Factors associated with death 1 year after lower extremity bypass in Northern New England

Optimal cut-off value of preprocedural geriatric nutritional risk index for predicting the clinical outcomes of patients undergoing endovascular revascularization for peripheral artery disease

BACKGROUND

Malnutrition measured by the geriatric nutritional risk index (GNRI) was reported to be associated with poor prognosis for patients with peripheral artery disease (PAD). However, the optimal cut-off value of preprocedural GNRI for critical limb ischemia (CLI) and intermittent claudication (IC) is unknown. We aimed to determine its optimal cut-off value for CLI or IC patients requiring endovascular revascularization.

METHODS

We explored data of 2246 patients (CLI: n = 1061, IC: n = 1185) registered in the Tokyo-taMA peripheral vascular intervention research COmraDE (TOMA-CODE) registry, which prospectively enrolled consecutive PAD patients who underwent endovascular revascularization in 34 hospitals in Japan from August 2014 to August 2016. The optimal cut-off values of GNRI were assessed by the survival classification and regression tree (CART) analyses, and the survival curve analyses for major adverse cardiovascular and limb events (MACLEs) were performed for these cut-off values.

RESULTS

In addition to the first cut-off value of 96.2 in CLI and 85.6 in IC, the survival CART provided an additional cut-off value of 78.2 in CLI and 106.0 in IC for further risk stratification. The survival curve was significantly stratified by the GNRI-based malnutrition status in both CLI [high risk: 47.7% (51/107), moderate: 30.1% (118/392), and low: 10.2% (53/520), log-rank p < 0.001] and IC [high risk: 14.3% (7/49), moderate: 4.5% (29/646), and low: 0.5% (2/407), log-rank p < 0.001]. The multivariate Cox-proportional hazard analysis showed that a higher GNRI was significantly associated with a better outcome in both CLI [hazard ratio (HR) per 1-point increase: 0.97, 95% CI: 0.96-0.98, p < 0.001] and IC (HR: 0.94, 95% CI: 0.91-0.97, p < 0.001).

CONCLUSIONS

Preprocedural nutritional status significantly stratified future events in patients with PAD. Given that the optimal cut-off value of GNRI in CLI was almost 10-points lower than that of IC, using a disease-specific cut-off value is important for risk stratification.

A Global Vascular Guidelines–Based Bypass-Preferred Population and Their Surgical Risk Among CLTI Patients Treated With Endovascular Therapy in a Real-World Practice

Purpose:

To determine in a chronic limb-threatening ischemia (CLTI) population who underwent endovascular therapy (EVT) how many patients would have been categorized as preferred for bypass surgery according to the Global Vascular Guidelines (GVG) and ascertain their surgical risk.

Materials and Methods:

The current study analyzed 1043 CLTI patients who presented WIfI (wound, ischemia, and foot infection) stage ≥2 and underwent EVT between April 2010 and December 2017. Of these, 176 were excluded for lack of angiographic or other data, leaving 867 CLTI patients (mean age 74±10 years; 523 men) for stratification according to the GVG into bypass-preferred, indeterminate, or EVT-preferred groups. The GVG recommend bypass as the first-line treatment when the wound is severe (WIfI stage ≥3) and lesions are complex (GLASS stage III). Surgical risk was estimated using the modified PREVENT III risk score. To further stratify the bypass-preferred population according to mortality risk, a survival decision tree was constructed using recursive partitioning.

Results:

The bypass-preferred group accounted for 55% [95% confidence interval (CI) 51% to 58%] of the overall population. The decision tree analysis extracted a low-mortality risk subgroup with a survival rate of 99% (95% CI 98% to 100%) at 1 month and 80% (95% CI 73% to 87%) at 2 years. According to the PREVENT III score, 34% (95% CI 27% to 42%) of the low mortality risk subgroup were classified as high surgical risk.

Conclusion:

A high proportion of patients undergoing EVT were considered bypass preferred based on the GVG, and the survival of these patients was not significantly different whether they were high or low surgical risk.

Predictive Model for Mortality Risk Including the Wound, Ischemia, Foot Infection Classification in Patients Undergoing Revascularization for Critical Limb Ischemia

Background:

The aim of this study was to develop a predictive model for mortality risk based on preoperative risk factors, including the Wound, Ischemia, Foot Infection (WIfI) classification, in patients undergoing revascularization for critical limb ischemia.

Methods:

We analyzed a database of the Surgical reconstruction versus Peripheral Intervention in Patients With Critical Limb Ischemia registry, a multicenter, prospective, observational study that included 520 critical limb ischemia patients (192 surgical and 328 endovascular patients).

Results:

Multivariate Cox regression analysis identified old age, impaired mobility, low body mass index, renal failure, heart failure, and high WIfI grade as independent risk factors for all-cause mortality (all P <0.05). The risk score comprising these risk factors discriminated the mortality risk well; the 2-year survival rate was >90% in the first quantile of the risk score and ≈20% in the fifth quantile. The area under the time-dependent receiver operating characteristics curve was 0.829 for thirty-day mortality and 0.811 for 2-year mortality. Adding more detailed preoperative information to the predictive model revealed that cystatin C-based estimated glomerular filtration rate, left ventricular ejection fraction, and cholinesterase levels were additional independent risk factors, but the predictive accuracy of the model was not significantly improved, according to the time-dependent receiver operating characteristics curve and net reclassification improvement.

Conclusions:

The current study developed a risk score for mortality using preoperative risk factors, including the WIfI classification, in critical limb ischemia patients undergoing revascularization.

Functional prognosis of critical limb ischemia and efficacy of restoration of direct flow below the ankle

OBJECTIVE

Patients with critical limb ischemia have serious systemic comorbidities and are at high risk of impairment of limb function. In this study, we assessed the prognostic factors of limbs after revascularization.

METHODS

In this retrospective single-center cohort study, from April 2008 to December 2012, we treated 154 limbs of 121 patients with critical limb ischemia by the endovascular therapy-first approach based on the patients' characteristics. The primary end point was amputation-free survival. Secondary end points were patency of a revascularized artery, major adverse limb events, or death. Furthermore, we investigated the ambulatory status one year after revascularization as prognosis of limb function.

RESULTS

Endovascular therapy was performed in 85 limbs in 65 patients as the initial therapy (endovascular therapy group) and surgical reconstructive procedures (bypass group) were performed in 69 limbs in 56 patients. Early mortality within 30 days was not observed in either group. The primary patency rate was significantly better in the bypass group than in the endovascular therapy group ( p < 0.0001). Furthermore, the secondary patency rate was similar between the two groups ( p = 0.0096). There were no significant differences in amputation-free survival and major adverse limb event between the two groups. Univariate analysis showed that ulcer healing ( p < 0.0001), no hypoalbuminemia ( p = 0.0019), restoration of direct flow below the ankle ( p = 0.0219), no previous cerebrovascular disease ( p = 0.0389), and Rutherford 4 ( p = 0.0469) were predictive factors for preservation of ambulatory status one year after revascularization. In multivariate analysis, ulcer healing ( p < 0.0001) and restoration of direct flow below the ankle ( p = 0.0060) were significant predictors.

