Cilostazol, an Inhibitor of Type 3 Phosphodiesterase, Produces Endothelium-Independent Vasodilation in Pressurized Rabbit Cerebral Penetrating Arterioles

Long-term effectiveness and safety of cilostazol versus clopidogrel in secondary prevention of noncardioembolic ischemic stroke

PURPOSE

Cilostazol is a widely used antiplatelet drug for secondary stroke prevention in Asia, but its comparison with clopidogrel is not well understood. This study aims to investigate the effectiveness and safety of cilostazol compared to clopidogrel for the secondary prevention of noncardioembolic ischemic stroke.

METHODS

This retrospective comparative effectiveness research analyzed 1:1 propensity scorematched data from insured individuals between 2012 and 2019, using administrative claims data in Health Insurance Review and Assessment in Korea. Patients with diagnosis codes for ischemic stroke without cardiac disease were included and divided into two groups, those receiving cilostazol and those receiving clopidogrel. The primary outcome was a recurrent ischemic stroke. Secondary outcomes included all-cause death, myocardial infarction, hemorrhagic stroke, and a composite of these outcomes. The safety outcome was major gastrointestinal bleeding.

RESULTS

The study analyzed 4,754 patients in the propensity scorematched population and found no statistically significant difference in recurrent ischemic stroke (cilostazol group vs clopidogrel group, 2.7% vs 3.2%; 95% CI, 0.62-1.21), the composite outcome of recurrent ischemic stroke, all-cause death, myocardial infarction, and hemorrhagic stroke (5.1% vs 5.5%; 0.75-1.22), and major gastrointestinal bleeding (1.3% vs 1.5%; 0.57-1.47) between patients receiving cilostazol and those receiving clopidogrel. In subgroup analysis, cilostazol was associated with a lower incidence of recurrent ischemic stroke compared to clopidogrel in hypertensive patients (2.5% vs 3.9%; interaction P = 0.041).

CONCLUSIONS

This real-world study suggests that cilostazol is effective and safe for noncardioembolic ischemic stroke and may be associated with better effectiveness in hypertensive patients compared to clopidogrel.

Pleiotropic Role of Tenascin-C in Central Nervous System Diseases: From Basic to Clinical Applications

The extracellular matrix is composed of a variety of macromolecular substances secreted by cells, which form a complex network that supports and connects tissue structures, regulates the morphogenesis of tissues, and maintains the physiological activities of cells. Tenascin-C, a secreted extracellular matrix glycoprotein, is abundantly expressed after exposure to pathological stimuli. It plays an important regulatory role in brain tumors, vascular diseases, and neurodegenerative diseases by mediating inflammatory responses, inducing brain damage, and promoting cell proliferation, migration, and angiogenesis through multiple signaling pathways. Therefore, tenascin-C may become a potential therapeutic target for intracranial diseases. Here, we review and discuss the latest literature regarding tenascin-C, and we comprehensively explain the role and clinical significance of tenascin-C in intracranial diseases.

Ion channels as effectors of cyclic nucleotide pathways: Functional relevance for arterial tone regulation

Numerous mediators and drugs regulate blood flow or arterial pressure by acting on vascular tone, involving cyclic nucleotide intracellular pathways. These signals lead to regulation of several cellular effectors, including ion channels that tune cell membrane potential, Ca²⁺ influx and vascular tone. The characterization of these vasocontrictive or vasodilating mechanisms has grown in complexity due to i) the variety of ion channels that are expressed in both vascular endothelial and smooth muscle cells, ii) the heterogeneity of responses among the various vascular beds, and iii) the number of molecular mechanisms involved in cyclic nucleotide signalling in health and disease. This review synthesizes key data from literature that highlight ion channels as physiologically relevant effectors of cyclic nucleotide pathways in the vasculature, including the characterization of the molecular mechanisms involved. In smooth muscle cells, cation influx or chloride efflux through ion channels are associated with vasoconstriction, whereas K⁺ efflux repolarizes the cell membrane potential and mediates vasodilatation. Both categories of ion currents are under the influence of cAMP and cGMP pathways. Evidence that some ion channels are influenced by CN signalling in endothelial cells will also be presented. Emphasis will also be put on recent data touching a variety of determinants such as phosphodiesterases, EPAC and kinase anchoring, that complicate or even challenge former paradigms.

