Background

Percutaneous vascular interventions (PVIs) for peripheral artery disease have shifted from hospital-based facilities to office-based laboratories (OBLs). The transition to OBLs is due to a variety of factors such as technology advancement, increased efficiency, and financial incentives. We evaluated the impact of physicians switching to OBLs use from hospital-based facilities on procedure volume, procedure type, and patient outcomes.

Methods

We identified patients with PVI for lower extremity peripheral artery disease from 2006 to 2013 in a 20% Medicare sample and identified physicians who transitioned from predominantly hospital-based facilities to OBLs (switch physicians) and compared them with those who did not use OBLs (control physicians). The main outcomes investigated were average number of PVIs at 30 days and 1 year and atherectomy usage. Patient outcomes included above-ankle amputation, major adverse limb events, and death. We used a difference-in-difference model to control for time effects in a multivariate regression model, reported as an odds ratio (OR) and 95% confidence interval (CI).

Results

The cohort comprised 292 switch physicians, who treated 7134 patients (3888 before OBL use and 3246 after transitioning to OBLs), and 3715 control physicians treating 54,213 patients (36,327 in the preperiod and 17,886 in the postperiod). Switch and control physicians both treated more patients with lower extremity wounds during the study period; however, this increase was greater for control physician (0.7% vs 5.5%, P < .001). On average, patients treated by switch physicians had 0.05 (95% CI, 0.03-0.07; P < .001) underwent more PVIs within 30 days and 0.12 more PVIs (95% CI, 0.08-0.16; P < .001) within 1 year of the initial revascularization procedure after the physician transitioned to an OBL. Similarly, patients treated by switch physicians underwent 0.02 (95% CI, 0.01-0.03; P = .002) more atherectomy procedures at 30 days and 0.03 (95% CI, 0.01-0.05; P = .008) more atherectomy procedures at 1 year. Transitioning to OBLs was also associated with a decreased risk in above-ankle amputation at 30 days (OR, 0.58; 95% CI, 0.38-0.97; P = .009) and 1 year (OR, 0.75; 95% CI, 0.60-0.95; P = .01). However, no statistical difference was observed for major adverse limb events and mortality rates at 30 days and 1 year because patients treated by switch and control physicians experienced similar decreases.

Conclusions

Transitioning to OBLs was associated higher 30-day and 1-year PVI rates and atherectomy rates. Although transitioning to OBLs was associated with lower rates of above-ankle amputations, switch physicians treated a lower number of patients with lower extremity wounds.

Introduction

This study evaluated the mid-term patency of forearm loop arteriovenous grafts and the dilation of previously inadequate upper arm basilic and cephalic veins after failed forearm loop arteriovenous graft.

Methods

All access procedures from September 2009 to December 2015 were reviewed. Vein mapping measurements were used to determine whether there was "adequate" upper arm cephalic and/or basilic vein, defined as ⩾3 mm by duplex ultrasound, at the time of forearm loop arteriovenous graft creation. Outcomes of forearm loop arteriovenous graft were compared with upper arm arteriovenous fistula, and primary and cumulative patencies were evaluated.

Results

Thirty-eight forearm loop arteriovenous grafts and 278 upper arm arteriovenous fistulas were created. In the forearm loop arteriovenous graft cohort, nine were inserted with adequate upper arm vein, group A, and 29 were inserted with inadequate upper arm vein, group B. Cumulative patency was lower for forearm loop arteriovenous graft compared with upper arm arteriovenous fistula at 6 months, 1 year, and 2 years (67% vs 91%, 61% vs 85%, and 49% vs 80%, respectively, P < .01). Comparison of group A forearm loop arteriovenous graft and upper arm arteriovenous fistula did not show a statistical difference in cumulative patency at 6 months, 1 year, and 2 years (P = .80, .62, and .70, respectively). Of group B with failed forearm loop arteriovenous graft, 36% became candidates for upper arm arteriovenous fistula with dilation of ipsilateral upper arm cephalic or basilic vein to ⩾3 mm.

Conclusion

In this study, forearm loop arteriovenous graft with adequate upper arm vein did not show a statistical difference in mid-term patencies compared with upper arm arteriovenous fistula. For those forearm loop arteriovenous grafts with inadequate upper arm vein, approximately one-third of patients became candidates for upper arm arteriovenous fistula demonstrating the benefits forearm loop arteriovenous graft.

Background

Prescription opioids account for 40% of all U.S. opioid overdose deaths, and national efforts have intensified to reduce opioid prescriptions. Little is known about the relationship between peripheral artery disease (PAD) and high-risk opioid use. The objectives of this study were to evaluate this relationship and to assess the impact of PAD treatment on opiate use.

Methods

In this retrospective cohort study, the Truven Health MarketScan database (Truven Health Analytics, Ann Arbor, Mich), a deidentified national private insurance claims database, was queried to identify patients with PAD (two or more International Classification of Diseases, Ninth Revision diagnosis codes of PAD ≥2 months apart, with at least 2 years of continuous enrollment) from 2007 to 2015. Critical limb ischemia (CLI) was defined as the presence of rest pain, ulcers, or gangrene. The primary outcome was high opioid use, defined as two or more opioid prescriptions within a 1-year period. Multivariable analysis was used to determine risk factors for high opioid use.

