Clinical efficacy and safety of cilostazol: a critical review of the literature

The effect of cilostazol on late outcomes after endovascular treatment for occlusive femoropopliteal disease

OBJECTIVE

Restenosis and late occlusion remain a significant problem for endovascular treatment of peripheral artery disease. This meta-analysis aims to evaluate the effect of cilostazol on late outcomes after endovascular repair of occlusive femoropopliteal disease.

METHODS

A systematic literature review was conducted conforming to established criteria to identify articles published up to September 2023 evaluating late outcomes after endovascular treatment for atherosclerotic femoropopliteal disease. Eligible studies should compare outcomes between patients treated with cilostazol and patients not treated with cilostazol. Both prospective and retrospective studies were eligible. Late outcomes included primary patency (PP), restenosis, target lesion revascularization (TLR), and major amputation during follow-up.

RESULTS

Overall, 10 clinical studies were identified for analysis including 4721 patients (1831 with cilostazol vs 2890 without cilostazol) that were treated for 5703 lesions (2235 with cilostazol vs 3468 without cilostazol). All studies were performed in Japan. Mean follow-up was 24.1 ± 12.5 months. Cilostazol was associated with a lower risk for restenosis (pooled odds ratio [OR], 0.503; 95% confidence interval [CI], 0.383-0.660; P < .0001). However, no association was found between cilostazol and TLR (pooled OR, 0.918; 95% CI, 0.300-2.812; P = .881) as well as major amputation (pooled OR, 1.512; 95% CI, 0.734-3.116; P = .263). Regarding primary patency, cilostazol was associated with a higher 12-month PP (OR, 3.047; 95% CI, 1.168-7.946; P = .023), and a higher 36-month PP (OR, 1.616; 95% CI, 1.412-1.850; P < .0001). No association was found between cilostazol and mortality during follow-up (pooled OR, .755; 95% CI, 0.293-1.946; P = .561).

CONCLUSIONS

Cilostazol seems to have a positive effect on 1- to 3-year PP and restenosis rates among patients treated endovascularly for atherosclerotic femoropopliteal disease. A positive effect on TLR and amputation risk was not verified in this review.

A Practical Guide to Understanding and Treating Peripheral Artery Disease

ABSTRACT

Peripheral arterial disease (PAD) is the third leading cause of atherosclerotic morbidity after coronary heart disease and stroke yet is widely underdiagnosed and undertreated. Treatment of risk factors such as diabetes and cigarette smoking can benefit patients with PAD. Patients should have adequate blood pressure and lipid control to decrease clinical manifestations and symptoms of PAD. Use of antithrombotic medications should be individualized to the patient depending on the presence of symptoms, revascularization, and comorbidities. All patient care providers, including physicians, pharmacists, nurse practitioners, and physician assistants, should incorporate PAD screening in their at-risk patients to improve access for appropriate earlier diagnosis, initiation of guideline directed therapy, and risk factor modification to reduce both major adverse CV and limb outcomes. The purpose of this narrative review is to provide an overview of PAD and summarize clinical trial evidence and guideline recommendations for screening and treatment to increase awareness among health care providers to ultimately have a positive impact on patient care.

A Systematic Review and Meta-Analysis of Efficacy and Safety of Cilostazol Prescription in Patients With Femoropopliteal Peripheral Artery Disease After Endovascular Therapy

PURPOSE

The purpose of this study is to assess the efficacy and safety of cilostazol prescription in patients with femoropopliteal peripheral artery disease (PAD) after endovascular therapy (EVT).

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis of all studies reporting the outcomes of cilostazol after femoropopliteal EVT of PAD up to September 2022. Clinical outcomes of interest included primary patency, in-stent restenosis (ISR), vessel re-occlusion, freedom from target lesion revascularization (TLR), repeat revascularization, all-cause mortality, amputation, major adverse cardiovascular events (MACEs) and major adverse limb events (MALEs), and bleeding complication.

RESULTS

A total of 4 randomized controlled trials (RCTs) and 8 observational studies containing a total of 4898 patients met the inclusion criteria and were included in this systematic review and meta-analysis. We found that the use of cilostazol was associated with higher primary patency after femoropopliteal artery EVT (odds ratio [OR]=1.67, 95% confidence interval [CI]=1.50-1.87, p<0.001, I2=33.2%), a lower risk of ISR (OR=0.43, 95% CI=0.29-0.63, p<0.001, I2=37.6%), repeat revascularization (OR=0.43, 95% CI=0.24-0.76, p<0.005, I2=27.4%), and vessel re-occlusion (OR=0.59, 95% CI=0.38-0.93, p<0.05, I2=0%). There was an increase in freedom from TLR rate (OR=2.19, 95% CI=1.58-3.05, p<0.001, I2=0%), as well as a reduction in the occurrence of MALEs (OR=0.50, 95% CI=0.29-0.85, p<0.05, I2=0%). However, there was no significant difference in amputation, MACEs, all-cause mortality, and major bleeding complications. Subgroup analysis showed that cilostazol treatment in patients with femoropopliteal drug-eluting stents (DES) implantation remained associated with higher primary patency and a lower risk of ISR.

CONCLUSIONS

After EVT of femoropopliteal artery lesions, additional oral cilostazol enhances primary patency, reduces the occurrences of ISR and vessel re-occlusion, diminishes the risks associated with MALEs, lowers the need for repeat revascularization, and increases freedom from TLR rates. However, it does not impact amputation, MACEs, all-cause mortality, or major bleeding complications. These findings suggest cilostazol as a potentially safe and effective adjunct therapy in patients with femoropopliteal PAD after EVT.

CLINICAL IMPACT

After undergoing endovascular therapy (EVT) for femoropopliteal artery lesions, the addition of cilostazol to antiplatelet therapy can significantly improve primary patency, reducing the incidence of in-stent restenosis, repeat revascularization, vessel re-occlusion, and major adverse limb events while increasing freedom from target lesion revascularization rate. The simultaneous use of drug-eluting stents in the femoropopliteal artery lesions, combined with cilostazol, potentially results in a synergistic anti-stenotic effect. This therapeutic approach does not appear to be associated with an increased risk of major bleeding events or all-cause mortality. These findings provide additional evidence supporting the treatment of anti-stenosis in patients with femoropopliteal artery lesions after EVT.