CONCLUSIONS

Ulcer healing and restoration of direct flow below the ankle are independently associated with prognosis of limb functions in patients who undergo infrainguinal arterial reconstruction.

Upper Extremity Pulse Pressure Predicts Amputation-Free Survival after Lower Extremity Bypass

Increased pulse pressure reflects pathologic arterial stiffening and predicts cardiovascular events and mortality. The effect of pulse pressure on outcomes in lower extremity bypass patients remains unknown. We thus investigated whether preoperative pulse pressure could predict amputation-free survival in patients undergoing lower extremity bypass for atherosclerotic occlusive disease. An institutional database identified 240 included patients undergoing lower extremity bypass from 2005 to 2014. Preoperative demographics, cardiovascular risk factors, operative factors, and systolic and diastolic blood pressures were recorded, and compared between patients with pulse pressures above and below 80 mm Hg. Factors were analyzed in bi- and multivariable models to assess independent predictors of amputation-free survival. Kaplan-Meier analysis was performed to evaluate the temporal effect of pulse pressure ≥80 mm Hg on amputation-free survival. Patients with a pulse pressure ≥80 mm Hg were older, male, and had higher systolic and lower diastolic pressures. Patients with pulse pressure <80 mm Hg demonstrated a survival advantage on Kaplan-Meier analysis at six months (log-rank P = 0.003) and one year (P = 0.005) postoperatively. In multivariable analysis, independent risk factors for decreased amputation-free survival at six months included nonwhite race, tissue loss, infrapopliteal target, and preoperative pulse pressure ≥80 mm Hg (hazard ratio 2.60; P = 0.02), while only tissue loss and pulse pressure ≥80 mm Hg (hazard ratio 2.30, P = 0.02) remained predictive at one year. Increased pulse pressure is independently associated with decreased amputation-free survival in patients undergoing lower extremity bypass. Further efforts to understand the relationship between increased arterial stiffness and poor outcomes in these patients are needed.

Prospective Study of Postoperative Glycemic Control with a Standardized Insulin Infusion Protocol after Infrainguinal Bypass and Open Abdominal Aortic Aneurysm Repair

BACKGROUND

The aim of this study is to examine the effect of moderate postoperative glycemic control in diabetic and nondiabetic patients undergoing infrainguinal bypass (INFRA) or open abdominal aortic aneurysm (OAAA) repair.

METHODS

In a single center prospective study, we investigated postoperative glycemic control using a standardized insulin infusion protocol after elective INFRA bypass (n = 53, 62%) and OAAA repair (n = 33, 38%) between January 2013 and March 2015. The primary end point was optimal glycemic control, defined as having ≥85% of blood glucose values within the 80-150 mg/dL target range. Suboptimal glycemic control was defined as <85% of blood glucose values within the blood glucose target range. Secondary end points included in-hospital and 30-day surgical site infection (SSI) rates, composite adverse events, length of stay (LOS), and hospital cost.

RESULTS

Optimal glycemic control was achieved more commonly after OAAA repair than INFRA bypass (85% vs. 64%, P = 0.04). Moderate hypoglycemia (<70 mg/dL) was observed in 32 (37%) patients, while severe hypoglycemia (<50 mg/dL) was observed in 6 (7%) patients. SSI at 30 days was more common after INFRA bypass (n = 15, 29%) than OAAA repair (n = 2, 6%) (P = 0.01). In-hospital (6% vs. 6%, P = 1.0) and 30-day (24% vs. 22%, P = 1.0) SSI rates were similar for optimal versus suboptimal glycemic control patients after INFRA bypass. In-hospital (4% vs. 0%, P = 1.0) and 30-day (4% vs. 0%, P = 1.0) SSI rates were similar for optimal versus suboptimal glycemic control patients after OAAA repair. The percentage of blood glucose > 250 mg/dL was similar for patients with and without SSI (3% vs. 2%, P = 0.36). Adverse cardiac and pulmonary events after INFRA bypass were similar between groups (9% vs. 21%, P = 0.23; 0% vs. 5%, P = 0.36, respectively). Adverse cardiac and pulmonary events after OAAA repair were similar between groups (2% vs. 0%, P = 1.0; 4% vs. 0%, P = 1.0, respectively). Mean LOS was significantly lower in patients with optimal glycemic control after INFRA bypass (4.2 vs. 7.3 days, P = 0.02). Mean LOS was similar after OAAA repair for patients with optimal and suboptimal control (5.8 vs. 6.4 days, P = 0.46). Inpatient hospital costs after INFRA bypass were lower for the group with optimal (median $25,012, interquartile range [IQ] range $21,726-28,331) versus suboptimal glycemic control (median $28,944, IQ range 24,773-41,270, P = 0.02).

CONCLUSIONS

Postoperative hyperglycemia is common after INFRA bypass and OAAA repair and can be effectively ameliorated with an insulin infusion protocol. The protocol was low risk with reduced LOS and cost after INFRA bypass. Complications including SSI were not reduced in patients with optimal perioperative glycemic control.

Pre-operative predictors of poor outcomes in patients undergoing surgical lower extremity revascularisation - Retrospective cohort study

BACKGROUND

Surgical lower extremity revascularisation (LER) can lead to poor outcomes that include delayed hospital discharge, in-hospital mortality, major amputations and readmissions. The aim of this study was to identify pre-operative predictors associated with these poor clinical outcomes.

MATERIALS AND METHODS

All patients (n = 635; mean age 69; male 67.4%) who underwent surgical LER over a 5 year period in a single tertiary vascular institution were identified. Patients considered to have suffered a poor outcome (Group A) included all in-hospital mortality and major amputations, delayed discharges with a length of stay (LOS) over one standard deviation above the mean or any readmission under any specialty within 12 months. Group A included 247 patients (38.9%) and the good outcome group included the remaining 388 patients (61.1%) from which a sample of 99 patients were selected as controls (Group B).

RESULTS

Mean LOS for the entire study group was 14.4 ± 17.5 days, 12 month readmission rate was 29.1% and in-hospital mortality and major amputation rate was 2.7% and 1.4%, respectively. Pre-admission residence other than own home (OR 9.0; 95% CI 1.2-70.1; P = 0.036), atherosclerotic disease burden (OR 2.2; 95% CI 1.3-3.8; P = 0.003) and tissue loss (OR 3.0; 95% CI 1.6-5.3; P < 0.001) were identified as independent, statistically significant pre-operative predictors of poor outcome. Following discharge, group B patients had a significantly higher rate of amputation free survival and graft infection free survival (P < 0.001) compared to group A.

CONCLUSION

Recognition of pre-operative predictors of poor outcome should inform case selection and identify high risk patients requiring intensive perioperative optimisation and post discharge follow up.

Endovascular Versus Open Revascularization for Peripheral Arterial Disease

OBJECTIVE

The aim of this study was to determine whether endovascular or open revascularization provides an advantageous approach to symptomatic peripheral arterial disease (PAD) over the longer term.

SUMMARY OF BACKGROUND DATA

The optimal revascularization strategy for symptomatic lower extremity PAD is not established.

