Clinical characteristics of patients with Rutherford category IV, compared with V and VI

The effects of CYP2C19 genotype polymorphism and clopidogrel resistance on ischemic event occurrence in patients with peripheral arterial disease undergoing revascularization: A prospective cohort study

INTRODUCTION

Peripheral arterial disease (PAD) affects approximately 236 million people worldwide. Therefore, this study aimed to investigate the relationship between CYP2C19 genotype polymorphisms and clopidogrel resistance (CR) following revascularization in patients with PAD.

MATERIALS AND METHODS

In total, 345 patients who underwent PAD revascularization were monitored for five years and risk factors for ischemic events were identified. Platelet reactivity and CYP2C19 genotypes were measured, and patients were classified as normal, intermediate, or poor metabolizers based on their genotypes. The study endpoint was defined as an ischemic event, that encompassed major adverse cardiovascular or limb events, or all-cause death.

RESULTS

In this study, ischemic events following PAD revascularization were associated with patient age, prior minor amputation, the Rutherford category before revascularization, indications for revascularization, index ankle-branchial index before revascularization, CYP2C19 phenotypes, and CR. Intermediate and poor metabolism, the Rutherford category before revascularization, and CR were independent risk factors for ischemic events in patients after PAD revascularization. Similarly, intermediate and poor metabolism, the Rutherford category before revascularization, and CR were independent risk factors for ischemic events in patients with PAD after revascularization within five years. Intermediate and poor metabolizers had a higher platelet reactivity and risk of CR than normal metabolizers. However, poor metabolizers had a higher platelet reactivity and risk of CR than intermediate metabolizers. Furthermore, the hazard ratio for ischemic events increased with platelet reactivity. This effect was more prevalent in intermediate and poor metabolizers than in normal metabolizers.

CONCLUSIONS

Ischemic events in patients after PAD revascularization were affected by independent risk factors. Decreased clopidogrel metabolism increased the platelet reactivity and CR in patients after PAD revascularization. Furthermore, high platelet reactivity was associated with an increased risk of ischemic events in patients with intermediate and poor metabolism.

Arterial leg ulcers-Bacterial patterns, antimicrobial resistance and clinical characteristics, a retrospective single-centre cohort, 2012-2021

OBJECTIVE

Severe wound infections in patients with peripheral artery disease (PAD) are common, potentially life- and limb-threatening, and difficult to treat. Evidence on patients with infected leg ulcers in PAD is scarce. This study aims to provide insight into the microbiological patterns and antimicrobial resistance (AMR) of specific pathogens in patients with arterial leg ulcers.

METHODS AND DESIGN

In this retrospective, consecutive, single-centre study 16,553 patients underwent an endovascular revascularization procedure between 2012 and 2021. Of these, 1,142 patients had PAD Rutherford category 5 or 6 with infected leg ulcers. Logistic regression was used to identify risk factors for Staphylococcus aureus-associated infections.

RESULTS

A total of 3,431 bacterial isolates were detected, of which 2,335 (68.1%) bacterial isolates were gram-positive and 1,096 (31.9%) were gram-negative species. The most prevalent bacteria were S. aureus (18.6%), Enterococcus faecalis (9.1%) and S. epidermidis (7.8%). Pseudomonas aeruginosa (5.6%), Proteus mirabilis (3.7%) and Escherichia coli (3.4%). The resistance of S. aureus isolates to clindamycin was 11.0%. Resistance to oxacillin was rare (1.5%). P. aeruginosa is frequently resistant to ciprofloxacin (14.4%) whilst intrinsically resistant to trimethoprim/sulfamethoxazole. P. mirabilis and E. coli were frequently resistant to both ciprofloxacin (7.3; 20.7%) and trimethoprim/sulfamethoxazole (24.6; 22.6%), respectively. Resistance to amoxicillin/clavulanic acid was high among E. coli isolates (36.8%). Multi-drug resistance (MDR) was rare among S. aureus and P. aeruginosa isolates. In contrast, the proportion of MDR was high in E. coli isolates. End-stage renal disease was independently positively associated with S. aureus identification (p = .042).