European stroke organisation (ESO) guideline on cerebral small vessel disease, part 2, lacunar ischaemic stroke

A quarter of ischaemic strokes are lacunar subtype, typically neurologically mild, usually resulting from intrinsic cerebral small vessel pathology, with risk factor profiles and outcome rates differing from other stroke subtypes. This European Stroke Organisation (ESO) guideline provides evidence-based recommendations to assist with clinical decisions about management of lacunar ischaemic stroke to prevent adverse clinical outcomes. The guideline was developed according to ESO standard operating procedures and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. We addressed acute treatment (including progressive lacunar stroke) and secondary prevention in lacunar ischaemic stroke, and prioritised the interventions of thrombolysis, antiplatelet drugs, blood pressure lowering, lipid lowering, lifestyle, and other interventions and their potential effects on the clinical outcomes recurrent stroke, dependency, major adverse cardiovascular events, death, cognitive decline, mobility, gait, or mood disorders. We systematically reviewed the literature, assessed the evidence and where feasible formulated evidence-based recommendations, and expert concensus statements. We found little direct evidence, mostly of low quality. We recommend that patients with suspected acute lacunar ischaemic stroke receive intravenous alteplase, antiplatelet drugs and avoid blood pressure lowering according to current acute ischaemic stroke guidelines. For secondary prevention, we recommend single antiplatelet treatment long-term, blood pressure control, and lipid lowering according to current guidelines. We recommend smoking cessation, regular exercise, other healthy lifestyle modifications, and avoid obesity for general health benefits. We cannot make any recommendation concerning progressive stroke or other drugs. Large randomised controlled trials with clinically important endpoints, including cognitive endpoints, are a priority for lacunar ischaemic stroke.

The perspective of cAMP/cGMP signaling and cyclic nucleotide phosphodiesterases in aortic aneurysm and dissection

Aortic aneurysm (AA) and dissection (AD) are aortic diseases caused primarily by medial layer degeneration and perivascular inflammation. They are lethal when the rupture happens. Vascular smooth muscle cells (SMCs) play critical roles in the pathogenesis of medial degeneration, characterized by SMC loss and elastin fiber degradation. Many molecular pathways, including cyclic nucleotide signaling, have been reported in regulating vascular SMC functions, matrix remodeling, and vascular structure integrity. Intracellular cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) are second messengers that mediate intracellular signaling transduction through activating effectors, such as protein kinase A (PKA) and PKG, respectively. cAMP and cGMP are synthesized by adenylyl cyclase (AC) and guanylyl cyclase (GC), respectively, and degraded by cyclic nucleotide phosphodiesterases (PDEs). In this review, we will discuss the roles and mechanisms of cAMP/cGMP signaling and PDEs in AA/AD formation and progression and the potential of PDE inhibitors in AA/AD, whether they are beneficial or detrimental. We also performed database analysis and summarized the results showing PDEs with significant expression changes under AA/AD, which should provide rationales for future research on PDEs in AA/AD.

The Role of Cilostazol, a Phosphodiesterase-3 Inhibitor, in the Development of Atherosclerosis and Vascular Biology: A Review with Meta-Analysis

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading global cause of mortality. Addressing this vital and pervasive condition requires a multifaceted approach, in which antiplatelet intervention plays a pivotal role, together with antihypertensive, antidiabetic, and lipid-lowering therapies. Among the antiplatelet agents available currently, cilostazol, a phosphodiesterase-3 inhibitor, offers a spectrum of pharmacological effects. These encompass vasodilation, the impediment of platelet activation and aggregation, thrombosis inhibition, limb blood flow augmentation, lipid profile enhancement through triglyceride reduction and high-density lipoprotein cholesterol elevation, and the suppression of vascular smooth muscle cell proliferation. However, the role of cilostazol has not been clearly documented in many guidelines for ASCVD. We comprehensively reviewed the cardiovascular effects of cilostazol within randomized clinical trials that compared it to control or active agents and involved individuals with previous coronary artery disease or stroke, as well as those with no previous history of such conditions. Our approach demonstrated that the administration of cilostazol effectively reduced adverse cardiovascular events, although there was less evidence regarding its impact on myocardial infarction. Most studies have consistently reported its favorable effects in reducing intermittent claudication and enhancing ambulatory capacity in patients with peripheral arterial disease. Furthermore, cilostazol has shown promise in mitigating restenosis following coronary stent implantation in patients with acute coronary syndrome. While research from more diverse regions is still needed, our findings shed light on the broader implications of cilostazol in the context of atherosclerosis and vascular biology, particularly for individuals at high risk of ASCVD.

The anti-platelet drug cilostazol enhances heart rate and interrenal steroidogenesis and exerts a scant effect on innate immune responses in zebrafish

RATIONALE

Cilostazol, an anti-platelet phosphodiesterase-3 inhibitor used for the treatment of intermittent claudication, is known for its pleiotropic effects on platelets, endothelial cells and smooth muscle cells. However, how cilostazol impacts the endocrine system and the injury-induced inflammatory processes remains unclear.

METHODS

We used the zebrafish, a simple transparent model that demonstrates rapid development and a strong regenerative ability, to test whether cilostazol influences heart rate, steroidogenesis, and the temporal and dosage effects of cilostazol on innate immune cells during tissue damage and repair.

RESULTS

While dosages of cilostazol from 10 to 100 μM did not induce any noticeable morphological abnormality in the embryonic and larval zebrafish, the heart rate was increased as measured by ImageJ TSA method. Moreover, adrenal/interrenal steroidogenesis in larval zebrafish, analyzed by whole-mount 3β-Hsd enzymatic activity and cortisol ELISA assays, was significantly enhanced. During embryonic fin amputation and regeneration, cilostazol treatments led to a subtle yet significant effect on reducing the aggregation of Mpx-expressing neutrophil at the lesion site, but did not affect the immediate injury-induced recruitment and retention of Mpeg1-expressing macrophages.

CONCLUSIONS

Our results indicate that cilostazol has a significant effect on the heart rate and the growth as well as endocrine function of steroidogenic tissue; with a limited effect on the migration of innate immune cells during tissue damage and repair.

