The RCRI substantially underestimates in-hospital cardiac events in patients undergoing elective or urgent vascular surgery, especially after LEB, EVAR, and OAAA. The VSG-CRI more accurately predicts in-hospital cardiac events after vascular surgery and represents an important tool for clinical decision making.

Long-term morphologic changes after endovascular aneurysm repair depend on endograft type.

Objective Although carotid endarterectomy (CEA) is performed to prevent stroke, long-term survival is essential to ensure benefit, especially in asymptomatic patients. We examined factors associated with 5-year survival following CEA in patients with asymptomatic internal carotid artery (ICA) stenosis. Methods Prospectively collected data from 4114 isolated CEAs performed for asymptomatic stenosis across 24 centers in the Vascular Study Group of New England between 2003 and 2011 were used for this analysis. Late survival was determined with the Social Security Death Index. Cox proportional hazard models were used to identify risk factors for mortality within the first 5 years after CEA and to calculate a risk score for predicting 5-year survival. Results Overall 3- and 5-year survival after CEA in asymptomatic patients were 90% (95% CI 89%-91%) and 82% (95% CI 81%-84%), respectively. By multivariate analysis, increasing age, diabetes, smoking history, congestive heart failure, chronic obstructive pulmonary disease, poor renal function (estimated glomerular filtration rate <60 or dialysis dependence), absence of statin use, and worse contralateral ICA stenosis were all associated with worse survival. Patients classified as low (27%), medium (68%), and high risk (5%) based on number of risk factors had 5-year survival rates of 96%, 80%, and 51%, respectively (P < .001). Conclusions More than four out of five asymptomatic patients selected for CEA in the Vascular Study Group of New England achieved 5-year survival, demonstrating that, overall, surgeons in our region selected appropriate patients for carotid revascularization. However, there were patients selected for surgery with high risk profiles, and our models suggest that the highest risk patients (such as those with multiple major risk factors including age ≥80, insulin-dependent diabetes, dialysis dependence, and severe contralateral ICA stenosis) are unlikely to survive long enough to realize a benefit of prophylactic CEA for asymptomatic stenosis. Predicting survival is important for decision making in these patients.

Objective The objective of this study was to develop and to validate the Vascular Quality Initiative (VQI) Cardiac Risk Index (CRI) for prediction of postoperative myocardial infarction (POMI) after vascular surgery. Methods We developed risk models for in-hospital POMI after 88,791 nonemergent operations from the VQI registry, including carotid endarterectomy (CEA; n = 45,340), infrainguinal bypass (INFRA; n = 18,054), suprainguinal bypass (SUPRA; n = 2678), endovascular aneurysm repair (EVAR; n = 18,539), and open abdominal aortic aneurysm repair (OAAA repair; n = 4180). Multivariable logistic regression was used to create an all-procedure and four procedure-specific risk calculators based on the derivation cohort from 2012 to 2014 (N = 61,236). Generalizability of the all-procedure model was evaluated by applying it to each procedure subtype. The models were validated using a cohort (N = 27,555) from January 2015 to February 2016. Model discrimination was measured by area under the receiver operating characteristic curve (AUC), and performance was validated by bootstrapping 5000 iterations. The VQI CRI calculator was made available on the Internet and as a free smart phone app available through QxCalculate. Results Overall POMI incidence was 1.6%, with variation by procedure type as follows: CEA, 0.8%; EVAR, 1.0%; INFRA, 2.6%; SUPRA, 3.1%; and OAAA repair, 4.3% (P < .001). Predictors of POMI in the all-procedure model included age, operation type, coronary artery disease, congestive heart failure, diabetes, creatinine concentration >1.8 mg/dL, stress test status, and body mass index (AUC, 0.75; 95% confidence interval =CI], 0.73-0.76). The all-procedure model demonstrated only minimally reduced accuracy when it was applied to each procedure, with the following AUCs: CEA, 0.65 (95% CI, 0.59-0.70); INFRA, 0.69 (95% CI, 0.64-0.73); EVAR, 0.72 (95% CI, 0.65-0.80); SUPRA, 0.62 (95% CI, 0.52-0.72); and OAAA, 0.63 (95% CI, 0.56-0.70). Procedure-specific models had unique predictors and showed improved prediction compared with the all-procedure model, with the following AUCs: CEA, 0.69 (95% CI, 0.66-0.72); INFRA, 0.75 (95% CI, 0.73-0.78); EVAR, 0.76 (95% CI, 0.73-0.80); and OAAA, 0.72 (95% CI, 0.69-0.77). Bias-corrected AUC (95% CI) from internal validation for the models was as follows: all procedures, 0.75 (0.73-0.76); CEA, 0.68 (0.65-0.71); INFRA, 0.74 (0.72-0.76); EVAR, 0.73 (0.70-0.78); and OAAA repair, 0.68 (0.65-0.73). Conclusions The VQI CRI is a useful and valid clinical decision-making tool to predict POMI after vascular surgery. Procedure-specific models improve accuracy when they include unique risk factors.

