The vascular and biochemical effects of cilostazol in patients with peripheral arterial disease

The effect of cilostazol on the platelet-derived growth factor-beta/beta isoform reduction on venous hyperplasia in an experimental balloon-induced injury model

BACKGROUND

Intimal hyperplasia is the response to endothelial injury. Platelet-derived growth factor is released early and favors the formation of intimal hyperplasia. Although multiple treatments, from open surgery to endovascular techniques, have been used they remain controversial. There is currently interest in developing pharmacological strategies to address this pathology. Local vascular inflammation induced by vessel barotrauma generates intimal hyperplasia due to mechanical stress over the venous endothelium. Cilostazol is a selective phosphodiesterase type 3 (PDE3) selective inhibitor with a regulatory effect over intimal hyperplasia. The objective was to investigate cilostazol's role in inhibiting smooth muscle cell proliferation due to changes in the expression and release of PDGF-BB isoform and the effect on developing IH using an experimental model of vascular barotrauma (balloon-induced injury model).

METHODS

We included 12 New Zealand rabbits. The balloon-induced injury model (BIIM) and experimental group cilostazol (20 mg/kg/day) included 6 rabbits each. Contralateral veins from 6 rabbits used in BIIM model has been taken as control group. We measured and compared the expression of PDGF-BB and the development of IH. A pathologist board chooses a PDGFRα antibody to localized its expression by immunohistochemistry analysis. Subsequently, using an automated immunohistochemical staining machine, the PDGFR expression was evaluated using a Zeiss Primo Star 4 light microscope.

RESULTS

The measurement obtained in the intimal layer was: 126.12 μm2 in the CG, 232 μm2 in the BIIM group, and 178 μm2 in the EG. A statistically significant difference was observed. Baseline serum concentrations of PDGF-BB in the BIIM group were 0.22 pg/mL. At 12 h 0.42 pg/mL, and 0.17 pg/mL at seven days. In the experimental group, the basal levels were 0.33 pg/mL. With the use of cilostazol, a lower peak was obtained at 12 h (0.08 pg/mL). This difference was statistically significant.

CONCLUSIONS

Cilostazol induced a significant reduction of IH caused by barotrauma in the venous endothelium, which correlates with decrease in the PDGF-BB in serum. This could be attributed to the pharmacologic effect on PDGFR expression.

Do Patients With Arterial Occlusive Disease of Different Etiologies Benefit Equally From Cilostazol?

BACKGROUND

Cilostazol is a guideline-recommended drug that improves intermittent claudication and quality of life in patients with chronic atherosclerotic peripheral arterial disease. The drug is used for most etiologies of arterial occlusive diseases in clinical practice. This study aimed to evaluate whether patients benefit equally from cilostazol regardless of etiology.

METHODS

Patients on cilostazol were divided into 4 groups according to arterial occlusive disease etiology: (1) atherosclerosis, (2) diabetic angiopathy, (3) embolism/thrombosis, and (4) Buerger disease. Patients' maximum walking distance, ankle-brachial index score and distal tissue oxygen saturation (Sto2), clinical improvement onset time, ability to reach maximum benefit time, vascular surgeries, and wounds were compared before they started cilostazol and after 12 months. Results were evaluated at a statistical significance of P < .05.

RESULTS

In 194 patients, 307 target extremities were evaluated in the 4 disease groups. After cilostazol use, maximum walking distance, ankle-brachial index score, and distal Sto2 increased significantly in all groups (P < .001), but distal Sto2 in the diabetic angiopathy and Buerger disease groups was significantly lower than in the atherosclerosis group (P < .001). Ankle-brachial index and distal Sto2 differences in the Buerger disease group were significantly lower (both P < .001). The vascular surgery counts decreased significantly in the atherosclerosis and embolism/thrombosis groups (P = .019 and P = .004, respectively).

CONCLUSION

Patients with nonatherosclerotic arterial occlusive disease also benefit from cilostazol, but patients with Buerger disease or diabetic angiopathy seem to benefit less. Combining cilostazol with anticoagulant or antiaggregant agents and closer monitoring of these patients may produce better results.

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-imprinted polymer film-coated electrode as an electrochemical chemosensor for selective determination of cilostazol and its active primary metabolite

An electrochemical chemosensor for cilostazol (CIL) determination was devised, engineered, and tested. For that, a unique conducting film of the functionalized thiophene-appended carbazole-based polymer, molecularly imprinted with cilostazol (MIP-CIL), was potentiodynamically deposited on a Pt disk electrode by oxidative electropolymerization. Thanks to electro-oxidation potentials lower than that of CIL, the carbazole monomers outperformed pyrrole, thiophene, and phenol monomers, in this electropolymerization. The pre-polymerization complexes quantum-mechanical and molecular dynamics analysis allowed selecting the most appropriate monomer from the three thiophene-appended carbazoles examined. The electrode was then used as a selective CIL chemosensor in the linear dynamic concentration range of 50 to 924 nM with a high apparent imprinting factor, IF = 10.6. The MIP-CIL responded similarly to CIL and CIL's pharmacologically active primary metabolite, 3,4-dehydrocilostazol (dhCIL), thus proving suitable for their determination together. Simulated models of the MIP cavities binding of the CIL, dhCIL, and interferences' molecules allowed predicting chemosensor selectivity. The MIP film sorption of CIL and dhCIL was examined using DPV by peak current data fitting with the Langmuir (L), Freundlich (F), and Langmuir-Freundlich (LF) isotherms. The LF isotherm best described this sorption with the sorption equilibrium constant (K_LF) for CIL and dhCIL of 12.75 × 10^-6 and 0.23 × 10^-6 M, respectively. Moreover, the chemosensor cross-reactivity to common interferences study resulted in the selectivity to cholesterol and dehydroaripiprazole of 1.52 and 8.0, respectively. The chemosensor proved helpful in determining CIL and dhCIL in spiked human plasma with appreciable recovery (99.3-134.1%) and limit of detection (15 nM).

