Medical management of claudication

Sex and Racial Disparities in Peripheral Artery Disease

Several studies have shown that women and racial and ethnic minority patients are at increased risk of developing lower extremity peripheral artery disease and suffering adverse outcomes from it, but a knowledge gap remains regarding the underlying causes of these increased risks. Both groups are more likely to be underdiagnosed, have poorly managed contributory comorbidities, and incur disparities in treatment and management postdiagnosis. Opportunities for improvement in the care of women and racial and ethnic minorities with peripheral artery disease include increased rates of screening, higher rates of clinical suspicion (particularly in the absence of typical symptoms of intermittent claudication), and more aggressive risk factor management before and after the diagnosis of peripheral artery disease.

Optimized drug-coated balloon angioplasty of the superficial femoral and proximal popliteal arteries using the Tack Endovascular System: Tack Optimized Balloon Angioplasty (TOBA) III 24-month results in standard and long lesions

OBJECTIVE

The Tack Endovascular System is a minimal-metal dissection repair device that is purpose-built to treat post-percutaneous angioplasty (PTA) arterial dissections in patients with peripheral arterial disease (PAD). The Tack Optimized Balloon Angioplasty (TOBA) III trial evaluated the safety and effectiveness of the Tack Endovascular System in patients with superficial femoral artery (SFA) and/or proximal popliteal artery (PPA) dissection after PTA with a drug-coated balloon (DCB). The objective of this study is to report the results in the standard- (SL) and long-lesion (LL) cohorts through 24 months.

DESIGN

The TOBA III study was a prospective, multicenter, single-arm study including patients suffering from Rutherford category 2-4 PAD. Outcomes were assessed according to pre-specified lesion length in SL ( ≥ 20 mm and ≤150 mm) and LL ( > 150 mm and ≤250 mm) cohorts. Follow-up was through 24 months.

RESULTS

TOBA III enrolled 201 patients, 169 patients in the SL cohort and 32 in the LL cohort. At 24 months, the Kaplan-Meier estimates of freedom from major adverse events were 91.7% and 82.6% for the SL cohort and LL cohort, respectively. Kaplan-Meier estimates of freedom from clinically driven-target lesion revascularization (CD-TLR) were 92.3% in the SL cohort and 82.6% in the LL cohort. At 24 months, 78.8% of SL patients and 69.2% of LL patients experienced an improvement of >2 Rutherford categories (both cohorts p < 0.001). The baseline ankle-brachial index improved from 0.68 ± 0.18 to 0.93 ± 0.16 in the SL (p < 0.001) and from 0.62 ± 0.23 to 0.87 ± 0.15 in the LL cohort (p < 0.001) at 24 months.

CONCLUSION

The 24-month results of the TOBA III trial support the safety and effectiveness of the Tack Endovascular System in patients who required post-PTA dissection repair in the SFA and PPA following DCB angioplasty for claudication and rest pain. In both the SL and LL cohorts, Tack placement was associated with sustained freedom from CD-TLR through 24 months as well as sustained improvements in Rutherford categories, ankle-brachial index, and quality of life.

Identifying potentially avoidable femoral to popliteal expanded polytetrafluoroethylene bypass for claudication using cross-site blinded peer review

OBJECTIVE

The surgical treatment of claudication can be associated with significant morbidity and costs. There are growing concerns that some patients proceed to interventions without first attempting evidence-based nonoperative management. We used a direct, cross-site, blinded expert review to evaluate the appropriateness of the surgical treatment of claudication.

METHODS

We enlisted practicing vascular surgeons to perform retrospective clinical assessments of lower extremity bypass procedures in a statewide clinical registry. Cases were limited to elective, open, infrainguinal bypasses performed for claudication using prosthetic grafts. Reviewing surgeons were randomly assigned 10 cases from a sample of 139 anonymized bypass operations and instructed to evaluate procedural appropriateness based on their expert opinion and evidence-based guidelines for preoperative treatment, namely, antiplatelet, statin, cilostazol, exercise, and smoking cessation therapy as documented in the medical record. Ninety-day episode payments were estimated from a distinct but similar cohort of patients undergoing lower extremity bypass for claudication.

RESULTS

Of 325 total reviews, surgeons stated they would not have recommended bypass in 134 reviews (41%) and deemed bypass inappropriate in 122 reviews (38%). The most common reason for inappropriateness was lack of preoperative medical and lifestyle therapy, which was present in 63% of reviews where bypass was deemed appropriate and 39% of reviews where bypass was deemed inappropriate (P < .001). Surgeons stated they would have recommended additional preoperative therapy in 65% of reviews where bypass was deemed inappropriate and 35% of reviews where bypass was deemed appropriate (P < .001). The mean total episode payments in a similar cohort of 1458 patients undergoing elective open lower extremity bypass for claudication were $31,301 ± $21,219. Extrapolating to the 325 reviews, the 134 reviews in which surgeons would not have recommended bypass were associated with potentially avoidable estimated total payments of $4,194,334, and the 122 reviews in which bypass was deemed inappropriate were associated with potentially avoidable estimated total payments of $3,818,722.