CONCLUSION

S. aureus was the most common pathogen in arterial leg ulcers with end-stage renal disease being an independent risk factor. Clindamycin resistance was common, making empirical therapy likely to fail. Isolated E. coli species had a high proportion of MDR.

Peripheral Artery Disease in Vulnerable Patient Populations: Outcomes of Orbital Atherectomy in Native Americans Compared to Non-Native Americans. A Single-Center Experience in Rural Oklahoma

BACKGROUND/PURPOSE

Although the incidence of peripheral artery disease (PAD) and amputations is higher in Native Americans (NA) than Caucasians, the study of revascularization NA is limited, resulting in their under representation in clinical studies. Orbital atherectomy (OA) is widely utilized for endovascular revascularization of significantly calcified peripheral arteries and has been shown to improve limb salvage rates.

METHODS/MATERIALS

A cohort of 74 consecutive PAD subjects undergoing OA treatment was retrospectively analyzed via Kaplan Meier (KM) and Propensity Score Matched (PSM) analysis.

RESULTS

A significant proportion of the subjects were NA (16.2%). Compared to the non-NA, the NA had higher numerical baseline rates of wounds, dialysis, chronic kidney disease (CKD), and critical limb ischemia, but were numerically less likely to smoke and had similar rates of diabetes. There were very high rates of severe calcification (100% vs. 87%) and pre-procedure diameter stenosis (99% vs. 95%) in both groups. The NA and non-NA had good angiographic outcomes, resulting in low rates of post-procedure residual diameter stenosis (10% vs. 11%). Lastly, KM analysis indicated high freedom from amputation in both groups at 1 year (89% vs. 95%), as well as in the PSM subjects (89% vs. 100%).

CONCLUSIONS

Despite numerically higher rates of co-morbidities at baseline (e.g., CKD, dialysis, and presence of non-healing wounds), the NA underwent successful revascularization with OA, resulting in high freedom from amputation at 1-year. Given the small sample size of NA, these results may not be generalizable-thus, larger studies on NA are warranted.

One-Year Outcomes of Peripheral Endovascular Device Intervention in Critical Limb Ischemia Patients: Sub-Analysis of the LIBERTY 360 Study

Background

High-risk patients with advanced peripheral artery disease (PAD), including critical limb ischemia (CLI), are often excluded from peripheral endovascular device intervention clinical trials, leading to difficulty in translating trial results into real-world practice. There is a need for prospectively assessed studies to evaluate peripheral endovascular device intervention outcomes in CLI patients.

Methods

LIBERTY 360 is a prospective, observational, multi-center study designed to evaluate the procedural and long-term clinical outcomes of peripheral endovascular device intervention in real-world patients with symptomatic lower-extremity PAD. One thousand two hundred and four patients were enrolled and stratified based on Rutherford Classification (RC): RC2-3 (N=501), RC4-5 (N=603), and RC6 (N=100). For this sub-analysis, RC5 and RC6 patients (RC5-6; N=404) were pooled and 1-year outcomes were assessed.

Results

Procedural complications rarely (1.7%) resulted in post-procedural hospitalization and 89.1% of RC5-6 patients were discharged to home. Considering the advanced disease state in RC5-6 patients, there was a high freedom from 1-year major adverse event rate of 65.5% (defined as target vessel revascularization, death to 30 days, and major target limb amputation). At 1 year, freedom from major amputation was 89.6%. Wounds identified at baseline on the target limb had completely healed in 172/243 (70.8%) of the RC5-6 subjects by 1 year. Additionally, the overall quality of life, as measured by VascuQoL, improved from baseline to 1 year.

Conclusion

LIBERTY investigated real-world PAD patients with independent oversight of outcomes. This analysis of LIBERTY RC5-6 patients demonstrates that peripheral endovascular device intervention can be successful in CLI patients, with low rates of major amputation and improvement in wound healing and quality of life through 1-year follow-up.

LIBERTY 360, https://clinicaltrials.gov/ct2/show/NCT01855412, ClinicalTrials.gov Identifier: NCT01855412.

