Cilostazol has beneficial effects in treatment of intermittent claudication: results from a multicenter, randomized, prospective, double-blind trial

Semaglutide and walking capacity in people with symptomatic peripheral artery disease and type 2 diabetes (STRIDE): a phase 3b, double-blind, randomised, placebo-controlled trial

BACKGROUND

Peripheral artery disease is a highly morbid type of atherosclerotic vascular disease involving the legs and is estimated to affect over 230 million individuals globally. Few therapies improve functional capacity and health-related quality of life in people with lower limb peripheral artery disease. We aimed to evaluate whether semaglutide improves function as measured by walking ability as well as symptoms, quality of life, and outcomes in people with peripheral artery disease and type 2 diabetes.

METHODS

STRIDE was a double-blind, randomised, placebo-controlled trial done at 112 outpatient clinical trial sites in 20 countries in North America, Asia, and Europe. Participants were aged 18 years and older, with type 2 diabetes and peripheral artery disease with intermittent claudication (Fontaine stage IIa, able to walk >200 m) and an ankle-brachial index of less than or equal to 0·90 or toe-brachial index of less than or equal to 0·70. Participants were randomly assigned (1:1) using an interactive web response system to receive subcutaneous semaglutide 1·0 mg once per week for 52 weeks or placebo. The primary endpoint was the ratio to baseline of the maximum walking distance at week 52 measured on a constant load treadmill in the full analysis set. Safety was evaluated in the safety analysis set. This trial is registered with ClinicalTrials.gov, NCT04560998 and is now completed.

FINDINGS

From Oct 1, 2020, to July 12, 2024, 1363 patients were screened for eligibility, of whom 792 were randomly assigned to semaglutide (n=396) or placebo (n=396). 195 (25%) participants were female and 597 (75%) were male. Median age was 68·0 years (IQR 61·0-73·0). The estimated median ratio to baseline in maximum walking distance at week 52 was significantly greater in the semaglutide group than the placebo group (1·21 [IQR 0·95-1·55] vs 1·08 [0·86-1·36]; estimated treatment ratio 1·13 [95% CI 1·06-1·21]; p=0·0004). Six serious adverse events in five (1%) participants in the semaglutide group and nine serious adverse events in six (2%) participants in the placebo group were possibly or probably treatment related, with the most frequent being serious gastrointestinal events (two events reports by two [1%] in the semaglutide group and five events reported by three [1%] in the placebo group). There were no treatment-related deaths.

INTERPRETATION

Semaglutide increased walking distance in patients with symptomatic peripheral artery disease and type 2 diabetes. Research implications include the need for future studies to further elucidate mechanisms of benefit and to assess the efficacy and safety in patients with peripheral artery disease who do not have type 2 diabetes.

FUNDING

Novo Nordisk.

Design and baseline characteristics of the STRIDE trial: evaluating semaglutide in people with symptomatic peripheral artery disease and type 2 diabetes

BACKGROUND

People with lower extremity peripheral artery disease (PAD) suffer from a high burden of symptoms and significant functional impairment. There are few therapies that improve function and reduce symptoms in this population. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been shown to improve glycaemic control, reduce body weight, and reduce the risk of major adverse cardiovascular events in people with atherosclerotic cardiovascular disease and type 2 diabetes (T2D).

METHODS AND RESULTS

STRIDE (NCT04560998) is a randomized, placebo-controlled, double-blind phase 3b trial evaluating 1 mg once-weekly subcutaneous semaglutide (GLP-1 RA) vs. placebo, in people with symptomatic PAD (Fontaine IIa claudication) and T2D. Eligible participants were ≥18 years, had haemodynamically stable PAD, had no planned intervention, and were not receiving a GLP-1 RA. The primary endpoint is change in maximum walking distance on a constant-load treadmill (CLT). Secondary endpoints include quality of life and cardiometabolic assessments. A total of 792 participants were randomized in 20 countries. Participants' median age was 68 and median T2D duration 12 years. Risk factors included 25.6% current smokers, 87.9% with hypertension, and 42.7% with coronary heart disease. The mean BMI was 29.6 kg/m2 and the mean HbA1C was 7.3%. Participants exhibited baseline functional impairment with a median maximum walking distance of 186 m on a CLT.

CONCLUSION

STRIDE has enrolled participants with symptomatic PAD and T2D, frequent risk factors and comorbidities, and functional impairment. The trial will provide evidence for the functional outcomes with semaglutide in people with PAD and T2D.

Benefits of Cilostazol's Effect on Vascular and Neuropathic Complications Caused by Diabetes

Diabetes mellitus (DM) is a global health concern with a rising incidence, particularly in aging populations and those with a genetic predisposition. Over time, DM contributes to various complications, including nephropathy, retinopathy, peripheral arterial disease (PAD), and neuropathy. Among these, diabetic neuropathy and PAD stand out due to their high prevalence and significant impact on patients' quality of life. Diabetic distal symmetric polyneuropathy, the most common form of diabetic neuropathy, is driven by neuroinflammation stemming from prolonged hyperglycemia. Simultaneously, hyperglycemia significantly increases the risk of PAD, a condition further exacerbated by factors like smoking, age, and sedentary lifestyles. PAD frequently manifests as claudication, a debilitating symptom marked by pain and cramping during physical activity, which limits mobility and worsens patients' outcomes. Cilostazol, a phosphodiesterase-3 inhibitor, has proven effective in managing intermittent claudication in PAD by improving walking distances and enhancing blood flow. Recent studies have also explored its potential benefits for diabetic neuropathy. Cilostazol's mechanisms include vasodilation, platelet inhibition, and increased cyclic adenosine monophosphate (cAMP) levels, which may contribute to improved neurological outcomes. However, variability in the clinical evidence due to inconsistent treatment protocols highlights the need for further investigation. This review explores cilostazol's mechanisms of action and therapeutic applications for managing neuropathy and PAD in diabetic patients, aiming to provide insights into its potential as a dual-purpose pharmacological agent in this high-risk population.

Pharmacological Treatment of Degenerative Cervical Myelopathy: A Critical Review of Current Evidence

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults, representing substantial morbidity and significant financial and resource burdens. Typically, patients with progressive DCM will eventually receive surgical treatment. Nonetheless, despite advancements in pharmacotherapeutics, evidence for pharmacological therapy remains limited. Health professionals from various fields would find interest in pharmacological agents that could benefit patients with mild DCM or enhance surgical outcomes. This review aims to consolidate all clinical and experimental evidence on the pharmacological treatment of DCM. We conducted a comprehensive narrative review that presents all pharmacological agents that have been investigated for DCM treatment in both humans and animal models. Riluzole exhibits effectiveness solely in rat models, but not in treating mild DCM in humans. Cerebrolysin emerges as a potential neuroprotective agent for myelopathy in animals but had contradictory results in clinical trials. Limaprost alfadex demonstrates motor function improvement in animal models and exhibits promising outcomes in a small clinical trial. Glucocorticoids not only fail to provide clinical benefits but may also lead to adverse events. Cilostazol, anti-Fas ligand antibody, and Jingshu Keli display promise in animal studies, while erythropoietin, granulocyte colony-stimulating factor and limaprost alfadex exhibit potential in both animal and human research. Existing evidence mainly rests on weak clinical data and animal experimentation. Current pharmacological efforts target ion channels, stem cell differentiation, inflammatory, vascular, and apoptotic pathways. The inherent nature and pathogenesis of DCM offer substantial prospects for developing neurodegenerative or neuroprotective therapies capable of altering disease progression, potentially delaying surgical intervention, and optimizing outcomes for those undergoing surgical decompression.

Peripheral Vascular Disease

Peripheral artery disease is most often caused by atherosclerosis. Arterial insufficiency from atherosclerotic blockages in the limbs can impair walking distance and put patients with severe disease at risk of limb loss. Management of the disease centers around early diagnosis, supervised exercise therapy and lifestyle modification, optimizing medical care (with the goal of reducing fatal cardiac and cerebrovascular events), and revascularization.

Current Medical Therapy and Revascularization in Peripheral Artery Disease of the Lower Limbs: Impacts on Subclinical Chronic Inflammation

Peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CeVD) are characterized by atherosclerosis and inflammation as their underlying mechanisms. This paper aims to conduct a literature review on pharmacotherapy for PAD, specifically focusing on how different drug classes target pro-inflammatory pathways. The goal is to enhance the choice of therapeutic plans by considering their impact on the chronic subclinical inflammation that is associated with PAD development and progression. We conducted a comprehensive review of currently published original articles, narratives, systematic reviews, and meta-analyses. The aim was to explore the relationship between PAD and inflammation and evaluate the influence of current pharmacological and nonpharmacological interventions on the underlying chronic subclinical inflammation. Our findings indicate that the existing treatments have added anti-inflammatory properties that can potentially delay or prevent PAD progression and improve outcomes, independent of their effects on traditional risk factors. Although inflammation-targeted therapy in PAD shows promising potential, its benefits have not been definitively proven yet. However, it is crucial not to overlook the pleiotropic properties of the currently available treatments, as they may provide valuable insights for therapeutic strategies. Further studies focusing on the anti-inflammatory and immunomodulatory effects of these treatments could enhance our understanding of the mechanisms contributing to the residual risk in PAD and pave the way for the development of novel therapies.