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.

Network Meta-Analysis Comparing the Outcomes of Treatments for Intermittent Claudication Tested in Randomized Controlled Trials

Background No network meta-analysis has considered the relative efficacy of cilostazol, home exercise therapy, supervised exercise therapy (SET), endovascular revascularization (ER), and ER plus SET (ER+SET) in improving maximum walking distance (MWD) over short- (<1 year), moderate- (1 to <2 years), and long-term (≥2 years) follow-up in people with intermittent claudication. Methods and Results A systematic literature search was performed to identify randomized controlled trials testing 1 or more of these 5 treatments according to Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. The primary outcome was improvement in MWD assessed by a standardized treadmill test. Secondary outcomes were adverse events and health-related quality of life. Network meta-analysis was performed using the gemtc R statistical package. The Cochrane collaborative tool was used to assess risk of bias. Forty-six trials involving 4256 patients were included. At short-term follow-up, home exercise therapy (mean difference [MD], 89.4 m; 95% credible interval [CrI], 20.9-157.7), SET (MD, 186.8 m; 95% CrI, 136.4-237.6), and ER+SET (MD, 326.3 m; 95% CrI, 222.6-430.6), but not ER (MD, 82.5 m; 95% CrI, -2.4 to 168.2) and cilostazol (MD, 71.1 m; 95% CrI, -24.6 to 167.9), significantly improved MWD (in meters) compared with controls. At moderate-term follow-up, SET (MD, 201.1; 95% CrI, 89.8-318.3) and ER+SET (MD, 368.5; 95% CrI, 195.3-546.9), but not home exercise therapy (MD, 99.4; 95% CrI, -174.0 to 374.9) or ER (MD, 84.2; 95% CrI, -35.3 to 206.4), significantly improved MWD (in meters) compared to controls. At long-term follow-up, none of the tested treatments significantly improved MWD compared to controls. Adverse events and quality of life were reported inconsistently and could not be meta-analyzed. Risk of bias was low, moderate, and high in 4, 24, and 18 trials respectively. Conclusions This network meta-analysis suggested that SET and ER+SET are effective at improving MWD over the moderate term (<2 year) but not beyond this. Durable treatments for intermittent claudication are needed.

Cilostazol for secondary stroke prevention: systematic review and meta-analysis

Background

Stroke is one of the leading causes of death worldwide. Cilostazol, an antiplatelet and phosphodiesterase 3 inhibitor, has not been clearly established for ischaemic stroke use. We aim to determine the efficacy and safety of cilostazol for secondary stroke prevention.

Methods

MEDLINE, EMBASE, Cochrane Library, Web of Science and ClinicalTrials.gov were searched from inception to 25 September 2020, for randomised trials comparing the efficacy and safety of cilostazol monotherapy or dual therapy with another antiplatelet regimen or placebo, in patients with ischaemic stroke. Version 2 of the Cochrane risk-of-bias tool for randomised trials (RoB 2) was used to assess study quality. This meta-analysis was reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

Eighteen randomised trials comprising 11 429 participants were included in this meta-analysis. Most trials possessed low risk of bias and were of low heterogeneity. Cilostazol significantly reduced the rate of ischaemic stroke recurrence (risk ratio, RR=0.69, 95% CI 0.58 to 0.81), any stroke recurrence (RR=0.64, 95% CI 0.54 to 0.74) and major adverse cardiovascular events (RR=0.67, 95% CI 0.56 to 0.81). Cilostazol did not significantly decrease mortality (RR=0.90, 95% CI 0.64 to 1.25) or increase the rate of good functional outcome (Modified Rankin Scale score of 0–1; RR=1.07, 95% CI 0.95 to 1.19). Cilostazol demonstrated favourable safety profile, significantly reducing the risk of intracranial haemorrhage (RR=0.46, 95% CI 0.31 to 0.68) and major haemorrhagic events (RR=0.49, 95% CI 0.34 to 0.70).

Conclusions

Cilostazol demonstrated superior efficacy and safety profiles compared with traditional antiplatelet regimens such as aspirin and clopidogrel for secondary stroke prevention but does not appear to affect functional outcomes. Future randomised trials can be conducted outside East Asia, or compare cilostazol with a wider range of antiplatelet agents.

Therapeutic Effects of Medication Use on Intermittent Claudication: A Network Meta-analysis

OBJECTIVE

To systematically evaluate the therapeutic effects of commonly used drugs for the treatment of intermittent claudication in patients with peripheral arterial diseases.

METHODS

We systematically searched bibliographic databases for randomized clinical trials published between 2000 and 2020, through the China National Knowledge Infrastructure, WanFang Data, PubMed, MEDLINE, Embase, and Cochrane library. Included studies focused on therapeutic effects of beraprost, clopidogrel, aspirin, sarpogrelate and cilostazol on treating intermittent claudication. The outcome measures were maximum walking distance, pain-free walking distance, ankle-brachial index, and severe adverse events. The quality of included trials was evaluated by using the bias risk assessment tool recommended by the Cochrane, after extracting data from the literatures. Stata was used to conduct the network meta-analysis.

RESULTS

There were 27 randomized control trials included in the study, covering in total 9491 patients. The network meta-analysis results showed that for maximum walking distance, better therapeutic effect was noted in using beraprost, sarpogrelate, and cilostazol. Beraprost, beraprost combined with aspirin, and sarpogrelate were better in improving pain-free walking distance than other drugs. For the ankle-brachial index, cilostazol combined with clopidogrel, sarpogrelate, and beraprost had better therapeutic effects than others. The use of sarpogrelate, beraprost, and aspirin was associated with a lower ratio of severe adverse events than the use of cilostazol and placebo.

