Adjunctive Cilostazol Versus Double-Dose Clopidogrel After Drug-Eluting 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.

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

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

Cilostazol: a Review of Basic Mechanisms and Clinical Uses

Primarily used in the treatment of intermittent claudication, cilostazol is a 2-oxyquinolone derivative that works through the inhibition of phosphodiesterase III and related increases in cyclic adenosine monophosphate (cAMP) levels. However, cilostazol has been implicated in a number of other basic pathways including the inhibition of adenosine reuptake, the inhibition of multidrug resistance protein 4, among others. It has been observed to exhibit antiplatelet, antiproliferative, vasodilatory, and ischemic-reperfusion protective properties. As such, cilostazol has been investigated for clinical use in a variety of settings including intermittent claudication, as an adjunctive for reduction of restenosis after coronary and peripheral endovascular interventions, and in the prevention of secondary stroke, although its widespread implementation for indications other than intermittent claudication has been limited by relatively modest effect sizes and lack of studies in western populations. In this review, we highlight the pleiotropic effects of cilostazol and the evidence for its clinical use.

Durable Polymer Versus Biodegradable Polymer Drug-Eluting Stents After Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome: The HOST-REDUCE-POLYTECH-ACS Trial

BACKGROUND

Large-scale randomized comparison of drug-eluting stents (DES) based on durable polymer versus biodegradable polymer technology is currently insufficient in patients with acute coronary syndrome (ACS). The present study aimed to prove the noninferiority of the durable polymer DES (DP-DES) compared with the biodegradable polymer DES (BP-DES) in such patients.

METHODS

The HOST-REDUCE-POLYTECH-ACS (Harmonizing Optimal Strategy for Treatment of Coronary Artery Diseases-Comparison of Reduction of Prasugrel Dose or Polymer Technology in ACS Patients) trial is an investigator-initiated, randomized, open-label, adjudicator-blinded, multicenter, noninferiority trial comparing the efficacy and safety of DP-DES and BP-DES in patients with ACS. The primary end point was a patient-oriented composite outcome (a composite of all-cause death, nonfatal myocardial infarction, and any repeat revascularization) at 12 months. The key secondary end point was device-oriented composite outcome (a composite of cardiac death, target-vessel myocardial infarction, or target lesion revascularization) at 12 months.

RESULTS

A total of 3413 patients were randomized to receive the DP-DES (1713 patients) and BP-DES (1700 patients). At 12 months, patient-oriented composite outcome occurred in 5.2% in the DP-DES group and 6.4% in the BP-DES group (absolute risk difference, -1.2%; P_{noninferiority}<0.001). The key secondary end point, device-oriented composite outcome, occurred less frequently in the DP-DES group (DP-DES vs BP-DES, 2.6% vs 3.9%; hazard ratio, 0.67 [95% CI, 0.46-0.98]; P=0.038), mostly because of a reduction in target lesion revascularization. The rate of spontaneous nonfatal myocardial infarction and stent thrombosis were extremely low, with no significant difference between the 2 groups (0.6% versus 0.8%; P=0.513 and 0.1% versus 0.4%; P=0.174, respectively).

CONCLUSIONS

In ACS patients receiving percutaneous coronary intervention, DP-DES was noninferior to BP-DES with regard to patient-oriented composite outcomes at 12 months after index percutaneous coronary intervention. Registration: URL: https://wwwclinicaltrials.gov; Unique identifier: NCT02193971.

Comparison of Shear Stress-Induced Thrombotic and Thrombolytic Effects Among 3 Different Antithrombotic Regimens in Patients With Acute Coronary Syndrome

Shear stress (SS)-induced platelet activation is suggested as an essential mechanism of the acute coronary syndrome (ACS). We aimed to compare SS-induced thrombotic and thrombolytic activities among 3 treatment regimens in patients with ACS who underwent percutaneous coronary intervention (PCI). Patients were nonrandomly enrolled and treated with one of 3 regimens (TICA: ticagrelor 180 mg/d; RIVA: clopidogrel 75 mg/d and rivaroxaban 5 mg/d; CLP: clopidogrel 75 mg/d), administered in addition to aspirin (100 mg/d) for 30 days. The global thrombosis test was applied to measure SS-induced thrombotic (occlusion time [OT]) and thrombolytic activity (lysis time [LT]) at day 2 and 30. Aspirin reaction unit (ARU) and P2Y12 reaction unit (PRU) were simultaneously measured using VerifyNow. Group differences in the OT, LT, ARU, and PRU were evaluated. Seventy-five patients (25 patients in each group) finished 30 days of follow-up. Clinical and angiographic characteristics did not differ among the 3 groups, except ACS subtype and pre-PCI coronary flow. No major adverse cardiovascular events occurred in any group during follow-up. The OT and LT did not differ among the 3 groups at day 30 (OT: TICA, 447.2 ± 87.1 vs RIVA, 458.5 ± 70.3, vs CLP, 471.9 ± 90.7, LT: 1522.3 ± 426.5 vs 1734.6 ± 454.3 vs 1510.2 ± 593.9) despite significant differences in the PRU among the 3 groups. Shear stress-induced thrombotic and thrombolytic activities did not differ among the 3 investigated antithrombotic treatments.

