The Prostacyclin Analogue Beraprost Sodium Prevents Occlusion of Bypass Grafts in Patients with Lower Extremity Arterial Occlusive Disease: A 20-Year Retrospective Study

Combination therapy with beraprost sodium and aspirin for acute ischemic stroke: a single-center retrospective study

OBJECTIVES

To evaluate the effectiveness and safety of the combination of beraprost sodium (BPS) and aspirin in patients with acute ischemic stroke (AIS).

METHODS

There were 384 patients with AIS enrolled in this single-center, retrospective study. The BPS group comprised patients who received combination therapy with BPS and aspirin, and the control group comprised those who received only aspirin. Primary measurements were glomerular filtration rate (GFR), cystatin-c (Cys-C), National Institute of Health Stroke Scale (NIHSS) score, modified activities of daily living index (MBI), modified Rankin scale (mRS), and blood coagulation indexes. Recurrence and adverse events were recorded.

RESULTS

There were no significant differences in patient characteristics at baseline between the two groups. GFR and Cys-C levels increased in the BPS group compared with the control group. After treatment, the NIHSS and mRS score were significantly lower in the BPS group compared with the control group, whereas the MBI scores were significantly higher in the BPS group compared with the control group. There was no significant difference in blood coagulation between the two groups. There were no serious adverse events in either group.

CONCLUSIONS

Combination therapy with BPS and aspirin may be a safe and effective treatment for AIS.

Beraprost sodium versus clopidogrel for preventing vascular thromboembolic events of arteriovenous fistula in uraemic patients: a retrospective study with a mean 3-year follow-up

OBJECTIVE

This study aimed to evaluate the efficacy of beraprost sodium (BPS) or clopidogrel (CL) using vascular thromboembolic events (VTEs) of arteriovenous fistula as a primary endpoint in patients with end-stage renal disease (ESRD) undergoing arteriovenous fistula surgery.

METHODS

We performed a multicentre, retrospective cohort study from August 2012 to August 2016. We studied patients with ESRD who underwent arteriovenous fistula surgery and received peroral administration of 40 µg BPS, three times per day, for 1 month, or 75 mg CL (initial dose of 300 mg), one time per day, for 1 month. The time to first on-study VTE was the primary endpoint.

RESULTS

The BPS-treated cohort had a significantly delayed time to first VTE compared with the CL-treated cohort (hazard ratio 0.33, 95% confidence interval 0.18-0.56). An increased incidence of VTEs was detected in the 1-month follow-up, with rates of 2.4% and 8.7% for BPS and CL, respectively. This difference persisted over time, with rates of 8.0% and 18.1% at the final follow-up, respectively.

CONCLUSION

CL-treated patients with ESRD have a greater risk of VTEs compared with BPS-treated patients. CL-treated patients also tend to experience a VTE within the first month after cessation of oral administration.

The mechanistic basis of prostacyclin and its stable analogues in pulmonary arterial hypertension: Role of membrane versus nuclear receptors

Pulmonary arterial hypertension (PAH) is a progressive disease of distal pulmonary arteries in which patients suffer from elevated pulmonary arterial pressure, extensive vascular remodelling and right ventricular failure. To date prostacyclin (PGI2) therapy remains the most efficacious treatment for PAH and is the only approved monotherapy to have a positive impact on long-term survival. A key thing to note is that improvement exceeds that predicted from vasodilator testing strongly suggesting that additional mechanisms contribute to the therapeutic benefit of prostacyclins in PAH. Given these agents have potent antiproliferative, anti-inflammatory and endothelial regenerating properties suggests therapeutic benefit might result from a slowing, stabilization or even some reversal of vascular remodelling in vivo. This review discusses evidence that the pharmacology of each prostacyclin (IP) receptor agonist so far developed is distinct, with non-IP receptor targets clearly contributing to the therapeutic and side effect profile of PGI2 (EP3), iloprost (EP1), treprostinil (EP2, DP1) along with a family of nuclear receptors known as peroxisome proliferator-activated receptors (PPARs), to which PGI2 and some analogues directly bind. These targets are functionally expressed to varying degrees in arteries, veins, platelets, fibroblasts and inflammatory cells and are likely to be involved in the biological actions of prostacylins. Recently, a highly selective IP agonist, selexipag has been developed for PAH. This agent should prove useful in distinguishing IP from other prostanoid receptors or PPAR binding effects in human tissue. It remains to be determined whether selectivity for the IP receptor gives rise to a superior or inferior clinical benefit in PAH.