Background Some patients who undergo lower extremity bypass (LEB) for critical limb ischemia ultimately require amputation. The functional outcome achieved by these patients after amputation is not well known. Therefore, we sought to characterize the functional outcome of patients who undergo amputation after LEB, and to describe the pre- and perioperative factors associated with independent ambulation at home after lower extremity amputation. Methods Within a cohort of 3,198 patients who underwent an LEB between January, 2003 and December, 2008, we studied 436 patients who subsequently received an above-knee (AK), below-knee (BK), or minor (forefoot or toe) ipsilateral or contralateral amputation. Our main outcome measure consisted of a “good functional outcome,” defined as living at home and ambulating independently. We calculated univariate and multivariate associations among patient characteristics and our main outcome measure, as well as overall survival. Results Of the 436 patients who underwent amputation within the first year following LEB, 224 of 436 (51.4%) had a minor amputation, 105 of 436 (24.1%) had a BK amputation, and 107 of 436 (24.5%) had an AK amputation. The majority of AK (75 of 107, 72.8%) and BK amputations (72 of 105, 70.6%) occurred in the setting of bypass graft thrombosis, whereas nearly all minor amputations (200 of 224, 89.7%) occurred with a patent bypass graft. By life-table analysis at 1 year, we found that the proportion of surviving patients with a good functional outcome varied by the presence and extent of amputation (proportion surviving with good functional outcome = 88% no amputation, 81% minor amputation, 55% BK amputation, and 45% AK amputation, p = 0.001). Among those analyzed at long-term follow-up, survival was slightly lower for those who had a minor amputation when compared with those who did not receive an amputation after LEB (81 vs. 88%, p = 0.02). Survival among major amputation patients did not significantly differ compared with no amputation (BK amputation 87%, p = 0.14, AK amputation 89%, p = 0.27); however, this part of the analysis was limited by its sample size (n = 212). In multivariable analysis, we found that the patients most likely to remain ambulatory and live independently despite undergoing a lower extremity amputation were those living at home preoperatively (hazard ratio [HR]: 6.8, 95% confidence interval [CI]: 0.94–49, p = 0.058) and those with preoperative statin use (HR: 1.6, 95% CI: 1.2–2.1, p = 0.003), whereas the presence of several comorbidities identified patients less likely to achieve a good functional outcome: coronary disease (HR: 0.6, 95% CI: 0.5–0.9, p = 0.003), dialysis (HR: 0.5, 95% CI: 0.3–0.9, p = 0.02), and congestive heart failure (HR: 0.5, 95% CI: 0.3–0.8, p = 0.005). Conclusions A postoperative amputation at any level impacts functional outcomes following LEB surgery, and the extent of amputation is directly related to the effect on functional outcome. It is possible, based on preoperative patient characteristics, to i...

Objective Many patients undergoing vascular surgical procedures are not on appropriate medical therapy. This study sought to examine the variation and impact of antiplatelet (AP) and statin therapy on early and late mortality in patients undergoing vascular surgery in our region. Methods We studied all patients (n = 14,489) undergoing elective carotid endarterectomy (n = 6978), carotid stenting (n = 524), and suprainguinal (n = 763) and infrainguinal bypass (n = 3053), as well as patients with known coronary risk factors undergoing open (n = 1044) and endovascular (n = 2127) abdominal aortic aneurysm repair from 2005 to 2012 in the Vascular Study Group of New England. Optimal medical management was defined as treatment with both AP and statin agents, preoperatively and at discharge. We analyzed temporal, procedural, and center variation of medication use. Multivariable analyses were used to determine the adjusted impact of AP and statin therapy on 30-day mortality and 5-year survival. Results Optimal medical management improved over the study interval (55% in 2005 to 68% in 2012; P trend < .01) with carotid interventions having the highest rates of optimal medications use (carotid artery stenting, 78%; carotid endarterectomy, 74%) and abdominal aortic aneurysm repair in patients with known cardiac risk factors having the lowest (open, 57%; endovascular aneurysm repair, 56%). Optimal medication use varied by center as well (range, 40%-86%). Preoperative AP and statin use was associated with reduced 30-day mortality (odds ratio, 0.76; 95% confidence interval [CI], 0.5-1.05; P = .09). AP and statin prescription at discharge was additive in survival benefit with improved 5-year survival (hazard ratio, 0.5; 95% CI, 0.4-0.7; P< .01) that was consistent across procedure types. Patients prescribed AP and statin at discharge had 5-year survival of 79% (95% CI, 77%-81%) compared with only 61% (95% CI, 52%-68%; P< .001) for patients on neither medication. Conclusions AP and statin therapy preoperatively and at discharge was associated with reduced 30-day mortality and an absolute 18% improved 5-year survival after vascular surgery. However, one-third of patients are suboptimally managed in real world practice. This demonstrates an opportunity for quality improvement that can substantially improve survival after vascular surgery.