Atherogenic lipid stress induces platelet hyperactivity through CD36-mediated hyposensitivity to prostacyclin: the role of phosphodiesterase 3A

Prostacyclin (PGI₂) controls platelet activation and thrombosis through a cyclic adenosine monophosphate (cAMP) signaling cascade. However, in patients with cardiovascular diseases this protective mechanism fails for reasons that are unclear. Using both pharmacological and genetic approaches we describe a mechanism by which oxidized low density lipoproteins (oxLDL) associated with dyslipidemia promote platelet activation through impaired PGI₂ sensitivity and diminished cAMP signaling. In functional assays using human platelets, oxLDL modulated the inhibitory effects of PGI₂, but not a phosphodiesterase (PDE)-insensitive cAMP analog, on platelet aggregation, granule secretion and in vitro thrombosis. Examination of the mechanism revealed that oxLDL promoted the hydrolysis of cAMP through the phosphorylation and activation of PDE3A, leading to diminished cAMP signaling. PDE3A activation by oxLDL required Src family kinases, Syk and protein kinase C. The effects of oxLDL on platelet function and cAMP signaling were blocked by pharmacological inhibition of CD36, mimicked by CD36-specific oxidized phospholipids and ablated in CD36^−/− murine platelets. The injection of oxLDL into wild-type mice strongly promoted FeCl3-induced carotid thrombosis in vivo, which was prevented by pharmacological inhibition of PDE3A. Furthermore, blood from dyslipidemic mice was associated with increased oxidative lipid stress, reduced platelet sensitivity to PGI₂ex vivo and diminished PKA signaling. In contrast, platelet sensitivity to a PDE-resistant cAMP analog remained normal. Genetic deletion of CD36 protected dyslipidemic animals from PGI₂ hyposensitivity and restored PKA signaling. These data suggest that CD36 can translate atherogenic lipid stress into platelet hyperactivity through modulation of inhibitory cAMP signaling.

Long-Term Comparison of Platinum Chromium Everolimus-Eluting Stent vs. Cobalt Chromium Zotarolimus-Eluting Stent - 3-Year Outcomes From the HOST-ASSURE Randomized Clinical Trial

BACKGROUND

There are limited data on the long-term outcome of platinum chromium-based everolimus-eluting stents (PtCr-EES) vs. cobalt chromium-based zotarolimus-eluting stents (CoCr-ZES).Methods and Results:A total of 3,755 patients undergoing percutaneous coronary intervention (PCI) were randomized 2:1 to PtCr-EES or CoCr-ZES, and 96.0% of patients completed the 3-year clinical follow-up. The primary outcome was target lesion failure (TLF), defined as a composite of cardiac death, target vessel-related myocardial infarction (MI), and clinically-driven target lesion revascularization (TLR). At 3 years, TLF occurred in 5.3% and in 5.4% of the PtCr-EES and CoCr-ZES groups, respectively (hazard ratio 0.978; 95% confidence interval 0.730-1.310, P=0.919). There were no significant differences in the individual components of TLF. Routine angiographic follow-up was performed in 38.9% of the total patients. In a landmark analysis of the subgroup that had follow-up angiography, the clinically-driven TLR rate of CoCr-ZES was significantly higher than PtCr-EES group during the angiography follow-up period (P=0.009). Overall definite and probable stent thrombosis rates were very low in both groups (0.5% vs. 0.6%, P=0.677).

CONCLUSIONS

PtCr-EES and CoCr-ZES had similar and excellent long-term outcomes in both efficacy and safety after PCI in an all-comer population.

Comparison of Minimally Invasive Direct Coronary Artery Bypass and Percutaneous Coronary Intervention Using Second-Generation Drug-Eluting Stents for Coronary Artery Disease - Propensity Score-Matched Analysis

BACKGROUND

Some studies comparing minimally invasive direct coronary artery bypass (MIDCAB) and percutaneous coronary intervention (PCI) have reported MIDCAB's superiority, but they did not investigate contemporary PCI with newer generation drug-eluting stents (DES). We compared clinical outcomes after MIDCAB with previously reported outcomes after PCI with second-generation DES.Methods and Results:We retrospectively reviewed the records of patients treated with MIDCAB. Baseline characteristics and clinical outcomes after MIDCAB were compared with those for left anterior descending artery disease treated via PCI. The primary outcomes were major adverse cardiovascular and cerebrovascular events (MACCE), a composite of cardiovascular death, non-fatal myocardial infarction, ischemic stroke, and target vessel revascularization (TVR). A propensity score-matching (PSM) analysis was conducted to adjust for between-group differences in baseline characteristics. We analyzed 77 patients treated with MIDCAB and 2,206 treated with PCI. The MIDCAB group was older and had more severe coronary disease and a higher incidence of left ventricular dysfunction. Over a 3-year follow-up, the PCI group had favorable MACCE outcomes. After PSM, there were no between-group differences in MACCE (MIDCAB, 15.6% vs. PCI, 23.4%; hazard ratio [HR], 0.80; 95% CI: 0.38-1.68, P=0.548) or TVR (MIDCAB, 2.6% vs. PCI, 5.2%; HR, 0.51; 95% CI: 0.10-3.09, P=0.509).