CONCLUSIONS

Among the commonly used drugs for the treatment of intermittent claudication, beraprost and sarpogrelate may have better efficacy in improving the walking distance and ankle-brachial index, with a beneficial effect on cardiovascular and cerebrovascular comorbidities.

Effects of Postoperative Percutaneous Coronary Intervention, Pharmacologic Treatment, and Predisposing Factors on Clinical Outcomes in Patients With and Without Type 2 Diabetes Along With Critical Limb Ischemia

PURPOSE

Critical limb ischemia (CLI) has been identified as being connected to rates of cardiovascular mortality and lower extremity amputation (LEA). This prospective study investigated the effects of percutaneous coronary intervention (PCI), pharmacologic treatment, and predisposing factors on clinical outcomes in patients with and without type 2 diabetes mellitus (DM) along with CLI after endovascular intervention.

METHODS

249 consecutive patients with CLI (Fontaine stages III-IV) received pharmacologic treatment after successful endovascular intervention. Their primary patency rates of infrapopliteal lesions and cardiovascular and amputation events during a 36-month follow-up period were assessed.

FINDINGS

Patients with DM were more likely to be younger (P = 0.026); 50% (n = 63), 42.9% (n = 54), 52.4% (n = 66), and 77% (n = 97) of DM patients had arterial calcification, end-stage renal disease, diabetic neuropathy, and Fontaine stage IV (P < 0.001, P < 0.001, P < 0.001, and P = 0.019, respectively). The primary patency rates were 61%, 48.8%, and 42.3% at 12, 24, and 36 months, in the patients without DM (P = 0.034, P = 0.013, and P = 0.005). Patients with DM had higher risks of 36-month coronary artery disease, cerebrovascular accident, mortality, and LEA (P = 0.005, P = 0.042, P = 0.042, and P < 0.001). Patients with CLI receiving long-term cilostazol treatment had a better primary patency and amputation-free survival, and a lower risk of mortality at 36 months (P < 0.001, P < 0.001, and P = 0.001). Statin use was associated with 36-month amputation-free survival but not with primary patency (P = 0.032 and P = 0.088). Subgroup multivariate Cox analyses showed that primary patency was independently associated with long-term cilostazol treatment, PCI in the first postoperative year, and direct revascularization in the DM group, whereas in the control group, long-term cilostazol treatment was the main independent factor. The risk of amputation was independently associated with a high high-sensitivity chronic reactive protein level, diabetic neuropathy, sole use of an oral hypoglycemic agent, and lack of supervised exercise.

IMPLICATIONS

Long-term cilostazol treatment, aggressive management of dyslipidemia, and meticulous assessment and prevention of postoperative unstable coronary artery disease should be considered in CLI patients with and without DM to maximize clinical outcomes. PCI in the first postoperative year may be a predisposing factor for patency failure in patients with CLI, especially those with DM. A large-scale prospective randomized trial should be conducted to confirm these findings (TVGH IRB No. 2013-08-020B).

Health-related quality of life amongst people diagnosed with abdominal aortic aneurysm and peripheral artery disease and the effect of fenofibrate

The aims of this study were, firstly, to assess the effect of concurrent peripheral artery disease (PAD) on the health-related quality of life (QOL) of people diagnosed with a small abdominal aortic aneurysm (AAA); and secondly, to test whether the peroxisome proliferator-activated receptor α agonist fenofibrate improved QOL of people diagnosed with a small AAA, including those diagnosed with concurrent PAD. The study included both a cross-sectional observational study and a randomized placebo-controlled clinical trial. 140 people diagnosed with a 35-49 mm diameter AAA, 56 (40%) of whom had concurrent PAD, and 25 healthy controls were prospectively recruited. QOL was assessed with the short form (SF) 36. Findings in participants that were diagnosed with both AAA and PAD were compared separately with those of participants that had a diagnosis of AAA alone or who had neither AAA nor PAD diagnosed (healthy controls). All participants diagnosed with an AAA were then randomly allocated to 145 mg of fenofibrate per day or identical placebo. Outcomes were assessed by changes in the domains of the SF-36 and ankle brachial pressure Index (ABPI) from randomization to 24 weeks. Data were analyzed using Mann-Whitney U tests. Participants diagnosed with both AAA and PAD had significantly worse QOL than participants diagnosed with AAA alone or healthy controls. Fenofibrate did not significantly alter SF-36 scores or ABPI over 24 weeks. Fenofibrate does not improve QOL of people diagnosed with small AAA, irrespective of whether they have concurrent PAD.Trial registration: ACTN12613001039774 Australian New Zealand Clinical Trials Registry.

Comparison of efficacy between trimetazidine and cilostazol in the treatment of arteriosclerosis obliterans in lower extremity

This study compared the efficacy and long-term survival rate of trimetazidine and cilostazol in the treatment of lower extremity arteriosclerosis obliterans (ASO). A retrospectively analysis on the medical records of 206 patients with ASO who were admitted to The Central Hospital of Wuhan from January 2011 to May 2013 was performed, including 94 patients treated with trimetazidine (group A) and 112 patients treated with cilostazol (group B). On the basis of the same basic treatment, both groups were applied with these two drugs after two courses of treatments. Then the efficacy of clinical treatment, dorsal artery blood flow, anterior femoral artery, posterior tibial artery blood flow, brachial artery index, toe-brachial index, painless walking distance, maximum walking distance, adverse reactions, 5-year survival rates were compared. The total effective rate of clinical efficacy in group B was higher than group A (P<0.05). After the first course of treatment, the above indicators increased in both groups (P<0.05). After the end of the second course of treatment, the above-mentioned index values in both groups were significantly increased (P<0.05). The improvement of the above indicators in group B were better than the trimetazidine group in both the first and second treatment courses (P<0.05). In group A, there were 15 cases of patients with lethargy and hypodynamia and 9 cases of dizziness and headache. There were significant differences between the 7th and 3rd cases of patients when compared to group B (P<0.05). The 5-year survival rate of group A was lower than group B (P<0.05). The clinical efficacy of cliostazol in the treatment of ASO had a good effect, and there was only a few adverse reactions and the long-term survival rate was high. It is worthy of being promoted in clinical practice.