Antiplatelet therapy in aneurysmal subarachnoid hemorrhage: an updated meta-analysis

Antiplatelet therapy (AT) may serve to reduce the effects of aneurysmal subarachnoid hemorrhage (aSAH)-induced pro-coagulant state in the cerebral circulation. Several studies, however, have delivered conflicting conclusions on the efficacy of AT post aSAH. Systematic searches of Medline, Embase, and Cochrane Central were undertaken on 27th March 2023. The primary outcome was delayed cerebral ischaemia (DCI). Secondary outcomes were symptomatic and angiographic vasospasm, good functional outcome (modified Rankin Scale [mRS] with scores 0-2), hemorrhagic events, and in-hospital mortality. Twenty-two studies reporting 4378 patients with aSAH were included in the meta-analysis. AT was associated with lower rates of DCI (RR=0.62, 95% CI: 0.43; 0.89), symptomatic vasospasm (RR=0.63, 95% CI: 0.46; 0.86), and moderate/severe angiographic vasospasm (RR=0.74, 95% CI: 0.65; 0.84), with no effect on hemorrhagic complications (RR=1.36, 95% CI: 0.77; 2.41). When analyzing only post-ictal use of AT, AT additionally favored rates of good functional outcomes (RR=1.18, 95% CI: 1.10; 1.26) and in-hospital mortality (RR=0.56, 95% CI: 0.39; 0.80). In the subgroup treated with cilostazol, AT was associated with lower rates of DCI (RR=0.40, 95% CI: 0.32), symptomatic vasospasm (RR=0.47, 95% CI: 0.33; 0.65), moderate/severe angiographic vasospasm (RR=0.75, 95% CI: 0.57; 0.98) and good functional outcome (RR=1.24, 95% CI: 1.08; 1.43). In the surgically treated aSAH subgroup, AT favored rates of symptomatic vasospasm (RR=0.55, 95% CI: 0.30; 0.98), moderate/severe angiographic vasospasm (RR=0.70, 95% CI: 0.54; 0.90) and good functional outcome (RR=1.23, 95% CI: 1.09; 1.41). In the endovascularly treated aSAH subgroup, AT was associated with lower rates of in-hospital mortality (RR=0.60, 95% CI: 0.41; 0.88). In aSAH patients, post-ictal AT is associated with benefits in terms of rates of DCI, vasospasm, good functional outcomes, and in-hospital mortality without an increased risk of hemorrhagic events.

Long-Term Effectiveness of Cilostazol in Patients with Hemodialysis with Peripheral Artery Disease

AIM

The aim of this study was to investigate the effects of continuous cilostazol use on emergency department (ED) visits, hospitalizations, and vascular outcomes in patients with hemodialysis (HD) with peripheral artery disease (PAD).

METHODS

This retrospective cohort study recruited 558 adult patients, who had received chronic HD for at least 90 days between January 1, 2008 and December 31, 2012, from the National Health Insurance Research Database. Eligible patients were divided into two groups based on continuing or discontinuing cilostazol treatment. Outcome measures were ED visits, hospitalizations, mortality, and vascular outcomes such as percutaneous transluminal angioplasty, surgical bypass, lower leg amputation, ischemic stroke, hemorrhagic stroke, and cardiovascular events.

RESULTS

Patients with continuous cilostazol use had significantly higher prevalence of stroke, cancer, vintage, and the use of angiotensin receptor blocker and β-blocker, but significantly lower incidence of ischemic stroke and cardiovascular events, as well as lower mortality, than those without continuous cilostazol use (all p＜.05). Continuous cilostazol use was independently associated with lower risk of ED visits, hemorrhagic stroke, and cardiovascular events (adjusted hazard ratios: 0.79, 0.29, and 0.67; 95% confidence intervals: 0.62-0.98, 0.10-0.84, and 0.48-0.96, respectively; all p＜.05). Continuous cilostazol use was significantly associated with higher ED visit-free and cardiovascular event-free rates (log-rank test; p＜.05).

CONCLUSION

Continuous treatment of cilostazol in patients with HD with PAD significantly decreases the risk of ED visits, hemorrhagic stroke, and cardiovascular events and improves ED visit-free and cardiovascular event-free rates during long-term follow-up.

Comparison of Cilostazol versus Clopidogrel in Addition to Aspirin in Patients with Ischemic Stroke who Underwent Intracranial or Extracranial Artery Stent Implantation

AIMS

The role of cilostazol after intracranial or extracranial artery stent implantation is still unclear. Therefore, we designed this trial to explore the efficacy and safety of cilostazol in this particular population.

METHODS

In this retrospective study, patients were divided into the cilostazol or clopidogrel group by the antiplatelet therapy received after artery stent implantation. The primary efficacy endpoint was ischemic stroke. Bleeding events and other antiplatelet drug-related adverse reactions (ADRs) were also recorded. Neurological function prognosis was evaluated by the modified Rankin Scale (mRS) after discharge.

RESULTS

A total of 156 patients were enrolled; 56 underwent intracranial artery stenting, 95 underwent extracranial artery stenting, and 5 underwent intracranial combined with extracranial artery stenting. Any stroke and bleeding events in the hospital of the two groups were comparable (P=0.38, P=0.34, respectively). The incidence of stroke recurrence tended to be lower in the cilostazol group, although not significant (cilostazol vs. clopidogrel, 1.35% vs. 4.88%, P=0.25). There was a significant difference of any bleeding events between the two groups (cilostazol vs. clopidogrel, 5.41% vs. 20.73%, P=0.02). During follow-up, we did not observe an apparent increase of ADRs in the cilostazol group (cilostazol vs. clopidogrel, palpitation 4.05% vs. 2.44%, P=0.58; gastrointestinal discomfort events 8.11% vs. 12.20%, P=0.80). There were no differences between the two groups of neurological function prognosis (P=0.29).

CONCLUSIONS

Cilostazol-based dual antiplatelet therapy could be recommended as an effective and safe therapy regimen among patients undergoing intracranial or extracranial artery stent implantation.