CONCLUSIONS

Clinical outcomes were similar between MIDCAB and PCI using second-generation DES over 3 years of follow-up.

The Dipyridamole Added to Dual Antiplatelet Therapy in Cerebral Infarction After First Acute Myocardial Infarction: A Nationwide, Case-Control Study

Background and Purpose: No previous study has compared the impact of dipyridamole-based triple antiplatelet therapy on secondary stroke prevention and long-term outcomes to that of dual antiplatelet therapy (DAPT) in patients with acute myocardial infarction (AMI) and previous stroke. This study aimed to evaluate the impact of dipyridamole added to DAPT on stroke prevention and long-term outcomes in patients with cerebral infarction after first AMI.

Methods: This nationwide, case-control study included 75,789 patients with cerebral infarction after first AMI. A 1:4 propensity score matching ratio was adopted based on multiple variables. Finally, the data of 4,468 patients included in the DAPT group and 1,117 patients included in the Dipyridamole-DAPT group were analyzed. Primary outcome was overall survival. Secondary outcomes were cumulative event rate of recurrent MI or stroke, and cumulative intracerebral hemorrhage (ICH) and gastrointestinal bleeding rate.

Results: Long-term survival rate was comparable between the two groups (log-rank P = 0.1117), regardless of sex analyses. However, after first year, DAPT subgroup revealed better survival over DAPT-dipyridamole subgroup (log-rank P = 0.0188). In age subgroup analysis, a lower survival rate was detected in younger patients from the Dipyridamole-DAPT group after first year (log-rank P = 0.0151), but no survival difference for older patients. No benefit of Dipyridamole-DAPT was detected for patients after AMI, regardless of the myocardial infarction type. DAPT was superior to Dipyridamole-DAPT in patients who underwent percutaneous coronary intervention (PCI) (log-rank P = 0.0153) and ST elevation myocardial infarction after first year (log-rank P = 0.0019). Dipyridamole-DAPT did not reduce cumulative event rate of recurrent MI or stroke in patients after AMI. Moreover, Dipyridamole-DAPT increased the cumulative ICH rate (log-rank P = 0.0026), but did not affect the cumulative event rate of gastrointestinal bleeding. In Cox analysis, dipyridamole did not improve long-term survival.

Conclusions: This nationwide study showed that Dipyridamole-DAPT, compared with DAPT, did not improve long-term survival in patients with stroke after AMI, and was related to poor outcomes after 1 year. Dipyridamole-DAPT did not reduce recurrent rate of MI or stroke, but increased the ICH rate without impacting the incidence of gastrointestinal bleeding.

Adverse clinical outcomes associated with double dose clopidogrel compared to the other antiplatelet regimens in patients with coronary artery disease: a systematic review and meta-analysis

BACKGROUND

Recently, several newer antiplatelet treatment strategies have been used in patients with coronary artery disease (CAD). Apart from the dual antiplatelet therapy (DAPT) consisting of aspirin and clopidogrel, double dose clopidogrel (DDC), triple antiplatelet therapy (TAPT) consisting of aspirin, clopidogrel and cilostazol and other newer antiplatelet agents have shown to be effective in different ways. In this analysis, we aimed to systematically compare the adverse clinical outcomes and the bleeding events which were observed when DDC was compared to the other antiplatelet regimens in patients with CAD.

METHODS

English publications comparing DDC with other antiplatelet regimens were searched from MEDLARS/MEDLINE, EMBASE, www.ClinicalTrials.gov and Google Scholar. Adverse cardiovascular outcomes and bleeding events were the study endpoints. Statistical analysis was carried out by the RevMan 5.3 software whereby odds ratios (OR) with 95% confidence intervals (CIs) were calculated.

