcomes following vascular surgery using the Vascular Quality Initiative database

Developing machine learning algorithms to predict outcomes following vascular surgery using the Vascular Quality Initiative database

Association between aortic pathology, surgeon experience, and regional variability on use of intravascular ultrasonography during thoracic endovascular aortic repair

ObjectiveIntravascular ultrasound (IVUS) is a useful adjunct to obtain precise intraluminal measurements during thoracic endovascular aortic repair (TEVAR), but IVUS examination is not routinely used by all surgeons or centers during TEVAR. We sought to identify patient- and system-related factors that influence the decision to use IVUS examination during TEVAR. MethodsA retrospective review of the Vascular Quality Initiative (VQI) database was performed to identify all patients undergoing TEVAR from 2015 to 2019. Multivariable logistic regression modeling with three-fold repeated cross-validation was performed to identify predictors of IVUS use during TEVAR. Association of IVUS use with contrast volume and radiation exposure was also assessed. ResultsA total of 12,414 patients undergoing TEVAR met the inclusion criteria. Of these, IVUS examination was used in 41.3% of cases (n = 5121). IVUS use was more common in younger patients with fewer comorbidities; however, IVUS examination was also more commonly deployed in symptomatic patients and those with a higher preoperative American Society of Anesthesiology classification. IVUS examination was use in 80% (n = 3385/4213) TEVAR procedures performed for type B aortic dissection, which accounted for 50% of total IVUS use and only 11% of cases during which IVUS examination was not used (n = 822/7293) (P < .01). In multivariable analysis, the strongest independent predictor of IVUS use was aortic dissection (odds ratio, 13.7; 95% confidence interval, 11.7-16.3; P < .001, with aortic aneurysm as the reference). Surgeon years of independent practice experience was not associated with IVUS use, but when accounting for clustering on physicians and geographic regions, these variables explained 15% of the variance observed in the final risk-adjusted model. After adjustment for confounding factors, IVUS use was associated with a significant decrease in fluoroscopy time and contrast volume (both P < .001). ConclusionsThe decision to use IVUS examination during TEVAR is most heavily influenced by aortic pathology. Although surgeon experience was not associated with the decision to use IVUS examination, there was substantial variation in IVUS examination use among individual surgeons and VQI regions. IVUS use was associated with decreased contrast administration and fluoroscopy use but did not appear to have an impact on survival or re-intervention. Although aortic dissection was strongly associated with IVUS use, a significant number of TEVAR for dissection were performed without IVUS examination. Further research is warranted to identify the barriers to IVUS use as well as the risks and benefits of IVUS use during TEVAR so that quality benchmarks can be established and resource use is improved.

Octogenarians fare better under local anesthesia for elective endovascular aortic aneurysm repair

ObjectiveWith an aging patient population, an increasing number of octogenarians are undergoing elective endovascular abdominal aortic aneurysm repair (EVAR) in the United States. Multiple studies have shown that, for the general population, use of local anesthetic (LA) for EVAR is associated with improved short-term and long-term outcomes as compared with performing these operations under general anesthesia (GA). Therefore, this study aimed to study the association of LA for elective EVARs with perioperative outcomes, among octogenarians. MethodsThe Vascular Quality Initiative database (2003-2021) was used to conduct this study. Octogenarians (Aged ≥80 years) were selected and sorted into two study groups: LA (Group I) and GA (Group II). Our primary outcomes were length of stay and mortality. Secondary outcomes included operative time, estimated blood loss, return to operating room, cardiopulmonary complications, and discharge location. ResultsOf the 16,398 selected patients, 1197 patients (7.3%) were included in Group I, and 15,201 patients (92.7%) were in Group II. Procedural time was significantly shorter for the LA group (114.6 vs 134.6; P < .001), as was estimated blood loss (152 vs 222 cc; P < .001). Length of stay was significantly shorter (1.8 vs 2.6 days; P < .001), and patients were more likely to be discharged home (LA 88.8% vs GA 86.9%; P = .036) in the LA group. Group I also experienced fewer pulmonary complications; only 0.17% experienced pneumonia and 0.42% required ventilator support compared with 0.64% and 1.02% in Group II, respectively. This finding corresponded to fewer days in the intensive care unit for Group I (0.41 vs 0.69 days; P < .001). No significant difference was seen in 30-day mortality cardiac, renal, or access site-related complications. Return to operating room was also equivocal between the two groups. Multivariate regression analysis confirmed GA was associated with a significantly longer length of stay and significantly higher rates of non-home discharge (adjusted odds ratio [AOR], 1.59; P < .001 and AOR, 1.40; P = .025, respectively). When stratified by the New York Heart Association classification system, classes I, II, III, and IV (1.55; P < .001; 1.26; P = .029; 2.03; P < .001; 4.07; P < .001, respectively) were associated with significantly longer hospital stays. ConclusionsThe use of LA for EVARs in octogenarians is associated with shorter lengths of stay, fewer respiratory complications, and home discharge. These patients also experienced shorter procedure times and less blood loss. There was no statistically significant difference in 30-day mortality, return to operating room, or access-related complications. LA for octogenarians undergoing EVAR should be considered more frequently to shorten hospital stays and decrease complication rates.