A Randomized Controlled Trial Evaluating Outcome Impact of Cilostazol in Patients with Coronary Artery Disease or at a High Risk of Cardiovascular Disease

Previous studies found that cilostazol has a favorable effect on glucose and lipid homeostasis, endothelial function, atherosclerosis, and vasculo-angiogenesis. However, it is poorly understood whether these effects can translate into better clinical outcomes. This study investigated the outcome effect of cilostazol in patients with coronary artery disease (CAD) or at a high risk of cardiovascular (CV) disease. We conducted a randomized, double-blind, placebo-controlled trial involving 266 patients who received cilostazol, 200 mg/day (n = 134) or placebo (n = 132). Pre-specified clinical endpoints including composite major adverse cardiovascular events (MACE) (CV death, non-fatal myocardial infarct, non-fatal stroke, hospitalization for heart failure, or unplanned coronary revascularization), the composite major coronary event (MCE) and major adverse CV and cerebrovascular event (MACCE), were prospectively assessed. The mean duration of follow-up was 2.9 years. Relative to placebo, cilostazol treatment had a borderline effect on risk reduction of MACE (hazard ratio [HR], 0.67; 95% confidence interval (CI), 0.34–1.33), whereas the beneficial effect in favor of cilostazol was significant in patients with diabetes mellitus or a history of percutaneous coronary intervention (p for interaction, 0.02 and 0.06, respectively). Use of cilostazol, significantly reduced the risk of MCE (HR, 0.38; 95% CI, 0.17–0.86) and MACCE (HR, 0.47; 95% CI, 0.23–0.96). A significantly lower risk of angina pectoris (HR, 0.38; 95% CI, 0.17–0.86) was also observed in the cilostazol group. After multi-variable adjustment, cilostazol treatment independently predicted a lower risk of MCE. In conclusion, these results suggest cilostazol may have beneficial effects in patients with CAD or at a high risk of CV disease.

Emerging Therapeutics in the Management of Connective Tissue Disease. Part II. Dermatomyositis and Scleroderma

The management of connective tissue diseases is dramatically evolving with the advent of biologics and novel oral systemic therapeutics. Despite involvement in the care of these complex patients, there is a knowledge gap in the field of dermatology regarding these emerging agents. The second article in this continuing medical education series discusses new and emerging therapeutics for dermatomyositis and scleroderma that target cells, intracellular signaling pathways, and cytokines.

The Protective Effect of Cilostazol in Genotoxicity Induced by Methotrexate in Human Cultured Lymphocytes

BACKGROUND

Methotrexate is an antagonist of folic acid that has been shown to be genotoxic to healthy body cells via induction of oxidative stress. Cilostazol is a phosphodiesterase III inhibitor and a potent antioxidant drug.

OBJECTIVE

To evaluate the potential protective effect of cilostazol on methotrexate genotoxicity.

METHODS

The genotoxic effect of methotrexate by measuring the frequency of chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) in human cultured lymphocytes was studied.

RESULTS

Methotrexate significantly increased the frequency of CAs and SCEs (p < 0.0001) as compared to control cultures. This chromosomal damage induced by methotrexate was considerably decreased by pretreatment of the cells with cilostazol (P < 0.01). Moreover, the results showed that methotrexate resulted in a notable reduction (P < 0.01) in cells kinetic parameters, the mitotic index (MI) and the proliferative index (PI). Similarly, cilostazol significantly reduced the mitotic index, which could be related to the anti-proliferative effect (P < 0.01).

CONCLUSION

Methotrexate is genotoxic, and cilostazol could prevent the methotrexate-induced chromosomal damage with no modulation of methotrexate-induced cytotoxicity.

A new simple method for quantification of cilostazol and its active metabolite in human plasma by LC-MS/MS: Application to pharmacokinetics of cilostazol associated with CYP genotypes in healthy Chinese population

A simple, sensitive, and fully automated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous quantification of cilostazol (CIL) and its active metabolite, 3,4-dehydro cilostazol (CIL-M), in human plasma. Plasma samples were processed by protein precipitation in 2 mL 96-deep-well plates, and all liquid transfer steps were performed through robotic liquid handling workstation, enabling the whole procedure fast, compared to the reported methods. Separation of analytes was successfully achieved on a UPLC BEH C₁₈ column (2.1 × 100 mm, 1.7 μm) with mobile phase A (5 mM ammonium formate containing 0.1% formic acid) and mobile phase B (methanol) at a flow rate of 0.30 mL min^-1 . The total run time was 3.5 min per sample. Mass spectrometric detection was conducted by electrospray ion source in positive ion multiple reaction monitoring mode. Calibration curves were linear over the concentration range of 1.0-800 ng·mL^-1 for CIL and 0.05-400 ng·mL^-1 for CIL-M. The coefficient of variation for the assay's precision was 12.3%, and the accuracy was 88.8-99.8%. It was fully validated and successfully applied to assess the influence of CYP genotypes on the pharmacokinetics of CIL after oral administration of 50 mg tablet formulations of CIL to healthy Chinese volunteers. The results suggest that, in Chinese population, the genotype of CYP3A5 affects the plasma exposure of CIL.

Could cilostazol be beneficial in COVID-19 treatment? Thinking about phosphodiesterase-3 as a therapeutic target

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) that has emerged and rapidly spread across the world. The COVID-19 severity is associated to viral pneumonia with additional extrapulmonary complications. Hyperinflammation, dysfunctional immune response and hypercoagulability state are associated to poor prognosis. Therefore, the repositioning of multi-target drugs to control the hyperinflammation represents an important challenge for the scientific community. Cilostazol, a selective phosphodiesterase type-3 inhibitor (PDE-3), is an antiplatelet and vasodilator drug, that presents a range of pleiotropic effects, such as antiapoptotic, anti-inflammatory, antioxidant, and cardioprotective activities. Cilostazol also can inhibit the adenosine uptake, which enhances intracellular cAMP levels. In the lungs, elevated cAMP promotes anti-fibrotic, vasodilator, antiproliferative effects, as well as mitigating inflammatory events. Interestingly, a recent study evaluated antiplatelet FDA-approved drugs through molecular docking-based virtual screening on viral target proteins. This study revealed that cilostazol is a promising drug against COVID-19 by inhibiting both main protease (M^pro) and Spike glycoprotein, reinforcing its use as a promising therapeutic approach for COVID-19. Considering the complexity associated to COVID-19 pathophysiology and observing its main mechanisms, this article raises the hypothesis that cilostazol may act on important targets in development of the disease. This review highlights the importance of drug repurposing to address such an urgent clinical demand safely, effectively and at low cost, reinforcing the main pharmacological actions, to support the hypothesis that a multi-target drug such as cilostazol could play an important role in the treatment of COVID-19.

Medical therapy for cardiovascular and limb-related risk reduction in critical limb ischemia

Critical limb ischemia (CLI) constitutes the most advanced form of peripheral artery disease (PAD) and is characterized by ischemic rest pain, tissue loss and/or gangrene. Optimized medical care and risk factor modification in addition to revascularization could reduce the incidence of cardiovascular events and major adverse limb events, improving patients' quality of life and promising higher survival rates. Adequate adherence to cardioprotective medications, including antithrombotic therapy (e.g., antiplatelets, anticoagulants), cholesterol-lowering agents (e.g., statins, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors), angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), and smoking cessation should be strongly encouraged for patients with CLI. This review examines these guideline-recommended therapies in terms of cardiovascular and limb-related risk reduction in patients with CLI.