RESULTS

A total number of 23,065 participants were included. Results of this analysis showed major adverse cardiac events (MACEs), all-cause mortality, cardiac death, stroke, stent thrombosis, revascularization and myocardial infarction (MI) to have been similarly manifested in patients who were treated with DDC versus the control group with OR: 0.98, 95% CI: 0.78-1.22; p = 0.83, OR: 0.95, 95% CI: 0.77-1.17; p = 0.62, OR: 0.97, 95% CI: 0.79-1.20; p = 0.81, OR: 0.98, 95% CI: 0.65-1.48; p = 0.94, OR: 0.84, 95% CI: 0.40-1.75; p = 0.64, OR: 0.88, 95% CI: 0.52-1.49; p = 0.63, and OR: 0.89, 95% CI: 0.65-1.21; p = 0.45 respectively. Any minor and major bleedings were also similarly manifested. When DDC was compared to DAPT, no significant difference was observed in any bleeding event with OR: 1.58, 95% CI: 0.86-2.91; p = 0.14. Even when DDC was compared with either ticagrelor or prasugrel or TAPT, still no significant difference was observed in terms of bleeding outcomes.

CONCLUSIONS

In patients with CAD, adverse clinical outcomes were not significantly different when DDC was compared to the other antiplatelet regimens. In addition, bleeding events were also similarly manifested when DDC was compared to DAPT, TAPT or ticagrelor/prasugrel.

Stent thrombosis associated with drug eluting stents on addition of cilostazol to the standard dual antiplatelet therapy following percutaneous coronary intervention: a systematic review and meta-analysis of published randomized controlled trials

Background

In this analysis, we aimed to systematically compare stent thrombosis (ST) and its different subtypes following treatment with DAPT (aspirin + clopidogrel) versus TAPT (aspirin + clopidogrel + cilostazol).

Methods

Studies were included if: they were randomized controlled trials (RCTs) comparing TAPT (cilostazol + aspirin + clopidogrel) with DAPT (aspirin + clopidogrel); they reported ST or its subtype including definite, probable, acute, sub-acute and late ST as their clinical outcomes. RevMan software (version 5.3) was used to carry out this analysis whereby odds ratios (OR) and 95% confidence intervals (CI) were generated.

Results

Statistical analysis of the data showed no significant difference in total ST with the addition of cilostazol to the standard DAPT with OR: 0.65, 95% CI: 0.38–1.10; P = 0.11, I² = 6%. Moreover, when ST was further subdivided and analyzed, still, no significant difference was observed in acute, sub-acute, late, definite and probable ST with OR: 0.48, 95% CI: 0.13–1.74; P = 0.27, I² = 0%, OR: 0.56, 95% CI: 0.22–1.40; P = 0.21, I² = 0%, OR: 0.72, 95% CI: 0.23–2.28; P = 0.58, I² = 0%, OR: 1.18, 95% CI: 0.38–3.69; P = 0.77, I² = 3% and OR: 0.75, 95% CI: 0.17–3.55; P = 0.70, I² = 0% respectively. No change was observed during a short term (≤ 6 months) and a longer (≥ 1 year) follow-up time period.

Conclusions

This current analysis showed no significant difference in stent thrombosis with the addition of cilostazol to the standard dual antiplatelet therapy during any follow-up time period after PCI.

Cilostazol, a phosphodiesterase 3 inhibitor, activates proteasome-mediated proteolysis and attenuates tauopathy and cognitive decline

Alzheimer's disease and several variants of frontotemporal degeneration including progressive supranuclear palsy and corticobasal degeneration are characterized by the accumulation of abnormal tau protein into aggregates. Most proteins, including tau, are degraded via the ubiquitin proteasome system, but when abnormal tau accumulates, the function of 26S proteasomes is downregulated. The negative effect of tau aggregates on the function of the proteasome can have deleterious consequences on protein homeostasis and disease progression. Developing therapies aimed at clearing abnormal tau are thus of considerable interest. In the present study, we investigated the effect of cilostazol, an FDA-approved selective phosphodiesterase 3 inhibitor, on a mouse model of tauopathy (line rTg4510). Administration of cilostazol for 30 days enhanced proteasome function via the cyclic adenosine 3',5'-monophosphate/protein kinase A pathway and attenuated tauopathy and cognitive decline in rTg4510 mice. These results suggest that cilostazol, or other FDA-approved drugs acting via the same pathway, has the potential to be repurposed for the treatment of patients with early-stage tauopathy.

The Evolving Concept of Dual Antiplatelet Therapy after Percutaneous Coronary Intervention: Focus on Unique Feature of East Asian and "Asian Paradox"

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is essential after percutaneous coronary intervention (PCI), while many studies have focused on determining the optimal degree of platelet inhibition and optimal DAPT duration to minimize complications after PCI. Current guidelines developed by the American College of Cardiology/American Heart Association and the European Society of Cardiology summarize previous studies and provide recommendations. However, these guidelines are mainly based on Western patients, and their characteristics might differ from those of East Asian patients. Previous data suggested that East Asian patients have unique features with regard to the response to antiplatelet agents. On comparing Western and East Asian patients, it was found that East Asian patients have a lower rate of ischemic events and higher rate of bleeding events after PCI, despite a higher on-treatment platelet reactivity, which is referred to as the “East Asian paradox.” As the main purpose of DAPT is to minimize ischemic and bleeding complications after PCI, these differences should be clarified before adopting the guidelines for East Asian patients. Therefore, in this article, we will review various issues regarding DAPT in East Asian patients, with a focus on the unique characteristics of East Asian patients, previous studies regarding antiplatelet agents in East Asian patients, and a guideline from an East Asian perspective.