CONCLUSIONS

In this cross-site expert peer review study, 40% of lower extremity bypasses were deemed premature and, therefore, potentially avoidable, primarily owing to a lack of medical and lifestyle management before surgery. Reviews deemed inappropriate were associated with approximately $4 million in potentially avoidable costs. This approach could inform performance feedback among surgeons to help align clinical practice with evidence-based recommendations for the treatment of claudication.

Keeping an eye on the diabetic foot: The connection between diabetic eye disease and wound healing in the lower extremity

Diabetic eye disease is strongly associated with the development of diabetic foot ulcers (DFUs). DFUs are a common and significant complication of diabetes mellitus (DM) that arise from a combination of micro- and macrovascular compromise. Hyperglycemia and associated metabolic dysfunction in DM lead to impaired wound healing, immune dysregulation, peripheral vascular disease, and diabetic neuropathy that predisposes the lower extremities to repetitive injury and progressive tissue damage that may ultimately necessitate amputation. Diabetic retinopathy (DR) is caused by cumulative damage to the retinal mic-rovasculature from hyperglycemia and other diabetes-associated factors. The severity of DR is closely associated with the development of DFUs and the need for lower extremity revascularization procedures and/or amputation. Like the lower extremity, the eye may also suffer end-organ damage from macrovascular compromise in the form of cranial neuropathies that impair its motility, cause optic neuropathy, or result in partial or complete blindness. Additionally, poor perfusion of the eye can cause ischemic retinopathy leading to the development of proliferative diabetic retinopathy or neovascular glaucoma, both serious, vision-threatening conditions. Finally, diabetic corneal ulcers and DFUs share many aspects of impaired wound healing resulting from neurovascular, sensory, and immunologic compromise. Notably, alterations in serum biomarkers, such as hemoglobin A1c, ceruloplasmin, creatinine, low-density lipoprotein, and high-density lipoprotein, are associated with both DR and DFUs. Monitoring these parameters can aid in prognosticating long-term outcomes and shed light on shared pathogenic mechanisms that lead to end-organ damage. The frequent co-occurrence of diabetic eye and foot problems mandate that patients affected by either condition undergo reciprocal comprehensive eye and foot evaluations in addition to optimizing diabetes management.

Systematic review the efficacy and safety of cilostazol, pentoxifylline, beraprost in the treatment of intermittent claudication: A network meta-analysis

Objective

To evaluate the efficacy and safety of cilostazol, pentoxifylline, beraprost for intermittent claudication due to lower extremity arterial occlusive disease.

Methods

Randomized controlled clinical trials were identified from PubMed, Scopus, EMbase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, SinoMed, Wanfang and Chongqing VIP databases, from the database inception to 31/12/2021. The outcome measures were walking distance measured by treadmill (maximum and pain-free walking distance), ankle-brachial index and adverse events. The quality of included studies was assessed by the Cochrane bias risk assessment tool. A network meta-analysis was carried out with Stata 16.0 software.

Results

There were 29 RCTs included in the study, covering total 5352 patients. Cilostazol was ranked first for both maximum and pain-free walking distance, followed by beraprost and pentoxifylline. For cilostazol, pentoxifylline and beraprost, maximum walking distance increased by 62.93 95%CI(44.06, 81.79), 32.72 95%CI(13.51, 55.79) and 43.90 95%CI(2.10, 85.71) meters, respectively relative to placebo, and pain-free walking distance increased by 23.92 95%CI(11.24, 36.61), 15.16 95%CI(2.33, 27.99) and 19.78 95%CI(-3.07, 42.62) meters. For cilostazol, pentoxifylline, beraprost and cilostazol combined with beraprost, ankle-brachial index increased by 0.06 95%CI(0.04, 0.07), -0.01 95%CI(-0.08, 0.05), 0.18 95%CI(0.12, 0.23) and 0.23 95%CI(0.18, 0.27), respectively relative to placebo. The pentoxifylline and cilostazol was associated with a lower ratio of adverse events than beraprost and cilostazol combined with beraprost.

Conclusion

Cilostazol, pentoxifylline and beraprost were all effective treatments for intermittent claudication; cilostazol with good tolerance was likely to be the most effective in walking distance, while beraprost and cilostazol combined with beraprost were more prominent in the ankle-brachial index.