METHODS

We evaluated amputation-free survival, overall survival, and relative rate of subsequent vascular intervention after endovascular or open lower extremity revascularization for propensity-score matched cohorts of Medicare beneficiaries with PAD from 2006 through 2009.

RESULTS

Among 14,685 eligible patients, 5928 endovascular and 5928 open revascularization patients were included in matched analysis. Patients undergoing endovascular repair had improved amputation-free survival compared with open repair at 30 days (7.4 vs 8.9%, P = 0.002). This benefit persisted over the long term: At 4 years, 49% of endovascular patients had died or received major amputation compared with 54% of open patients (P < 0.001). An endovascular procedure was associated with a risk-adjusted 16% decreased risk of amputation or death compared with open over the study period (hazard ratio: 0.84; 95% confidence interval, 0.79-0.89; P < 0.001). The amputation-free survival benefit associated with an endovascular revascularization was more pronounced in patients with congestive heart failure or ischemic heart disease than in those without (P = 0.021 for interaction term). The rate of subsequent intervention at 30 days was 7.4% greater for the endovascular vs the open revascularization cohort. At 4 years, this difference remained stable at 8.6%.

CONCLUSIONS

Using population-based data, we demonstrate that an endovascular approach is associated with improved amputation-free survival over the long term with only a modest relative increased risk of subsequent intervention.

Impact of diabetes on mortality in peripheral artery disease: a meta-analysis

BACKGROUND

There are accumulating studies showing the association between diabetes and all-cause mortality in peripheral vascular disease. However, the results in these studies are conflicting regarding the impact of diabetes on outcome.

HYPOTHESIS

Diabetes is associated with increased risk of mortality in peripheral artery disease.

METHODS

Using MEDLINE and Scopus, we searched for studies published before January 2016. Additionally, studies were identified by manual search of references of original articles or review studies on this topic. Of the 1072 initially identified records, 21 studies with 15,857 patients were included in the final analysis.

RESULTS

Diabetes was associated with a statistically significant increased risk of all-cause mortality (odds ratio: 1.89, 95% confidence interval: 1.51-2.35, P < 0.001), without detected publication bias (Egger bias = 0.75, P = 0.631). The stronger effect on outcome was obtained in patients with critical limb ischemia (odds ratio: 2.38, 95% confidence interval: 1.22-4.63, P < 0.001) as the most severe form of peripheral vascular disease.

CONCLUSIONS

Diabetes is associated with an increased risk of mortality in peripheral vascular disease, and the effect is even more pronounced in patients with critical limb ischemia.

Toe-Brachial Index in the Second Toe: Substitutability to Toe-Brachial Index in the Great Toe and Ankle-Brachial Index

Objective: Toe-brachial index (TBI) is usually measured in the great toe (TBI-1). However, this is not always possible. To determine the usefulness of TBI measurement in the second toe (TBI-2), we examined the relation between systolic pressure in the second toe (toe pressure [TP-2]) and that in the great toe (TP-1) and evaluated the association between TBI and ankle-brachial index (ABI). Materials and Methods: We retrospectively analyzed patients who underwent a series of measurements of TBI-2, TBI-1, and ABI using an automatic oscillometric device at Kawasaki Medical School Hospital, Japan in 2012. Results: We evaluated 114 feet without severe ischemia symptoms in 57 patients (median age: 73 years). TP-2 was similar to TP-1 (correlation coefficient [r] = 0.769, 95% confidence interval [CI]: 0.681-0.836, p <0.001). ABI showed a mild correlation with TBI-2 (r = 0.463, 95% CI: 0.303-0.598, p <0.001) and a moderate correlation with TBI-1 (r = 0.586, 95% CI: 0.450-0.696, p <0.001). The TBIs of 0.65 and 0.5 corresponded to the ABIs of about 1.0 and 0.9, respectively, in both toes. Conclusion: TBI-2 measurement can be considered as an acceptable substitute to TBI-1 or ABI measurement to assess the patients in whom ABI and TBI-1 cannot be measured.

Prognostic factor of the two-year mortality after revascularization in patients with critical limb ischemia

Purposes

The aim of this study was to evaluate the risk factors for the two-year survival after revascularization of critical limb ischemia.

Methods

Between 2008 and 2012, 142 patients underwent revascularization. A retrospective analysis was performed to measure the risk factor.

Results

A total 85 patients underwent surgical revascularization, 31 patients underwent endovascular therapy while 26 patients underwent hybrid therapy. By multivariate analysis, the following variables were considered to be risk factors: ejection fraction <50 % (HR, 3.14; 95% CI, 1.22–7.95; P = 0.02), serum albumin level <2.5 g/dL (HR, 3.45; 95% CI, 1.01–11.7; P = 0.04) and nonambulatory status (HR, 4.11; 95% CI, 1.79–9.70; P < 0.01). The two-year survival rate of the patients with no risk factors was 85.5%, while the patients with at least one risk factor had an unfavorable prognosis (one; 56.7%, two; 45.4%).

Conclusions

The nonambulatory status, serum albumin level <2.5 g/dL and ejection fraction <50% were the risk factors for the two-year mortality after revascularization in critical limb ischemia patients. These risk factors may be useful for the treatment strategy of critical limb ischemia patients.

Outcomes of lower extremity revascularization among the hemodialysis-dependent

OBJECTIVE

Optimal patient selection for lower extremity revascularization remains a clinical challenge among the hemodialysis-dependent (HD). The purpose of this study was to examine contemporary real world open and endovascular outcomes of HD patients to better facilitate patient selection for intervention.

METHODS

A regional multicenter registry was queried between 2003 and 2013 for HD patients (N = 689) undergoing open surgical bypass (n = 295) or endovascular intervention (n = 394) for lower extremity revascularization. Patient demographics and comorbidities were recorded. The primary outcome was overall survival. Secondary outcomes included graft patency, freedom from major adverse limb events, and amputation-free survival (AFS). Multivariate analysis was performed to identify independent risk factors for death and amputation.

RESULTS

Among the 689 HD patients undergoing lower extremity revascularization, 66% were male, and 83% were white. Ninety percent of revascularizations were performed for critical limb ischemia and 8% for claudication. Overall survival at 1, 2, and 5 years survival remained low at 60%, 43%, and 21%, respectively. Overall 1- and 2-year AFS was 40% and 17%. Mortality accounted for the primary mode of failure for both open bypass (78%) and endovascular interventions (80%) at two years. Survival, AFS, and freedom from major adverse limb event outcomes did not differ significantly between revascularization techniques. At 2 years, endovascular patency was higher than open bypass (76% vs 26%; 95% confidence interval [CI], 0.28-0.71; P = .02). Multivariate analysis identified age ≥80 years (hazard ratio [HR], 1.9; 95% CI, 1.4-2.5; P < .01), indication of rest pain or tissue loss (HR, 1.8; 95% CI, 1.3-2.6; P < .01), preoperative wheelchair/bedridden status (HR, 1.5; 95% CI, 1.1-2.1; P < .01), coronary artery disease (HR, 1.5; 95% CI, 1.2-1.9; P < .01), and chronic obstructive pulmonary disease (HR, 1.4; 95% CI, 1.1-1.8; P = .01) as independent predictors of death. The presence of three or more risk factors resulted in predicted 1-year mortality of 64%.