Perioperative Outcomes of Lower Extremity Revascularization for Rest Pain and Tissue Loss

BACKGROUND

Critical limb ischemia (CLI) is the clinical manifestation of severe peripheral artery disease presenting as rest pain (RP) and tissue loss (TL). Most studies compare CLI as a homogenous group with claudication with limited database studies specifically studying these differences. We hypothesize that CLI should be stratified into RP and TL because of significant differences in disease severity, comorbidities, and outcomes.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2016 was reviewed. All patients with a postoperative diagnosis of CLI undergoing femoral to popliteal bypass (FPB) with vein or graft were identified. Patients were stratified into cohorts based on International Classification of Disease (ICD)-9 or ICD-10 codes for RP or TL (gangrene or ulcer). Univariate and multivariate analyses were performed to examine 30-day mortality, morbidity, major amputation, and readmission adjusting for demographics, comorbidities, and procedural details.

RESULTS

There were 5,304 patients. Compared to RP, patients with TL were older (P < 0.0001) and more likely to be dependent (P < 0.0001). TL patients were also more likely to have diabetes (P < 0.0001), congestive heart failure (P < 0.0001), renal failure (P = 0.004), dialysis (P < 0.0001), history of wound infection (P < 0.0001), and sepsis (P < 0.0001). TL patients had higher American Society of Anesthesiologists class (P < 0.0001), were less likely to be transferred from home (P < 0.0001), and more likely to receive an FPB with vein (P = 0.03). Patients with TL had worse perioperative outcomes compared with RP in terms of pneumonia (P = 0.004), unplanned intubation (P = 0.009), cardiac arrest requiring cardiopulmonary resuscitation (P = 0.003), bleeding requiring transfusions (P < 0.0001), sepsis (P < 0.0001), septic shock (P = 0.02), and reoperation (P < 0.0001). TL was associated with significantly higher 30-day morbidity (P < 0.0001), 30-day mortality (P < 0.0001), major amputation (P = 0.0004), and readmission rates (P = 0.005). Patients with TL compared with those with RP also had longer hospital stays (P < 0.0001) and days between operation to discharge (P < 0.0001). TL was independently associated with increased 30-day morbidity (OR: 1.16 [1.00-1.35]) and major amputation (OR: 2.48 [1.29-4.76]) compared with RP.

CONCLUSIONS

Patients with RP and TL have drastic differences that impact perioperative mortality and readmissions. TL is an independent predictor of 30-day morbidity and major amputation. The stratification of CLI into RP and TL can provide insight into variations in outcomes and provide a means to quantify the risks associated with the 2 manifestations of the disease.

Contemporary cardiovascular outcomes in Taiwanese patients undergoing endovascular therapy for symptomatic lower extremity peripheral arterial disease

BACKGROUND/PURPOSE

To investigate contemporary cardiovascular (CV) outcomes in Taiwanese patients with symptomatic low extremity peripheral artery disease treated with endovascular therapy.

METHODS

An observational cohort study with up to 155 months of follow-up was conducted using a single-center registry database between July 2005 and June 2017. Long-term outcomes and predictors of future CV events were analyzed in 936 patients with 1246 affected legs.

RESULTS

This study cohort comprised 21% claudicants and 79% critical limb ischemia (CLI) patients. Compared with claudicants, CLI patients had higher rates of medical comorbidities, tissue inflammation, and lesion complexities. During the study period, 349 patients died (130 CV deaths and 219 non-CV deaths), 306 had non-fatal CV events. The rates of 5-year freedom from all-cause mortality, major CV events (MACEs), and non-fatal CV events were 54.9%, 67.1%, and 56.6% respectively. For CLI patients, independent factors for all-cause mortality were age (odds ratio [OR] 1.03), atrial fibrillation (OR 1.79), albumin (OR 0.62), hematocrit (OR 0.96), body mass index (OR 0.94), C-reactive protein (OR 1.18), dialysis (OR 2.16), and non-ambulance (OR 2.05). Congestive heart failure, dialysis, and non-ambulance independently predicted the MACEs (OR 2.04, 1.93, and 1.67, respectively). For claudicants, coronary artery disease (CAD) was the essential factor for all-cause mortality (OR 2.24), MACE (OR 2.76) and non-fatal CV events (OR 1.82).