Comparison of Effects between Clopidogrel and Cilostazol on Cerebral Perfusion in Nonsurgical Adult Patients with Symptomatically Ischemic Moyamoya Disease: Subanalysis of a Prospective Cohort

BACKGROUND AND PURPOSE

Adult patients with symptomatically ischemic moyamoya disease (MMD) initially undergo medical treatment alone including antiplatelet drugs when symptomatic cerebral hemispheres do not exhibit hemodynamic compromise. The purpose of the present study subanalyzing the same patient cohort used in a previous study was to determine which antiplatelet drug, clopidogrel or cilostazol, provides better improvement of cerebral perfusion in such patients.

METHODS

All patients without cerebral misery perfusion on ¹⁵O gas positron emission tomography (PET) did not undergo revascularization surgery and were treated with medication alone, including antiplatelet therapy. Patients ≥50years and <50years initially received clopidogrel and cilostazol, respectively. When a patient suffered side effects of an antiplatelet drug, they were switched to the other antiplatelet drug. Cerebral blood flow (CBF) in the symptomatic hemisphere was measured at inclusion and at 2years after inclusion using ¹⁵O gas PET.

RESULTS

Of 68 patients, 31 and 38 were treated with clopidogrel and cilostazol, respectively, for 2years after inclusion. For patients treated with clopidogrel, CBF did not differ between first and second PET. For patients treated with cilostazol, CBF was significantly greater in the second PET than in the first PET. On multivariate analysis, cilostazol administration was an independent predictor of CBF improvement in the symptomatic hemisphere (95% confidence interval, 1.34-139.20; P =.0271).

CONCLUSIONS

Cilostazol improves cerebral perfusion better than clopidogrel in adult patients with symptomatically ischemic MMD not accompanied by misery perfusion.

Cilostazol enhances atorvastatin-induced vasodilation of female rat aorta during aging

Statins have cholesterol-independent effects including an increased vascular nitric oxide activity and are commonly used by patients with cardiovascular disease. Such patients frequently have cardiovascular diseases, which may be treated with cilostazol, a platelet aggregation inhibitor. This study was designed to investigate whether combined use of cilostazol would increase the inhibitory effect of statin on vascular smooth muscle and how maturation would affect these responses. Female Wistar rats, aged 3–4 months (young) and 14–15 months (adult), were sacrificed by cervical dislocation and the thoracic aorta was dissected and cut into 3- to 4-mm-long rings. The rings were mounted under a resting tension of 1 g in a 20-ml organ bath filled with Krebs–Henseleit solution. Rings were precontracted with phenylephrine (10−6 M), and the presence of endothelium was confirmed with acetylcholine (10−6 M). Then, the concentration–response curves were obtained for atorvastatin alone (10−10 to 3 × 10−4 M; control) and in the presence of cilostazol (10−6 M) in young and adult rat aortas. This experimental protocol was also carried out in aorta rings, which had been pretreated with NG-nitro-l-arginine methyl ester (l-NAME, 10−4 M). Atorvastatin induced concentration-dependent relaxations in young and adult rat thoracic aorta rings precontracted with phenylephrine. The pIC50 value of atorvastatin was significantly decreased in adult rat aortas. In addition, pretreatment of aortas with cilostazol enhanced the potency of atorvastatin in both young and adult aortas. Incubation with l-NAME did not completely eliminate the relaxations to atorvastatin in the presence of cilostazol. These results suggest that combined application of cilostazol with atorvastatin was significantly more potent than atorvastatin alone. Combined drug therapy may be efficacious in delaying the occurrence of cardiovascular events.