Efficacy and safety of cilostazol-based triple antiplatelet therapy compared with clopidogrel-based dual antiplatelet therapy in patients with acute ST-elevation myocardial infarction undergoing percutaneous coronary intervention: A multicenter, randomized, open-label, phase 4 trial

BACKGROUND

Previous studies reported that compared to conventional dual antiplatelet therapy (DAT; aspirin + clopidogrel), triple antiplatelet therapy (TAT), involving the addition of cilostazol to DAT, had better clinical outcomes in patients with ST-elevation myocardial infarction (STEMI). However, the optimal duration of TAT is yet to be determined.

METHODS

In total, 985 patients with STEMI who underwent primary percutaneous coronary intervention (PCI) with drug-eluting stents (DESs) were prospectively enrolled in 15 PCI centers in South Korea and China. We randomly assigned patients into 3 groups: DAT (aspirin and clopidogrel for 12 months), TAT 1M (aspirin, clopidogrel, and cilostazol for 1 month), and TAT 6M (aspirin, clopidogrel, and cilostazol for 6 months). The primary endpoint was 1-year major adverse cardiovascular events (MACEs), defined as a composite of all-cause death, recurrent myocardial infarction, stroke, or repeat revascularization.

RESULTS

The primary endpoint did not differ among the 3 groups (8.8% in DAT, 11.0% in TAT 1M, and 11.6% in TAT 6M; hazard ratio for TAT 1M vs DAT, 1.302; 95% confidence interval [CI], 0.792-2.141; P = .297; hazard ratio for TAT 6M vs DAT, 1.358; 95% CI, 0.829-2.225; P = .225). With respect to in-hospital outcomes, more bleeding events occurred in the TAT group than in the DAT group (1.3% vs 4.7% vs 2.6%, P = .029), with no significant differences in major bleeding events. Additionally, the TAT group had a higher incidence of headaches (0% vs 1.6% vs 2.6%, P = .020).

CONCLUSIONS

The addition of cilostazol to DAT did not reduce the incidence of 1-year MACEs compared with DAT alone. Instead, it may be associated with an increased risk of drug intolerance and side effects, including in-hospital bleeding and headaches.

Real-World Safety and Effectiveness of Controlled-Release Cilostazol in Patients with Symptomatic Peripheral Artery Disease

BACKGROUND

Cilostazol is the only first-line medication for treating intermittent claudication, and the controlled-release (CR) formulation is associated with a lower prevalence of adverse events (AEs).

OBJECTIVE

The objective of the study was to assess the safety and effectiveness of cilostazol CR in patients with symptomatic peripheral artery disease (PAD).

METHODS

In this multicentre (113 sites), open-label, prospective observational study, we evaluated the real-world safety and effectiveness of cilostazol CR 200 mg once daily in patients with symptomatic PAD treated in routine clinical settings. The primary endpoint was the incidence and severity of AEs, and their causal relationship with cilostazol CR. The secondary endpoint was the effectiveness of the drug, as assessed by each patient's physician, for improving intermittent claudication.

RESULTS

Among 2063 participants who received cilostazol CR for a mean duration of 88.6 days, 99 (4.80 %) experienced adverse drug reactions (ADRs), although no unexpected adverse reactions were observed. There was no significant difference in the incidence of ADRs according to patient demographics and comorbidities (all p > 0.05). The treatment was 'effective' in 1600 patients (78.93 %), although effectiveness significantly differed according to the patients' sex and the presence of comorbidities, including diabetes mellitus, hypertension, and coronary artery disease (all p < 0.01).

CONCLUSIONS

This study demonstrated the tolerability and effectiveness of cilostazol CR treatment in patients with symptomatic PAD.

Reversal of spatial memory impairment by phosphodiesterase 3 inhibitor cilostazol is associated with reduced neuroinflammation and increased cerebral glucose uptake in aged male mice

The nucleotide second messenger 3', 5'-cyclic adenosine monophosphate (cAMP) and 3', 5'-cyclic guanosine monophosphate (cGMP) mediate fundamental functions of the brain, including learning and memory. Phosphodiesterase 3 (PDE3) can hydrolyze both cAMP and cGMP and appears to be involved in the regulation of their contents in cells. We previously demonstrated that long-term administration of cilostazol, a PDE3 inhibitor, maintained good memory performance in aging mice. Here, we report on studies aimed at determining whether cilostazol also reverses already-impaired memory in aged male mice. One month of oral 1.5% cilostazol administration in 22-month-old mice reversed age-related declines in hippocampus-dependent memory tasks, including the object recognition and the Morris water maze. Furthermore, cilostazol reduced neuroinflammation, as evidenced by immunohistochemical staining, and increased glucose uptake in the brain, as evidence by positron emission tomography (PET) with 2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG). These results suggest that already-expressed memory impairment in aged male mice that depend on cyclic nucleotide signaling can be reversed by inhibition of PDE3. The reversal of age-related memory impairments may occur in the central nervous system, either through cilostazol-enhanced recall or strengthening of weak memories that otherwise may be resistant to recall.

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.

Cilostazol Attenuates AngII-Induced Cardiac Fibrosis in apoE Deficient Mice

Cardiac fibrosis is characterized by the net accumulation of extracellular matrix in the myocardium and is an integral component of most pathological cardiac conditions. Cilostazol, a selective inhibitor of phosphodiesterase type III with anti-platelet, anti-mitogenic, and vasodilating properties, is widely used to treat the ischemic symptoms of peripheral vascular disease. Here, we investigated whether cilostazol has a protective effect against Angiotensin II (AngII)-induced cardiac fibrosis. Male apolipoprotein E-deficient mice were fed either a normal diet or a diet containing cilostazol (0.1% wt/wt). After 1 week of diet consumption, the mice were infused with saline or AngII (1000 ng kg−1 min−1) for 28 days. AngII infusion increased heart/body weight ratio (p < 0.05), perivascular fibrosis (p < 0.05), and interstitial cardiac fibrosis (p < 0.0001), but were significantly attenuated by cilostazol treatment (p < 0.05, respectively). Cilostazol also reduced AngII-induced increases in fibrotic and inflammatory gene expression (p < 0.05, respectively). Furthermore, cilostazol attenuated both protein and mRNA abundance of osteopontin induced by AngII in vivo. In cultured human cardiac myocytes, cilostazol reduced mRNA expression of AngII-induced osteopontin in dose-dependent manner. This reduction was mimicked by forskolin treatment but was cancelled by co-treatment of H-89. Cilostazol attenuates AngII-induced cardiac fibrosis in mice through activation of the cAMP−PKA pathway.

A Case Series Analysis of Major Vascular Revascularization

Purpose

Atherosclerosis is a generalized disorder and can begin to develop in the abdominal aorta by the second decade of life. The nature of these lesions in coronaries and aorta is atheromatous and less sclerotic when compared to peripheral arteries. A broad spectrum of presentations and different types of lesions demand a personalized approach for the best outcome. This study is a case series analysis of major vascular revascularization. We aim to study various revascularization surgeries and underline the wide range of vascular lesions to which it is applied.

Methods

This is a study based on accrual patient records of all major vascular revascularization surgical/interventional procedures conducted at a tertiary care center for one year.

Results

A total of 110 patients were operated on for vascular diseases. Among these, 86 (78.81%) were men, and 24 (21.81%) were women. The femoropopliteal segment (n=47) was most commonly involved, followed by the common carotid artery (n=20). Atherosclerosis was the main cause of vascular occlusion (81.8%), followed by aneurysm of the aorta (14.5%) and coarctation of the aorta (2.7%). Smoking (62.2%) accounted to be the leading risk factor, followed by hypertension, diabetes, and hyperlipidemia. The majority of patients had a good outcome (92.7%). Minor complications (7.3%) include seroma formation and wound infection, which were managed conservatively. The repair was performed by autologous vein graft in 30% of patients and by synthetic polytetrafluoroethylene (PTFE) graft in 70% of patients. Carotid artery stenting was the most common endovascular procedure performed (n=5). Femoropopliteal bypass grafting was the most common procedure, followed by carotid endarterectomy (n=20) and aortofemoral bypass (n=14).