Tolerability, safety and intermediary pharmacological effects of cilostazol and isosorbide mononitrate, alone and combined, in patients with lacunar ischaemic stroke: The LACunar Intervention-1 (LACI-1) trial, a randomised clinical trial

BACKGROUND

Lacunar stroke, a frequent clinical manifestation of small vessel disease (SVD), differs pathologically from other ischaemic stroke subtypes and has no specific long-term secondary prevention. Licenced drugs, isosorbide mononitrate (ISMN) and cilostazol, have relevant actions to prevent SVD progression.

METHODS

We recruited independent patients with clinically confirmed lacunar ischaemic stroke without cognitive impairment to a prospective randomised clinical trial, LACunar Intervention-1 (LACI-1). We randomised patients using a central web-based system, 1:1:1:1 with minimisation, to masked ISMN 25 mg bd, cilostazol 100 mg bd, both ISMN and cilostazol started immediately, or both with start delayed. We escalated doses to target over two weeks, sustained for eight weeks. Primary outcome was the proportion achieving target dose. Secondary outcomes included symptoms, safety (haemorrhage, recurrent vascular events), cognition, haematology, vascular function, and neuroimaging. LACI-1 was powered (80%, alpha 0.05) to detect 35% (90% versus 55%) difference between the proportion reaching target dose on one versus both drugs at 55 patients. Registration ISRCTN12580546.

FINDINGS

LACI-1 enrolled 57 participants between March 2016 and August 2017: 18 (32%) females, mean age 66 (SD 11, range 40-85) years, onset-randomisation 203 (range 6-920) days. Most achieved full (64%) or over half (87%) dose, with no difference between cilostazol vs ISMN, single vs dual drugs. Headache and palpitations increased initially then declined similarly with dual versus single drugs. There was no between-group difference in BP, pulse-wave velocity, haemoglobin or platelet function, but pulse rate was higher (mean difference, MD, 6.4, 95%CI 1.2-11.7, p = 0.02), platelet count higher (MD 35.7, 95%CI 2.8, 68.7, p = 0.03) and white matter hyperintensities reduced more (Chi-square p = 0.007) with cilostazol versus no cilostazol.

INTERPRETATION

Cilostazol and ISMN are well tolerated when the dose is escalated, without safety concerns, in patients with lacunar stroke. Larger trials with longer term follow-up are justified.

FUNDING

Alzheimer's Society (AS-PG-14-033).

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.

Population pharmacodynamics of cilostazol in healthy Korean subjects

Cilostazol is used for the treatment of intermittent claudication, ulceration and pain. This study was conducted to develop a population pharmacodynamic (PD) model for cilostazol's closure time (CT) prolongation effect in healthy Korean subjects based on a pharmacokinetic (PK) model previously developed. PD data were obtained from 29 healthy subjects who participated in a study conducted in 2009 at Severance Hospital. The PK model used was a two-compartment model with first order absorption. CT data were best described by a turnover model with a fractional turnover rate constant (K_out) inhibited by drug effects (Eff), which were represented by a sigmoid E_max model [Eff = E_max · C^γ / (EC₅₀^γ+Cγ)] with E_max being maximum drug effect, EC₅₀ drug plasma concentration at 50% of E_max, C drug plasma concentrations, and γ the Hill coefficient. For the selected PD model, parameter estimates were 0.613 hr⁻¹ for K_out, 0.192 for E_max, 730 ng/ml for EC₅₀ and 5.137 for γ. Sex and caffeine drinking status significantly influenced the baseline CT, which was 85.36 seconds in male non-caffeine drinkers and increased by 15.5% and 16.4% in females and caffeine drinkers, respectively. The model adequately described the time course of CT. This was the first population PD study for cilostazol's CT prolongation effect in a Korean population.

Effect of cilostazol on plasma levels of proprotein convertase subtilisin/kexin type 9

The protein complex proprotein convertase subtilisin/kexin type 9 (PCSK9) serves as an important target for the prevention and treatment of atherosclerosis and lipid homeostasis. This study investigated the effect of cilostazol on plasma PCSK9 concentrations. We performed a post hoc analysis of two prospective, double-blind, randomized controlled trials including 115 patients of whom 61 received cilostazol 200 mg/day and 54 received placebo for 12 weeks. Linear regression analysis was performed to determine the associations between several parameters and changes in PCSK9 levels. Use of cilostazol, but not placebo, significantly increased plasma PCSK9 concentrations, high-density lipoprotein cholesterol levels, and number of circulating endothelial progenitor cells (EPCs), and decreased triglyceride levels with a trend toward an increase in total cholesterol (TC) levels. A reduction in hemoglobin A1C and an increase in plasma vascular endothelial growth factor and adiponectin levels with cilostazol treatment were also found. Changes in the number of circulating EPCs were positively correlated and the TC concentrations were inversely correlated with changes in the PCSK9 levels. After adjusting for changes in levels of TC and numbers of circulating EPCs and history of metabolic syndrome, use of cilostazol remained independently associated with changes in plasma PCSK9 levels. In conclusion, cilostazol treatment was significantly and independently associated with an increase in plasma PCSK9 levels in patients with peripheral artery disease or at a high risk of cardiovascular disease regardless of background statin use and caused an improvement in some metabolic disorders and levels of vasculo-angiogenic biomarkers.