Introduction Bowel ischemia is a rare but devastating complication following abdominal aortic aneurysm (AAA) repair. Its rarity has prohibited extensive risk factor analysis, particularly since the widespread adoption of endovascular repair (EVAR). Therefore, the purpose of this study was to assess the incidence of postoperative bowel ischemia following AAA repair in the endovascular era, and identify risk factors for its occurrence. Methods All patients undergoing AAA repair, either intact or ruptured, in the Vascular Study Group of New England between January 2003 and November 2014 were included. We compared patients with postoperative bowel ischemia to those without, and stratified by indication (intact and ruptured) and treatment approach (open repair and EVAR). Criteria for diagnosis were endoscopic or clinical evidence of ischemia, including bloody stools in patients who died before diagnostic procedures were performed. Independent predictors of postoperative bowel ischemia were established using multivariable logistic regression analysis. Results A total of 7312 patients were included, with 6668 intact (67.0% EVAR), and 644 ruptured AAA repairs (31.5% EVAR). The incidence of bowel ischemia following intact repair was 1.6% (open repair: 3.6%, EVAR: 0.6%), and 15.2% following ruptured repair (open repair: 19.3%, EVAR: 6.4%). Ruptured AAA was the most important determinant of postoperative bowel ischemia (OR:6.4, 95%CI:4.5 – 9.0), followed by open repair (OR:2.9, 95%CI:1.8 – 4.7). Additional predictive patient factors were advanced age (OR:1.4 per 10 years, 95%CI:1.1 – 1.7), female gender (OR:1.6, 95%CI:1.1 – 2.2), hypertension (OR:1.8, 95%CI:1.1 – 3.0), heart failure (OR:1.8, 95%CI:1.2 – 2.8), and current smoking (OR:1.5, 95%CI:1.1 – 2.1). Other risk factors included unilateral interruption of the hypogastric artery (OR:1.7, 95%CI:1.0 – 2.8), prolonged operative time (OR:1.2 per 60 min. increase, 95%CI:1.1 – 1.3), blood loss >1L (OR:2.0, 95%CI:1.3 – 3.0), and a distal anastomosis to the femoral artery (OR:1.7, 95%CI:1.1 – 2.7). Bowel ischemia patients had a significantly higher perioperative mortality after both intact (open repair: 20.5% vs. 1.9%, P<.001; EVAR: 34.6% vs. 0.9%, P<.001), as well ruptured AAA repair (open repair: 48.2% vs. 25.6%, P<.001; EVAR: 30.8% vs. 21.1%, P<.001). Conclusion This study underlines that although bowel ischemia following AAA repair is rare, the associated outcomes are very poor. The cause of postoperative bowel ischemia is multifactorial in nature, and can be attributed to patient factors, as well as operative characteristics. These data should be considered during pre-operative risk assessment, and optimization of both patient and procedure in an effort to reduce the risk of postoperative bowel ischemia.

Cellular adaptation to hypoxia depends, in part, on the transcription factor hypoxia-inducible factor-1 (HIF-1). Normoxic cells exposed to an inflammatory milieu often manifest phenotypic changes, such as increased glycolysis, that are reminiscent of those observed in hypoxic cells. Accordingly, we investigated the effects of cytomix, a mixture containing IFN-gamma, TNF, and IL-1beta on the expression of HIF-1-dependent proteins under normoxic and hypoxic conditions. Incubation of intestine-derived epithelial cells (IEC-6) under 1% O(2) increased HIF-1 DNA binding and expression of aldolase A, enolase-1, and VEGF mRNA. Incubation of normoxic cells with cytomix for 48 h also markedly increased HIF-1 DNA binding and expression of mRNAs for these proteins. Incubation of hypoxic cells with cytomix did not inhibit HIF-1 DNA binding or upregulation of HIF-1-dependent genes in response to hypoxia. Neither cytomix nor hypoxia increased steady-state levels of HIF-1alpha mRNA. Incubation of IEC-6 cells with cytomix induced nitric oxide (NO.) biosynthesis, which was blocked if the cultures contained l-N(G)-(1-iminoethyl)lysine hydrochloride (l-NIL). Treatment with l-NIL, however, failed to significantly alter aldolase A, enolase-1, and VEGF mRNA levels in normoxic cytomix-treated cells. Proinflammatory cytokines activate the HIF-1 pathway and increase expression of glycolytic genes in nontransformed rat intestinal epithelial cells, largely through an NO.-independent mechanism.