CONCLUSIONS

Overall survival and AFS among HD patients remains poor, irrespective of revascularization strategy. Mortality remains the primary driver for these findings and justifies a prudent approach to patient selection. Focus for improved results should emphasize predictors of survival to better identify those most likely to benefit from revascularization.

Determinants of survival and major amputation after peripheral endovascular intervention for critical limb ischemia

OBJECTIVE

Our objective was to analyze periprocedural and 1-year outcomes of peripheral endovascular intervention (PVI) for critical limb ischemia (CLI).

METHODS

We reviewed 1244 patients undergoing 1414 PVIs for CLI (rest pain, 29%; tissue loss, 71%) within the Vascular Study Group of New England (VSGNE) from January 2010 to December 2011. Overall survival (OS), amputation-free survival (AFS), and freedom from major amputation at 1 year were analyzed using the Kaplan-Meier method. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The number of arteries treated during each procedure were 1 (49%), 2 (35%), 3 (12%), and ≥4 (5%). Target arterial segments and TransAtlantic Inter-Society Consensus classifications were aortoiliac, 27% (A, 48%; B, 28%; C, 12%; and D, 12%); femoral-popliteal, 48% (A, 29%; B, 34%; C, 20%; and D, 17%); and infrapopliteal, 25% (A, 17%; B, 14%; C, 25%; D, 44%). Technical success was 92%. Complications included access site hematoma (5.0%), occlusion (0.3%), and distal embolization (2.4%). Mortality and major amputation rates were 2.8% and 2.2% at 30 days, respectively. Overall percutaneous or open reintervention rate was 8.0% during the first year. At 1-year, OS, AFS, and freedom from major amputation were 87%, 87%, and 94% for patients with rest pain and 80%, 71%, and 81% for patients with tissue loss. Independent predictors of reduced 1-year OS (C index = .74) included dialysis (HR, 3.8; 95% CI, 2.8-5.1; P < .01), emergency procedure (HR, 2.5; 95% CI, 1.0-6.2; P = .05), age >80 years (HR, 2.2; 95% CI, 1.7-2.8; P < .01), not living at home preoperatively (HR, 2.0; 95% CI, 1.4-2.8; P < .01), creatinine >1.8 mg/dL (HR, 1.9; 95% CI, 1.3-2.8; P < .01), congestive heart failure (HR, 1.7; 95% CI, 1.3-2.2; P < .01), and chronic β-blocker use (HR, 1.4; 95% CI, 1.0-1.9; P = .03), whereas independent preoperative ambulation (HR, 0.7; 95% CI, 0.6-0.9; P = .014) was protective. Independent predictors of major amputation (C index = .69) at 1 year included dialysis (HR, 2.7; 95% CI, 1.6-4.5; P < .01), tissue loss (HR, 2.0; 95% CI, 1.1-3.7; P = .02), prior major contralateral amputation (HR, 2.0; 95% CI, 1.1-3.5; P = .02), non-Caucasian race (HR, 1.7; 95% CI, 1.0-2.9; P = .045), and male gender (HR, 1.6; 95% CI, 1.1-2.6; P = .03), whereas smoking (HR, .60; 95% CI, 0.4-1.0; P = .042) was protective.

CONCLUSIONS

Survival and major amputation after PVI for CLI are associated with different patient characteristics. Dialysis dependence is a common predictor that portends especially poor outcomes. These data may facilitate efforts to improve patient selection and, after further validation, enable risk-adjusted outcome reporting for CLI patients undergoing PVI.

Risk Factors for 30-Day Hospital Readmission in Patients Undergoing Treatment for Peripheral Artery Disease

Early hospital readmission among vascular surgery patients is a focus of Medicare’s new reimbursement structure. We aim to identify factors associated with 30-day readmission after lower extremity interventions to treat peripheral artery disease (PAD). Retrospective analysis of 174 consecutive patients discharged from the vascular surgery service between January 1, 2011, and July 31, 2012, after procedures for lower extremity PAD was performed. Of 174 patients, 37 were readmitted within 30 days of discharge. There were no significant differences in baseline characteristics between the readmitted and the nonreadmitted groups. In a multivariate logistic regression model, urgent operation and advanced chronic kidney disease (CKD) were associated with increased risk of 30-day readmission. The most common reasons for readmission were infection of the surgical site or index limb (18 of 37), followed by unresolved limb symptoms (13 of 37). The 30-day readmission is frequent after lower extremity interventions to treat PAD. Urgent operative intervention and advanced CKD appear to be risk factors for early hospital readmission.

Functional outcomes after lower extremity revascularization in nursing home residents: a national cohort study

IMPORTANCE

Lower extremity revascularization often seeks to allow patients with peripheral arterial disease to maintain the ability to walk, a key aspect of functional independence. Surgical outcomes in patients with high levels of functional dependence are poorly understood.

OBJECTIVE

To determine functional status trajectories, changes in ambulatory status, and survival after lower extremity revascularization in nursing home residents.

DESIGN

Using full Medicare claims data for 2005 to 2009, we identified nursing home residents who underwent lower extremity revascularization. With the Minimum Data Set for Nursing Homes activities of daily living summary score, we examined changes in their ambulatory and functional status after surgery. We identified patient and surgery characteristics associated with a composite measure of clinical and functional failure-death or nonambulatory status 1 year after surgery.

SETTING

All nursing homes in the United States participating in Medicare or Medicaid.

PARTICIPANTS

Nursing home residents who underwent lower extremity revascularization.

MAIN OUTCOMES AND MEASURES

Functional status, ambulatory status, and death.

RESULTS

During the study period, 10,784 long-term nursing home residents underwent lower extremity revascularization. Prior to surgery, 75% of the residents were not walking; 40% had experienced functional decline. One year after surgery, 51% of patients had died, 28% were nonambulatory, and 32% had sustained functional decline. Among 1672 residents who were ambulatory before surgery, 63% had died or were nonambulatory at 1 year; among 7188 who were nonambulatory, 89% had died or were nonambulatory. After multivariate adjustment, factors independently associated with death or nonambulatory status were 80 years or older (adjusted hazard ratio [AHR], 1.28; 95% CI, 1.16-1.40), cognitive impairment (AHR, 1.23; 95% CI, 1.18-1.29), congestive heart failure (AHR, 1.16; 95% CI, 1.11-1.22), renal failure (AHR, 1.09; 95% CI, 1.04-1.14), emergent surgery (AHR, 1.29; 95% CI, 1.23-1.35), nonambulatory status before surgery (AHR, 1.88; 95% CI, 1.78-1.99), and decline in activities of daily living before surgery (AHR, 1.23; 95% CI, 1.18-1.28).

CONCLUSIONS AND RELEVANCE

Of nursing home residents in the United States who undergo lower extremity revascularization, few are alive and ambulatory 1 year after surgery. Most who were still alive had gained little, if any, function.