How important is aspirin adherence when evaluating effectiveness of low-dose aspirin?

Low-dose aspirin (LDA) is advocated for women at high-risk of pre-eclampsia, providing a modest, 10%, reduction in risk. Cardiology meta-analyses demonstrate 18% reduction in serious vascular events with LDA. Non-responsiveness to aspirin (sometimes termed aspirin resistance) and variable clinical effectiveness are often attributed to suboptimal adherence. The aim of this review was to identify the scope of adherence assessments in RCTs evaluating aspirin effectiveness in cardiology and obstetrics and discuss the quality of information provided by current methods. We searched MEDLINE, EMBASE and the Cochrane Library, limited to humans and English language, for RCTs evaluating aspirin in cardiology; 14/03/13-13/03/16 and pregnancy 1957-13/03/16. Search terms; 'aspirin', 'acetylsalicylic acid' appearing adjacent to 'myocardial infarction' or 'pregnancy', 'pregnant', 'obstetric' were used. 38% (25/68) of obstetric and 32% (20/62) of cardiology RCTs assessed aspirin adherence and 24% (6/25) and 29% (6/21) of obstetric and cardiology RCTs, respectively, defined acceptable adherence. Semi-quantitative methods (pill counts, medication weighing) prevailed in obstetric RCTs (93%), qualitative methods (interviews, questionnaires) were more frequent in obstetrics (67%). Two obstetric RCTs quantified serum thromboxane B₂ and salicylic acid, but no quantitative methods were used in cardiology Aspirin has proven efficacy, but suboptimal adherence is widespread and difficult to accurately quantify. Little is currently known about aspirin adherence in pregnancy. RCTs evaluating aspirin effectiveness show over-reliance on qualitative adherence assessments vulnerable to inherent inaccuracies. Reliable adherence data is important to assess and optimise the clinical effectiveness of LDA. We propose that adherence should be formally assessed in future trials and that development of quantitative assessments may prove valuable for trial protocols.

Cigarette Smoking Does Not Enhance Clopidogrel Responsiveness After Adjusting VerifyNow P2Y12 Reaction Unit for the Influence of Hemoglobin Level

OBJECTIVES

The authors performed this analysis to examine whether the enhanced clopidogrel responsiveness in current smokers is maintained after adjusting the influence of hemoglobin on VerifyNow P2Y12 reaction unit (PRU).

BACKGROUND

PRU is consistently reported to be lower in current smokers. However, PRU has a significant inverse relationship with hemoglobin level, and smokers have higher hemoglobin levels. Because the association between PRU and hemoglobin is likely to be an in vitro phenomenon, we hypothesized that the observed difference in PRU between nonsmokers and current smokers is the result of confounding effect of hemoglobin rather than true difference in platelet reactivity.

METHODS

Three cohorts were combined for the analysis (SNUBH [Seoul National University Bundang Hospital], n = 459; CILON-T [influence of CILostazol-based triple antiplatelet therapy ON ischemic complication after drug-eluting stenT implantation], n = 715; HOST-ASSURE [Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen], n = 1,357). The final combined cohort consisted of 1,314 patients who underwent percutaneous coronary intervention and had VerifyNow P2Y12 assay results. General linear model (analysis of covariance) was used to control the effect of hemoglobin on PRU.

RESULTS

A significant inverse correlation was observed between PRU and hemoglobin (r = -0.389; p < 0.001). Current smokers showed a significantly higher hemoglobin level (13.5 ± 1.6 vs. 14.4 ± 1.5; p < 0.001) but lower PRU level (230.1 ± 90.7 vs. 212.2 ± 83.6; p < 0.001). After adjusting the influence of hemoglobin on PRU, there was no difference in PRU between nonsmokers and current smokers (224.1 [95% confidence interval: 218.7 to 229.5] vs. 225.3 [95% confidence interval: 217.2 to 233.3]; p = 0.813).

CONCLUSIONS

The observed difference in PRU between nonsmokers and current smokers is largely attributable to the difference in hemoglobin level. Enhanced clopidogrel responsiveness in cigarette smokers is not confirmed in this study and the concept of the smokers' paradox needs further validation.

A laboratory association between hemoglobin and VerifyNow P2Y12 reaction unit: A systematic review and meta-analysis

BACKGROUND

VerifyNow P2Y12 assay is used widely to evaluate residual platelet reactivity in patients taking P2Y12 receptor antagonists. However, a laboratory association between VerifyNow P2Y12 reaction unit (PRU) and hemoglobin, which might lead to wrong interpretation of the data, is reported. We performed these systematic review and meta-analysis to clearly define the relationship between PRU and hemoglobin and to elucidate whether the relationship, if any, is a true biological association or is just a laboratory error.