Binding and activity of the prostacyclin receptor (IP) agonists, treprostinil and iloprost, at human prostanoid receptors: treprostinil is a potent DP1 and EP2 agonist

The prostacyclin analogues, iloprost and treprostinil are extensively used in treating pulmonary hypertension. Their binding profile and corresponding biochemical cellular responses on human prostanoid receptors expressed in cell lines, have now been compared. Iloprost had high binding affinity for EP1 and IP receptors (Ki 1.1 and 3.9 nM, respectively), low affinity for FP, EP3 or EP4 receptors, and very low affinity for EP2, DP1 or TP receptors. By contrast, treprostinil had high affinity for the DP1, EP2 and IP receptors (Ki 4.4, 3.6 and 32 nM, respectively), low affinity for EP1 and EP4 receptors and even lower affinity for EP3, FP and TP receptors. In functional assays, iloprost had similar high activity in elevating cyclic AMP levels in cells expressing the human IP receptor and stimulating calcium influx in cells expressing EP1 receptors (EC50 0.37 and 0.3 nM, respectively) with the rank order of activity on the other receptors comparable to the binding assays. As with binding studies, treprostinil elevated cyclic AMP with a similar high potency in cells expressing DP1, IP and EP2 receptors (EC50 0.6, 1.9 and 6.2 nM, respectively), but had low activity at the other receptors. Activation of IP, DP1 and EP2 receptors, as with treprostinil, can all result in vasodilatation of human pulmonary arteries. However, activation of EP1 receptors can provoke vasoconstriction, and hence may offset the IP-receptor mediated vasodilator effects of iloprost. Treprostinil may therefore differ from iloprost in its overall beneficial pulmonary vasorelaxant profile and other pharmacological actions, especially in diseases where the IP receptor is down-regulated.

Neuroprotective properties of prostaglandin I2 IP receptor in focal cerebral ischemia

We and others have identified that inhibition of cyclooxygenase might not be the optimal approach to limiting brain damage after stroke. Now we are investigating the unique properties of the various prostaglandin receptors to determine whether blocking those that mediate toxicity or stimulating those that reduce toxicity will improve neurological outcomes. Here, we determined the respective contribution of the prostaglandin I(2) (PGI(2)) receptor in transient middle cerebral artery (MCA) occlusion (tMCAO) and permanent MCAO (pMCAO) preclinical stroke models by using male wildtype (WT) and IP receptor knockout (IP(-/-)) C57Bl/6 mice. In addition, we investigated the putative preventive and therapeutic effects of the IP receptor agonist beraprost. The infarct volumes and neurological deficit scores (NDS) were significantly greater in IP(-/-) than in WT mice after both tMCAO and pMCAO. Interestingly, beraprost pretreatment (50 or 100 microg/kg p.o.) 30 min before tMCAO and post-treatment (100 microg/kg p.o.) at 2 or 4.5 h of reperfusion significantly reduced the neurological deficit score and infarct volume in WT mice. Post-treatment with beraprost (100 microg/kg p.o.) 4.5 h after pMCAO also significantly decreased neurological deficits and infarct volume in WT mice. Together, these novel findings suggest for the first time that PGI(2) IP receptor activation can attenuate anatomical and functional damage following ischemic stroke.

Current management of peripheral arterial occlusive disease: a review of pharmacologic agents and other interventions

Peripheral arterial occlusive disease (PAOD) of the lower extremities is becoming more prevalent worldwide. Nonsurgical treatment options provide the foundation for management. Lifestyle and risk factor modification should be emphasized in this patient population because of the associated adverse cardiovascular events. This includes implementation of a regular walking and smoking-cessation programs, aggressive control of hyperlipidemia, hypertension and diabetes mellitus, and treatment of hyperhomocysteinemia. Antiplatelet agents such as aspirin (acetylsalicylic acid) or clopidogrel are not specifically indicated for claudication but these drugs should be used in all patients with PAOD to prevent secondary ischemic events. Currently, cilostazol is the only US FDA approved agent that appears effective for the treatment of claudication symptoms. Several agents have been used with success outside of the US and others are still undergoing testing. Definitive recommendations cannot be made on the use of these drugs until further evaluation is completed. Ongoing research with new strategies for angiogenesis and the use of progenitor cells has yielded encouraging results, particularly for patients with critical limb ischemia and limited options. Advances in endovascular technology over the last several years have greatly enhanced the ability to diagnose and treat specific anatomic lesions that previously would have required open surgical correction. The use of percutaneous transluminal angioplasty and stents in the lower extremities has had considerable success when following specific guidelines such as those set forth by the TransAtlantic Inter-Society Consensus Working Group.

Beraprost sodium enhances neovascularization in ischemic myocardium by mobilizing bone marrow cells in rats

Beraprost sodium, an orally active prostacyclin analogue, has vasoprotective effects such as vasodilation and antiplatelet activities. We investigated the therapeutic potential of beraprost for myocardial ischemia. Immediately after coronary ligation of Sprague-Dawley rats, beraprost (200 microg/kg/day) or saline was subcutaneously administered for 28 days. Four weeks after coronary ligation, administration of beraprost increased capillary density in ischemic myocardium, decreased infarct size, and improved cardiac function in rats with myocardial infarction. Beraprost markedly increased the number of CD34-positive cells and c-kit-positive cells in plasma. Also, four weeks after coronary ligation of chimeric rats with GFP-expressing bone marrow, bone marrow-derived cells were incorporated into the infarcted region and its border zone. Treatment with beraprost increased the number of GFP/von Willebrand factor-double-positive cells in the ischemic myocardium. These results suggest that beraprost has beneficial effects on ischemic myocardium partly by its ability to enhance neovascularization in ischemic myocardium by mobilizing bone marrow cells.