Evaluation and Treatment of the Acute Cerebral Infarction with Convexal Subarachnoid Hemorrhage

Non-traumatic convexal subarachnoid hemorrhage (CSAH) is a comparatively infrequent with various vascular and nonvascular causes, it rarely occurs concomitant to acute ischemic stroke. We report a case of a 59-year-old woman, visited emergency room with right side subjective weakness spontaneously. Magnetic resonance diffusion-weighted images revealed an acute infarction of anterior cerebral arterial territory. Computed tomographic angiography showed a left frontal CSAH without any vascular lesions. And other laboratory studies were non-specific. We treated with dual antiplatelet drugs (cilostazole [Otsuka Pharmaceutical Co., Ltd. tokyo, Japan] and Aspirin [Bayer Pharma AG., Leverkusen, Germany]). She has done well for a follow-up period. (5 months) This case demonstrates the CSAH with acute infarction is rare but need to work up to identify the etiology and antiplatelet dugs are taken into account for treatments.

Continuous daily use of cilostazol prevents in-stent restenosis following carotid artery stenting: serial angiographic investigation of 229 lesions

BACKGROUND

Several studies have reported that cilostazol (CLS) may reduce in-stent restenosis (ISR) after carotid artery stenting (CAS). However, it is not known for how long CLS must be continued to prevent ISR.

METHODS

We retrospectively reviewed a prospectively collected database of patients who underwent elective CAS and follow-up angiography at 3 months and 1 year after the procedure. ISR was defined as stenosis of 50% or greater on digital subtraction angiography. The cumulative incidence rates of angiographic ISR were compared between the three groups, divided according to duration of CLS use : (1) patients who were maintained on CLS for 12 months or more after CAS (12M CLS group, n=70), (2) patients who were treated with CLS for the first 3 months after CAS (3M CLS group, n=23), and (3) patients who did not receive CLS (no CLS group, n=136).

RESULTS

A total of 229 lesions in 199 patients were included in our analysis. During a median follow-up of 365 days, ISR was detected in 15 lesions. The cumulative ISR rates overall and in the 12M CLS, 3M CLS, and no CLS groups were 5.6%, 0%, 5.0%, and 8.4%, respectively, at 1 year, and the log rank test showed that there was a significant difference between the three groups (p<0.05). Cox regression analysis demonstrated that the 12M CLS group had a significantly lower risk of ISR than the 3M CLS group (adjusted relative risk (aRR) 3.06e-10, 95% CI 0 to 0.51, p<0.05) and the no CLS group (aRR 1.41e-10, 95% CI 0 to 0.15, p<0.001), whereas no difference was found between the 3M CLS group and the no CLS group.

CONCLUSIONS

An overall cumulative ISR rate of 5.6% was documented angiographically at 1 year after CAS. Continuous daily use of CLS (for at least 1 year) may have a beneficial effect on long term prevention of ISR.

Efficacy and Safety of Cilostazol Therapy in Ischemic Stroke: A Meta-analysis

BACKGROUND

Antiplatelet therapy is recommended for patients who have experienced ischemic stroke. We performed a meta-analysis to compare the efficacy and safety of cilostazol with other antiplatelet therapies in patients with ischemic stroke.

METHODS

PubMed, EMBASE, MEDLINE, and the Cochrane Library were searched for randomized controlled trials published in English from May 1999 to May 2013. Clinical outcomes were compared by pooled and meta-regression analyses.