Using Machine Learning (XGBoost) to Predict Outcomes After Infrainguinal Bypass for Peripheral Artery Disease.

To develop machine learning (ML) algorithms that predict outcomes after infrainguinal bypass. Infrainguinal bypass for peripheral artery disease carries significant surgical risks; however, outcome prediction tools remain limited. The Vascular Quality Initiative database was used to identify patients who underwent infrainguinal bypass for peripheral artery disease between 2003 and 2023. We identified 97 potential predictor variables from the index hospitalization [68 preoperative (demographic/clinical), 13 intraoperative (procedural), and 16 postoperative (in-hospital course/complications)]. The primary outcome was 1-year major adverse limb event (composite of surgical revision, thrombectomy/thrombolysis, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained 6 ML models using preoperative features. The primary model evaluation metric was the area under the receiver operating characteristic curve (AUROC). The top-performing algorithm was further trained using intraoperative and postoperative features. Model robustness was evaluated using calibration plots and Brier scores. Overall, 59,784 patients underwent infrainguinal bypass, and 15,942 (26.7%) developed 1-year major adverse limb event/death. The best preoperative prediction model was XGBoost, achieving an AUROC (95% CI) of 0.94 (0.93-0.95). In comparison, logistic regression had an AUROC (95% CI) of 0.61 (0.59-0.63). Our XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs (95% CI's) of 0.94 (0.93-0.95) and 0.96 (0.95-0.97), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.08 (preoperative), 0.07 (intraoperative), and 0.05 (postoperative). ML models can accurately predict outcomes after infrainguinal bypass, outperforming logistic regression.

Abstract 17625: Comparative Analysis of Mortality and Amputation Rates in Patients Undergoing Atherectomy for Infra-Popliteal Peripheral Arterial Disease: Insight From the VQI

Introduction: Infra-popliteal peripheral arterial disease (IPPAD) poses challenges due to complex vasculature. The BASIL-2 trial demonstrated superiority in endovascular treatment compared with surgical bypass in patients with IPPAD. However, the choice of endovascular modality has not been conclusive. Hypothesis: Combining plain balloon angioplasty (POBA)+atherectomy is associated with improved clinical outcomes compared to POBA. Methods: Patients that underwent POBA vs POBA+Atherectomy for IPPAD from the Vascular Quality Initiative database were identified. Propensity score matching (PSM) was employed to balance the distribution of confounding variables for mortality identified on multivariable logistic regression. Patient characteristics and long-term outcomes between the two treatment groups were compared. Results: A total of 10,494 individuals (74.6%) were treated with POBA, while 3,569 (25.4%) were treated with POBA+atherectomy. PSM ensured minimal differences in baseline characteristics, such as indication for procedure and prior revascularization. The atherectomy group was associated with higher technical success and lower perioperative complications, such as renal complications and hematoma, at the expense of higher rates of distal embolization. During long term follow up, patients who underwent atherectomy had lower rates of major amputation but lower freedom from reintervention. There were no differences in major adverse limb events and mortality. Conclusion: Combining POBA with atherectomy appears to be a safe approach in IPPAD, with lower rates of long-term amputation at the cost of higher risk for future re-intervention.