Conclusion

The application of novel techniques such as cavo-atrial shunt in Budd-Chiari syndrome calls attention to the broadened scope of vascular surgery, and the modification of the conventional method of the carotid endarterectomy underscores the evolution of vascular revascularization. Our study thus highlighted that a wide spectrum of vascular lesions ranging from carotid artery stenosis to extensive below-knee disease, either atherosclerotic or aneurysmal, can be successfully treated with surgical revascularization techniques.

Therapeutic angiogenesis-based strategy for peripheral artery disease

Peripheral artery disease (PAD) poses a great challenge to society, with a growing prevalence in the upcoming years. Patients in the severe stages of PAD are prone to amputation and death, leading to poor quality of life and a great socioeconomic burden. Furthermore, PAD is one of the major complications of diabetic patients, who have higher risk to develop critical limb ischemia, the most severe manifestation of PAD, and thus have a poor prognosis. Hence, there is an urgent need to develop an effective therapeutic strategy to treat this disease. Therapeutic angiogenesis has raised concerns for more than two decades as a potential strategy for treating PAD, especially in patients without option for surgery-based therapies. Since the discovery of gene-based therapy for therapeutic angiogenesis, several approaches have been developed, including cell-, protein-, and small molecule drug-based therapeutic strategies, some of which have progressed into the clinical trial phase. Despite its promising potential, efforts are still needed to improve the efficacy of this strategy, reduce its cost, and promote its worldwide application. In this review, we highlight the current progress of therapeutic angiogenesis and the issues that need to be overcome prior to its clinical application.

Impact of Cilostazol Pharmacokinetics on the Development of Cardiovascular Side Effects in Patients with Cerebral Infarction

This study investigated the impact of polymorphisms of metabolic enzymes on plasma concentrations of cilostazol and its metabolites, and the influence of the plasma concentrations and polymorphisms on the cardiovascular side effects in 30 patients with cerebral infarction. Plasma concentrations of cilostazol and its active metabolites, and CYP3A5*3 and CYP2C19*2 and *3 genotypes were determined. The median plasma concentration/dose ratio of OPC-13213, an active metabolite by CYP3A5 and CYP2C19, was slightly higher and the median plasma concentration rate of cilostazol to OPC-13015, another active metabolite by CYP3A4, was significantly lower in CYP3A5*1 carriers than in *1 non-carriers (p = 0.082 and p = 0.002, respectively). The CYP2C19 genotype did not affect the pharmacokinetics of cilostazol. A correlation was observed between changes in pulse rate from the baseline and plasma concentrations of cilostazol (R = 0.539, p = 0.002), OPC-13015 (R = 0.396, p = 0.030) and OPC-13213 (R = 0.383, p = 0.037). A multiple regression model, consisting of factors of the plasma concentration of OPC-13015, levels of blood urea nitrogen, and pulse rate at the start of the therapy explained 55.5% of the interindividual variability of the changes in pulse rate. These results suggest that plasma concentrations of cilostazol and its metabolites are affected by CYP3A5 genotypes, and plasma concentration of OPC-13015, blood urea nitrogen, and pulse rate at the start of therapy may be predictive markers of cardiovascular side effects of cilostazol in patients with cerebral infarction.

Update on Cilostazol: A Critical Review of Its Antithrombotic and Cardiovascular Actions and Its Clinical Applications

Cilostazol, a phosphodiesterase III inhibitor, has vasodilating and antiplatelet properties with a low rate of bleeding complications. It has been used over the past 25 years for improving intermittent claudication in patients with peripheral artery disease (PAD). Cilostazol also has demonstrated efficacy in patients undergoing percutaneous revascularization procedures for both PAD and coronary artery disease. In addition to its antithrombotic and vasodilating actions, cilostazol also inhibits vascular smooth muscle cell proliferation via phosphodiesterase III inhibition, thus mitigating restenosis. Accumulated evidence has shown that cilostazol, due to its "pleiotropic" effects, is a useful, albeit underutilized, agent for both coronary artery disease and PAD. It is also potentially useful after ischemic stroke and is an alternative in those who are allergic or intolerant to classical antithrombotic agents (eg, aspirin or clopidogrel). These issues are herein reviewed together with the pharmacology and pharmacodynamics of cilostazol. Large studies and meta-analyses are presented and evaluated. Current guidelines are also discussed, and the spectrum of cilostazol's actions and therapeutic applications are illustrated.

No benefit of vorapaxar on walking performance in patients with intermittent claudication

Background: The effect of pharmacologic agents in improving walking and quality of life measures in patients with intermittent claudication (IC) is variable. The objective of this study was to investigate the effect of the novel antithrombotic vorapaxar on symptom status in patients with IC. Methods: The study was a multicenter, randomized, placebo-controlled trial wherein patients with IC were treated with either vorapaxar or placebo in addition to a home exercise program for 6 months. Walking performance and quality of life were assessed by graded treadmill test (GTT) and 12-Item Short-Form Survey (SF-12), respectively, at baseline and at 6 months. A total of 102 subjects were randomized across 12 centers. Results: Of the subjects randomized, 66 completed all study assessments and comprised the dataset that was analyzed. After 6 months, there was no significant difference between the vorapaxar and placebo groups in walking performance, as reflected by the GTT, or in quality of life, as reflected by the SF-12. There were no severe bleeding events in either group. Conclusion: This study found no benefit of vorapaxar in patients with IC and reiterates the need for future drug therapy studies that expand the benefits of supervised exercise therapy in patients with IC. ClinicalTrials.gov Identifier: NCT02660866.

Phosphodiesterase-4 Inhibitors for Non-COPD Respiratory Diseases

Selective phosphodiesterase (PDE) inhibitors are a class of nonsteroid anti-inflammatory drugs for treating chronic inflammatory diseases. Modulation of systemic and airway inflammation is their pivotal mechanism of action. Furthermore, PDE inhibitors modulate cough reflex and inhibit airway mucus secretion. Roflumilast, a selective PDE4 inhibitor, has been extensively studied for the efficacy and safety in chronic obstructive pulmonary disease (COPD) patients. According to the mechanisms of action, the potential roles of PDE inhibitors in treating chronic respiratory diseases including severe asthma, asthma-COPD overlap (ACO), noncystic fibrosis bronchiectasis, and chronic cough are discussed. Since roflumilast inhibits airway eosinophilia and neutrophilia in COPD patients, it reduces COPD exacerbations in the presence of chronic bronchitis in addition to baseline therapies. The clinical studies in asthma patients have shown the comparable efficacy of roflumilast to inhaled corticosteroids for improving lung function. However, the clinical trials of roflumilast in severe asthma have been limited. Although ACO is common and is also associated with poor outcomes, there is no clinical trial regarding its efficacy in patients with ACO despite a promising role in reducing COPD exacerbation. Since mucus hypersecretion is a result of neutrophil secretagogue in patients with chronic bronchitis, experimental studies have shown that PDE4s are regulators of the cystic fibrosis transmembrane conductance regulator (CFTR) in human airway epithelial cells. Besides, goblet cell hyperplasia is associated with an increased expression of PDE. Bronchiectasis and chronic bronchitis are considered neutrophilic airway diseases presenting with mucus hypersecretion. They commonly coexist and thus lead to severe disease. The role of roflumilast in noncystic fibrosis bronchiectasis is under investigation in clinical trials. Lastly, PDE inhibitors have been shown modulating cough from bronchodilation, suppressing transient receptors potential (TRP), and anti-inflammatory properties. Hence, there is the potential role of the drug in the management of unexplained cough. However, clinical trials for examining its antitussive efficacy are pivotal. In conclusion, selective PDE4 inhibitors may be potential treatment options for chronic respiratory diseases apart from COPD due to their promising mechanisms of action.

Cilostazol for intermittent claudication

BACKGROUND

Peripheral arterial disease (PAD) affects between 4% and 12% of people aged 55 to 70 years, and 20% of people over 70 years. A common complaint is intermittent claudication (exercise-induced lower limb pain relieved by rest). These patients have a three- to six-fold increase in cardiovascular mortality.  Cilostazol is a drug licensed for the use of improving claudication distance and, if shown to reduce cardiovascular risk, could offer additional clinical benefits. This is an update of the review first published in 2007.

OBJECTIVES

To determine the effect of cilostazol on initial and absolute claudication distances, mortality and vascular events in patients with stable intermittent claudication.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and AMED databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries, on 9 November 2020.