Potentially Inappropriate Prescriptions in Heart Failure with Reduced Ejection Fraction (PIP-HFrEF)

Heart failure (HF) is a chronic debilitating and potentially life-threatening condition. Heart Failure patients are usually at high risk of polypharmacy and consequently, potentially inappropriate prescribing leading to poor clinical outcomes. Based on the published literature, a comprehensive HF-specific prescribing review tool is compiled to avoid medications that may cause HF or harm HF patients and to optimize the prescribing practice of HF guideline-directed medical therapies. Recommendations are made in line with the last versions of ESC guidelines, ESC position papers, scientific evidence, and experts' opinions.

Cilostazol protects against acetic acid-induced colitis in rats: Possible role for cAMP/SIRT1 pathway

The phosphodiesterase-3 inhibitor, cilostazol has been recently shown to protect against chemically induced colitis in animal models. However, whether cyclic adenosine monophosphate (cAMP) contributes to the anti-inflammatory activity of cilostazol in colitis is still unknown. In the current study, we investigated the role of cAMP/silent information regulator-1 (SIRT-1) pathway in the protective effect of cilostazol using rat model of acetic acid-induced colitis. Upregulation of SIRT1 activity and expression has been recently shown to protect against chemically induced colitis. Our results demonstrated that cilostazol alleviated the histopathological changes associated with acetic acid-induced colitis. Interestingly, pre-administration of cilostazol increased cAMP concentration and SIRT1 expression in colonic mucosa to levels similar to that observed in control animals without induction of colitis. In addition, cilostazol inhibited the SIRT1 targets; NF-κB, Akt and MAPK inflammatory pathways as demonstrated by suppression of acetic acid-induced upregulation of NF-κB activity, p-AKT levels and the expression of p38 MAPK. NF-κB activity and the levels of p-AKT, tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) were similar in rats pretreated with cilostazol prior to induction of colitis and the control rats without colitis. Furthermore, cilostazol reduced acetic acid-induced oxidative stress and apoptosis. In conclusion, the protective effect of cilostazol against acetic acid-induced colitis may be attributed to activation of SIRT1 expression by cAMP. SIRT1 is suggested to contribute to cilostazol-induced suppression of NF-κB, Akt and MAPK inflammatory pathways, oxidative stress and apoptosis.

Vardenafil and cilostazol can improve vascular reactivity in rats with diabetes mellitus and rheumatoid arthritis co-morbidity

Endothelial dysfunction and vascular reactivity defects secondary to metabolic and immunological disorders carry risk of serious cardiovascular complications. Here, the effects of the phosphodiesterase (PDE) inhibitors vardenafil and cilostazol were examined against rheumatoid arthritis (RA)/diabetes mellitus (DM)-co-morbidity-induced endothelial dysfunction and vascular reactivity defects. After setting of RA/DM-co-morbidity model, rats were divided into a normal control group, an RA/DM-co-morbidity group, and two treatment groups receiving oral vardenafil (10 mg/kg/day) and cilostazol (30 mg/kg/day) for 21 days after RA/DM-co-morbidity induction. Aorta was isolated for biochemical estimations of the pro-inflammatory vasoconstrictor molecules angiotensin-II (Ang-II) and endothelin-1 (ET-1), the adhesion molecules P-selectin and vascular cell adhesion molecule-1 (VCAM-1), the energy sensor adenosine-5'-monophosphate-activated protein kinase (AMPK), and the vasodilator anti-inflammatory molecule vasoactive intestinal peptide (VIP) using enzyme-linked immunosorbent assay (ELISA) and western blot analysis. Immunohistochemical estimations of endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 were performed coupled with histopathological examination using routine hematoxylin and eosin (H&E) and special Masson trichrome staining. The in vitro study was conducted using aortic strips where cumulative concentration response curves were done for the endothelium-dependent relaxing factor acetylcholine and the endothelium-independent relaxing factor sodium nitroprusside after submaximal contraction with phenylephrine. Vardenafil and cilostazol significantly improved endothelial integrity biomarkers in vivo supported with histopathological findings in addition to improved vasorelaxation in vitro. Apart from their known PDE inhibition, up-regulation of vascular AMPK and eNOS coupled with down-regulation of Ang-II, ET-1, P-selectin, VCAM-1 and MMP-2 may explain vardenafil and cilostazol protective effect against RA/DM-co-morbidity-induced endothelial dysfunction and vascular reactivity defects.

Outcomes with cilostazol after endovascular therapy of peripheral artery disease

The role of cilostazol after endovascular therapy (EVT) of peripheral artery disease (PAD) remains unclear. We conducted a meta-analysis for all studies reporting the outcomes of cilostazol after EVT of PAD from January 2000 through November 2018 with the outcomes of interest including primary patency, major adverse limb events (MALE), target lesion revascularization (TLR), and major amputation. We included eight studies (three randomized controlled trials (RCTs) and five observational studies) with a total of 3846 patients (4713 lesions). During a mean follow-up duration of 12.5 ± 5 months, the use of cilostazol was associated with higher primary patency (OR 2.28, 95% CI (1.77, 2.94), p < 0.001, I² = 24%), lower risk of TLR (OR 0.37, 95% CI (0.26, 0.52), p < 0.001, I² = 0%), and lower risk of major amputation (OR 0.15, 95% CI (0.04, 0.62), p = 0.008, I² = 0%). The use of cilostazol in RCTs was associated with significantly higher odds of primary patency compared with observational studies (OR 3.37 vs 2.28, p-interaction = 0.03). After further subgroup analysis, cilostazol remained associated with higher primary patency regardless of the use of anticoagulants (warfarin) (p-interaction = 0.49). We conclude that the use of cilostazol after EVT of femoropopliteal and iliac lesions is associated with improved primary patency and lower risk of major amputation and TLR. The favorable impact of cilostazol is independent of the use of warfarin. PROSPERO identifier: CRD42018092715.