Long-term cilostazol administration prevents age-related decline of hippocampus-dependent memory in mice

Phosphodiesterases (PDEs) are enzymes that hydrolyze and inactivate 3', 5'-cyclic adenosine monophosphate (cAMP) and/or 3', 5'-cyclic guanosine monophosphate (cGMP). The regulation of intracellular signaling pathways mediated by cyclic nucleotides is imperative to synaptic plasticity and memory in animals. Because PDEs play an important role in this regulation, PDE inhibitors are considered as candidate compounds for treating cognitive and memory disorders. In the present study, we tested whether cilostazol, a selective PDE3 inhibitor, prevents the cognitive deterioration that occurs during the course of normal aging in mice. Ten months of cilostazol administration (1.5%) in 13-month-old mice improved spatial memory when tested at 23 months of age. First, it prevented the decline in the ability of these aged mice to recognize a change in an object's location in the object recognition task. Second, spatial memory of these cilostazol-treated aged mice in the Morris water maze was comparable to that of untreated middle-aged mice (13 months old). Cilostazol administration had no effect on the emotional states and physical ability of aged mice. Thus, long-term cilostazol administration prevented hippocampus-dependent memory decline in aged mice, allowing them to achieve a level of cognitive performance similar to middle-aged mice and without negative behavioral side effects. Considering its well-established safety in other medical contexts, cilostazol may be a potential therapeutic candidate drug for staving off cognitive decline in the aging human population.

Long-term cilostazol administration ameliorates memory decline in senescence-accelerated mouse prone 8 (SAMP8) through a dual effect on cAMP and blood-brain barrier

Phosphodiesterases (PDEs), which hydrolyze and inactivate 3', 5'-cyclic adenosine monophosphate (cAMP) and 3', 5'-cyclic guanosine monophosphate (cGMP), play an important role in synaptic plasticity that underlies memory. Recently, several PDE inhibitors were assessed for their possible therapeutic efficacy in treating cognitive disorders. Here, we examined how cilostazol, a selective PDE3 inhibitor, affects brain functions in senescence-accelerated mouse prone 8 (SAMP8), an animal model of age-related cognitive impairment. Long-term administration of cilostazol restored the impaired context-dependent conditioned fear memory of SAMP8 to match that in normal aging control substrain SAMR1. Cilostazol also increased the number of cells containing phosphorylated cAMP-responsive element binding protein (CREB), a downstream component of the cAMP pathway. Finally, cilostazol improves blood-brain barrier (BBB) integrity, demonstrated by reduced extravasation of 2-deoxy-2-¹⁸F-fluoro-d-glucose and Evans Blue dye in the brains of SAMP8. This improvement in BBB integrity was associated with an increased amount of zona occludens protein 1 (ZO-1) and occludin proteins, components of tight junctions integral to the BBB. The results suggest that long-term administration of cilostazol exerts its beneficial effects on age-related cognitive impairment through a dual mechanism: by enhancing the cAMP system in the brain and by maintaining or improving BBB integrity.

New developments in the pharmacological treatment of hypertension: dead-end or a glimmer at the horizon?

Arterial hypertension is the most prevalent controllable disease world-wide. Yet, we still need to further improve blood pressure control, deal with resistant hypertension, and we hope to reduce risk "beyond blood pressure." The number of candidate molecules aspiring for these aims is constantly declining. The new possible approaches to combat high blood pressure include neprilysin/neutral endopeptidase (NEP) inhibition, particularly when combined with an angiotensin receptor blockade (such as the ARNI, LCZ696), phosphodiesterase 5 (PDE5) inhibition (KD027/Slx-2101), natriuretic agents (PL3994), or a long-lasting vasointestinal peptide (VIP) analogue (PB1046). Other options exploit the protective arm of the renin-angiotensin-aldosterone system by stimulating the angiotensin AT2 receptor (compound 21), the Mas receptor (AVE-0991), or the angiotensin converting enzyme 2. Finally, we review the possibilities how to optimize the use of the available treatment options by using drug combinations or by tailoring therapy to each patient's angiotensin peptide profile.

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, characterised by pain in the legs or buttocks that occurs with exercise and which subsides with rest. Compared with age-matched controls, people with intermittent claudication have a three- to six-fold increase in cardiovascular mortality. Symptoms of intermittent claudication, walking distance, and quality of life can be improved by risk factor modification, smoking cessation, and a structured exercise programme. Antiplatelet treatment is beneficial in patients with intermittent claudication for the reduction of vascular events but has not previously been shown to influence claudication distance. This is an update of a review first published in 2007.

OBJECTIVES

To determine the effect of cilostazol (an antiplatelet treatment) on improving initial and absolute claudication distances, and in reducing mortality and vascular events in patients with stable intermittent claudication.

SEARCH METHODS

For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched October 2013) and CENTRAL (2013, Issue 9).

SELECTION CRITERIA

Double-blind, randomised controlled trials (RCTs) of cilostazol versus placebo, or versus other antiplatelet agents 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 performed the meta-analysis as a fixed-effect model with weighted mean differences (WMDs) and 95% confidence intervals (CIs) for continuous data, and odds ratios (ORs) with 95% CIs for dichotomous data.