SELECTION CRITERIA

We considered double-blind, randomised controlled trials (RCTs) of cilostazol versus placebo, or versus other drugs used to improve claudication distance in patients with stable intermittent claudication.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for selection and independently extracted data. Disagreements were resolved by discussion. We assessed the risk of bias with the Cochrane risk of bias tool. Certainty of the evidence was evaluated using GRADE. For dichotomous outcomes, we used odds ratios (ORs) with corresponding 95% confidence intervals (CIs) and for continuous outcomes we used mean differences (MDs) and 95% CIs. We pooled data using a fixed-effect model, or a random-effects model when heterogeneity was identified. Primary outcomes were initial claudication distance (ICD) and quality of life (QoL). Secondary outcomes were absolute claudication distance (ACD), revascularisation, amputation, adverse events and cardiovascular events.

MAIN RESULTS

We included 16 double-blind, RCTs (3972 participants) comparing cilostazol with placebo, of which five studies also compared cilostazol with pentoxifylline. Treatment duration ranged from six to 26 weeks. All participants had intermittent claudication secondary to PAD. Cilostazol dose ranged from 100 mg to 300 mg; pentoxifylline dose ranged from 800 mg to 1200 mg. The certainty of the evidence was downgraded by one level for all studies because publication bias was strongly suspected. Other reasons for downgrading were imprecision, inconsistency and selective reporting. Cilostazol versus placebo Participants taking cilostazol had a higher ICD compared with those taking placebo (MD 26.49 metres; 95% CI 18.93 to 34.05; 1722 participants; six studies; low-certainty evidence). We reported QoL measures descriptively due to insufficient statistical detail within the studies to combine the results; there was a possible indication in improvement of QoL in the cilostazol treatment groups (low-certainty evidence). Participants taking cilostazol had a higher ACD compared with those taking placebo (39.57 metres; 95% CI 21.80 to 57.33; 2360 participants; eight studies; very-low certainty evidence). The most commonly reported adverse events were headache, diarrhoea, abnormal stools, dizziness, pain and palpitations. Participants taking cilostazol had an increased odds of experiencing headache compared to participants taking placebo (OR 2.83; 95% CI 2.26 to 3.55; 2584 participants; eight studies; moderate-certainty evidence).Very few studies reported on other outcomes so conclusions on revascularisation, amputation, or cardiovascular events could not be made. Cilostazol versus pentoxifylline There was no difference detected between cilostazol and pentoxifylline for improving walking distance, both in terms of ICD (MD 20.0 metres, 95% CI -2.57 to 42.57; 417 participants; one study; low-certainty evidence); and ACD (MD 13.4 metres, 95% CI -43.50 to 70.36; 866 participants; two studies; very low-certainty evidence). One study reported on QoL; the study authors reported no difference in QoL between the treatment groups (very low-certainty evidence). No study reported on revascularisation, amputation or cardiovascular events. Cilostazol participants had an increased odds of experiencing headache compared with participants taking pentoxifylline at 24 weeks (OR 2.20, 95% CI 1.16 to 4.17; 982 participants; two studies; low-certainty evidence).

AUTHORS' CONCLUSIONS

Cilostazol has been shown to improve walking distance in people with intermittent claudication. However, participants taking cilostazol had higher odds of experiencing headache. There is insufficient evidence about the effectiveness of cilostazol for serious events such as amputation, revascularisation, and cardiovascular events. Despite the importance of QoL to patients, meta-analysis could not be undertaken because of differences in measures used and reporting. Very limited data indicated no difference between cilostazol and pentoxifylline for improving walking distance and data were too limited for any conclusions on other outcomes.

Microbleeds and clinical outcome in acute mild stroke patients treated with antiplatelet therapy: ADS post-hoc analysis

BACKGROUND AND PURPOSE

In this post-hoc analysis using acute dual study dataset, the impacts of cerebral microbleeds (MBs) after mild stroke on clinical outcome were investigated.

METHODS

The number of MBs on admission was categorized as 1) no MBs, 2) MBs 1-4, 3) MBs 5-9, and 4) MBs ≥ 10. The efficacy outcome was defined as neurological deterioration and stroke recurrence within 14 days. Safety outcomes included ICH and/or SAH as well as extracranial hemorrhages.

RESULTS

Of the 1102 patients, 780 (71%) had no MBs on admission, while 230 (21%) had MBs 1-4, 48 (4%) had MBs 5-9, and 44 (4%) had MBs ≥ 10. The number of MBs was not associated with the neurological deterioration and/or stroke recurrence (p = 0.934), ICH and/or SAH (p = 0.743), and extracranial hemorrhage (p = 0.205). Favorable outcome was seem in 84% in the No MBs group, 83% in the MBs 1-4, 94% in the MBs 5-9, and 85% in the MBs ≥ 10 (p = 0.304). Combined cilostazol and aspirin therapy did not alter any rates of efficacy and safety outcomes among the no MBs, MBs 1-4, MBs 5-9, and MBs ≥ 10 groups compared to aspirin alone (all p > 0.05). By multivariate regression analysis, a history of ICH and diastolic blood pressure were the independent parameters to all of the MBs criteria (presence, MBs ≥ 5, and MBs ≥ 10).

CONCLUSIONS

MBs did not alter the clinical outcome at 3 months of onset. Elevated diastolic blood pressure and a history of ICH were the essential parameters related to the MBs.

[Randomized study of tolerability, safety and efficacy of Pletax in intermittent claudication]

AIM

This study was aimed at assessing tolerability, safety and therapeutic efficacy of Pletax® (cilostazol) compared with Trental® (pentoxifylline) in patients with moderate-to-severe intermittent claudication.

PATIENTS AND METHODS

The study included a total of one hundred 40-to-65-year-old patients presenting with confirmed diagnosis of moderate-to-severe intermittent claudication. Depending on the therapeutic regimen, the patients were divided into two groups. Group 1: 50 patients orally took Pletax® (cilostazol) at a dose of 100 mg twice daily 30 minutes before meals or 2 hours after meals together with conventional therapy. Group 2: 50 patients took oral Trental® (pentoxifylline) in a dose of 400 mg 3 times daily 30 minutes before meals or 2 hours after meals along with conventional therapy. The duration of the follow up period amounted to 24 weeks for both groups. The treadmill test was carried out at room temperature, with the running track tilt angle of 0° at a speed of 3 km/h. The primary parameters of efficacy were as follows: the dynamics of the minimal walking distance (a distance walked by the patient until the appearance of pain in the extremity) and dynamics of the maximal walking distance (a distance walked by the patients until full stop due to pain in the extremity).

RESULTS

Analysing efficacy demonstrated higher results of Pletax® compared with Trental®. The obtained findings suggested that Pletax® showed a significant clinical effect as soon as at 2 weeks, followed by advantage during the whole period of follow up. Analysing the parameters of the minimal and maximal walking distances in the group of patients taking Pletax® demonstrated clear superiority over the Trental® group as soon as by week 2 of administration, which preserved during the whole follow-up period. The minimal pain-free walking distance in the Pletax group at baseline amounted to 92.9±83.4 m (Trental group - 92.3±78.4; p=0.3), followed by an increase at week 8 to 126±115 m (Trental group - 116±96.3; p=0.51), at week 16 to 136±116 m (Trental group - 118±95.5; p=0.04), at week 24 to 149±126 b (Trental group - 127±98.9; p=0.01). At the same time, the effect of Pletax® and Trental® on the secondary parameter of efficacy, i.e., the ankle-brachial index was comparable: at baseline - 0.472 and 0.482 (p=0.28), at 2 weeks - 0.48 and 0.483 (p=031), at 8 weeks - 0.49 and 0.485 (p=0.74), at 16 weeks - 0.494 and 0.492 (p=0.2), at 24 weeks - 0.501 and 0.496 (p=0.45).

CONCLUSION

The obtained findings demonstrated advantages of Pletax® over Trental®, manifesting themselves in the achievement of the highest parameters by such criteria as the minimal and maximal walking distance. High safety and efficacy of Pletax® were confirmed by low frequency of unfavourable events during therapy.

[Resuscitative endovascular balloon occlusion of the aorta in haemodynamically unstable patients with bleeding (webinar review)]

This article reviews a webinar of the European Society for Vascular Surgery and the Endovascular Trauma and Resuscitation Management Society, dedicated to using endovascular balloon occlusion of the aorta in haemodynamically unstable patients, briefly covering the main conclusions of the reports and underlining prospects of this method. Possibilities of using aortic balloon occlusion arise interest of various-specialty medical experts, and the number of scientific works in this field has increasingly been growing, thus explaining the need for measures and studies on the subject concerned.