RESULTS

Nine studies involving 6328 patients satisfied our inclusion criteria. Stroke recurrence (including hemorrhagic and ischemic) with cilostazol use was 5.3% (157) versus 8.3% (248) in control group (risk ratio .63 [.52-.76], 95% confidence interval [CI]). Poststroke intracranial hemorrhage was .5% (16) with cilostazol versus 1.6% (46) in control group (risk ratio .36 [.21-.63], 95% CI). Poststroke extracranial bleeding complications occurred in 2.4% (66) of the patients taking cilostazol versus 3.9% (108) in control group (risk ratio .62 [.46-.83], 95% CI). No significant difference in cerebrovascular events (nonfatal stroke, intracranial hemorrhage, and transient ischemic attack) was found between the cilostazol group (8.2%, 246) versus control group (12.0%, 360; risk ratio .71 [.50-1.01], 95% CI). In addition, the cilostazol therapy brought about a nonsignificant reduction of cardiac adverse events (heart failure, myocardial infarction, and angina pectoris) comparing with control groups, with 3.8% (99) of the cilostazol group versus 4.7% (123) of control group (risk ratio, .81 [.62-1.04], 95% CI).

CONCLUSIONS

Cilostazol, alone or in combination with aspirin, significantly reduces stroke recurrence, poststroke intracranial hemorrhage, and extracranial bleeding in patients with a prior ischemic stroke as compared with other antiplatelet therapies.

A randomised, multicentre, double blind, placebo controlled trial to evaluate the efficacy and safety of cilostazol in patients with vasospastic angina

OBJECTIVES

We conducted a randomised, double blind, placebo controlled trial to assess the efficacy and safety of cilostazol, a selective inhibitor of phosphodiesterase 3, in patients with vasospastic angina (VSA).

BACKGROUND

Cilostazol has been shown to induce vascular dilatation, but its efficacy in patients with VSA is unknown.

METHODS

Between October 2011 and July 2012, 50 patients with confirmed VSA who had ≥1 angina episodes/week despite amlodipine therapy (5 mg/day) were randomly assigned to receive either cilostazol (up to 200 mg/day) or placebo for 4 weeks. All patients were given diaries to record the frequency and severity of chest pain (0-10 grading). The primary endpoint was the relative reduction of the weekly incidence of chest pain.

RESULTS

Baseline characteristics were similar between the two groups. Among 49 evaluable patients (25 in the cilostazol group, 24 in the placebo group), the primary endpoint was significantly greater in the cilostazol group compared with the placebo group (-66.5±88.6% vs -17.6±140.1%, respectively, p=0.009). The secondary endpoints, including a change in the frequency of chest pain (-3.7±0.5 vs -1.9±0.6, respectively, p=0.029), a change in the chest pain severity scale (-2.8±0.4 vs -1.1±0.4, respectively, p=0.003), and the proportion of chest pain-free patients (76.0% vs 33.3%, respectively, p=0.003) also significantly favoured cilostazol. Headache was the most common adverse event in both groups (40.0% vs 20.8%, respectively, p=0.217).

CONCLUSIONS

Cilostazol is an effective therapy for patients with VSA uncontrolled by conventional amlodipine therapy, and has no serious side effects.

TRIAL REGISTRATION NUMBER

NCT01444885.

Chinese herbal medicine for aspirin resistance: a systematic review of randomized controlled trials

Aspirin resistance (AR) is a prevalent phenomenon and leads to significant clinical consequences, but the current evidence for effective interventional strategy is insufficient. The objective of this systematic review is thus to assess the efficacy and safety of Chinese herbal medicine (CHM) for AR. A systematical literature search was conducted in 6 databases until December 2012 to identify randomized controlled trials (RCTs) of CHM for AR. As a result, sixteen RCTs with a total of 1011 subjects were identified, suggesting that the interests of the medical profession and the public in the use of CHM for AR have grown considerably in the recent years. Tongxinluo capsule and Danshen-based prescriptions were the most frequently used herbal prescriptions, while danshen root, milkvetch root, Leech, and Rosewood were the most frequently used single herbs. Despite the apparent reported positive findings, it is premature to determine the efficacy and safety of CHM for the treatment of AR due to poor methodological quality and insufficient safety data. However, CHMs appeared to be well tolerated in all included studies. Thus, CHM as a promising candidate is worthy of improvement and development for further clinical AR trials. Large sample-size and well-designed rigorous RCTs are needed.