Potentiation of imatinib by cilostazol in sensitive and resistant gastrointestinal stromal tumor cell lines involves YAP inhibition

Despite the introduction of tyrosine kinase inhibitors, gastrointestinal stromal tumors (GIST) resistance remains a major clinical challenge. We previously identified phosphodiesterase 3A (PDE3A) as a potential therapeutic target expressed in most GIST. The PDE3 inhibitor cilostazol reduced cell viability and synergized with the tyrosine kinase inhibitor imatinib (Gleevec™) in the imatinib-sensitive GIST882 cell line. Here, we found that cilostazol potentiated imatinib also in the imatinib-resistant GIST48 cell line. Cilostazol induced nuclear exclusion, hence inactivation, of the transcriptional co-activator YAP, in a cAMP-independent manner. Verteporfin, a YAP/TEAD interaction inhibitor, reduced by 90% the viability of both GIST882 and GIST48 cells. Our results highlight the potential use of compounds targeting PDE3A or YAP in combined multitherapy to tackle GIST resistance.

Treatment Strategies for the Claudicant

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

Effect of Cilostazol on the Pharmacokinetics of Simvastatin in Healthy Subjects

Purpose

We evaluated potential drug-drug interactions between cilostazol and simvastatin, both CYP3A substrates, in healthy subjects.

Methods

An open-label, two-period, fixed-sequence clinical study was conducted. Seventeen subjects were given a single oral dose of simvastatin 40 mg on day 1 and multiple oral doses of cilostazol 100 mg twice daily on days 2 to 5 followed by a single dose of cilostazol and simvastatin on day 6. Plasma concentrations of simvastatin and its active metabolite, simvastatin acid, were measured using liquid chromatography-tandem mass spectrometry for pharmacokinetic assessment. Moreover, serum lipid profiles under fasting conditions were determined.

Results

The geometric mean ratios of the area under the plasma concentration-time curve from time zero to time infinity of simvastatin combined with cilostazol to that of simvastatin alone were 1.64 (90% CI, 1.38-1.95) for simvastatin and 1.31 (1.04-1.66) for simvastatin acid. In addition, coadministration with cilostazol significantly increased the maximum concentration of simvastatin and simvastatin acid, up to 1.8-fold and 1.6-fold, respectively. However, the effects of a single dose of simvastatin on serum lipid profiles were not affected notably when simvastatin was coadministered with cilostazol.

Conclusions

Multiple doses of cilostazol increased the systemic exposure of simvastatin and simvastatin acid following a single dose of simvastatin.

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.

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.

Association of platelet response to cilostazol with clinical outcome and CYP genotype in patients with cerebral infarction

INTRODUCTION

Cilostazol, an anti-platelet drug that inhibits phosphodiesterase 3, is beneficial for patients with atherothrombosis. In contrast to other anti-platelet drugs such as aspirin and thienopyridines, little information is available on the relationship between platelet responses to cilostazol and clinical outcomes.

MATERIALS AND METHODS

We conducted a prospective study on patients with cerebral infarction who were treated with cilostazol. The platelet response to cilostazol was assessed with our new assay for the phosphorylation of vasodilator-stimulated phosphoprotein (VASP) subsequent to the pharmacological action of cilostazol. Patients were followed up for 2 years and the relationship between VASP assay results and the recurrence of thrombotic events was examined. We also investigated the effects of CYP3A5 and CYP2C19 genotypes involved in the metabolism of cilostazol on the platelet response to cilostazol.

RESULTS

Among the 142 patients enrolled, 130 completed the 2-year follow-up and the recurrence of thrombotic events was noted in 8 (6.2%). VASP phosphorylation levels were significantly lower in patients with than in those without recurrence. The combined genotype of CYP3A5*1/*3 and CYP2C19*1/*1 was associated with a low level of VASP phosphorylation, while either genotype was not. A multivariate analysis showed that high residual platelet reactivity during the cilostazol treatment, which was defined by a low response of platelet VASP phosphorylation to cilostazol, was an independent risk factor for the recurrence of thrombotic events.

CONCLUSION

A low platelet response to cilostazol determined by a new platelet assay was associated with the recurrence of thrombotic events in patients with cerebral infarction.

Effects of açaí and cilostazol on skin microcirculation and viability of TRAM flaps in hamsters

BACKGROUND

Tissue necrosis caused by insufficient perfusion is a major complication in flap transfer. This study evaluated whether treatment with cilostazol or hydroalcoholic extract of seeds of Euterpe oleracea Mart. (açaí) protects the transverse rectus abdominis myocutaneous (TRAM) flap against ischemic damage in hamsters.

MATERIALS AND METHODS

Fifty-four hamsters were divided into three oral treatment groups: placebo, açaí, or cilostazol. Caudally based, unipedicled TRAM flaps were raised, sutured back, classified into four vascular zones (I-IV), and evaluated for tissue viability, capillary blood flow (CBF), perfused vessel density (PVD), and microvascular flow index (MFI) by orthogonal polarization spectral imaging at three time points: immediately postoperatively (IPO), 24 h postoperatively (24hPO), and 7 d postoperatively (7POD).

RESULTS

Comparing to placebo, açaí increased PVD at IPO and açaí and cilostazol increased CBF and PVD at 24hPO in zone I; cilostazol increased CBF, PVD, and MFI at IPO, and CBF at 24hPO in zone II; açaí and cilostazol increased CBF at all time points and PVD and MFI at IPO and 24hPO in zone III; cilostazol increased CBF at IPO and 7POD, açaí increased CBF at 7POD, and both increased PVD and MFI at all time points in zone IV; and açaí and cilostazol increased the percentage of viable area in zones III and IV.

CONCLUSIONS

Açaí and cilostazol treatments had a protective effect against ischemic damage to TRAM flaps in hamsters, improving microvascular blood flow and increasing the survival of flap zones contralateral to the vascular pedicle (zones III and IV).

Cilostazol for the prevention of pneumonia: a systematic review

Background

Pneumonia is a very common disease, especially among the elderly. Various drugs’ preventive effects against pneumonia have been reported. The antiplatelet drug cilostazol is used to prevent pneumonia, but the robustness of its efficacy is unclear. This review estimates the effectiveness of cilostazol for preventing pneumonia in elderly individuals.

Methods

The following databases were searched from the earliest record to January 2016, without language restriction (the secondary search was conducted on February 2017): MEDLINE, Cochrane Library, CINAHL, and Ichushi-Web. Studies were included if they were published randomized controlled trials investigating the preventive effect of cilostazol on pneumonia in the elderly. The outcome was the incidence of pneumonia.