The 100 most cited articles in the diagnosis and management of peripheral artery disease

OBJECTIVE

Peripheral artery disease (PAD) is a highly prevalent disease that places major lifestyle limitations and mortality risk on affected individuals. As the understanding of the disease has grown in the medical community, it is unknown which literature has made the greatest impact on the knowledge of PAD. We performed a bibliometric analysis using the number of citations as an indication of impact to analyze the top 100 most influential articles on PAD management.

METHODS

A retrospective search of the Web of Science (Thomson Reuters, New York, NY) database for English-only publications was conducted in November 2020. We identified initial references from the database using the search terms "Peripheral Arterial Disease," "Peripheral Vascular Disease," "Claudication," "Critical Limb Ischemia," "Chronic Limb Threatening Ischemia," "Rest Pain," "Ischemic Ulcer," "Toe Gangrene," "Ankle Brachial Index," and "Leg Ischemia" in Web of Science Core Collections. Articles were ranked based on the number of citations and then analyzed based on citation count and average number of citations per year. Additional metrics included the overall average number of publications per year, the journals, journal discipline, author (including degree and gender), institution, country, topic area, and the level of evidence.

RESULTS

The most popular articles were published between 1959 and 2017, with 46,716 citations in total (average 27.26 citations/y). The most popular article had 2225 citations in total and was Rutherford's "Recommended standards for reports dealing with lower extremity ischemia: Revised version." Peak years of citations were 2016, 2014, and 2018 (2753, 2674, and 2639 citations, respectively). Top journals for the most cited publications were Circulation, Journal of Vascular Surgery, and the Lancet with 21, 13, and 7 articles, respectively. A majority of articles originated from the United States (58 articles), followed by the United Kingdom (15 articles) and Germany (13 articles). Major topic areas of interest and trends in the progressive understanding of PAD were noted. Top areas of focus included surgical interventions (29%), therapeutic angiogenesis (15%), epidemiological studies in PAD (14%), and diagnosis and evaluation (13%). In the top cited literature, 48% (14/29) of surgical articles investigated endovascular interventions for PAD.

CONCLUSIONS

Overall, PAD research has evolved from basic epidemiological studies to advanced management with continued investigation toward future, improved treatments for PAD.

TurboHawk plaque rotation system for treatment of arteriosclerosis occlusion in lower extremities: A pilot retrospective study

This pilot study retrospectively assessed the feasible efficacy of TurboHawk plaque rotation system (THPRS) for treatment of arteriosclerosis occlusion in lower extremities (AOLE).A total of 36 eligible patients with AOLE were included in this pilot retrospective study. We divided all those patients into a treatment group and a control group, each group 18 patients. All patients in both groups administered conventional therapy. Additionally, all patients in the treatment group received THPRS, while all patients in the control group received percutaneous transluminal angioplasty (PTA) and percutaneous transluminal stenting (PTS). All outcomes were evaluated and analyzed at 3-month after surgery.At 3-month postsurgery, there were not significant statistical differences in clinical manifestations (intermittent claudication, P = .49; resting pain, P = .28), ankle brachial index change (P = .07), 6-minute walk distance (P = .43), and complications between 2 groups.This pilot study did not show better outcome improvement of THPRS for patients with AOLE. We cautiously draw the present conclusion, because it suffers from several major restrictions. Thus, further studies with larger sample size and longer term follow-up are still needed to warrant the current conclusion.

Targeting Uremic Toxins to Prevent Peripheral Vascular Complications in Chronic Kidney Disease

Chronic kidney disease (CKD) exhibits progressive kidney dysfunction and leads to disturbed homeostasis, including accumulation of uremic toxins, activated renin-angiotensin system, and increased oxidative stress and proinflammatory cytokines. Patients with CKD are prone to developing the peripheral vascular disease (PVD), leading to poorer outcomes than those without CKD. Cumulative evidence has showed that the synergy of uremic milieu and PVD could exaggerate vascular complications such as limb ischemia, amputation, stenosis, or thrombosis of a dialysis vascular access, and increase mortality risk. The role of uremic toxins in the pathogenesis of vascular dysfunction in CKD has been investigated. Moreover, growing evidence has shown the promising role of uremic toxins as a therapeutic target for PVD in CKD. This review focused on uremic toxins in the pathophysiology, in vitro and animal models, and current novel clinical approaches in reducing the uremic toxin to prevent peripheral vascular complications in CKD patients.

Peripheral Artery Disease in Diabetes Mellitus: Focus on Novel Treatment Options

Diabetes mellitus (DM) and peripheral artery disease (PAD) are two clinical entities closely associated. They share many pathophysiological pathways such as inflammation, endothelial dysfunction, oxidative stress and pro-coagulative unbalance. Emerging data focusing on agents targeting these pathways may be promising. Moreover, due to the increased cardiovascular risk, there is a growing interest in cardiovascular and "pleiotropic" effects of novel glucose lowering drugs. This review summarizes the main clinical features of PAD in patients, the diagnostic process and current medical/interventional approaches, ranging from "classical treatment" to novel agents.

Cilostazol restores autophagy flux in bafilomycin A1-treated, cultured cortical astrocytes through lysosomal reacidification: roles of PKA, zinc and metallothionein 3

Cilostazol, a phosphodiesterase 3 inhibitor, reduces the amyloid-beta (Aβ) burden in mouse models of Alzheimer disease by as yet unidentified mechanisms. In the present study, we examined the possibility that cilostazol ameliorates lysosomal dysfunction. Astrocytes treated with bafilomycin A1 (BafA1) exhibited markedly reduced DND-189 and acridine orange (AO) fluorescence, indicating reduced lysosomal acidity. In both cases, BafA1-induced alkalization was reversed by addition of cilostazol, dibutyryl cAMP or forskolin. All three agents significantly increased free zinc levels in lysosomes, and addition of the zinc chelator TPEN abrogated lysosomal reacidification. These treatments did not raise free zinc levels or reverse BafA1-mediated lysosomal alkalization in metallothionein 3 (Mt3)-null astrocytes, indicating that the increases in zinc in astrocytes were derived mainly from Mt3. Lastly, in FITC-Aβ-treated astrocytes, cilostazol reversed lysosomal alkalization, increased cathepsin D activity, and reduced Aβ accumulation in astrocytes. Cilostazol also reduced mHtt aggregate formation in GFP-mHttQ74–expressing astrocytes. Collectively, our results present the novel finding that cAMP/PKA can overcome the v-ATPase blocking effect of BafA1 in a zinc- and Mt3-dependent manner.

Tackling Elevated Risk in PAD: Focus on Antithrombotic and Lipid Therapy for PAD

The PAD population is at increased risk of major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Risk factor modification, symptom control, antithrombotic, and lipid therapies are the mainstays of PAD medical therapy. Recent data has challenged prior recommendations regarding the optimal secondary prevention strategies in PAD. PURPOSE OF REVIEW: To review clinical evidence from large randomized controlled trials showing the benefit of antithrombotic and lipid therapy in the PAD population. RECENT FINDINGS: The COMPASS trial challenged prior recommendations regarding anticoagulation in PAD. Among the PAD subgroup, rivaroxaban 2.5 mg plus aspirin reduced MACE (HR 0.72, 95% CI 0.57-0.90, p = 0.0047), MALE (HR 0.54, 95% CI 0.35-0.82, p = 0.0037), and major amputation (HR 0.30, 95% CI 0.11-0.80, p = 0.011) compared with aspirin monotherapy. The THEMIS trial showed a 55% risk reduction for MALE with ticagrelor DAPT compared with aspirin monotherapy (HR 0.45, 95% CI 0.23-0.86). The FOURIER trial revealed that lowering LDL cholesterol below current targets with a PCSK9 inhibitor reduced MACE (HR 0.73, 95% CI 0.59-0.91, p = 0.0040) and MALE (HR 0.43, 95% CI 0.19-0.99, p = 0.042) in subjects with symptomatic PAD. Recent high-quality evidence shows the benefit of antiplatelet therapy, anticoagulation therapy, and lipid therapy in reducing MACE and MALE in PAD. Despite these findings, implementation remains a challenge and focus should now shift towards adopting evidence-based recommendations in clinical practice.

Entering Cardiac Rehabilitation With Peripheral Artery Disease: A RETROSPECTIVE COMPARISON TO CORONARY ARTERY DISEASE

PURPOSE

Supervised exercise is recommended for patients with peripheral artery disease (PAD) and patients with coronary artery disease (CAD). Both conditions share common etiology as atherosclerotic diseases. The clinical profile, cardiorespiratory fitness, and exercise prescriptions of PAD, CAD, and patients with concomitant PAD and CAD (BOTH) have yet to be compared upon entry into cardiac rehabilitation (CR).