METHODS

Through a comprehensive electronic and manual search, 10 studies were selected for the cohort level meta-analysis. Among 10 studies, we were able to retrieve the raw data of 5 studies, and a patient-level meta-analysis was performed. Potential publication bias was searched by funnel plot analysis and was actively adjusted, if present, by trim and fill method.

RESULTS

The pooled analysis revealed a significant inverse correlation between PRU and hemoglobin (r=-0.349; P<.001; 10 studies with 4,793 patients). VerifyNow P2Y12 base unit, which reflects off-drug platelet reactivity, was also inversely correlated with hemoglobin (r=-0.526; P<.001; 8 studies with 4,395 patients). % Inhibition (r=0.081; P=.059; 6 studies with 3,832 patients) and ΔPRU (r=-0.037; P=.188; 5 studies with 3,521 patients) were not associated with hemoglobin. A significant inverse association between PRU and hemoglobin was also observed in the patient-level meta-analysis (3,533 patients pooled from 5 studies; r=-0.335; P<.001). Light transmission aggregometry (r=0.160; P=.072; 4 studies with 1,144 patients) and multiple electrode platelet aggregometry (r=-0.029; P=.394; 3 studies with 7,645 patients) showed no significant association with hemoglobin.

CONCLUSIONS

A significant inverse association was observed between PRU and hemoglobin which is likely to be a laboratory error. Clinicians should be aware that this association might lead to wrong interpretation of the data.

Oral antiplatelet drugs in patients with chronic kidney disease (CKD): a review

Oral Antiplatelet Drugs (OAD) have a proven track record in the risk reduction of major cardiovascular events in patients with cardiovascular disease and normal kidney function. However, major gaps exist in our understanding of their effects on thrombosis and bleeding in chronic kidney disease (CKD). Clinical practice guidelines are ambiguous about use of such drugs in CKD patients, because patients with moderate to severe CKD were systematically excluded from clinical trials evaluating the efficacy and safety of OAD. Paradoxically, CKD patients are at high risk of thrombosis and major bleeding events. Thus, choosing the right combination of OAD for cardiovascular protection in these patients is challenging. Patients with CKD exhibit high rates of OAD hyporesponsiveness. It is, therefore, imperative to explore the mechanisms responsible for poor response to OAD in CKD patients in order to use these drugs more safely and effectively. This review explores suggested mechanisms of platelet dysfucntion in CKD patients and the available evidence on the efficacy and safety of oral antiplatelet drugs in patients with renal dysfunction.

Antiplatelet Therapy of Cilostazol or Sarpogrelate with Aspirin and Clopidogrel after Percutaneous Coronary Intervention: A Retrospective Cohort Study Using the Korean National Health Insurance Claim Database

Background/Objectives

Addition of cilostazol or sarpogrelate to the standard dual antiplatelet therapy of aspirin and clopidogrel has been implemented in patients that underwent percutaneous coronary intervention (PCI) with stents in Korea. This study aimed to evaluate the efficacy and safety of triple antiplatelet therapies.

Methods

This retrospective cohort study was performed using the Korean National Insurance Claim Data of the Health Insurance Review and Assessment Service from January 1, 2009 to December 31, 2014. The study cohort population consisted of patients with ischemic heart diseases and a history of PCI. They were treated with antiplatelet therapy of aspirin, clopidogrel (AC); aspirin, clopidogrel, cilostazol (ACCi); or aspirin, clopidogrel, sarpogrelate (ACSa) during the index period from January 1, 2010 to December 31, 2011. During the follow-up period up to December 31, 2014, the major adverse cardiac or cerebral events (MACCE) including death, myocardial infarction, target lesion revascularization, and ischemic stroke were assessed. Bleeding complications were also evaluated as adverse drug events.

Results

Out of 93,876 patients with PCI during the index period, 69,491 patients started dual (AC) or triple therapy (ACSa or ACCi). The clinical outcomes of comparing ACSa and ACCi therapy showed beneficial effects in the ACSa group in the prevention of subsequent cardiac or cerebral events. After Propensity score-matching between ACSa and ACCi groups, there were significant differences in MI and revascularization, with corresponding HR of 0.38 (95% CI, 0.20–0.73) and 0.66 (95% CI, 0.53–0.82) in ACSa vs. ACCi at 12 months, respectively. At the 24-month follow-up, the triple therapy groups (ACS or ACC) had a higher incidence of MACCE compared to the dual therapy (AC) group; ACSa vs. AC HR of 1.69 (95% CI, 1.62–1.77); ACC vs. AC HR of 1.22 (95% CI, 1.06–1.41). There was no significant difference in severe or life-threatening bleeding risk among three groups; ACSa vs. AC, HR of 0.68 (95% CI, 0.37–1.24), ACCi vs. AC, HR of 0.91 (95% CI, 0.77–1.09).