Results

Two trials were identified that met the search criteria (1423 participants). Both trials compared cilostazol with no antiplatelet in patients with a history of cerebral infarction. A meta-analysis was not performed because of the small number of trials and the heterogeneity of the data. Both trials suggested that cilostazol reduced the incidence of pneumonia (risk ratio [RR] 0.40; 95% confidence interval [CI] 0.22–0.73 in one trial, RR 0.20; 95% CI 0.06–0.69 in the other) and the recurrence of cerebral infarction (0.43; 0.21–0.90, 0.53; 0.34–0.81, respectively). The quality of evidence provided by the trials was very low, mainly because of the high risk of bias.

Conclusions

It is difficult to draw conclusions on the basis of two trials. Moreover, in the two trials, cilostazol could have reduced the incidence of pneumonia via a reduction of the recurrence of cerebral infarction, which suggests that other antiplatelets could also have the same effects. Stronger evidence is required from large trials assessing the effectiveness of cilostazol for the prevention of pneumonia.

Trial registration

PROSPERO (CRD42016036724).

Electronic supplementary material

The online version of this article (10.1186/s41479-018-0046-5) contains supplementary material, which is available to authorized users.

Roles of A-Kinase Anchoring Proteins and Phosphodiesterases in the Cardiovascular System

A-kinase anchoring proteins (AKAPs) and cyclic nucleotide phosphodiesterases (PDEs) are essential enzymes in the cyclic adenosine 3′-5′ monophosphate (cAMP) signaling cascade. They establish local cAMP pools by controlling the intensity, duration and compartmentalization of cyclic nucleotide-dependent signaling. Various members of the AKAP and PDE families are expressed in the cardiovascular system and direct important processes maintaining homeostatic functioning of the heart and vasculature, e.g., the endothelial barrier function and excitation-contraction coupling. Dysregulation of AKAP and PDE function is associated with pathophysiological conditions in the cardiovascular system including heart failure, hypertension and atherosclerosis. A number of diseases, including autosomal dominant hypertension with brachydactyly (HTNB) and type I long-QT syndrome (LQT1), result from mutations in genes encoding for distinct members of the two classes of enzymes. This review provides an overview over the AKAPs and PDEs relevant for cAMP compartmentalization in the heart and vasculature and discusses their pathophysiological role as well as highlights the potential benefits of targeting these proteins and their protein-protein interactions for the treatment of cardiovascular diseases.

Cilostazol Improves Wound Healing in Patients Undergoing Open Bypass for Ischemic Tissue Loss: A Propensity Score Matching Analysis

BACKGROUND

Few reports have described the effects of medication on the wound healing of ischemic ulcers after revascularization. This study was conducted to investigate the effects of cilostazol on wound healing in patients who underwent infrainguinal bypass for ischemic tissue loss.

METHODS

Two hundred sixty-three limbs undergoing de novo infrainguinal bypass for tissue loss from January 2004 to December 2015 were divided into 2 groups based on whether or not cilostazol was administered after surgery. The end point was wound healing. The 1-year outcomes of the groups were analyzed using the Kaplan-Meier method, and a propensity score matching analysis was performed to examine the effects of cilostazol on wound healing. In addition, the significant predictors were determined using a Cox proportional hazards regression analysis.

RESULTS

Sixty-one and 202 limbs were included in the cilostazol and non-cilostazol group, respectively. The cilostazol group showed superior wound healing to the non-cilostazol group (cilostazol versus non-cilostazol, 1-year wound healing rate: 92% vs. 81%; median wound healing time: 45 vs. 78 days, P = 0.002). The results of the cilostazol group remained superior after a propensity score matching (cilostazol versus non-cilostazol, 1-year wound healing rate: 95% vs. 83%; median wound healing time: 45.5 vs. 57 days, P = 0.048). A Cox proportional hazards regression analysis indicated that foot infection, Rutherford classification, diabetes mellitus, coronary artery disease, angiosome, the administration of cilostazol, and graft patency were significant factors that influenced wound healing.

CONCLUSIONS

The postoperative use of cilostazol help to promote wound healing after open surgery.

Routine clinical anti-platelet agents have limited efficacy in modulating hypershear-mediated platelet activation associated with mechanical circulatory support

INTRODUCTION

Continuous flow ventricular assist devices (cfVADs) continue to be limited by thrombotic complications associated with disruptive flow patterns and supraphysiologic shear stresses. Patients are prescribed complex antiplatelet therapies, which do not fully prevent recurrent thromboembolic events. This is partially due to limited data on antiplatelet efficacy under cfVAD-associated shear conditions.

MATERIALS AND METHODS

We investigated the efficacy of antiplatelet drugs directly acting on three pathways: (1) cyclooxygenase (aspirin), (2) phosphodiesterase (dipyridamole, pentoxifylline, cilostazol), and (3) glycoprotein IIb-IIIa (eptifibatide). Gel-filtered platelets treated with these drugs were exposed for 10min to either constant shear stresses (30dyne/cm² and 70dyne/cm²) or dynamic shear stress profiles extracted from simulated platelet trajectories through a cfVAD (Micromed DeBakey). Platelet activation state (PAS) was measured using a modified prothrombinase-based assay, with drug efficacy quantified based on PAS reduction compared to untreated controls.

RESULTS AND CONCLUSIONS

Significant PAS reduction was observed for all drugs after exposure to 30dyne/cm² constant shear stress, and all drugs but dipyridamole after exposure to the 30th percentile shear stress waveform of the cfVAD. However, only cilostazol was significantly effective after 70dyne/cm² constant shear stress exposure, though no significant reduction was observed upon exposure to median shear stress conditions in the cfVAD. These results, coupled with the persistence of reported clinical thrombotic complication, suggest the need for the development of new classes of drugs that are especially designed to mitigate thrombosis in cfVAD patients, while reducing or eliminating the risk of bleeding.