Effect of cilostazol in the treatment of acute ischemic stroke in the lenticulostriate artery territory

BACKGROUND

Cilostazol, an inhibitor of phosphodiesterase 3, has various pleiotropic effects besides its antiplatelet activity. This study examined the efficacy of cilostazol for the treatment of acute perforating artery infarction.

METHODS

In this prospective, randomized, open-label, blinded-end point trial, 100 patients with cerebral infarction in the territory of the lenticulostriate arteries were enrolled within 48 h of onset. Patients were randomly treated with both cilostazol and ozagrel for 14 days (n = 50, cilostazol group) or ozagrel alone for 14 days (n = 50, control group). The primary end point was the proportion of favorable outcomes 30 days after randomization as defined by a modified Rankin Scale (mRS) score of 0-2. Secondary end points included the incidence of neurological deterioration (an increase of ≥ 2 on the National Institutes of Health Stroke Scale within 7 days).

RESULTS

Favorable outcomes (mRS scores 0-2) were similar in both groups (81.3 and 82.0% in the cilostazol and control groups, respectively). The incidence of neurological deterioration was lower in the cilostazol group than the control group (12.5 and 16.0%, respectively) with a 21.9% relative risk reduction, although the difference was not statistically significant.

CONCLUSIONS

Cilostazol did not prevent the neurological deterioration of perforating artery infarction.

Cilostazol prevents endothelin-induced smooth muscle constriction and proliferation

Cilostazol is a phosphodiesterase inhibitor that has been shown to inhibit platelet activation. Endothelin is known to be the most potent endogenous growth promoting and vasoactive peptide. In patients and animal models with stroke, the level of circulating endothelin increases and complicates the recovery progress contributed by vascular constriction (an immediate pathology) and vascular proliferation (a long-term pathology). However, the effects of cilostazol on endothelin have not been explored. To demonstrate the dual-antagonizing effects of cilostazol on vasoconstriction and cell proliferation induced by endothelin, we used primary culture of mouse vascular smooth muscle cells in vitro, mouse femoral artery ex vivo, and intracranial basilar artery ex vivo. We show that the dual-inhibition effects of cilostazol are mediated by blocking endothelin-induced extracellular calcium influx. Although cilostazol does not inhibit endothelin-induced intraorganellar calcium release, blockade of extracellular calcium influx is sufficient to blunt endothelin-induced vasoconstriction. We also show that cilostazol inhibits endothelin-induced cellular proliferation by blocking extracellular calcium influx. Inhibition of cAMP-dependent protein kinase (PKA) can block anti-proliferation activity of cilostazol, confirming the downstream role of PKA in cellular proliferation. To further demonstrate the selectivity of the dual-antagonizing effects of cilostazol, we used a different phosphodiesterase inhibitor. Interestingly, sildenafil inhibits endothelin-induced vasoconstriction but not cellular proliferation in smooth muscle cells. For the first time, we show selective dual-antagonizing effects of cilostazol on endothelin. We propose that cilostazol is an excellent candidate to treat endothelin-associated diseases, such as stroke.

Platelet aggregometry in the presence of PGE(1) provides a reliable method for cilostazol monitoring

INTRODUCTION

Cilostazol has been shown to be effective for prevention and treatment of cerebral infarction. However, there appears to be no widely accepted method appropriate for monitoring cilostazol. We attempted to establish an assay system for cilostazol monitoring, using platelet aggregation induced by arachidonic acid (AA) in the presence of PGE(1) which upregulates intracellular cyclic AMP.

METHODS

Blood was drawn from stroke patients before and after cilostazol intake. AA-induced platelet aggregation after pretreatment with 0~30nM PGE(1) for 2minutes was measured by light transmittance aggregometry.