Underutilization of Medical Management of Peripheral Artery Disease Among Patients with Claudication Undergoing Lower Extremity Bypass

OBJECTIVE

First-line treatment of peripheral artery disease (PAD) involves medical therapy and lifestyle modification. Multiple professional organizations such as the Society for Vascular Surgery (SVS) and the American Heart Association/American College of Cardiology (AHA/ACC) make Class I recommendations for medical management including antiplatelet, statin, antihypertensive, and cilostazol medications, as well as lifestyle therapy including exercise and smoking cessation. Although evidence supports up-front medical and lifestyle management prior to surgical intervention, it is unclear how well this occurs in contemporary clinical practice. It is also unclear whether variability in first-line treatment prior to revascularization is associated with postoperative outcomes. This study examined the proportion of patients with claudication actively receiving evidence-based therapy prior to surgery in a statewide surgical registry.

METHODS

We conducted a retrospective cohort study of adult patients undergoing elective open lower extremity bypass for claudication from 2012-2021 within a statewide surgical quality registry. The primary exposure was optimal medical therapy defined as an antiplatelet agent, a statin, and an angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) (if the patient had hypertension) on the patient's home medication list on admission for surgery, all of which are Class I recommendations. Despite also being Class I recommendations, cilostazol was not included in the primary exposure due to its highly selective use and our inability to capture intolerance and/or contraindications which are common, and lifestyle therapies were not included as they were only recorded at the time of discharge rather than preoperatively. The primary outcomes were mortality, hospital readmission, amputation, wound complication, myocardial infarction (MI), non-patent bypass, and non-independent ambulatory status at 30 days and 1 year after surgery. Multivariable logistic regression was performed to estimate the association of receiving optimal vs. non-optimal medical therapy.

RESULTS

3,829 patients with claudication underwent bypass surgery during the study period, with a mean age of 64.8 (9.8) years, 2,690 (70.3%) males, and 1,873 (48.9%) current smokers. 1,822 (47.6%) patients were on optimal medical therapy prior to surgery. Additionally, at discharge, 66.5% of smokers received referral to smoking cessation therapy and 54.1% of patients received referral to exercise therapy. In a multivariable logistic regression, compared to patients not on optimal medical therapy, patients on optimal medical therapy prior to surgery had lower 30-day odds of mortality (aOR 0.45 [95% CI 0.26-0.78]) and MI (aOR 0.46 [95% CI 0.28-0.76]) and lower 1-year odds of mortality (aOR 0.57 [95% CI 0.39-0.82]), MI (aOR 0.48 [95% CI 0.32-0.74]), and readmission (aOR 0.79 [95% CI 0.64-0.96]).

CONCLUSION

Although medical and lifestyle management is recommended as first-line treatment for patients with PAD, only half of patients were on optimal medical therapy prior to surgery. Patients receiving optimal therapy had a lower risk of postoperative mortality, MI, and readmission. This suggests that not only are there significant opportunities to improve clinical utilization of evidence-based treatment of PAD, but that doing so can benefit patients postoperatively.

Connecting veterans with smoking cessation services in less than 3 minutes

ABSTRACT

Veterans smoke disproportionately higher (nearly 1.3 times greater) than the general population and puts them at greater risk for tobacco-related illnesses. Annual screenings by the primary care providers are conducted at Veterans Health Administration (VHA) primary care clinics, but this practice may be inadequate to overcome the chronicity of smoking. The Ask, Advise, Refer strategy for smoking cessation was integrated in the workflow and implemented by the nursing staff at a VHA outpatient surgery clinic. Nurses established smoking status, advised smokers to quit, and for those interested, provided the smoker a list of resources Department of Veterans Affairs' approved smoking cessation options (telephone, text, and web-based interventions). All the smokers took a referral card containing a list of resources to help them quit smoking. During the follow-up phone calls after the clinic visit, 19% of patients reported using at least one of the resources listed on the card. Each clinical encounter should be viewed by health care providers as a window of opportunity to promote smoking cessation. The simplicity of the AAR strategy is effective in promoting smoking cessation especially in busy outpatient settings.

A randomized, placebo-controlled trial of canakinumab in patients with peripheral artery disease