METHODS

Cardiopulmonary, demographic, and anthropometric assessments were conducted at entry to CR between January 2006 and December 2017.

RESULTS

Among 9701 consecutively enrolled patients, there were 94.6% with CAD (n = 9179), 1.5% with PAD (n = 143), and 3.9% with BOTH (n = 379). Only 5.4% (n = 522) of all patients entering CR had a diagnosis of PAD. Compared with CAD, patients with PAD and BOTH were older (mean ± SD = 62.5 ± 11.1 vs 67.9 ± 11.4 and 69.2 ± 9.8 yr, P < .01), had higher resting systolic blood pressure (124 ± 17 vs 130 ± 17 and 133 ± 18 mm Hg, P < .01), had lower cardiorespiratory fitness (19.7 ± 6.3 vs 15.6 ± 4.8 and 15 ± 4.5 mL/kg/min, P < .01), and were more likely to have diabetes (25% vs 35% and 41%, P < .01), abdominal obesity (39% vs 54% and 51%, P < .01), and initially prescribed lower-intensity exercise (84.4 ± 14.1 vs 74.1 ± 15.7 and 70.0 ± 14.6 m/min exercise pace, P < .01), reflecting the complex nature of patients diagnosed with PAD.

CONCLUSIONS

Patients referred with PAD have a cardiovascular risk profile that places them at a greater risk for a repeat or first cardiac event compared with patients with CAD. Referral to structured exercise and risk factor modification programs should be considered to aid in the management of PAD.

Peripheral Vascular Disease in Women: Therapeutic Options in 2019

PURPOSE OF REVIEW

In recent years, there have been advances in the prevention, management, and control of peripheral vascular disease (PVD). There is a trend towards aggressive risk factor modification, noninvasive screening, and endovascular revascularization with surgical approaches reserved only for select cases. This article reviews the different management strategies ranging from pharmacotherapy, revascularization, and rehabilitation with an emphasis on the response of women to these therapies.

RECENT FINDINGS

Overall, the representation of women in the majority of the published data in this arena remains poor. Studies examining medical therapy and endovascular and surgical revascularization were not designed to address sex disparities. Nevertheless, we dissect these therapies and their relevant randomized trials. The paucity of data investigating the response of women to the different management options makes it difficult to make any evidence-based recommendations. This not only applies to the type of intervention, but also the appropriate timing and risks entailed.

Progress in the development of antiplatelet agents: Focus on the targeted molecular pathway from bench to clinic

Antiplatelet drugs serve as a first-line antithrombotic therapy for the management of acute ischemic events and the prevention of secondary complications in vascular diseases. Numerous antiplatelet therapies have been developed; however, currently available agents are still associated with inadequate efficacy, risk of bleeding, and variability in individual response. Understanding the mechanisms of platelet involvement in thrombosis and the clinical development process of antiplatelet agents is critical for the discovery of novel agents. The functions of platelets in thrombosis are regulated by two major mechanisms: the interaction between surface receptors and their ligands, and the downstream intracellular signaling pathways. Recently, most of the progress made in antiplatelet drug development has been achieved with P2Y receptor antagonists. Additionally, the usage of GP IIb/IIIa receptor antagonists has decreased, because it is associated with a higher risk of bleeding and thrombocytopenia. Agents targeting other platelet surface receptors such as PARs, TP receptor, EP3 receptor, GPIb-IX-V receptor, P-selectin, as well as intracellular signaling factors, such as PI3Kβ, have been evaluated in an attempt to develop the next generation of antiplatelet drugs, reduce or eliminate interpatient variability of drug efficacy and significantly lower the risk of drug-induced bleeding. The aim of this review is to describe the pathways of platelet activation in thrombosis, and summarize the development process of antiplatelet agents, as well as the preclinical and clinical evaluations performed on these agents.

Therapeutic opportunities in colon cancer: Focus on phosphodiesterase inhibitors

Despite novel technologies, colon cancer remains undiagnosed and 25% of patients are diagnosed with metastatic colon cancer. Resistant to chemotherapeutic agents is one of the major problems associated with treating colon cancer which creates the need to develop novel agents targeting towards newer targets. A phosphodiesterase is a group of isoenzyme, which, hydrolyze cyclic nucleotides and thereby lowers intracellular levels of cAMP and cGMP leading to tumorigenic effects. Many in vitro and in vivo studies have confirmed increased PDE expression in different types of cancers including colon cancer. cAMP-specific PDE inhibitors increase intracellular cAMP that leads to activation of effector molecules-cAMP-dependent protein kinase A, exchange protein activated by cAMP and cAMP gated ion channels. These molecules regulate cellular responses and exert its anticancer role through different mechanisms including apoptosis, inhibition of angiogenesis, upregulating tumor suppressor genes and suppressing oncogenes. On the other hand, cGMP specific PDE inhibitors exhibit anticancer effects through cGMP dependent protein kinase and cGMP dependent cation channels. Elevation in cGMP works through activation of caspases, suppression of Wnt/b-catenin pathway and TCF transcription leading to inhibition of CDK and survivin. These studies point out towards the fact that PDE inhibition is associated with anti-proliferative, anti-apoptotic and anti-angiogenic pathways involved in its anticancer effects in colon cancer. Thus, inhibition of PDE enzymes can be used as a novel approach to treat colon cancer. This review will focus on cAMP and cGMP signaling pathways leading to tumorigenesis and the use of PDE inhibitors in colon cancer.

Randomized control trial comparing the effect of cilostazol and aspirin on changes in carotid intima-medial thickness

Antiplatelet drugs are effective in preventing recurrence of atherosclerosis in type 2 diabetes (T2D) patients. However, the efficacy and usefulness of antiplatelet drugs on the progression of carotid intima-media thickness (IMT), a marker for evaluating early atherosclerotic vascular disease, has not been analyzed. We conducted a prospective, randomized, open, 36-month trial comparing cilostazol vs. aspirin. A total of 415 T2D patients (age range 38-83 years; 206 females) without macrovascular complications were randomized to either an aspirin (100 mg/day) or cilostazol (200 mg/day) treatment. Patients underwent B-mode ultrasonography annually to assess the IMT and serum levels of inflammatory markers were measured before and after each treatment. Potential confounders were statistically adjusted, and included lipid profiles, HbA1c, body mass index, waist circumference, anti-hypertensive and statin medications. The decrease in mean left, maximum left, mean right and maximum right IMT were significantly greater with cilostazol compared with aspirin (- 0.094 ± 0.186 mm vs. 0.006 ± 0.220 mm, p < 0.001; - 0.080 ± 0.214 mm vs. 0.040 ± 0.264 mm, p < 0.001; - 0.064 ± 0.183 mm vs. 0.004 ± 0.203 mm, p = 0.015; - 0.058 ± 0.225 mm vs. 0.023 ± 0.248 mm, p = 0.022, respectively). And these differences remained significant after adjustment of potential confounders. Compared with aspirin, cilostazol treatment was associated with significantly increased HDL cholesterol (p = 0.039) and 25-hydroxy vitamin D levels (p = 0.001). Cilostazol treatment was associated with significantly lowered IMT in T2D patients compared to aspirin, independent of conventional cardiovascular risk factors. Cilostazol may inhibit plaque formation and have beneficial effects on atherosclerosis through vasodilatory and antiplatelet effects.

[Conservative treatment of chronic lower limb ischemia in ambulatory practice (in Russian only)]

Peripheral artery disease is still one of the most important surgical problems. General surgeons treat the majority of patients with chronic lower limb ischemia due to the lack of specialized surgical care. Current methods for risk factors adjustment, exercise therapy and the most common drugs for intermittent claudication management are reviewed in the article. The effect of these medicines on subjective (pain-free walking distance, maximal walking distance, etc.) and objective (ankle-brachial index) parameters and the incidence of complications are analyzed.