Results

A total of 178,880 patients met the inclusion criteria, 35% of whom had CLI. Mean ± standard deviation follow-up time was 5.3 ± 2.1 years. An average of 24.7% of patients met the high opioid use criteria in any given calendar year, with a small but significant decline in high opioid use after 2010 (P < .01). During years of high opioid use, 5.9 ± 5.5 yearly prescriptions were filled. A new diagnosis of PAD increased high opioid use (21.7% before diagnosis vs 27.3% after diagnosis; P < .001). A diagnosis of CLI was also associated with increased high opioid use (25.4% before diagnosis vs 34.5% after diagnosis; P < .001). Multivariable analysis identified back pain (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.84-1.93; P < .001) and illicit drug use (OR, 1.87; 95% CI, 1.72-2.03; P < .001) as the highest predictors of high opioid use. A diagnosis of CLI was also associated with higher risk (OR, 1.61; 95% CI, 1.57-1.64; P < .001). A total of 43,443 PAD patients (24.3%) underwent 80,816 PAD-related procedures. After exclusion of periprocedural opioid prescriptions (4.9% of all opioid prescriptions), the yearly percentage of high opioid users increased from 25.8% before treatment to 29.6% after treatment (P < .001).

Conclusions

Patients with PAD are at increased risk for high opioid use, with nearly one-quarter meeting described criteria. CLI and treatment for PAD additionally increase high opioid use. In addition to heightened awareness and active opioid management, our findings warrant further investigation into underlying causes and deterrents of high-risk opioid use.

Screening for asymptomatic peripheral artery disease (aPAD) with the ankle-brachial index (ABI) test is hypothesized to reduce disease progression and cardiovascular (CV) events by identifying individuals who may benefit from early initiation of medical therapy. Using a Markov model, we evaluated the cost effectiveness of initiating medical therapy (e.g. statin and ACE-inhibitor) after a positive ankle-brachial index (ABI) screen in 65-year-old patients. We modeled progression to symptomatic PAD (sPAD) and CV events with and without ABI screening, evaluating differences in costs and quality-adjusted life years (QALYs). The cost of the ABI test, physician visit, new medication, CV events, and interventions for sPAD were incorporated in the model. We performed sensitivity analysis on model variables with uncertainty. Our model found an incremental cost of US $338 and an incremental QALY of 0.00380 with one-time ABI screening, resulting in an incremental cost-effectiveness ratio (ICER) of $88,758/QALY over a 35-year period. The variables with the largest effects in the ICER were aPAD disease prevalence, cost of monthly medication after a positive screen and 2-year medication adherence rates. Screening high-risk populations, such as tobacco users, where the prevalence of PAD may be 2.5 times higher, decreases the ICER to $24,092/QALY. Our analysis indicates the cost effectiveness of one-time screening for aPAD depends on prevalence, medication costs, and adherence to therapies for CV disease risk reduction. Screening in higher-risk populations under favorable assumptions about medication adherence results in the most favorable cost effectiveness, but limitations in the primary data preclude definitive assessment of cost effectiveness.

Objective

Effective strategies to reduce costs associated with endovascular aneurysm repair (EVAR) remain elusive for many medical centers. In this study, targeted interventions to reduce inpatient EVAR costs were identified and implemented.

Methods

From June 2015 to February 2016, we analyzed the EVAR practice at a high-volume academic medical center to identify, to rank, and ultimately to reduce procedure-related costs. In this analysis, per-patient direct costs to the hospital were compared before (September 2013-May 2015) and after (March 2016-January 2017) interventions were implemented. Improvement efforts concentrated on three categories that accounted for a majority of costs: implants, rooming costs, and computed tomography scans performed during the index hospitalization.

Results

Costs were compared between 141 EVAR procedures before implementation (PRE period) and 47 EVAR procedures after implementation (POST period). Based on data obtained through the Society for Vascular Surgery EVAR Cost Demonstration Project, it was determined that implantable device costs were higher than those at peer institutions. New purchasing strategies were implemented, resulting in a 30.8% decrease in per-case device costs between the PRE and POST periods. Care pathways were modified to reduce use of and costs for computed tomography scans obtained during the index hospitalization. Compared with baseline, per-case imaging costs decreased by 92.9% (P < .001), including a 99.0% (P = .001) reduction in postprocessing costs. Care pathways were also implemented to reduce preprocedural rooming for patients traveling long distances the day before surgery, resulting in a 50% decrease in utilization rate (35.4% PRE to 17.0% POST; P = .021), without having a significant impact on median postprocedural length of stay (PRE, 2 days [interquartile range, 1-11 days]; POST, 2 days [1-7 days]; P = .185). Medication costs also decreased by 38.2% (P < .001) as a hospital-wide effort.