Abstract 14618: Comparative Outcomes of Elective Endovascular Abdominal Aortic Aneurysm Repair in Patients With Preoperative Cardiac Stress Testing

Introduction: The use of cardiac stress testing (CST) before endovascular abdominal aortic aneurysm (EVAR) repair is controversial. While prior research has explored the utility of CST before EVAR, EVAR outcomes in patients with different CST results have not been studied. The objective of this study is to evaluate EVAR outcomes in patients with abnormal CST. Hypothesis: Patients with abnormal CST before EVAR have inferior outcomes compared to patients with normal CST. Methods: The Vascular Quality Initiative (VQI) database for EVAR was reviewed. Patients who underwent CST prior to elective EVAR were included. In VQI, abnormal CST is defined as having ischemia, infarction, or both ischemia and infarction (BII). Outcomes of patients with normal and abnormal CST were compared, including a subgroup analysis of CST abnormalities. Results: A total of 19,964 patients were included and 23.7% (4,723) had abnormal CST. Patients with abnormal CST were more commonly males with comorbidities. Patients with abnormal CST had significantly more perioperative complications including MACE and one-year mortality compared to patients with normal CST. ( Table ) Regression analysis revealed that abnormal CST was independently associated with increased perioperative MACE (OR=1.59 [1.28-1.97]) and one-year mortality (HR=1.11 [1.00-1.23]). Subgroup analysis of patients with abnormal CST showed that patients with BII had significantly more perioperative MACE (6.8% vs 4.1%, P =0.002) and mortality (1.1% vs 0.4%, P =0.040) compared to patients with either ischemia or infarction. BII was independently associated with MACE (OR=1.62 [1.06-2.41]) and 30-day mortality (OR=3.28 [1.21-8.16]) compared to either abnormality. Conclusions: Patients with abnormal CST have worse outcomes after elective EVAR compared to patients with normal CST, particularly patients with BII. CST is a useful tool for perioperative and long-term risk stratification in patients undergoing elective EVAR.

Abstract 16935: Distressed Community Index in Patients Undergoing Carotid Artery Stenting in Medicare-Linked Vascular Quality Initiative Registry

Introduction: Patients with high community-level socioeconomic distress have worse cardiovascular outcomes, yet its impact on carotid artery stenting (CAS) outcomes is unknown. We assessed the association between the Distressed Community Index (DCI), a zip-code level measure of community distress, with post-CAS mortality and stroke. Methods: We used the Vascular Quality Initiative database linked with Medicare claims outcomes data to identify patients undergoing CAS between 2015 and 2019. From a time-dependent ROC curve and using Youden index, we classified patients as high community distress if DCI≥65. Thirty-six-month cumulative mortality incidence using Kaplan-Meier by DCI groups, and hierarchical Cox regression with random intercept for site for linear DCI were used. For stroke, we used 36-month cumulative incidence function by DCI groups, and Fine and Gray models accounting for competing risk of death for linear DCI. Models were later adjusted for patient and procedural characteristics. Results: The final complete-case cohort included 8,595 patients (2,580/30% DCI≥65), had a mean age of 74.7 (±7.8) years, was 92.7% white and 97.6% non-Hispanic/Latino. The 36-month cumulative mortality incidence was similar in both groups (26.0% vs 22.5%, P=0.236). A 10-point increase in DCI did not increase mortality risk (unadjusted HR 1.00; 95% CI 0.98-1.03 and adjusted HR 1.01; 95% CI 0.87-1.17). At 36 months the high community distress group experienced higher stroke risk (29.8% vs 22.9%, P=0.008). However, a 10-point increase in DCI did not increase stroke risk (unadjusted sub-HR: 1.01; 95% CI 0.99-1.03, adjusted sub-HR: 1.00; 95% CI 0.98-1.02). Conclusions: In this selective set of patients with underrepresentation of demographic groups, for those who get prioritized to CAS, higher community distress was associated with an increased unadjusted 36-month stroke risk by DCI group. However, a 10-point increase in DCI was nonsignificant regardless of adjustment.

Comparative Analysis of Mortality and Amputation Rates in Patients Undergoing Atherectomy for Infra-Popliteal Peripheral Arterial Disease: Insight From the VQI.

Infra-popliteal peripheral arterial disease (IPPAD) poses challenges due to high restenosis and occlusion rates. The BASIL-2 trial demonstrated the superiority of endovascular treatment compared with surgical bypass in patients with IPPAD. However, the association between different endovascular modalities and clinical outcomes has not been conclusive. Combining plain old balloon angioplasty (POBA) with atherectomy is associated with improved clinical outcomes compared with POBA alone. Patients who underwent POBA vs POBA+atherectomy for IPPAD from the Vascular Quality Initiative database were identified. To mitigate potential selection bias, we employed propensity score matching (PSM) to balance the distribution of confounding variables for mortality identified on multivariable logistic regression. Subsequently, we compared patient characteristics and long-term outcomes between the 2 treatment groups. Among patients who underwent endovascular intervention for IPPAD, 19 979 individuals (80.8%) were treated with POBA alone, while 4747 (19.2%) were treated with both POBA+atherectomy after PSM. Propensity score matching ensured minimal differences in baseline characteristics, such as indication for lower extremity revascularization (LER) and history of LER. After PSM, patients receiving POBA+atherectomy experienced higher rates of technical success and lower perioperative complications, such as renal complications and hematoma, compared with POBA alone. During long-term follow-up, patients who underwent atherectomy had lower rates of major amputation and major adverse limb events (MALE) but slightly lower freedom from reintervention. Nonetheless, there were no differences in mortality. Combining POBA with atherectomy appears to be a safe approach in patients with IPPAD, with lower rates of long-term amputation and MALE at the cost of a higher risk of reintervention. The use of adjunctive atherectomy is associated with improved long-term outcomes in patients with infra-popliteal disease.