Conclusion

Sarpogrelate-containing triple antiplatelet therapy demonstrated comparable rates of MACCE prevention to the conventional dual antiplatelet therapy after PCI without significantly increasing bleeding risk during the two-year follow-up period.

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

Cilostazol is a unique antiplatelet agent that has been commercially available for over two decades. As a phosphodiesterase III inhibitor, it reversibly inhibits platelet aggregation yet also possesses vasodilatory and antiproliferative properties. It has been widely studied in a variety of disease states, including peripheral arterial disease, cerebrovascular disease, and coronary artery disease with percutaneous coronary intervention. Overall, cilostazol appears to be a promising agent in the management of these disease states with a bleeding profile comparable to placebo; even when combined with other antiplatelet agents, cilostazol does not appear to increase the rate of bleeding. Despite the possible benefit of cilostazol, its use is limited by tolerability as some patients often report drug discontinuation due to headache, diarrhea, dizziness, or increased heart rate. To date, it has been predominantly studied in the Asian population, making it difficult to extrapolate these results to a more diverse patient population. This paper discusses the evolving role of cilostazol in the treatment of vascular diseases.

The pharmacokinetic and pharmacodynamic interaction of clopidogrel and cilostazol in relation to CYP2C19 and CYP3A5 genotypes

AIM

The primary objective of the present study was to evaluate the pharmacokinetic and pharmacodynamic interactions between clopidogrel and cilostazol in relation to the CYP2C19 and CYP3A5 genotypes.

METHODS

In a randomized, three-way crossover study, 27 healthy subjects were administered clopidogrel (300 mg), cilostazol (100 mg) or clopidogrel + cilostazol orally. Plasma concentrations of clopidogrel, cilostazol and their active metabolites (clopidogrel thiol metabolite, 3,4-dehydrocilostazol and 4″-trans-hydroxycilostazol), and adenosine diphosphate-induced platelet aggregation were measured for pharmacokinetic and pharmacodynamic assessment.

RESULTS

The area under the plasma concentration-time curve (AUC) of the active thiol metabolite of clopidogrel was highest in the CYP2C19 extensive metabolizers (EM) and lowest in the poor metabolizers (PM). Cilostazol decreased the thiol metabolite AUC by 29% in the CYP3A5*1/*3 genotype [geometric mean ratio (GMR) 0.71; 90% confidence interval (CI) 0.58, 0.86; P = 0.020] but not in the CYP3A5*3/*3 genotype (GMR 0.93; 90% CI 0.80, 1.10; P = 0.446). Known effects of the CYP2C19 and CYP3A5 genotypes on the exposure of cilostazol and its metabolites were observed but there was no significant difference in the AUC of cilostazol and 3,4-dehydrocilostazol between cilostazol and clopidogrel + cilostazol. The inhibition of platelet aggregation from 4 h to 24 h (IPA4-24 ) following the administration of clopidogrel alone was highest in the CYP2C19 EM genotype and lowest in the CYP2C19 PM genotype (59.05 ± 18.95 vs. 36.74 ± 13.26, P = 0.023). However, the IPA of the CYP2C19 PM following co-administration of clopidogrel and cilostazol was comparable with that of the CYP2C19 EM and intermediate metabolizers (IM) only in CYP3A5*3/*3 subjects.

CONCLUSIONS

The additive antiplatelet effect of cilostazol plus clopidogrel is maximized in subjects with both the CYP2C19 PM and CYP3A5*3/*3 genotypes because of a lack of change of clopidogrel thiol metabolite exposure in CYP3A5*3/*3 as well as the highest cilostazol IPA in CYP2C19 PM and CYP3A5*3/*3 subjects.

It Is Not Mandatory to Use Triple Rather Than Dual Anti-Platelet Therapy After a Percutaneous Coronary Intervention With a Second-Generation Drug-Eluting Stent

It has been shown that triple antiplatelet therapy with cilostazol results in better clinical outcomes than dual therapy in patients treated with a first-generation drug-eluting stent (DES); however, it is unclear whether triple antiplatelet therapy has a similar efficacy after the implantation of second-generation DES.In the COACT (Cath Olic medical center percutAneous Coronary in Tervention) registry, 1248 study subjects who underwent percutaneous coronary intervention with an everolimus- or zotarolimus-eluting stent (Endeavor, Xience V, or Promus) were analyzed. The patients were divided into 2 groups after propensity score matching (n = 724; M = 422 [58.3%]; mean age = 66.1 ± 11.0 years): Group 1: patients treated with dual antiplatelet drugs (aspirin and clopidogrel; n = 362; M = 213 [58.8%]; mean age = 65.6 ± 11.7 years); Group 2: patients treated with triple antiplatelet drugs (aspirin, clopidogrel, and cilostazol; n = 362; M = 209 [57.7%]; mean age = 65.6 ± 11.7 years). The mean follow-up duration was 13 ± 10 months, and the cumulative incidence of major cardiovascular events (MACE) was 6.3% in Group 1 and 7.7% in Group 2. There were no significant differences in MACE (death, nonfatal myocardial infarction, and stroke) between the 2 groups (OR, 1.210; 95% CI: 0.772-1.898; P = 0.406). Kaplan-Meier curves for MACE did not show any survival benefit for triple antiplatelet therapy, even in patients with acute coronary syndrome.In patients treated with a second-generation DES implantation, there is no added clinical benefit to using triple rather than dual antiplatelet therapy.