Amelioration of high fat diet-induced nephropathy by cilostazol and rosuvastatin

Multiple comorbidities of metabolic disorders are associated with facilitated chronic kidney disease progression. Anti-platelet cilostazol is used for the treatment of peripheral artery disease. In this study, we investigated the potential beneficial effects of cilostazol and rosuvastatin on metabolic disorder-induced renal dysfunctions. C57BL/6 mice that received high fat diet (HFD) for 22 weeks and a low dose of streptozotocin (STZ, 40 mg/kg) developed albuminuria and had increased urinary cystatin C excretion, and cilostazol treatment (13 weeks) improved these markers. Histopathological changes, including glomerular mesangial expansion, tubular vacuolization, apoptosis, and lipid accumulation were ameliorated by cilostazol treatment. Tubulointerstitial fibrosis that was indicated by the increases in collagen and transforming growth factor-β1 subsided by cilostazol. Renoprotective effects were also observed in rosuvastatin-treated mice, and combinatorial treatment with cilostazol and rosuvastatin demonstrated enhanced ameliorative effects in histopathological evaluations. Notably, repressed renal heme oxygenase-1 (Ho-1) level in HFD/STZ mice was restored in cilostazol group. Further, we demonstrated that cilostazol enhanced Nrf2/Ho-1 signaling in cultured proximal tubular epithelial cells. Collectively, these results suggest the potential advantageous use of cilostazol as an adjunctive therapy with statins for the amelioration of metabolic disorder-associated renal injury.

Unfractionated and Low-Molecular-Weight Heparin and the Phosphodiesterase Inhibitors, IBMX and Cilostazol, Block Ex Vivo Equid Herpesvirus Type-1-Induced Platelet Activation

Equid herpes virus type-1 (EHV-1) is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation. We hypothesized that coagulation inhibitors that suppress thrombin generation (heparins) or platelet inhibitors that impede post-receptor thrombin signaling [phosphodiesterase (PDE) antagonists] would inhibit EHV-1-induced platelet activation ex vivo. We exposed platelet-rich plasma (PRP) collected from healthy horses to the RacL11 abortigenic and Ab4 neuropathogenic strains of EHV-1 at 1 plaque-forming unit/cell in the presence or absence of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH) or the PDE inhibitors, 3-isobutyl-1methylxanthine (IBMX), and cilostazol. We assessed platelet activation status in flow cytometric assays by measuring P-selectin expression. We found that all of the inhibitors blocked EHV-1- and thrombin-induced platelet activation in a dose-dependent manner. Platelet activation in PRP was maximally inhibited at concentrations of 0.05 U/mL UFH and 2.5 μg/mL LMWH. These concentrations represented 0.1–0.2 U/mL anti-factor Xa activity measured in chromogenic assays. Both IBMX and cilostazol showed maximal inhibition of platelet activation at the highest tested concentration of 50 μM, but inhibition was lower than that seen with UFH and LMWH. Our results indicate that heparin anticoagulants and strong non-selective (IBMX) or isoenzyme-3 selective (cilostazol) PDE antagonists inhibit ex vivo EHV-1-induced platelet activation. These drugs have potential as adjunctive therapy to reduce the serious complications associated with EHV-1-induced thrombosis. Treatment trials are warranted to determine whether these drugs yield clinical benefit when administered to horses infected with EHV-1.

Drugs That May Cause or Exacerbate Heart Failure: A Scientific Statement From the American Heart Association

Heart failure is a common, costly, and debilitating syndrome that is associated with a highly complex drug regimen, a large number of comorbidities, and a large and often disparate number of healthcare providers. All of these factors conspire to increase the risk of heart failure exacerbation by direct myocardial toxicity, drug-drug interactions, or both. This scientific statement is designed to serve as a comprehensive and accessible source of drugs that may cause or exacerbate heart failure to assist healthcare providers in improving the quality of care for these patients.

Cyclic nucleotide phosphodiesterases in heart and vessels: A therapeutic perspective

Cyclic nucleotide phosphodiesterases (PDEs) degrade the second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), thereby regulating multiple aspects of cardiac and vascular muscle functions. This highly diverse class of enzymes encoded by 21 genes encompasses 11 families that are not only responsible for the termination of cyclic nucleotide signalling, but are also involved in the generation of dynamic microdomains of cAMP and cGMP, controlling specific cell functions in response to various neurohormonal stimuli. In the myocardium and vascular smooth muscle, the PDE3 and PDE4 families predominate, degrading cAMP and thereby regulating cardiac excitation-contraction coupling and smooth muscle contractile tone. PDE3 inhibitors are positive inotropes and vasodilators in humans, but their use is limited to acute heart failure and intermittent claudication. PDE5 is particularly important for the degradation of cGMP in vascular smooth muscle, and PDE5 inhibitors are used to treat erectile dysfunction and pulmonary hypertension. There is experimental evidence that these PDEs, as well as other PDE families, including PDE1, PDE2 and PDE9, may play important roles in cardiac diseases, such as hypertrophy and heart failure, as well as several vascular diseases. After a brief presentation of the cyclic nucleotide pathways in cardiac and vascular cells, and the major characteristics of the PDE superfamily, this review will focus on the current use of PDE inhibitors in cardiovascular diseases, and the recent research developments that could lead to better exploitation of the therapeutic potential of these enzymes in the future.

Antiplatelet therapy - a summary for the general physicians

Platelets play a very important role in physiological haemostasis and thrombus formation. Platelet aggregation is the key pathophysiological factor in the development of arterial ischaemic events, including coronary artery disease, cerebrovascular accidents and peripheral arterial disease. As such, antiplatelet therapy plays a very important role in preventing recurrent events in the individuals who are affected by one of these conditions. Until recently, the repertoire of antiplatelet therapy was limited to aspirin and clopidogrel. However, this landscape has changed dramatically with the advent of newer and more potent agents, prasugrel and ticagrelor and also the glycoprotein IIb/IIIa antagonists. This armamentarium is likely to expand further with the advent of protease-activated receptor-1 antagonists and the intravenous cangrelor. This review summarises the different agents available and some practical considerations for their use from a general physician's perspective.

Prevention of Femoropopliteal In-Stent Restenosis With Cilostazol

Severe peripheral artery disease requires revascularization to relieve life-limiting ischemic symptoms. Postrevascularization in-stent restenosis continues to be a problem after femoropopliteal procedures. Our aim was to evaluate the use of cilostazol to prevent in-stent restenosis among patients with lower extremity arterial stenting. We performed a MEDLINE and EMBASE search and reviewed the abstracts and manuscripts following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary efficacy outcome was patency rate after stenting. The odds ratio estimates were pooled using the Mantel–Haenszel random-effects method. We identified 524 studies, and 20 articles were fully abstracted and 4 were included in the meta-analysis. The total number of patients included was 2434. Patients in the cilostazol group had better primary patency rates after endovascular stenting than those not taking cilostazol (odds ratio: 0.55; 95% confidence interval: 0.43-0.71). The use of cilostazol appears to prevent in-stent restenosis of high-risk patients.