CONCLUSION

Long-term survival and MACE-free rates were significantly worse in CLI patients than in claudicants. Malnutrition and inflammation were associated with long-term survival. CAD, low hematocrit, dialysis, CHF, and ambulatory status predicted future CV events.

A novel lesion crossing technique: Balloon deployment using FORcible Manner (BADFORM) technique

OBJECTIVES

We evaluated the efficacy and safety of a novel endovascular technique for crossing arterial lesions: The BAlloon Deployment using FORcible Manner (BADFORM) technique.

BACKGROUND

Endovascular treatment (EVT) for peripheral artery disease has been widely adopted, and developments in device technology and techniques have resulted in acceptable success rates. However, it may be difficult to deliver devices even after wire externalization, especially in the presence of an extremely long chronic total occlusion or severely calcified lesion. The BADFORM technique might be useful in these cases.

METHODS

We retrospectively reviewed ten consecutive EVT cases using the BADFORM technique performed at our institution between April 2015 and September 2016. In all cases, wire externalization was established with the rendezvous technique. The BADFORM technique was performed when antegrade passage of any device was impossible after wire externalization. Physicians positioned a low-profile balloon or microcatheter just proximal to the calcified lesion and attached the device to the externalized wire using a torque device at the proximal catheter exit port. The externalized wire was then pulled retrogradely.

RESULTS

All patients were receiving hemodialysis and had critical limb ischemia. All lesions were severely calcified, and 90% were chronic total occlusions. The technical success and procedure success rates were 90% and 70%, respectively. Delivered devices included five balloon catheters and four microcatheters. One procedure-related vessel injury occurred at the distal puncture site (digital artery), however, this was controlled by external manual compression.

CONCLUSIONS

The efficacy and safety of the BADFORM technique might be acceptable. © 2017 Wiley Periodicals, Inc.

Impact of diabetes on outcome in critical limb ischemia with tissue loss: a large-scaled routine data analysis

BACKGROUND

Patients with diabetes concomitant to critical limb ischemia (CLI) represent a sub-group at particular risk. Objective of this analysis is to evaluate the actual impact of diabetes on treatment, outcome, and costs in a real-world scenario in Germany.

METHODS

We obtained routine-data on 15,332 patients with CLI with tissue loss from the largest German health insurance, BARMER GEK from 2009 to 2011, including a follow-up until 2013. Patient data were analyzed regarding co-diagnosis with diabetes with respect to risk profiles, treatment strategy, in-hospital and long-term outcome including costs.

RESULTS

Diabetic patients received less overall revascularizations in Rutherford grades 5 and 6 (Rutherford grade 5: 45.0 vs. 55.5%; Rutherford grade 6: 46.5 vs. 51.8; p < 0.001) and less vascular surgery (Rutherford grade 5: 13.4 vs. 23.4; Rutherford grade 6: 19.7 vs. 29.6; p < 0.001), however more often endovascular revascularization in Rutherford grade 6 (31.0 vs. 28.1; p = 0.004) compared to non-diabetic patients. Diabetes was associated with a higher observed ratio of infections (35.3 vs. 23.5% Rutherford grade 5; 44.3 vs. 27.4% Rutherford grade 6; p < 0.001) and in-hospital amputations (13.0 vs. 7.3% Rutherford grade 5; 47.5 vs. 36.7% Ruth6; p < 0.001). Diabetes further increased the risk for amputation during follow-up [Rutherford grade 5: HR 1.51 (1.38-1.67); Rutherford grade 6: HR 1.33 (1.25-1.41); p < 0.001], but not for death.

CONCLUSIONS

Diabetes increases markedly the risk of amputation attended by higher costs in CLI patients with tissue loss (OR 1.67 at Rutherford 5, OR 1.53 at Rutherford 6; p < 0.001), but is associated with lower revascularizations. However, in Rutherford grades 5 and 6, concomitant diabetes does not further worsen the overall poor survival.