MAIN RESULTS

We included fifteen double-blind, RCTs comparing cilostazol with placebo, or medications currently known to increase walking distance e.g. pentoxifylline. There were a total of 3718 randomised participants with treatment durations ranging from six to 26 weeks. All participants had intermittent claudication secondary to PAD. Comparisons included cilostazol twice daily, with dosages of 50 mg, 100 mg and 150 mg compared with placebo, and cilostazol 100 mg, twice daily, compared with pentoxifylline 400 mg, three times daily. The methodological quality of the trials was generally low, with the majority being at an unclear risk for selection bias, performance bias, detection bias and other bias. Attrition bias was generally low, but reporting bias was high or unclear in the majority of the studies. For eight studies data were compatible for comparison by meta-analysis, but data for seven studies were too heterogenous to be pooled. For the studies included in the meta-analysis, for initial claudication distance (ICD - the distance walked on a treadmill before the onset of calf pain) there was an improvement in the cilostazol group for the 100 mg and 50 mg twice daily, compared with placebo (WMD 31.41 metres, 95% CI 22.38 to 40.45 metres; P < 0.00001) and WMD 19.89 metres, 95% CI 9.44 to 30.34 metres; P = 0.0002), respectively. ICD was improved in the cilostazol group for the comparison of cilostazol 150 mg versus placebo and cilostazol 100 mg versus pentoxifylline, but only single studies were used for these analyses. Absolute claudication distance (ACD - the maximum distance walked on a treadmill) was significantly increased in participants taking cilostazol 100 mg and 50 mg twice daily, compared with placebo (WMD 43.12 metres, 95% CI 18.28 to 67.96 metres; P = 0.0007) and WMD 32.00 metres, 95% CI 14.17 to 49.83 metres; P = 0.0004), respectively. As with ICD, ACD was increased in participants taking cilostazol 150 mg versus placebo, but with only one study an association cannot be clearly determined. Two studies comparing cilostazol to pentoxifylline had opposing findings, resulting in an imprecise CI (WMD 13.42 metres (95% CI -43.51 to 70.35 metres; P = 0.64). Ankle brachial index (ABI) was lowered in the cilostazol 100 mg group compared with placebo (WMD 0.06, 95% CI 0.04 to 0.08; P < 0.00001). The single study evaluating ABI for the comparison of cilostazol versus pentoxifylline found no change in ABI.There was no association between treatment type and all-cause mortality for any of the treatment comparisons, but there were very few events, and therefore larger, adequately powered studies will be needed to assess if there is a relationship. Only one study evaluated individual cardiovascular events, and from this study there is no clear evidence of a difference between any of the treatment groups and risk of myocardial infarction or stroke. We evaluated adverse side effects, and in general cilostazol was associated with a higher odds of headache, diarrhoea, abnormal stool, dizziness and palpitations. We only reported quality of life measures descriptively as there was insufficient statistical detail within the studies to combine the results, although there was a possible indication in improvement of quality of life in the cilostazol treatment groups.

AUTHORS' CONCLUSIONS

Cilostazol has been shown to be of benefit in improving walking distance in people with intermittent claudication secondary to PAD. Although there is an increase in adverse side effects, they are generally mild and treatable. There is currently insufficient data on whether taking cilostazol results in a reduction of all-cause mortality and cardiovascular events or an improvement in quality of life. Future research into the effect of cilostazol on intermittent claudication should carefully consider comparability, sample size and homogeneity when designing a study.

Cilostazol improves hippocampus-dependent long-term memory in mice

RATIONALE

Phosphodiesterases (PDEs) play an important role in the regulation of intracellular signaling mediated by cyclic adenosine monophosphate (cAMP). Recently, several PDE inhibitors were assessed for their possible cognitive enhancing properties. However, little is known about the effect of PDE3 inhibitors on memory function.

OBJECTIVES

We examined how the PDE3 inhibitor cilostazol affects C57BL/6 J mice as they perform various behavioral tasks. After behavioral assessment, brains of the mice were analyzed immunohistochemically to quantify the phosphorylation of cAMP-responsive element binding protein (CREB), a downstream component of the cAMP pathway.

RESULTS

Oral administration of cilostazol significantly enhanced recollection of the exact platform location in the Morris water maze probe test. Cilostazol also improved context-dependent long-term fear memory, without affecting short-term memory. No apparent effect was observed in cue-dependent fear memory. The results suggest that cilostazol selectively improves hippocampus-dependent long-term memory in these tasks. Cilostazol also significantly increased the number of phosphorylated-CREB-positive cells in hippocampal dentate gyrus.

CONCLUSIONS

These results suggest that cilostazol may exert its beneficial effects on learning and memory by enhancing the cAMP system in hippocampus, where it increases intracellular cAMP activity.

Cilostazol and outcome in outpatients with peripheral artery disease

BACKGROUND

Cilostazol increases the walking distance in patients with intermittent claudication, but there is scarce evidence of any effect on the risk for subsequent ischemic events, bleeding or death.

PATIENTS AND METHODS

We used data from the FRENA Registry to compare the clinical outcome in stable outpatients with intermittent claudication, according to the use of cilostazol.

RESULTS

As of January 2013, 1,317 patients with intermittent claudication were recruited in FRENA, of whom 191 (14.5%) received cilostazol. Over a mean follow-up of 18months, 39 patients developed myocardial infarction, 23 ischemic stroke, 20 underwent limb amputation, 15 had major bleeding and 70 died. There were no significant differences in the rate of subsequent ischemic events, major bleeding or death between patients receiving or not receiving cilostazol. On multivariate analysis, the use of cilostazol had no influence on the risk for subsequent myocardial infarction (hazard ratio [HR]: 0.97; 95% CI: 0.33-20.8), ischemic stroke (HR: 1.46; 95% CI: 0.48-4.43), limb amputation (HR: 0.34; 95% CI: 0.04-20.6), major bleeding (HR: 1.52; 95% CI: 0.33-7.09) or death (HR: 0.90; 95% CI: 0.40-20.0).

CONCLUSIONS

In stable outpatients with intermittent claudication, the use of cilostazol was not associated with increased rates of subsequent ischemic events, major bleeding or death.

Effect of Cilostazol Prescribed in a Pragmatic Treatment Program for Intermittent Claudication

Background:

Controlled trials of cilostazol for claudication demonstrate improvements in walking distance and quality of life. Without the structure of a study environment, it is not certain that cilostazol has similar efficacy.

Method:

Retrospective review of patients prescribed cilostazol for claudication was undertaken. Patients were advised to stop smoking and increase exercise but no formal programs were instituted. The primary outcome measure was patient-reported improvement in claudication symptoms. Secondary outcomes were smoking cessation and participation in regular exercise.