Arterial dissection during peripheral vascular interventions

ObjectiveArterial dissection (AD) is a known complication of peripheral vascular interventions (PVIs), but its incidence and significance have not been well-characterized. This study examines AD in the Vascular Quality Initiative database for patients treated for peripheral arterial disease. Our hypothesis is that AD is associated with decreased patency and worse limb outcomes. MethodsThe Vascular Quality Initiative PVI registry (2016-2021) was reviewed. Patients were divided based on the presence or absence of reported AD during the procedure. Trend of incidence and management of AD was derived. The characteristics and outcomes of patients with and without AD were compared. The primary endpoint was primary patency. ResultsThere was a total of 177,790 cases, and 3% had AD. The incidence of AD significantly increased over the study period from 2.4% to 3.6% (P = .007). Endovascular therapy was used to treat AD in 83.7% of cases, 14.5% were treated medically, and only 1.8% required open surgery. Patients with AD were significantly more likely to be female (47.4% vs 39.7%; P < .001). Patient with AD were more likely to have a history of smoking (79.7% vs 77.2%; P < .001), but were significantly less likely to be on dialysis (8.2% vs 9.3%; P < .001) compared with patients without AD. Patients with AD were more likely to have femoropopliteal disease (45.2% vs 38.0%; P < .001) and undergo treatment of more complex disease as denoted by higher mean number of lesions treated (1.95 ± 1.01 vs 1.71 ± 0.89; P < .001), longer occlusion length (8 ± 16 vs 7 ± 15 cm; P < .001), and more severe TransAtlantic Inter-Society Consensus grade (Grade D: 36.2% vs 29.1%; P < .001). The proportion of stenting as a treatment modality was higher in the dissection group (55.4% vs 41.1%; P < .001). After a mean follow-up of 828 days, patients with AD had significantly lower primary patency than patients without AD. Kaplan-Meier curves demonstrated that the AD group had lower primary patency (86.9% vs 91%; P < .001) and reintervention-free survival (79.5 % vs 84.1%; P < .001) at 1 year with difference in amputation-free survival. Cox proportional hazard regression confirmed the independent association of AD with primary patency and reintervention-free survival. ConclusionsAD is more common in women and is more likely to occur during treatment of the femoropopliteal segment. AD is associated with decreased primary patency and reintervention-free survival after PVI for peripheral arterial disease.

Using machine learning to predict outcomes following suprainguinal bypass

ObjectiveSuprainguinal bypass for peripheral artery disease (PAD) carries important surgical risks; however, outcome prediction tools remain limited. We developed machine learning (ML) algorithms that predict outcomes following suprainguinal bypass. MethodsThe Vascular Quality Initiative database was used to identify patients who underwent suprainguinal bypass for PAD between 2003 and 2023. We identified 100 potential predictor variables from the index hospitalization (68 preoperative [demographic/clinical], 13 intraoperative [procedural], and 19 postoperative [in-hospital course/complications]). The primary outcomes were major adverse limb events (MALE; composite of untreated loss of patency, thrombectomy/thrombolysis, surgical revision, or major amputation) or death at 1 year following suprainguinal bypass. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features (Extreme Gradient Boosting [XGBoost], random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). The best performing algorithm was further trained using intra- and postoperative data. Model robustness was evaluated using calibration plots and Brier scores. Performance was assessed on subgroups based on age, sex, race, ethnicity, rurality, median Area Deprivation Index, symptom status, procedure type, prior intervention for PAD, concurrent interventions, and urgency. ResultsOverall, 16,832 patients underwent suprainguinal bypass, and 3136 (18.6%) developed 1-year MALE or death. Patients with 1-year MALE or death were older (mean age, 64.9 vs 63.5 years; P < .001) with more comorbidities, had poorer functional status (65.7% vs 80.9% independent at baseline; P < .001), and were more likely to have chronic limb-threatening ischemia (67.4% vs 47.6%; P < .001) than those without an outcome. Despite being at higher cardiovascular risk, they were less likely to receive acetylsalicylic acid or statins preoperatively and at discharge. Our best performing prediction model at the preoperative stage was XGBoost, achieving an AUROC of 0.92 (95% confidence interval [CI], 0.91-0.93). In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). Our XGBoost model maintained excellent performance at the intra- and postoperative stages, with AUROCs of 0.93 (95% CI, 0.92-0.94) and 0.98 (95% CI, 0.97-0.99), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.12 (preoperative), 0.11 (intraoperative), and 0.10 (postoperative). Of the top 10 predictors, nine were preoperative features including chronic limb-threatening ischemia, previous procedures, comorbidities, and functional status. Model performance remained robust on all subgroup analyses. ConclusionsWe developed ML models that accurately predict outcomes following suprainguinal bypass, performing better than logistic regression. Our algorithms have potential for important utility in guiding perioperative risk mitigation strategies to prevent adverse outcomes following suprainguinal bypass.