RESULTS

AA-induced platelet aggregation was 73.1±2.2% in the absence of PGE(1), and pretreatment with 30nM PGE(1) had virtually no inhibitory effect on platelet aggregation prior to cilostazol intake. In contrast, after cilostazol intake, 30nM PGE(1) significantly inhibited platelet aggregation to 12.7±4.5% (p=7.8×10(-11)) , while in the absence of PGE(1) platelet aggregation remained similar to that of prior-to-cilostazol value (70.6±3.5%). The plasma concentration of cilostazol ranged from 0.55 to 3.51μM. In the presence of 30nM PGE(1), all the patients with cilostazol concentrations exceeding 1μM had their platelet aggregation inhibited almost completely. ROC analysis suggests that AA-induced platelet aggregation in the presence of 30nM PGE(1) had the excellent sensitivity (90.5%) and specificity (88.4%) for monitoring cilostazol.

CONCLUSIONS

AA-induced platelet aggregation in the presence of 30nM PGE(1) could give good estimate on plasma concentrations of cilostazol. It is suggested that this system is a good tool for monitoring cilostazol.

Cilostazol suppresses angiotensin II-induced vasoconstriction via protein kinase A-mediated phosphorylation of the transient receptor potential canonical 6 channel

OBJECTIVE

The goal of this study was to determine whether inhibition of transient receptor potential canonical (TRPC) channels underlies attenuation of angiotensin II (Ang II)-induced vasoconstriction by phosphodiesterase (PDE) 3 inhibition.

METHODS AND RESULTS

Pretreatment of rat thoracic aorta with cilostazol, a selective PDE3 inhibitor, suppressed vasoconstriction induced by Ang II but not that induced by KCl. The Ang II-induced contraction was largely dependent on Ca(2+) influx via receptor-operated cation channels. Cilostazol specifically suppressed diacylglycerol-activated TRPC channels (TRPC3/TRPC6/TRPC7) through protein kinase A (PKA)-dependent phosphorylation of TRPC channels in HEK293 cells. In contrast, we found that phosphorylation of TRPC6 at Thr69 was essential for the suppression of Ang II-induced Ca(2+) influx by PDE3 inhibition in rat aortic smooth muscle cells (RAoSMCs). Cilostazol specifically induced phosphorylation of endogenous TRPC6 at Thr69. The endogenous TRPC6, but not TRPC3, formed a ternary complex with PDE3 and PKA in RAoSMCs, suggesting the specificity of TRPC6 phosphorylation by PDE3 inhibition. Furthermore, inhibition of PDE3 suppressed the Ang II-induced contraction of reconstituted ring with RAoSMCs, which were abolished by the expression of a phosphorylation-deficient mutant of TRPC6.

CONCLUSIONS

PKA-mediated phosphorylation of TRPC6 at Thr69 is essential for the vasorelaxant effects of PDE3 inhibition against the vasoconstrictive actions of Ang II.

NT-702, a selective phosphodiesterase 3 inhibitor, dilates rabbit spinal arterioles via endothelium-dependent and endothelium-independent mechanisms

We investigated the effects of NT-702, a selective phosphodiesterase (PDE) 3 inhibitor, on arterioles isolated from rabbit lumbar spinal cords. NT-702 caused a dose-dependent dilation of the isolated spinal arterioles. The disruption of endothelium produced a significant reduction of higher concentrations (10(-7) and 10(-6) M), but not lower concentrations (less than 10(-8) M), of NT-702-induced vasodilation. The NT-702-induced vasodilation of the arterioles with endothelium was not affected by pretreatment with an inhibitor of nitric oxide, cyclooxygenase, or cytochrome P-450 monooxygenase. In contrast, catalase reduced significantly the higher concentrations of NT-702-induced vasodilation only. Tetraethylammonium (TEA) completely reduced the lower concentrations of NT-702-induced vasodilation, but decreased only partially the higher concentrations of NT-702-induced vasodilation of the arterioles with endothelium. Hydrogen peroxide dilated significantly the isolated arterioles with endothelium, the response of which was reduced significantly by TEA. KT5720 (a selective protein kinase inhibitor) significantly decreased both the lower and higher concentrations of NT-702-induced vasodilation of the arterioles with endothelium. The findings suggest that NT-702 dose-dependently dilated the isolated spinal arterioles of rabbits via endothelium-dependent and endothelium-independent mechanisms. Protein kinase A (PKA)- and TEA-sensitive K(+) channels may be involved in the NT-702-induced vasodilation. Moreover, hydrogen peroxide may contribute in part to the endothelium-dependent higher concentrations of NT-702-induced vasodilation.