Pharmacology in peripheral arterial disease: what the interventional radiologist needs to know

Peripheral arterial disease (PAD) is a progressive disease with significant morbidity and mortality. Risk factor control, using diet and lifestyle modification, exercise, and pharmacological methods, improves symptoms and reduces associated cardiovascular events in these patients. Antiplatelet agents and anticoagulants may be used to reduce the incidence of acute events related to thrombosis. The armamentarium available for symptom relief and disease modification is discussed. Novel treatments such as therapeutic angiogenesis are in their evolutionary phase with promising preclinical data.

Contemporary outcomes with percutaneous vascular interventions for peripheral critical limb ischemia in those with and without poly-vascular disease

Given the very ill nature of patients with critical limb ischemia (CLI), the use of percutaneous vascular interventions (PVIs) for limb salvage may or may not be efficacious; in particular, for those with polyvascular arterial disease. Herein, we reviewed large, multi-institutional outcomes of PVI in polyvascular and peripheral arterial disease (PAD) patients with CLI. An 18-hospital consortium collected prospective data on patients undergoing endovascular interventions for PAD with 6-month follow-up from January 2008 to December 2011. The patient cohort included 4459 patients with CLI; of those, 3141 patients had polyvascular (coronary artery disease, cerebrovascular disease and PAD) disease, whereas 1318 patients suffered from only PAD. All patients were elderly and with significant comorbidities. The mean ankle–brachial index (ABI) was 0.44 and was not different between those with and without polyvascular disease. Polyvascular patients had more femoropopliteal and infra-inguinal interventions and less aortoiliac interventions than PAD patients. Pre- and post-procedural cardioprotective medication use was less in the PAD patients as compared with polyvascular patients. Vascular complications requiring surgery were higher in PAD patients whereas other access complications were similar between groups. At 6-month follow-up, death was more common in the polyvascular group (6.7% vs 4.1%, p<0.001) as was repeat PVI, but no difference was found in the amputation rate. Considering the group as a whole at the 6-month follow-up, predictors of amputation/death included age (HR=1.01; 95% CI=1.002–1.02), anemia (HR=2.6; 95% CI=2.1–3.2), diabetes mellitus (HR=1.6; 95% CI=1.3–1.9), congestive heart failure (HR=1.6; 95% CI=1.4–1.9), and end-stage renal failure (HR=1.9; 95% CI=1.5–2.3), while female sex was protective (HR=0.7; 95% CI=0.6–0.8). In conclusion, from examination of this large, multicenter, multi-specialist practice registry, patients with polyvascular disease had higher 6-month mortality than PAD patients, but this was not a factor in 6-month limb amputation outcomes. This study also underscores that PAD patients still lag in cardioprotective medication use as compared with polyvascular patients.

Bypass vs. Endovascular Therapy of Infrapopliteal Lesions for Critical Limb Ischemia

OBJECTIVE

This study was conducted to determine whether to perform endovascular intervention or bypass surgery as a treatment option for critical limb ischemia (CLI) with lesions in the popliteal artery or below.

SUBJECTS AND METHODS

A total of 150 patients (164 limbs) with CLI underwent endovascular intervention or bypass surgery for lesions in the popliteal artery or below at our department between May 1995 and June 2011. Therapeutic outcomes were examined by surgical technique. An indication for endovascular intervention was established with the combination of (1) poor general condition, and (2) a stenotic or occlusive lesion ≤5 cm.

RESULTS

The bypass group (group B) comprised 119 patients (99 males, 20 females) with 131 affected limbs at 46 to 89 years of age (mean: 70 years). The endovascular intervention group (group E) comprised 31 patients (25 males, 6 females) with 33 affected limbs at 47 to 89 years of age (mean: 72 years). There was no significant difference in patient demography between the two groups. Regarding preoperative complications, hypertension was observed in 54% and 61% of the subjects in groups B and E, respectively, diabetes in 36% and 55%, renal dysfunction in 29% and 58%, ischemic heart disease in 27% and 32%, and cerebrovascular disorder in 18% and 23%; renal dysfunction accounted for a significantly higher percentage in group E. As for early postoperative complications, subjects in group B experienced wound infections (6 patients), hemorrhage (2), thrombosis (2), pneumonia (1), and another complication (1), and those in group E experienced wound infections (1) and another complication (1). The hospital mortality rate was 0.8% (1 patient) for group B and 0% for group E. The 3-year cumulative primary patency rate was 72% for group B and 54% for group E; the rate was significantly higher for group B. The 3-year secondary patency rate was 82% for group B and 60% for group E. The 3-year limb salvage rate was 86% for group B and 82% for group E; there was no significant difference between the two groups. The 5-year survival rate was 57% for group B and 42% for group E; the survival rate was significantly lower for group E.

CONCLUSION

For the study population of CLI patients with lesions in the popliteal artery or below, the patency rate was higher for the bypass group than for the endovascular intervention group, whereas there was no difference in the limb salvage rate. Based on the findings in prognosis for survival, the indication for endovascular intervention at our department is believed to be appropriate. (English translation of Jpn J Vasc Surg 2013; 22: 715-718).

Defining utility and predicting outcome of cadaveric lower extremity bypass grafts in patients with critical limb ischemia

OBJECTIVE

Despite poor long-term patency, acceptable limb salvage has been reported with cryopreserved saphenous vein bypass (CVB) for various indications. However, utility of CVB in patients with critical limb ischemia (CLI) remains undefined. The purpose of this analysis was to determine the role of CVB in CLI patients and to identify predictors of successful outcomes.

METHODS

A retrospective review of all lower extremity bypass (LEB) procedures at a single institution was completed, and CVB in CLI patients were further analyzed. The primary end point was amputation-free survival. Secondary end points included primary patency and limb salvage. Life tables were used to estimate occurrence of end points. Cox regression analysis was used to determine predictors of limb salvage.

RESULTS

From 2000 to 2012, 1059 patients underwent LEB for various indications, of whom 81 received CVB for either ischemic rest pain or tissue loss. Mean age (± standard deviation) was 66 ± 10 years (male, 51%; diabetes, 51%; hemodialysis dependence, 12%), and 73% (n = 59) had history of failed ipsilateral LEB or endovascular intervention. None had sufficient autogenous conduit for even composite vein bypass. Infrainguinal CVB (infrapopliteal target, 96%; n = 78) was completed for multiple indications including Rutherford class 4 (42%; n = 34), class 5 (40%; n = 32), and class 6 (18%; n = 15). Eleven (14%) had CLI and concomitant graft infection (n = 8) or acute on chronic ischemia (n = 3). Intraoperative adjuncts (eg, profundaplasty, suprainguinal stent or bypass) were completed in 49% (n = 40) of cases. Complications occurred in 36% (n = 29), with 30-day mortality of 4% (n = 3). Median follow-up for CLI patients was 11.8 (interquartile range, 0.4-28.4) months with corresponding 1- and 3-year actuarial estimated survival (± standard error mean) of 84% ± 4% and 62% ± 6%. Primary patency of CVB for CLI was 27% ± 6% and 17% ± 6% at 1 and 3 years, respectively. Amputation-free survival was 43% ± 6% and 23% ± 6% at 1 and 3 years, respectively, and significantly higher for rest pain (59% ± 9%, 36% ± 10%) compared with tissue loss (31% ± 7%, 14% ± 7%; log-rank, P = .04). Freedom from major amputation after CVB for CLI was 57% ± 6% and 43% ± 7% at 1 and 3 years. Multivariable predictors of limb salvage for the CVB CLI cohort included postoperative warfarin (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.2-0.8), dyslipidemia (HR, 0.4; 95% CI, 0.2-0.9), and rest pain (HR, 0.4; 95% CI, 0.2-0.9). Predictors of major amputation included graft infection (HR, 3.1; 95% CI, 1.1-9.0).