Machine learning to predict outcomes following endovascular abdominal aortic aneurysm repair.

Endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) carries important perioperative risks; however, there are no widely used outcome prediction tools. The aim of this study was to apply machine learning (ML) to develop automated algorithms that predict 1-year mortality following EVAR. The Vascular Quality Initiative database was used to identify patients who underwent elective EVAR for infrarenal AAA between 2003 and 2023. Input features included 47 preoperative demographic/clinical variables. The primary outcome was 1-year all-cause mortality. Data were split into training (70 per cent) and test (30 per cent) sets. Using 10-fold cross-validation, 6 ML models were trained using preoperative features with logistic regression as the baseline comparator. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Some 63 655 patients were included. One-year mortality occurred in 3122 (4.9 per cent) patients. The best performing prediction model for 1-year mortality was XGBoost, achieving an AUROC (95 per cent c.i.) of 0.96 (0.95-0.97). Comparatively, logistic regression had an AUROC (95 per cent c.i.) of 0.69 (0.68-0.71). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.04. The top 3 predictive features in the algorithm were 1) unfit for open AAA repair, 2) functional status, and 3) preoperative dialysis. In this data set, machine learning was able to predict 1-year mortality following EVAR using preoperative data and outperformed standard logistic regression models.

Intraoperative fusion imaging during transcarotid artery revascularization.

Transcarotid artery revascularization (TCAR) with reverse-flow neuroprotection has emerged as an alternative to transfemoral carotid artery stenting and carotid endarterectomy. However, it requires fluoroscopic guidance, exposing the patient and surgeon to radiation. Although fusion-guided endovascular aneurysm repair has been demonstrated to significantly decrease this radiation risk, not much is known about similar outcomes for TCAR. The purpose of this study is to evaluate the outcomes at a single institution using fusion-guided imaging during TCAR compared with regional TCAR cases in the Vascular Quality Initiative (VQI) registry without fusion imaging. A retrospective analysis was conducted of data collected from all patients undergoing TCAR with fusion-guided imaging (TCAR-F) at our hospital and patients undergoing TCAR alone within the VQI database. The primary outcomes included the total operative time, dose area product, fluoroscopy time, contrast usage, and flow-reversal time. The demographics and preoperative risk factors were also assessed in both groups. Continuous outcomes were compared using the Welch t test. Categorical outcomes were compared using the Fisher exact test. A total of 30 TCAR-F cases (January 2019 to May 2022) at our institution were compared against the regional VQI dataset (n= 2535). The TCAR-F cases had a lower dose area product (5.67 vs 93.1Gycm2; P< .0001), shorter fluoroscopy time (8.07 vs 16.4minutes; P< .0001), and less contrast usage (13.49 vs 76.7mL; P< .0001) compared with the regional averages of the same. The TCAR-F cases had a longer total operative time (117.3 vs 80.9minutes; P< .0001) and flow-reversal time (14.4 vs 11.7minutes; P= .025) compared with the regional cases. The results from this pilot study comparing TCAR-F patients at a single institution with VQI regional TCAR patients suggest that TCAR-F cases use less radiation and contrast compared with TCAR without fusion imaging. Fusion-guided imaging might provide radiation protection to both patients and surgeons and decrease contrast usage for the patient.