Rationale, Design, and Baseline Characteristics of the EPICOR Asia Study (Long-tErm follow-uP of antithrombotic management patterns In Acute CORonary Syndrome patients in Asia)

BACKGROUND

In-hospital and postdischarge mortality for acute coronary syndromes (ACS) vary across Asia and remain generally poorer than globally. The relationship between real-life antithrombotic management patterns (AMPs) and ACS-related outcomes in Asia is unclear.

METHODS

EPICOR Asia (Long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients in Asia) (NCT01361386) is a prospective, multinational, observational study of patients discharged after hospitalization for an ACS, with 2-year follow-up. The aim is to describe short- and long-term (up to 2 years post-index event) AMPs in patients hospitalized for ACS and to record clinical outcomes, healthcare resource use, and self-reported health status. Pre- and in-hospital management, AMPs, and associated outcomes, with particular focus on ischemic and bleeding events, will be recorded during the 2-year follow up.

RESULTS

Between June 2011 and May 2012, 13 005 patients were enrolled. From these, 12 922 patients surviving an ACS (6616 with STEMI, 2570 with NSTEMI, and 3736 with UA) were eligible for inclusion from 219 hospitals across 8 countries and regions in Asia: China (n = 8214), Hong Kong (n = 177), India (n = 2468), Malaysia (n = 100), Singapore (n = 93), South Korea (n = 705), Thailand (n = 957), and Vietnam (n = 208).

CONCLUSIONS

EPICOR Asia will provide information regarding clinical management and AMPs for ACS patients in Asia. Impact of AMPs on clinical outcomes, healthcare resource use, and self-reported health status both during hospitalization and up to 2 years after discharge will also be described.

Efficacy of cilostazol on platelet reactivity and cardiovascular outcomes in patients undergoing percutaneous coronary intervention: insights from a meta-analysis of randomised trials

BACKGROUND

Cilostazol overcomes high on-treatment platelet reactivity (HTPR) and reduces adverse cardiovascular (CV) outcomes after percutaneous coronary intervention (PCI). However, the role for triple antiplatelet therapy (TAPT) with cilostazol in addition to aspirin and clopidogrel after PCI is not well defined.

METHODS

We conducted a MEDLINE/EMBASE/CENTRAL search for randomised trials, until May 2014, evaluating TAPT compared with dual antiplatelet therapy (DAPT) of aspirin and clopidogrel alone in patients undergoing PCI and reporting platelet reactivity and/or CV outcomes. The primary platelet reactivity outcome was differences in platelet reactivity unit (PRU) with secondary outcomes of %platelet inhibition and rate of HTPR. The primary CV outcome was major adverse cardiovascular events (MACE), with secondary outcomes of death, cardiovascular death, myocardial infarction, stent thrombosis (ST), target lesion revascularisation (TLR) and target vessel revascularisation (TVR) as well as safety outcomes of bleeding and drug discontinuations.

RESULTS

In 17 trials that evaluated platelet reactivity outcomes, the mean PRU value was 47.73 units lower with TAPT versus DAPT (95% CI -61.41 to -34.04, p<0.0001; mean PRU 182.90 vs 232.65). TAPT also increased platelet inhibition by 12.71% (95% CI 10.76 to 14.67, p<0.0001), and led to a 60% reduction in the risk of HTPR (relative risk=0.40; 95% CI 0.30 to 0.53) compared with DAPT. Moreover, among the 34 trials that evaluated CV outcomes, TAPT reduced the risk of MACE (incident rate ratio (IRR)=0.68; 95% CI 0.60 to 0.78), TLR (IRR=0.57; 95% CI 0.44 to 0.73), TVR (IRR=0.69; 95% CI 0.59 to 0.81) and ST (IRR=0.63; 95% CI 0.40 to 0.98) with no difference for other outcomes including bleeding, even in trials using drug-eluting stents. Drug discontinuation due to adverse effects was, however, higher with TAPT vs DAPT (IRR=1.59; 95% CI 1.32 to 1.91).

CONCLUSIONS

In patients undergoing PCI, addition of cilostazol to DAPT results in decreased platelet reactivity and a significant reduction in CV outcomes including ST, even in the drug-eluting stent era.