CONCLUSIONS

In CLI patients with no autologous conduit and prior failed infrainguinal bypass, CVB outcomes are disappointing. CVB performs best in patients with rest pain, particularly those who can be anticoagulated with warfarin. However, it may be an acceptable option in patients with minor tissue loss or concurrent graft infection, but consideration should be weighed against the known natural history of nonrevascularized CLI and nonbiologic conduit alternatives, given potential cost implications.

Relationship between regional spending on vascular care and amputation rate

IMPORTANCE

Although lower extremity revascularization is effective in preventing amputation, the relationship between spending on vascular care and regional amputation rates remains unclear.

OBJECTIVE

To test the hypothesis that higher regional spending on vascular care is associated with lower amputation rates for patients with severe peripheral arterial disease.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 18,463 US Medicare patients who underwent a major peripheral arterial disease-related amputation during the period between 2003 and 2010.

EXPOSURE

Price-adjusted Medicare spending on revascularization procedures and related vascular care in the year before lower extremity amputation, across hospital referral regions.

MAIN OUTCOMES AND MEASURES

Correlation coefficient between regional spending on vascular care and regional rates of peripheral arterial disease-related amputation.

RESULTS

Among patients who ultimately underwent an amputation, 64% were admitted to the hospital in the year prior to the amputation for revascularization, wound-related care, or both; 36% were admitted only for their amputation. The mean cost of inpatient care in the year before amputation, including costs related to the amputation procedure itself, was $22,405, but it varied from $11,077 (Bismarck, North Dakota) to $42,613 (Salinas, California) (P < .001). Patients in high-spending regions were more likely to undergo vascular procedures as determined by crude analyses (12.0 procedures per 10,000 patients in the lowest quintile of spending and 20.4 procedures per 10,000 patients in the highest quintile of spending; P < .001) and by risk-adjusted analyses (adjusted odds ratio for receiving a vascular procedure in highest quintile of spending, 3.5 [95% CI, 3.2-3.8]; P < .001). Although revascularization was associated with higher spending (R = 0.38, P < .001), higher spending was not associated with lower regional amputation rates (R = 0.10, P = .06). The regions that were most aggressive in the use of endovascular interventions were the regions that were most likely to have high spending (R = 0.42, P = .002) and high amputation rates (R = 0.40, P = .004).

CONCLUSIONS AND RELEVANCE

Regions that spend the most on vascular care perform the most procedures, especially endovascular interventions, in the year before amputation. However, there is little evidence that higher regional spending is associated with lower amputation rates. This suggests an opportunity to limit costs in vascular care without compromising quality.

Endovascular-first approach is not associated with worse amputation-free survival in appropriately selected patients with critical limb ischemia

OBJECTIVE

Endovascular interventions for critical limb ischemia are associated with inferior limb salvage (LS) rates in most randomized trials and large series. This study examined the long-term outcomes of selective use of endovascular-first (endo-first) and open-first strategies in 302 patients from March 2007 to December 2010.

METHODS

Endo-first was selected if (1) the patient had short (5-cm to 7-cm occlusions or stenoses in crural vessels); (2) the disease in the superficial femoral artery was limited to TransAtlantic Inter-Society Consensus II A, B, or C; and (3) no impending limb loss. Endo-first was performed in 187 (62%), open-first in 105 (35%), and 10 (3%) had hybrid procedures.

RESULTS

The endo-first group was older, with more diabetes and tissue loss. Bypass was used more to infrapopliteal targets (70% vs 50%, P = .031). The 5-year mortality was similar (open, 48%; endo, 42%; P = .107). Secondary procedures (endo or open) were more common after open-first (open, 71 of 105 [68%] vs endo, 102 of 187 [55%]; P = .029). Compared with open-first, the 5-year LS rate for endo-first was 85% vs 83% (P = .586), and amputation-free survival (AFS) was 45% vs 50% (P = .785). Predictors of death were age >75 years (hazard ratio [HR], 3.3; 95% confidence interval [CI], 1.7-6.6; P = .0007), end-stage renal disease (ESRD) (HR, 3.4; 95% CI, 2.1-5.6; P < .0001), and prior stroke (HR, 1.6; 95% CI, 1.03-2.3; P = .036). Predictors of limb loss were ESRD (HR, 2.5; 95% CI, 1.2-5.4; P = .015) and below-the-knee intervention (P = .041). Predictors of worse AFS were older age (HR, 2.03; 95% CI, 1.13-3.7; P = .018), ESRD (HR, 3.2; 95% CI, 2.1-5.11; P < .0001), prior stroke (P = .0054), and gangrene (P = .024).

CONCLUSIONS

At 5 years, endo-first and open-first revascularization strategies had equivalent LS rates and AFS in patients with critical limb ischemia when properly selected. A patient-centered approach with close surveillance improves long-term outcomes for both open and endo approaches.

Critical limb ischemia: reporting outcomes and quality

The impetus to pursue quality in limb salvage is high in the current economic environment. This has been spurred on by the diffusion of multiple technologies, the lack of well-defined cost-effectiveness benchmarks, and the paucity of process and structure benchmarks. Furthermore, no national database exists to capture current activity and trends, and lead structure and process changes that could analyze outcomes and improve standards in peripheral interventions for limb salvage. This manuscript examines the challenges in measuring outcomes and quality in limb salvage and explores the components necessary for ensuring quality in limb salvage interventions.

Outcomes of lower extremity bypass performed for acute limb ischemia

OBJECTIVE

Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia.

METHODS

All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year.

RESULTS

Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38-3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09-1.83; P = .009) at 1 year.

CONCLUSIONS

Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year.

Critical appraisal of surgical revascularization for critical limb ischemia

Peripheral artery disease is growing in global prevalence and is estimated to afflict between 8 and 12 million Americans. Its most severe form, critical limb ischemia (CLI), is associated with high rates of limb loss, morbidity, and mortality. Revascularization is the cornerstone of limb preservation in CLI, and has traditionally been accomplished with open surgical bypass. Advances in catheter-based technologies, coupled with their broad dissemination among specialists, have led to major shifts in practice patterns in CLI. There is scant high-quality evidence to guide surgical decision making in this arena, and market forces have exerted profound influences. Despite this, available data suggest that the expected outcomes for both endovascular and open surgery in CLI are strongly dependent on definable patient factors such as anatomic distribution of disease, vein quality, and comorbidities. Optimal patient selection is paramount for maximizing benefit with each technique. This review summarizes some of the existing data and suggests a selective approach to revascularization in CLI, which continues to rely on vein bypass surgery as a primary option in appropriately selected patients.