Risk of Heart Failure Hospitalization Associated With Cilostazol in Diabetes: A Nationwide Case-Crossover Study

Background and Objective: It has been suggested to avoid cilostazol, the first-line therapy for peripheral arterial disease, in patients with congestive heart failure (HF). The objective of this study was to evaluate the risk of hospitalization for heart failure (HHF) associated with cilostazol use in the patients of diabetes mellitus. Methods: This case-crossover study retrieved records on diabetic patients > 20 years of age who were hospitalized for heart failure during the period of 2009-2011 from the Taiwan National Health Insurance Database. The "current" period was defined as 1-30 days prior to HHF whereas the 91-120 days prior to HHF served as the "reference" period. The exposure status just preceding the event is compared with exposure of the same person in one or more referent remote to the event. Adjusted odds ratios (OR) were used to estimate time-varying discordant exposure by the ratio of the number exposed to cilostazol only during the case period to the number exposed to cilostazol only during the control period. Results: A total of 47,506 diabetic patients were included in the analysis (average age: 72.7 ± 12.4, percentage of males: 48%). A total of 399 patients (0.84%) received cilostazol only in the current period, and 252 (0.53%) received cilostazol only in the reference period. After adjustment for other medications, a significant association was found between cilostazol and HHF (OR: 1.35, 95% CI: 1.14-1.59). After further adjustment for time-varying co-morbidities the ORs remained essentially the same. Sensitivity analyses using different definitions of control period (ranging from 31-60, 61-90, to 121-150 days before index date) yielded adjusted ORs of 1.43 (95% CI: 1.14-1.79), 1.31 (95% CI: 1.09-1.57) and 1.23 (95% CI: 1.06-1.44), respectively suggesting the robustness of our study findings. Conclusion: Use of cilostazol may be positively related to the risk of HHF. Further studies are warranted to explore the underlying mechanisms and to confirm the association.

[Clinical study of efficacy and safety of Aducil in patients with chronic lower limb ischaemia]

AIM

The study was aimed at assessing efficacy and safety of treatment with Aducil® (cilostazol) compared with Trental® 400 in patients with moderate-to-severe intermittent claudication due to peripheral atherosclerosis.

PATIENTS AND METHODS

The study included a total of one hundred and forty-five 36-to-75-year-old patients. The participants were distributed into 2 groups according to the inclusion/exclusion criteria in a 2 to 1 proportion: patients in group 1 received Aducil® 100 mg BID, in group 2 - Trental® 400 TID for 12 weeks. 142 subjects completed the protocol.

RESULTS

Analysis of the effectiveness of treatment according to the primary criterion showed a better effectiveness of Aducil® as compared with Trental® 400. Subjects who received Aducil® had a higher increase in the absolute maximum walking distance after 12 weeks of treatment as compared with those taking Trental® 400: 126±110 m versus 45±39 m, respectively (р<0.001). Subjects who received Aducil® had a statistically significant improvement in quality of life parameters such as physical and mental health components according to the SF-36 questionnaire after 12 weeks of treatment (р≤0.01). Subjects in Aducil® group had better quality of life with an increase from 34 to 40 points according to the physical component score, while patients in Trental® 400 group demonstrated minor positive changes (from 35 to 37 points); mean mental component score increased from 45 to 48 points in Aducil® group as compared with an increase from 45 to 47 points in Trental® 400 group. While self-reported physical health status was similar between the groups at baseline, subjects in Aducil® group reported better physical functioning after treatment (р=0.016). Two adverse events were registered in two subjects in Aducil® group.

CONCLUSION

Analysis of the study endpoints demonstrated that Aducil® had better treatment effectiveness in patients with chronic lower limb ischemia stage IIB according to the classification of A.V. Pokrovsky-Fontaine as compared with Trental® 400, while the safety profile and drug tolerance were similar between the two.

[Current aspects of performing treadmill test in patients with peripheral artery disease]

The protocols of performing treadmill tests (TMT) in patients presenting with peripheral artery disease have over the last decades undergone significant changes, with the alterations concerning not only the speed and time values of the load, but also the parameters measured. Currently, there is no unified generally accepted method of TMT, hence the need for an optimal protocol for carrying out this type of examination, which would help obtain reliable results in assessment of everyday life functional activity of patients and efficacy of various methods of treatment for peripheral atherosclerosis. The choice of an optimal methodology of performing a TMT in patients with intermittent claudication is extremely important because studying the haemodynamic parameters alone not always clearly reflect functional peculiarities of the course of the disease, since they depend not only on the presence of arterial stenoses or occlusions, but also on the activity of oxidative enzymes, endothelial and mitochondrial dysfunction, taking therapeutic agents, concomitant pathology and a series of other factors. The article is a review of the related literature contained in such databases as the Medline, PubMed, Russian Science Citation Index (RSCI) and Scopus and concerning TMT in patients with peripheral artery disease. The authors summarized the information from a total of 63 literature sources over the period from the 1970s to 2018.

Low molecular-weight fucoidan protects against hindlimb ischemic injury in type 2 diabetic mice through enhancing endothelial nitric oxide synthase phosphorylation

BACKGROUND

Diabetes mellitus (DM) complications are associated with ischemic injury. Angiogenesis is a therapeutic strategy for diabetic foot. The aim of this study was to investigate the possible angiogenic effect of low molecular weight fucoidan (LMWF) in diabetic peripheral arterial disease (PAD).

METHODS

Diabetic db/db mice and age-matched C57BL/6 mice underwent femoral artery ligation followed by LMWF (30, 60, 80 mg/kg per day, p.o.) or cilostazol (30 mg/kg/day, p.o.) treatment for 6 weeks. Endothelium-dependent vasodilation and blood flow of the hindlimb were measured. Histological and western blot analyses of CD34, vascular endothelial growth factor (VEGF), eNOS, and inflammatory factors in the gastrocnemius were performed. The effects of LMWF were confirmed in human umbilical vein endothelial cells (HUVEC).

RESULTS

Diabetic mice with ligation exhibited hindlimb ulceration, hydrosarca, and necrosis, increased expression of inflammatory factors, and decreased levels of VEGF and eNOS phosphorylation. Treatment with LMWF markedly ameliorated foot lesions, suppressed expression of inflammatory factors, and improved plantar perfusion by promoting endothelium-dependent vasodilation and revascularization in diabetic PAD mice. In high-glucose treated HUVEC, LMWF (40 μg/mL) reversed blunted endothelial cell proliferation, migration, and tube formation, and promoted eNOS phosphorylation and VEGF expression, whereas HUVEC pretreatment with 100 μmol/L N^G -nitro-l-arginine methyl ester, an eNOS antagonist, markedly inhibited the effects of LMWF.

CONCLUSION

This study demonstrates that LMWF alleviates hindlimb ischemic damage, at least in part by promoting eNOS phosphorylation, nitric oxide production, and VEGF expression, resulting in enhanced angiogenesis in the ischemic region.

PDE3 Inhibitors Repurposed as Treatments for Age-Related Cognitive Impairment

As the population of older individuals grows worldwide, researchers have increasingly focused their attention on identifying key molecular targets of age-related cognitive impairments, with the aim of developing possible therapeutic interventions. Two such molecules are the intracellular cyclic nucleotides, cAMP and cGMP. These second messengers mediate fundamental aspects of brain function relevant to memory, learning, and cognitive function. Consequently, phosphodiesterases (PDEs), which hydrolyze cAMP and cGMP, are promising targets for the development of cognition-enhancing drugs. Inhibitors that target PDEs work by elevating intracellular cAMP. In this review, we provide an overview of different PDE inhibitors, and then we focus on pharmacological and physiological effects of PDE3 inhibitors in the CNS and peripheral tissues. Finally, we discuss findings from experimental and preliminary clinical studies and the potential beneficial effects of the PDE3 inhibitor cilostazol on age-related cognitive impairments. In the innovation pipeline of pharmaceutical development, the antiplatelet agent cilostazol has come into the spotlight as a novel treatment for mild cognitive impairment. Overall, the repurposing of cilostazol may represent a potentially promising way to treat mild cognitive impairment, Alzheimer's disease, and vascular dementia. In this review, we present a brief summary of cAMP signaling and different PDE inhibitors, followed by a discussion of the pharmacological and physiological role of PDE3 inhibitors. In this context, we discuss the repurposing of a PDE3 inhibitor, cilostazol, as a potential treatment for age-related cognitive impairment based on recent research.

Prognostic factors of ulcer healing and amputation-free survival in patients with critical limb ischemia

Objective

A multidisciplinary approach is required to treat critical limb ischemia. We determined the poor prognostic factors of ischemic ulcer healing after optimal arterial revascularization, and assessed the efficacy of the medication therapy using cilostazol, which is a selective inhibitor of phosphodiesterase 3.

Methods

In this retrospective, single-center, cohort study, 129 limbs that underwent infrainguinal arterial revascularization for Rutherford class 5 critical limb ischemia were reviewed. The primary end point was the ulcer healing time after arterial revascularization. The secondary end point was the amputation-free survival rate.

Results

Of the 129 limbs, endovascular therapy was performed in 69 limbs, and surgical reconstructive procedures were performed in 60 limbs for initial therapy. Complete ulcer healing was achieved in 95 limbs (74%). The median ulcer healing time was 90 days. In multivariate analysis, no cilostazol use significantly inhibited ulcer healing ( p = 0.0114). A white blood cell count >10,000 ( p = 0.0185), a major defect after debridement ( p = 0.0215), and endovascular therapy ( p = 0.0308) were significant poor prognostic factors for ulcer healing. Additionally, ischemic heart disease ( p < 0.0001), albumin levels <3 g/dl ( p = 0.0016), no cilostazol use ( p = 0.0078), and a major defect after debridement ( p = 0.0208) were significant poor prognostic factors for amputation-free survival rate.