Results:

Over a 2-year period, 77 patients were prescribed cilostazol as initial treatment for claudication. Follow-up for 3 months was available for 69 (90%) patients. Noncompliance was reported in 20% of patients. Of the overall group, 58% (73% of compliant patients) of patients reported improvement in claudication symptoms, 4% of patients reported smoking cessation, and 7% reported regular exercise.

Conclusion:

Despite minimal behavior modification, up to 70% of patients taking cilostazol report an improvement in claudication symptoms with few side effects.

The hypolipidemic effect of cilostazol can be mediated by regulation of hepatic low-density lipoprotein receptor-related protein 1 (LRP1) expression

OBJECTIVES

Cilostazol, a selective phosphodiesterase 3 (PDE3) inhibitor, is a vasodilator and an anti-thrombotic agent. The mechanism whereby cilostazol reduces plasma triglyceride is not completely understood. Here we investigated the effect of cilostazol on a remnant lipoprotein receptor, low-density lipoprotein receptor-related protein 1 (LRP1), which has been reported to play an essential role in clearance of circulating triglyceride in the liver.

MATERIALS/METHODS

Total cellular expression, and functional and transcriptional regulation of LRP1 were analyzed in human hepatocarcinoma cell lines incubated with cilostazol. Also, C57BL/6 mice were subjected to high-fat diet (60% kcal) and cilostazol (30 mg/kg) treatment for 10 weeks.

RESULTS

Cilostazol increased both mRNA and protein expression of LRP1 in HepG2 and Hep3B cells. In addition, enhanced transcriptional activity of the LRP1 promoter containing a peroxisome proliferator response element (PPRE) was observed after cilostazol exposure. Cilostazol treatment enhanced the uptake of lipidated apoE3, and this effect was abolished when LRP1 was silenced by siRNA knockdown. High-fat diet induced hyperglycemia with high level of plasma triglycerides, and reduced hepatic LRP1 expression in mice. Treatment with cilostazol for the same period of time, however, successfully prevented this down-regulation of LRP1 expression and reduced plasma triglycerides.

CONCLUSION

Taken together, our results demonstrated that cilostazol enhances LRP1 expression in liver by activating PPARγ through the PPRE in the LRP1 promoter. Increased hepatic LRP1 may be essential for the reduction of circulating triglycerides brought about by cilostazol.

Cilostazol Reduces Angiographic Restenosis After Endovascular Therapy for Femoropopliteal Lesions in the Sufficient Treatment of Peripheral Intervention by Cilostazol Study

Background—

It remains unclear whether cilostazol, which has been shown to improve the clinical outcomes of endovascular therapy for femoropopliteal lesions, also reduces angiographic restenosis.

Methods and Results—

The Sufficient Treatment of Peripheral Intervention by Cilostazol (STOP-IC) study investigated whether cilostazol reduces the 12-month angiographic restenosis rate after percutaneous transluminal angioplasty with provisional nitinol stenting for femoropopliteal lesions. Two hundred patients with femoropopliteal lesions treated from March 2009 to April 2011 at 13 cardiovascular centers were randomly assigned 1:1 to receive oral aspirin with or without cilostazol. The primary end point was 12-month angiographic restenosis rate. Secondary end points were the restenosis rate on duplex ultrasound, the rate of major adverse cardiac events, and target lesion event-free survival. Researchers evaluated all follow-up data and assessed the end points in a blinded fashion. The mean lesion length and reference vessel diameter at the treated segment were 128±86 mm and 5.4±1.4 mm, respectively. The frequency of stent used was similar between groups (88% versus 90% in the cilostazol and noncilostazol group, respectively, P =0.82). During the 12-month follow-up period, 11 patients died and 152 patients (80%) had evaluable angiographic data at 12 months. The angiographic restenosis rate at 12 months was 20% (15/75) in the cilostazol group versus 49% (38/77) in the noncilostazol group ( P =0.0001) by intention-to-treat analysis. The cilostazol group also had a significantly higher event-free survival at 12 months (83% versus 71%, P =0.02), although cardiovascular event rates were similar in both groups.

Conclusions—

Cilostazol reduced angiographic restenosis after percutaneous transluminal angioplasty with provisional nitinol stenting for femoropopliteal lesions.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00912756; and URL: https://www.umin.ac.jp . Unique identifier: UMIN000002091.

Cost-Effectiveness of Cilostazol, Naftidrofuryl Oxalate, and Pentoxifylline for the Treatment of Intermittent Claudication in People With Peripheral Arterial Disease

We assessed the cost-effectiveness of cilostazol, naftidrofuryl oxalate, and pentoxifylline for intermittent claudication due to peripheral arterial disease (PAD) in adults whose symptoms continue despite a period of conventional management. A Markov decision model was developed to assess the lifetime costs and benefits of each vasoactive drug compared to no vasoactive drug and with each other. Regression analysis was undertaken to model the relationship between maximum walking distance and utility. Resource use data were sourced from the literature and sensitivity analyses were undertaken. Naftidrofuryl oxalate is more effective and less costly than cilostazol and pentoxifylline and has an estimated cost per quality-adjusted life year gained of around £6070 compared to no vasoactive drug. The analysis uses effectiveness evidence from a network meta-analysis. In contrast to previous guidelines recommending cilostazol, the analysis suggests that naftidrofuryl oxalate is the only vasoactive drug for PAD which is likely to be cost-effective.

Systematic review of the efficacy of cilostazol, naftidrofuryl oxalate and pentoxifylline for the treatment of intermittent claudication

BACKGROUND

A systematic review and network meta-analysis was undertaken to consider the evidence for the efficacy and tolerability of placebo, cilostazol, naftidrofuryl oxalate and pentoxifylline in patients with intermittent claudication due to peripheral arterial disease (PAD).