Blood transfusion for lower extremity bypass is associated with increased wound infection and graft thrombosis

BACKGROUND

Packed RBC transfusion has been postulated to increase morbidity and mortality after cardiac/general surgical operations, but its effects after lower extremity bypass (LEB) have not been studied extensively.

STUDY DESIGN

Using the Vascular Study Group of New England's database (2003-2010), we examined 1,880 consecutive infrainguinal LEB performed for critical limb ischemia. Perioperative transfusion was categorized as 0 U, 1 to 2 U, and ≥3 U. Cohort frequency group matching was used to compare groups of patients receiving 1 to 2 U and 0 U with patients receiving ≥3 U using age, coronary artery disease, diabetes, urgency, and indication of revascularization. Primary end points were perioperative mortality, wound infection, and loss of primary graft patency at discharge, as well as 1-year mortality and loss of primary graft patency.

RESULTS

In the study cohort, 1,532 LEBs (81.5%) received 0 U, 248 LEBs (13.2%) received 1 to 2 U, and 100 LEBs (5.3%) received ≥3 U transfusion. In the study cohort and group frequency matched cohort, transfusion was associated with significantly higher perioperative wound infection (0 U:4.8% vs 1 to 2 U: 6.5% vs ≥3 U: 14.0%; p = 0.0004) and graft thrombosis at discharge (4.5% vs 7.7% vs 15.3%; p < 0.0001). At 1 year, there were no differences in infection or graft patency. In multivariate analysis, transfusion was independently associated with increased perioperative wound infection in the study cohort and group frequency matched cohort (1 to 2 U vs 0 U: adjusted odds ratio [OR] = 1.4; 95% CI, 0.8-2.5; p = 0.263; ≥3 U vs 0 U: OR = 3.5; 95% CI, 1.8-6.7; p = 0.0002; overall p = 0.002) and increased graft thrombosis at discharge (1 to 2 U vs 0 U: OR = 2.1; 95% CI, 1.2-3.6; p = 0.01; ≥3 U vs 0 U: OR = 4.8; 95% CI, 2.5-9.2; p < 0.0001, overall p < 0.0001).

CONCLUSIONS

Perioperative transfusion in patients undergoing LEB is associated with increased perioperative wound infection and graft thrombosis. From this observational study, it appears transfusion does not have major consequences during mid-term follow-up, but the presumed benefits of blood replacement should be weighed carefully because of the increased risk of perioperative complications with transfusion.

Collective therapy and therapeutic strategy for critical limb ischemia

OBJECTIVE

To determine a treatment strategy based on the outcomes of various previous interventions for critical limb ischemia in arteriosclerosis obliterans (ASO).

MATERIAL AND METHODS

We examined outcomes of 292 ASO patients who had had critical limb ischemia between May 1995 and July 2009. Patients underwent the following procedures in 167 cases: aortofemoral bypass (n = 14), femorofemoral crossover bypass (n = 29), femoropopliteal bypass (n = 104) and femorotibial bypass (n = 40). Other procedures included bypass only (n = 147), bypass combined with thromboendarterectomy (n = 10), bypass combined with endovascular therapy (n = 6), bypass combined with lumbar sympathectomy (n = 2), endovascular therapy combined with thromboendarterectomy (n = 4), endovascular therapy (n = 19), lumbar sympathectomy (n = 6), conservative therapy (n = 65), and major amputation (n = 31). We also calculated P3 risk scores and measured transcutaneous oxygen pressure (tcPO2) and skin perfusion pressure (SPP) before and after therapy.

RESULTS

The limb salvage rate was 87% at 2 years in the arterial reconstruction group. In the low-risk group (a P 3 risk score of 3), the 1-year amputation-free survival rate was 96%. In the medium-risk group (a P 3 risk score of 4-7), the 1-year amputation-free survival rate was 88%. In the high-risk group (a P 3 risk score of 8), the 1-year amputation-free survival rate was 66%. The hospital death rate in the arterial reconstruction group was 3.2%, all of whom were patients who underwent bypass. The survival rate at 5 years was 65% and 36% in the conservative therapy only group. Ulcers healed in 140 out of 144 patients. The 4 patients with unhealed infections had tcPO2 or SPP values of more than 30 mmHg after treatment. Major amputations were performed in 4 of 5 patients who had tcPO2 or SPP values from 20 to 30 mmHg after treatment. Major amputations were performed in all 6 patients who had tcPO2 or SPP values of less than 20 mmHg after treatment.

CONCLUSION

In cases with tcPO2 or SPP values of more than 30 mmHg, an ulcer will probably heal, except in infected cases. We suggest that, if these values are less than 30 mmHg, complete revascularization should be performed. The P3 risk score was useful in predicting limb salvage in the current series. Hybrid therapy in bypass and endovascular therapy must be performed in cases where patients are in a generally poor condition. It is important to attempt amelioration in limb salvage and to control the operative mortality rate with sufficient perioperative control. (English Translation of Jpn J Vasc Surg 2011;20:905-911).

APC resistance due to Factor V Leiden is not related to baseline inflammatory mediators or survival up to 10 years in patients with critical limb ischemia

To prospectively evaluate the potential influence of resistance to activated protein C (APC-resistance) on the initial inflammatory response, amputation rate and survival during 10 years of follow-up in patients with critical limb ischemia (CLI). Two hundred and fifty-six consecutive CLI patients were analyzed for APC-ratio, the Factor V Leiden mutation and inflammatory mediators and then prospectively followed for 10 years. Inflammatory mediators, amputation rate, morbidity and mortality were compared between patients with and without APC resistance. Of the 256 CLI patients, 35 (14 %) were heterozygotes and 2 (1 %) homozygotes for the Factor V gene mutation, whereas 219 (86 %) patients were non-APC resistant. No significant differences were found between APC resistant and non-APC resistant patients regarding inflammatory mediators. Non-APC resistant patients more often had infrainguinal atherosclerosis (172 [79 %] vs 22 [59 %]; p = 0.017). Amputation rate at 1 year did not differ. Furthermore, there were no significant differences between groups regarding 1-, 3-, 5-, or 10-year survival. APC resistance in patients with CLI was not related to inflammatory activity, and had no impact on limb salvage or rate of amputation or long-term mortality. APC-resistant CLI-patients less frequently had infrainguinal arteriosclerosis, however.

An integrated biochemical prediction model of all-cause mortality in patients undergoing lower extremity bypass surgery for advanced peripheral artery disease

BACKGROUND

Patients with advanced peripheral artery disease (PAD) have a high prevalence of cardiovascular (CV) risk factors and shortened life expectancy. However, CV risk factors poorly predict midterm (<5 years) mortality in this population. This study tested the hypothesis that baseline biochemical parameters would add clinically meaningful predictive information in patients undergoing lower extremity bypass operations.

METHODS

This was a prospective cohort study of patients with clinically advanced PAD undergoing lower extremity bypass surgery. The Cox proportional hazard model was used to assess the main outcome of all-cause mortality. A clinical model was constructed with known CV risk factors, and the incremental value of the addition of clinical chemistry, lipid assessment, and a panel of 11 inflammatory parameters was investigated using the C statistic, the integrated discrimination improvement index, and Akaike information criterion.