Conclusions

Ulcer healing within 90 days after arterial revascularization is impaired by no cilostazol use, a white blood cell count >10,000, a major defect after debridement, and endovascular therapy. Furthermore, cilostazol improves amputation-free survival rate in patients with critical limb ischemia.

Anti-inflammatory properties of cilostazol: Its interruption of DNA binding activity of NF-κB from the Toll-like receptor signaling pathways

Cilostazol, a selective inhibitor of phosphodiesterase type III with anti-platelet, anti-mitogenic, and vasodilating properties, is widely used to treat ischemic symptoms of peripheral vascular disease. Ample evidence has suggested that cilostazol also exhibits an anti-inflammatory effect, but its anti-inflammatory mechanism is not fully understood. Here, we showed that cilostazol specifically inhibited expression of cytokines, which are induced by nuclear factor-κB (NF-κB) activation, in RAW264.7 macrophage cells stimulated with different Toll-like receptor (TLR) ligands. Cilostazol was found to significantly reduce TLR-4 and TLR-3 ligands-stimulated NF-κB transcriptional activity, which was quantified by luciferase reporter assays. However, cilostazol was without effect on IκBα degradation and NF-κB p65 phosphorylation and nuclear translocation after challenge with the TLR-4 ligand lipopolysaccharide (LPS). Cilostazol did not also prevent the LPS-induced increase in phosphorylated levels of the mitogen-activated protein kinase (MAPK) family. On the other hand, using chromatin immunoprecipitation assays, we demonstrated that cilostazol reduced the LPS-induced transcriptional activities of interleukin-6 and tumor necrosis factor-α by preventing the recruitment of NF-κB p65 to these gene promoters. When cilostazol was given to mice by oral gavage daily for 7 days, LPS-induced aberrant pro-inflammatory cytokine production and end-organ tissue injury were significantly reduced. The results of this study suggest that cilostazol is capable of directly interrupting DNA binding activity of NF-κB proteins from the TLR signaling pathways. The therapy to specifically intervene in this pathway may be potentially beneficial for the prevention of different inflammatory disorders.

MicroRNA-132 targeting PTEN contributes to cilostazol-promoted vascular smooth muscle cell differentiation

BACKGROUND AND AIMS

Cilostazol, beyond its antiplatelet effect, is also capable of promoting vascular smooth muscle cell (VSMC) differentiation. The aim of this study was to explore the potential role of PTEN, known to associate with VSMC differentiation, and its related microRNA (miRNA) in cilostazol-dependent effects.

METHODS AND RESULTS

Microarray analysis in balloon-injured rat carotid arteries comparing with and without balloon injury revealed that miR-132 was differentially expressed. Bioinformatic analysis predicts PTEN as a novel target of miR-132. Western blot and quantitative real-time reverse transcription-polymerase chain reaction along with in situ hybridization documented that cilostazol treatment enhanced PTEN and reduced miR-132 expression in the neointima of balloon-injured arteries. Treatment of cultured rat VSMCs with cilostazol resulted in the up-regulation of PTEN mRNA and the down-regulation of miR-132, supporting an in vitro relevance. Co-transfection experiments showed that transfection of miR-132 mimic into VSMCs suppressed PTEN 3'UTR activities, further reflecting that PTEN is the direct target of miR-132. Over-expression of miR-132 in VSMCs led to an attenuation of cilostazol-induced PTEN and its downstream VSMC differentiation marker (calponin) expression, confirming the critical role of miR-132 in VSMC differentiation. Transient transfection studies demonstrated that cilostazol reduced the activity of miR-132 promoter, which was mediated via cyclic AMP response element-binding protein. Notably, the use of lentivirus to over-express miR-132 in the neointima of balloon-injured arteries could reverse the effect of cilostazol in vivo.

CONCLUSIONS

These results suggest that miR-132 by targeting PTEN may be an important regulator in mediating cilostazol actions on VSMC differentiation.

The Physical Activity Daily (PAD) Trial: The rationale and design of a randomized controlled trial evaluating an internet walking program to improve maximal walking distance among patients with peripheral arterial disease

BACKGROUND

Despite established guidelines for regular walking as a first line therapy for adults with peripheral arterial disease (PAD), most patients do not walk routinely. This paper presents the design specifications for a randomized clinical trial to examine the effectiveness of an internet-based walking program compared to a telephone intervention, or the combination (internet-based with telephone counseling) for promotion of regular walking in patients with PAD.

METHODS

Sedentary adults with documented lower extremity PAD are being recruited from the University of Michigan Health System and the surrounding area. Participants are randomized to one of four arms in a 2×2 factorial design: 1) telephone counseling to promote walking, 2) an internet-based walking program with tailored step-count goals, 3) the combination of telephone counseling with the internet-based walking program, or 4) waitlist control. Participants receive a 4-month intervention phase, after which all participants are followed for an additional 8months to assess long-term adherence to regular walking. Outcomes are assessed at baseline, 4 and 12months. The primary outcome is walking distance assessed through a standardized treadmill protocol. Additional outcomes include change in step-counts measured with a commercial activity tracker, pain-free walking distance, and changes in health-related quality of life from baseline to follow-up.

CONCLUSION

Finding effective and feasible programs to promote walking among PAD patients is warranted. This study will add to current evidence regarding use of internet based programs with and without telephone counseling to promote regular walking in this population.

Protective effects of cilostazol on ethanol-induced damage in primary cultured hepatocytes

Alcoholic liver disease (ALD) caused by excessive alcohol consumption is associated with oxidative stress, mitochondrial dysfunction, and hepatocellular apoptosis. Cilostazol, a licensed clinical drug used to treat intermittent claudication, has been reported to act as a protective agent in a spectrum of diseases. However, little information regarding its role in ethanol-induced hepatocellular toxicity has been reported. In the current study, we investigated the protective effects and mechanisms of cilostazol on ethanol-induced hepatocytic injury. Rat primary hepatocytes were pretreated with cilostazol prior to ethanol treatment. MTT and LDH assay indicated that ethanol-induced cell death was ameliorated by cilostazol in a dose-dependent manner. Our results display that overproduction of intracellular reactive oxygen species (ROS) and 4-hydroxy-2-nonenal (4-HNE) induced by ethanol was attenuated by pretreatment with cilostazol. Furthermore, cilostazol significantly inhibited ethanol-induced generation of ROS in mitochondria. Importantly, it was shown that cilostazol could improve mitochondrial function in primary hepatocytes by restoring the levels of ATP and mitochondrial membrane potential (MMP). Additionally, cilostazol was found to reduce apoptosis induced by ethanol using a terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Mechanistically, we found that cilostazol prevented mitochondrial pathway-mediated apoptotic signals by reversing the expression of Bax and Bcl2, the level of cleaved caspase-3, and attenuating cytochrome C release. These findings suggest the possibility of novel ALD therapies using cilostazol.

Exercise Rehabilitation for Peripheral Artery Disease: A REVIEW

PURPOSE

To summarize evidence regarding exercise therapy for people with lower extremity peripheral artery disease (PAD).

METHODS

Literature was reviewed regarding optimal strategies for delivering exercise interventions for people with PAD. Randomized trial evidence and recent studies were emphasized.

RESULTS

Randomized clinical trial evidence consistently demonstrates that supervised treadmill exercise improves treadmill walking performance in people with PAD. A meta-analysis of 25 randomized trials (1054 participants) concluded that supervised treadmill exercise was associated with 180 m of improvement in maximal treadmill walking distance and 128 m of improvement in pain-free walking distance compared with a control group. Three randomized trials of 493 patients with PAD demonstrated that home-based walking exercise interventions that incorporate behavioral change techniques improve walking ability in patients with PAD. Furthermore, evidence suggests that home-based walking exercise improves the 6-min walk more than supervised treadmill exercise. Upper and lower extremity ergometry also significantly improved walking endurance in PAD. The Centers for Medicare & Medicaid Services recently determined that Medicare would cover 12 wk (36 sessions) of supervised treadmill exercise for patients with PAD.

CONCLUSIONS

Supervised treadmill exercise and home-based walking exercise each improve walking ability in patients with PAD. The availability of insurance coverage for supervised treadmill exercise for patients with PAD will make supervised treadmill exercise more widely available and accessible. Home-based exercise that incorporates behavioral change technique is an effective alternative for patients unwilling or unable to attend 3 supervised exercise sessions per week.