Contribuição na prevenção da isquemia cerebral pelo cilostazol, um inibidor da fosfodiesterase III: revisão de literatura

Esta revisão bibliográfica objetiva expor estas pesquisas sobre as ações do cilostazol no sistema nervoso central. O cilostazol é uma droga que demonstrou exercer inibição seletiva e potente da fosfodiesterase tipo III, ocasionando o aumento de adenosina cíclica -3',5'-monofosfato nas plaquetas, nas células endoteliais e nas células musculares lisas, sendo classificado como vasodilatador, antiagregante plaquetário e antitrombótico. É o fármaco de primeira escolha na claudicação intermitente devido à doença arterial obstrutiva periférica. Além disso, há evidências de que o cilostazol é eficaz no processo aterosclerótico cerebral, promovendo aumento do fluxo e volume sangüíneos e prevenindo infartos, especialmente lacunares e recorrentes, por diminuir a morte celular devido à apoptose e ao estresse oxidativo nas substâncias branca e parda.

Systemic haemodynamics in infants with vein of Galen malformation: assessment and basis for therapy

Systemic haemodynamics in three infants with severe cardiac failure secondary to vein of Galen malformation (VGAM) were studied using two-dimensional and Doppler echocardiography. In all cases, ventricular outputs were over two times normal and superior vena caval flows up to 10 times normal reflecting high flow through the low-resistance fistula. Severe pulmonary hypertension, right heart dilatation and retrograde flow in the descending aorta were uniformly present. Systemic blood flow below the head and neck was reduced resulting in metabolic acidosis at presentation. Two infants had patent arterial ducts, in which flow was entirely right to left and on entering the aorta passed predominantly retrogradely towards the VGAM. These findings provide a basis for understanding the pathophysiology of cardiac failure in VGAM and support treatment with pulmonary and systemic vasodilating agents.

Cerebrovascular Effects of Cilostazol in Patients With Atherosclerotic Disease

BACKGROUND

Cilostazol is a potent selective inhibitor of phosphodiesterase-3 of proven efficacy in intermittent claudication. It has antiplatelet effect and produces vasodilatation in several vascular territories. This drug has been approved in some countries for the prevention of recurrence of cerebral infarction. Limited data in patients with cerebral infarcts suggest improvement in cerebral blood flow. Dilatation of cerebral vessels with carbon-dioxide challenge can be assessed by transcranial Doppler technique. The percentage increase in blood flow velocity is called cerebral vasomotor reactivity (CVR).

OBJECTIVE

In this investigation we sought to measure CVR before and after oral administration of cilostazol.

METHODS

We studied patients with risk factors for atherosclerosis before they received cilostazol (100 mg twice daily) for intermittent claudication. CVR was assessed by measuring bilateral middle cerebral artery blood flow velocity during normoventilation and after 3 minutes of breathing 8% carbon dioxide. One average value was obtained from each patient. CVR was measured the day before cilostazol first dose, at 1 month, and 3 to 6 months later.

RESULTS

We examined 9 patients (8 men and 1 woman) aged 67.6 +/- 8.4 years. All patients had hypertension, 5 had diabetes, 4 were smokers, 5 had high cholesterol levels, and 4 had coronary artery disease. CVR was 54.4 +/- 14.4% at baseline, and increased to 64.2 +/- 18.6% after 1 month (P < .05) and to 67.1 +/- 13.3% at 3 to 6 months later (P < .01).

CONCLUSION

Our findings suggest that cilostazol increases CVR in patients with atherosclerotic disease.