Conclusions

Excessive costs associated with EVAR threaten the sustainability of these procedures in health care organizations. Targeted cost reduction efforts can effectively reduce expenses without compromising quality or limiting patients' access.

Preprocedural cross-sectional imaging (PCSI) for peripheral artery disease (PAD) may vary due to patient complexity, anatomical disease burden, and physician preference. The objective of this study was to determine the utility of PCSI prior to percutaneous vascular interventions (PVIs) for PAD. Patients receiving first time lower extremity angiograms from 2013 to 2015 at a single institution were evaluated for PCSI performed within 180 days, defined as computed tomography angiography (CTA) or magnetic resonance angiography (MRA) evaluating abdominal to pedal vasculature. The primary outcome was technical success defined as improving the target outflow vessels to <30% stenosis. Of the 346 patients who underwent lower extremity angiograms, 158 (45.7%) patients had PCSI, including 150 patients had CTA and 8 patients had MRA. Of these, 48% were ordered by the referring provider (84% at an outside institution). Preprocedural cross-sectional imaging was performed at a median of 26 days (interquartile range: 9-53) prior to the procedure. The analysis of the institution's 5 vascular surgeons identified PCSI rates ranging from 31% to 70%. On multivariate analysis, chronic kidney disease (odds ratio [OR] = 0.35; 95% confidence interval [CI]: 0.17-0.73) was associated with less PSCI usage, and inpatient/emergency department evaluation (OR = 3.20; 95% CI: 1.58-6.50) and aortoiliac disease (OR = 2.78; 95% CI: 1.46-5.29) were associated with higher usage. After excluding 31 diagnostic procedures, technical success was not statistically significant with PSCI (91.3%) compared to without PCSI (85.6%), P = .11. When analyzing 89 femoral-popliteal occlusions, technical success was higher with PCSI (88%) compared to procedures without (69%) P = .026. Our analysis demonstrates that routine ordering of PCSI may not be warranted when considering technical success of PVI; however, PCSI may be helpful in treatment planning. Further studies are needed to confirm these findings in another practice setting, with more prescriptive use of PCSI to improve procedural success, and thereby improve the value of PCSI.

Background

Identification of a safe and effective medical therapy for abdominal aortic aneurysm (AAA) disease remains a significant unmet medical need. Recent small cohort studies indicate that metformin, the world's most commonly prescribed oral hypoglycemic agent, may limit AAA enlargement. We sought to validate these preliminary observations in a larger cohort.

Methods

All patients with asymptomatic AAA disease managed in the Veterans Affairs Health Care System between 2003 and 2013 were identified by International Classification of Diseases, Ninth Revision codes. Those with a concomitant diagnosis of diabetes mellitus who also received two or more abdominal imaging studies (computed tomography, magnetic resonance imaging, or ultrasound) documenting the presence and size of an AAA, separated by at least 1 year, were included for review. Maximal AAA diameters were determined from radiologic reports. Further data acquisition was censored after surgical AAA repair, when performed. Comorbidities, active smoking status, and outpatient medication records (within 6 months of AAA diagnosis) were also queried. Yearly AAA enlargement rates, as a function of metformin treatment status, were compared using two statistical models expressed in millimeters per year: a multivariate linear regression (model 1) and a multivariate mixed-effects model with random intercept and random slope (model 2).

Results

A total of 13,834 patients with 58,833 radiographic records were included in the analysis, with radiology imaging follow-up of 4.2 ± 2.6 years (mean ± standard deviation). The average age of the patients at AAA diagnosis was 69.8 ± 7.8 years, and 39.7% had a metformin prescription within ±6 months of AAA. The mean growth rate for AAAs in the entire cohort was 1.4 ± 2.0 mm/y by model 1 analysis and 1.3 ± 1.6 mm/y by model 2 analysis. The unadjusted mean rate of AAA growth was 1.2 ± 1.9 mm/y for patients prescribed metformin compared with 1.5 ± 2.2 mm/y for those without (P < .001), a 20% decrease. This effect remained significant when adjusted for variables relevant on AAA progression: metformin prescription was associated with a reduction in yearly AAA growth rate of -0.23 mm (95% confidence interval, -0.35 to -0.16; P < .001) by model 1 analysis and 0.20 mm/y (95% confidence interval, -0.26 to -0.14; P < .001) by model 2 analysis. A subset analysis of 7462 patients with baseline AAA size of 35 to 49 mm showed a similar inhibitory effect (1.4 ± 2.0 mm/y to 1.7 ± 2.2 mm/y; P < .001). Patients' factors associated with an increased yearly AAA growth rate were baseline AAA size, metastatic solid tumors, active smoking, chronic obstructive pulmonary disease, and chronic renal disease. Factors associated with decreased yearly AAA growth rates included prescriptions for angiotensin II type 1 receptor blockers or sulfonylureas and the presence of diabetes-related complications.

Conclusions

In a nationwide analysis of diabetic Veterans Affairs patients, prescription for metformin was associated with decreased AAA enlargement. These findings provide further support for the conduct of prospective clinical trials to test the ability of metformin to limit progression of early AAA disease.