Extensive atherosclerotic plaque burden in the lower extremities often leads to symptomatic peripheral artery disease (PAD) including impaired walking performance and claudication. Interleukin-1β (IL-1β) may play an important pro-inflammatory role in the pathogenesis of this disease. Interruption of IL-1β signaling was hypothesized to decrease plaque progression in the leg macrovasculature and improve the mobility of patients with PAD with intermittent claudication. Thirty-eight patients (mean age 65 years; 71% male) with symptomatic PAD (confirmed by ankle-brachial index) were randomized 1:1 to receive canakinumab (150 mg subcutaneously) or placebo monthly for up to 12 months. The mean vessel wall area (by 3.0 T black-blood magnetic resonance imaging (MRI)) of the superficial femoral artery (SFA) was used to measure plaque volume. Mobility was assessed using the 6-minute walk test. Canakinumab was safe and well tolerated. Markers of systemic inflammation (interleukin-6 and high-sensitivity C-reactive protein) fell as early as 1 month after treatment. MRI (32 patients at 3 months; 21 patients at 12 months) showed no evidence of plaque progression in the SFA in either placebo-treated or canakinumab-treated patients. Although an exploratory endpoint, placebo-adjusted maximum and pain-free walking distance (58 m) improved as early as 3 months after treatment with canakinumab when compared with placebo. Although canakinumab did not alter plaque progression in the SFA, there is an early signal that it may improve maximum and pain-free walking distance in patients with symptomatic PAD. Larger studies aimed at this endpoint will be required to definitively demonstrate this. ClinicalTrials.gov Identifier: NCT01731990.

Treatment Strategies for the Claudicant

Peripheral arterial disease (PAD) is a prevalent, morbid, and mortal disease. Claudication represents an early, yet common manifestation of PAD. A clinical history and physical examination combined with an ankle-brachial index can help make a diagnosis of claudication. Due to the polyvascular nature of the underlying atherosclerosis, PAD is often associated with heart disease and stroke. Although health implications of PAD derive from both its limb and cardiovascular manifestations, claudication is life-threatening, less limb-threatening. Medical modification of cardiovascular risk factors and exercise are the cornerstone in the treatment of claudication. Revascularization in claudication is focused at improvement in claudication symptoms and functional status, rather than aggressive attempts at limb salvage. The aim of this article is to summarize the strategies in the treatment of claudication, to serve as a concise and informative reference for physicians who are managing these patients. A framework of the decision-making process in the management of patients with claudication is shown, which can be applied in clinical practice.

Cilostazol protects hepatocytes against alcohol-induced apoptosis via activation of AMPK pathway

Alcoholic liver disease (ALD) is a worldwide health problem and hepatocyte apoptosis has been associated with the development/progression of ALD. However, no definite effective pharmacotherapy for ALD is currently available. Cilostazol, a selective type III phosphodiesterase inhibitor has been shown to protect hepatocytes from ethanol-induced apoptosis. In the present study, the underlying mechanisms for the protective effects of cilostazol were examined. Primary rat hepatocytes were treated with ethanol in the presence or absence of cilostazol. Cell viability and intracellular cAMP were measured. Apoptosis was detected by Hoechst staining, TUNEL assay, and caspase-3 activity assay. The roles of cAMP and AMP-activated protein kinase (AMPK) pathways in the action of CTZ were explored using pharmacological inhibitors and siRNAs. Liver from mice received ethanol (5 g/kg body weight) by oral gavage following cilostazol treatment intraperitoneally was obtained for measurement of apoptosis and activation of AMPK pathway. Cilostazol inhibited ethanol-induced hepatocyte apoptosis and potentiated the increases in cAMP level induced by forskolin. However, the anti-apoptotic effect of cilostazol was not reversed by an inhibitor of adenylyl cyclase. Interestingly, cilostazol activated AMPK and increased the level of LC3-II, a marker of autophagy. The inhibition of AMPK abolished the effects of cilostazol on LC3-II expression and apoptosis. Moreover, the inhibition of LKB1 and CaMKK2, upstream kinases of AMPK, dampened cilostazol-inhibited apoptosis as well as AMPK activation. In conclusion, cilostazol protected hepatocytes from apoptosis induced by ethanol mainly via AMPK pathway which is regulated by both LKB1 and CaMKK2. Our results suggest that cilostazol may have potential as a promising therapeutic drug for treatment of ALD.

Review of biologic and behavioral risk factors linking depression and peripheral artery disease

The incidence of depression has been rising rapidly, and depression has been recognized as one of the world’s leading causes of disability. More recently, depression has been associated with an increased risk of symptomatic atherosclerotic disease as well as worse perioperative outcomes in patients with cardiovascular disease. Additionally, recent studies have demonstrated an association between depression and peripheral artery disease (PAD), which has been estimated to affect more than 200 million people worldwide. These studies have identified that depression is associated with poor functional and surgical outcomes in patients with PAD. Although the directionality and specific mechanisms underlying this association have yet to be clearly defined, several biologic and behavioral risk factors have been identified to play a role in this relationship. These factors include tobacco use, physical inactivity, medical non-adherence, endothelial and coagulation dysfunction, and dysregulation of the hypothalamic-pituitary-adrenal axis, autonomic system, and immune system. In this article, we review these potential mechanisms and the current evidence linking depression and PAD, as well as future directions for research and interventional strategies. Understanding and elucidating this relationship may assist in preventing the development of PAD and may improve the care that patients with PAD and comorbid depression receive.