RESULTS

The study monitored 225 patients for a median of 893 days (interquartile range, 539-1315 days). In this study, 50 patients (22.22%) died during the follow-up period. By life-table analysis (expressed as percent surviving ± standard error), survival at 1, 2, 3, 4, and 5 years, respectively, was 90.5% ± 1.9%, 83.4% ± 2.5%, 77.5% ± 3.1%, 71.0% ± 3.8%, and 65.3% ± 6.5%. Compared with survivors, decedents were older, diabetic, had extant coronary artery disease, and were more likely to present with critical limb ischemia as their indication for bypass surgery (P < .05). After adjustment for the above, clinical chemistry and inflammatory parameters significant (hazard ratio [95% confidence interval]) for all-cause mortality were albumin (0.43 [0.26-0.71]; P = .001), estimated glomerular filtration rate (0.98 [0.97-0.99]; P = .023), high-sensitivity C-reactive protein (hsCRP; 3.21 [1.21-8.55]; P = .019), and soluble vascular cell adhesion molecule (1.74 [1.04-2.91]; P = .034). Of the inflammatory molecules investigated, hsCRP proved most robust and representative of the integrated inflammatory response. Albumin, eGFR, and hsCRP improved the C statistic and integrated discrimination improvement index beyond that of the clinical model and produced a final C statistic of 0.82.

CONCLUSIONS

A risk prediction model including traditional risk factors and parameters of inflammation, renal function, and nutrition had excellent discriminatory ability in predicting all-cause mortality in patients with clinically advanced PAD undergoing bypass surgery.

Socioeconomic position is not associated with 30-day or 1-year mortality in demographically diverse vascular surgery patients

OBJECTIVES

Disparities in outcomes after surgical procedures have been attributed to race, sex, use of private insurance, and socioeconomic position (SEP). The purpose of this study was to determine the impact of SEP on mortality after lower-extremity bypass (LEB) surgery in a diverse patient population with extremes of SEP.

DESIGN

Analysis of an electronic medical database.

SETTING

A tertiary care hospital in a demographically diverse section of a large metropolitan area.

PARTICIPANTS

Six hundred nine (158 white men, 156 nonwhite men, 100 white women, and 195 non-white women) patients undergoing infrarenal lower-extremity arterial bypass surgery from July 1, 2002, to December 31, 2007.

MEASUREMENTS AND RESULTS

SEP was estimated using data from the 2000 US Census. The effects of race, sex, various comorbidities, the Revised Cardiac Risk Index, American Society of Anesthesiologists physical status, use of private insurance, indication for bypass surgery, and SEP on all-cause mortality was analyzed. SEP differed significantly among the 4 race-sex groups, with white men having the highest position (mean = 2.38) and non-white men having the lowest position (mean = -3.02). There was no statistically significant association in 30-day mortality among race-sex groups or with SEP. One-year mortality differed significantly between men and women for the entire cohort (13.7% and 24.1%, respectively; p < 0.01) but not among race groups or SEP.

CONCLUSIONS

Disparities in SEP are not associated with short- or long-term mortality after LEB surgery. Other comorbid risk factors are more important when determining outcomes and should be the focus of interventions to improve outcomes.

Validation of the Society for Vascular Surgery's objective performance goals for critical limb ischemia in everyday vascular surgery practice

BACKGROUND

To develop standardized metrics for expected outcomes in lower extremity revascularization for critical limb ischemia (CLI), the Society for Vascular Surgery (SVS) has developed objective performance goals (OPGs) based on aggregate data from randomized trials of lower extremity bypass (LEB). It remains unknown, however, if these targets can be achieved in everyday vascular surgery practice.

METHODS

We applied SVS OPG criteria to 1039 patients undergoing 1039 LEB operations for CLI with autogenous vein (excluding patients on dialysis) within the Vascular Study Group of New England (VSGNE). Each of the individual OPGs was calculated within the VSGNE dataset, along with its surrounding 95% confidence intervals (CIs) and compared to published SVS OPGs using χ(2) comparisons and survival analysis.

RESULTS

Across most risk strata, patients in the VSGNE and SVS OPG cohorts were similar (clinical high-risk [age >80 years and tissue loss]: 15.3% VSGNE; 16.2% SVS OPG; P = .58; anatomic high risk [infrapopliteal target artery]: 57.8% VSGNE; 60.2% SVS OPG; P = .32). However, the proportion of VSGNE patients designated as conduit high-risk (lack of single-segment great saphenous vein) was lower (10.2% VSGNE; 26.9% SVS OPG;P < .001). The primary safety endpoint, major adverse limb events (MALE) at 30 days, was lower in the VSGNE cohort (3.2%; 95% CI, 2.3-4.6) than the SVS OPG cohort (6.2%; 95% CI, 4.2-8.1; P = .05). The primary efficacy OPG endpoint, freedom from any MALE or postoperative death within the first year (MALE + postoperative death [POD]), was similar between VSGNE and SVS OPG cohorts (77%; 95% CI, 74%-80%) SVS OPG, 74% (95% CI, 71%-77%) VSGNE, P = .58). In the remaining safety and efficacy OPGs, the VSGNE cohort met or exceeded the benchmarks established by the SVS OPG cohort.

CONCLUSION

Community and academic centers in everyday vascular surgery practice can meet OPGs derived from centers of excellence in LEB. Quality improvement initiatives, as well as clinical trials, should incorporate OPGs in their outcome measures to facilitate communication and comparison of risk-adjusted outcomes in the treatment of CLI.

Critical limb ischemia

Critical limb ischemia (CLI), defined as chronic ischemic rest pain, ulcers, or gangrene attributable to objectively proven arterial occlusive disease, is the most advanced form of peripheral arterial disease. Traditionally, open surgical bypass was the only effective treatment strategy for limb revascularization in this patient population. However, during the past decade, the introduction and evolution of endovascular procedures have significantly increased treatment options. In a certain subset of patients for whom either surgical or endovascular revascularization may not be appropriate, primary amputation remains a third treatment option. Definitive high-level evidence on which to base treatment decisions, with an emphasis on clinical and cost effectiveness, is still lacking. Treatment decisions in CLI are individualized, based on life expectancy, functional status, anatomy of the arterial occlusive disease, and surgical risk. For patients with aortoiliac disease, endovascular therapy has become first-line therapy for all but the most severe patterns of occlusion, and aortofemoral bypass surgery is a highly effective and durable treatment for the latter group. For infrainguinal disease, the available data suggest that surgical bypass with vein is the preferred therapy for CLI patients likely to survive 2 years or more, and for those with long segment occlusions or severe infrapopliteal disease who have an acceptable surgical risk. Endovascular therapy may be preferred in patients with reduced life expectancy, those who lack usable vein for bypass or who are at elevated risk for operation, and those with less severe arterial occlusions. Patients with unreconstructable disease, extensive necrosis involving weight-bearing areas, nonambulatory status, or other severe comorbidities may be considered for primary amputation or palliative measures.