METHODS

MEDLINE, Embase, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Conference Proceedings, BIOSIS, National Research Register and MetaRegister databases were searched. Eligible studies were randomized controlled trials (RCTs) and published systematic reviews of patients with intermittent claudication due to PAD and whose symptoms persisted despite a period of conservative management. Study selection was conducted by one reviewer with involvement from a clinician. Data were extracted by one reviewer with no blinding to authors or journal, and checked by a second reviewer. Outcome measures were maximum walking distance (MWD) and pain-free walking distance (PFWD).

RESULTS

The review identified 1876 citations; 26 RCTs met the inclusion criteria for the systematic review. Eleven trials provided data relevant for the meta-analysis. Naftidrofuryl oxalate was ranked first for both MWD and PFWD (probability of 0·947 and 0·987, respectively, of being the best treatment) followed by cilostazol and pentoxifylline. For naftidrofuryl oxalate, cilostazol and pentoxifylline, MWD increased by 60 (95 per cent credible interval 20 to 114) per cent, 25 (11 to 40) per cent and 11 (-1 to 24) per cent respectively relative to placebo, and PFWD increased by 49, 13 and 9 per cent.

CONCLUSION

Naftidrofuryl oxalate and cilostazol are both effective treatments for claudication; naftidrofuryl oxalate is likely to be the most effective, with minimal serious adverse events.

Rating systems for evaluation of functional ankle instability: prospective evaluation in a cohort of patients treated with monopolar capacitive-coupled radiofrequency

Evaluation of patient outcomes should include the use of validated scoring systems to determine disease-specific outcomes. Many scoring systems are being used for disorders of the ankle joint. However, not all instruments are capable of detecting changes associated with functional ankle instability (FAI), since their focus is toward pathological entities with greater impact on individual's physical and mental well-being.

METHODS

In this prospective study, 6 instruments were used to evaluate outcomes associated with an intervention aimed at improving FAI. Twenty ankles that had been unsuccessfully treated for FAI were treated with a single session of noninvasive monopolar capacitive-coupled radiofrequency (mcRF) and followed prospectively.

RESULTS

Five out of 6 instruments failed to show changes that could be correlated with patients' outcomes. Only one instrument, the Cumberland Ankle Instability Tool (CAIT) demonstrated enough sensitivity and correlated well with meaningful clinical differences. Based on study's success criteria (proper function, no pain, no adverse events, and patient satisfaction), 78% of the ankles treated had successful outcomes whereas 87.5% evidenced significant improvement based on CAIT (P < .001). No adverse events were present during the study.

CONCLUSIONS

The study of FAI is hampered by the lack of disease-specific questionnaires, which oftentimes introduce ceiling or flooring effects. The CAIT was capable of detecting changes in patients' condition and response to the noninvasive mcRF procedure without evidencing ceiling or flooring effects. In this study, the CAIT was found to be reliable, valid, sensitive to changes of clinical importance, in addition to being short and practical to use.

Antithrombotic therapy in peripheral artery disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline focuses on antithrombotic drug therapies for primary and secondary prevention of cardiovascular disease as well as for the relief of lower-extremity symptoms and critical ischemia in persons with peripheral arterial disease (PAD).

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

The most important of our 20 recommendations are as follows. In patients aged ≥ 50 years with asymptomatic PAD or asymptomatic carotid stenosis, we suggest aspirin (75-100 mg/d) over no therapy (Grade 2B) for the primary prevention of cardiovascular events. For secondary prevention of cardiovascular disease in patients with symptomatic PAD (including patients before and after peripheral arterial bypass surgery or percutaneous transluminal angioplasty), we recommend long-term aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 1A). We recommend against the use of warfarin plus aspirin in patients with symptomatic PAD (Grade 1B). For patients undergoing peripheral artery percutaneous transluminal angioplasty with stenting, we suggest single rather than dual antiplatelet therapy (Grade 2C). For patients with refractory claudication despite exercise therapy and smoking cessation, we suggest addition of cilostazol (100 mg bid) to aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 2C). In patients with critical limb ischemia and rest pain unable to undergo revascularization, we suggest the use of prostanoids (Grade 2C). In patients with acute limb ischemia due to acute thrombosis or embolism, we recommend surgery over peripheral arterial thrombolysis (Grade 1B).

CONCLUSIONS

Recommendations continue to favor single antiplatelet therapy for primary and secondary prevention of cardiovascular events in most patients with asymptomatic PAD, symptomatic PAD, and asymptomatic carotid stenosis. Additional therapies for relief of limb symptoms should be considered only after exercise therapy, smoking cessation, and evaluation for peripheral artery revascularization.

[Peripheral arterial disease with lower limb claudication: Medical treatment]

Whereas the complaint from a patient with intermittent arterial claudication is walking impairment, prognosis is linked to an increased risk of cardiovascular ischemic events due to the diffuse nature of the atherosclerosis. The objectives of the medical treatment therefore include improvement of walking limit, prevention of myocardial infarction, stroke and cardiovascular death, and preventive measures to avoid progression to critical lower limb ischemia. The key areas of treatment focus on smoking cessation, exercise rehabilitation, with supervised therapy if possible, cardiovascular risk prevention with antiplatelet drugs, statins and angiotensin converting enzymes, and correction of atherosclerotic risk factors with well-defined targets (LDL less than 1g/L, HDL greater than 0.4g/L, HbA(1c) less than 6.5%, brachial blood pressure less than 140/90 or 130/80mmHg in case of diabetes or renal insufficiency, body mass index less than 25kg/m(2)). Limitation or avoidance of progression to local critical ischemia requires control of atherosclerotic risk factors and proper foot care. The patient with arterial claudication needs to understand the local and general risks of arterial atherosclerotic disease, and to be involved in his/her own treatment. Obtaining patient compliance to medical care is fundamental: specific educational workshops are of great value for this.