Jeong Rang Park

Accelerated platelet inhibition by switching from atorvastatin to a non-CYP3A4-metabolized statin in patients with high platelet reactivity (ACCEL-STATIN) study

AIMS CYP3A4-metabolized statins can influence the pharmacodynamic effect of clopidogrel. We sought to assess the impact of switching to a non-CYP3A4-metabolized statin on platelet function among patients receiving clopidogrel and atorvastatin with high on-treatment platelet reactivity (HPR). METHODS AND RESULTS Percutaneous coronary intervention (PCI)-treated patients (n= 50) with HPR [20 μM adenosine diphosphate (ADP)-induced maximal platelet aggregation (MPA) >50%] were enrolled during chronic administration of atorvastatin (10 mg/day) and clopidogrel (75 mg/day) (≥6 months). They were randomly assigned to a 15-day therapy with either rosuvastatin 10 mg/day (n= 25) or pravastatin 20 mg/day (n= 25). Platelet function was assessed before and after switching by conventional aggregometry and the VerifyNow P2Y12 assay. Genotyping was performed for CYP2C19*2/*3, CYP3A5*3, and ABCB1 C3435T alleles. The primary endpoint was the absolute change in 20 μM ADP-induced MPA. After switching, MPAs after stimuli with 20 and 5 μM ADP were decreased by 6.6% (95% confidence interval: 3.2-10.1%; P < 0.001), and 6.3% (95% confidence interval: 2.5-10.2%; P = 0.002), respectively. Fifty-two P2Y12 reaction units fell (95% confidence interval: 35-70; P < 0.001) and the prevalence of HPR decreased (24%; P < 0.001). Pharmacodynamic effects were similar after rosuvastatin and pravastatin therapy. In addition to smoking status, the combination of calcium channel blocker usage and ABCB1 C3435T genotype significantly affected the change of 20 μM ADP-induced MPA. CONCLUSIONS Among PCI-treated patients with HPR during co-administration of clopidogrel and atorvastatin, switching to a non-CYP3A4-metabolized statin can significantly decrease platelet reactivity and the prevalence of HPR. This switching effect appears similar irrespective of the type of non-CYP3A4-metabolized statin.

Risk Stratification Using Computed Tomography Coronary Angiography in Patients Undergoing Intermediate-Risk Noncardiac Surgery

OBJECTIVES This study evaluated whether coronary artery calcium scores (CACS) and the degree of stenosis that were measured with computed tomography coronary angiography (CTCA) predicted post-operative cardiovascular events in patients who were undergoing intermediate-risk noncardiac surgery. BACKGROUND Cardiovascular complications are important causes of mortality and morbidity in patients undergoing major noncardiac surgeries. METHODS A total of 239 patients underwent CTCA before intermediate-risk noncardiac surgeries. We measured CACS and the degree of stenosis with CTCA and assessed clinical risk factors according to the revised cardiac risk index (RCRI) scores. Post-operative cardiovascular events were defined as cardiac death, acute coronary syndrome, pulmonary edema, ventricular arrhythmia with hemodynamic compromise, and complete heart block. RESULTS Nineteen patients (8%) had post-operative cardiac events. The variables that correlated with the occurrence of cardiac events were RCRI (p < 0.001), CACS (p < 0.001), the presence of significant coronary artery stenosis (diameter stenosis ≥50%) (p = 0.01), and multivessel coronary artery disease (p < 0.001). In the receiver-operating characteristic (ROC) curve analysis of CACS for prediction of cardiac events, the cutoff value was 113 (sensitivity, 0.79; specificity, 0.61; area under the curve, 0.762). When comparing ROC curves of the combination models of RCRI, high CACS (≥113), and the presence of multivessel disease, RCRI plus high CACS, RCRI plus multivessel disease, and RCRI plus high CACS plus multivessel disease were significantly more predictable of post-operative cardiovascular events than RCRI alone. CONCLUSIONS In the pre-operative risk stratification of patients who were undergoing intermediate-risk noncardiac surgeries, CTCA evaluations showed additive value to RCRI.

Relation between the vasodilator-stimulated phosphoprotein phosphorylation assay and light transmittance aggregometry in East Asian patients after high-dose clopidogrel loading

OBJECTIVES We analyzed the relation between platelet aggregation measured by light transmittance aggregometry (LTA) and platelet reactivity index (PRI) measured by vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) assay. BACKGROUND It has been suggested that LTA and VASP-P assay correlate differently according to the level of P2Y12 receptor blockade by thienopyridines. METHODS We simultaneously measured platelet function by LTA and VASP-P assay in 466 East Asians undergoing elective percutaneous coronary intervention after a 600-mg clopidogrel loading. High on-clopidogrel platelet reactivity (HPR) was defined by published consensus criteria. RESULTS The degree of correlation between LTA and the VASP-P assay was different according to PRI levels. The correlation was lower in patients with poor responsiveness (PRI >60%) (n = 216) (0.035 ≤ r(2) ≤ 0.047), which was greater in responsive patients (PRI ≤60%) (n = 250) (0.315 ≤ r(2) ≤ 0.526). Despite a 600-mg loading, East Asians had a high prevalence of HPR (40.1%-63.5%), and the prevalence of HPR also differed between LTA and VASP-P assay. A PRI cutoff of >58% (area under curve, 0.829; 95% confidence intervals, 0.792-0.862; P < .001) corresponded to the published HPR cutoff by 5-μM adenosine diphosphate-induced maximal platelet aggregation >46%. CONCLUSIONS This is the largest study correlating platelet reactivity measured by LTA and VASP-P assay in a percutaneous coronary intervention-treated cohort. The correlation is dependent on the level of responsiveness. Future investigations are needed to better define the optimal cutoffs of HPR measured by LTA and VASP-P assay for personalized antiplatelet therapy.

Normal Echocardiographic Measurements in a Korean Population Study: Part I. Cardiac Chamber and Great Artery Evaluation

Background Measurement of the cardiac chamber is essential, and current guidelines recommend measuring and reporting values for both sides of the cardiac chamber during echocardiographic evaluation. Normal echocardiographic reference values have been suggested previously, but detailed information about right-sided chambers and values according to gender was not included. Methods This is a prospective multicenter (23 centers) study evaluating normal Korean adult subjects using comprehensive echocardiography. We included normal adult subjects (age; 20-79 years old) who had no significant cardiac disorders or illnesses, such as hypertension or diabetes, which could affect cardiac structure and function. We measured the cardiac chamber including both right and left ventricles as well as atria according to current echocardiography guidelines and compared values according to gender and age groups. Results A total of 1003 subjects were evaluated and the mean age was 48 ± 16 years. Left ventricular (LV) dimensions increased, but LV volume decreased in older subjects. Right ventricular (RV) area decreased in women and older subjects, and the RV long-axis dimension showed a similar trend. Left atrial (LA) volume increased in men but there were no differences in LA volume index between men and women. The dimension of great arteries increased in men and older subjects. Conclusion Since there were considerable differences between men and women and in the different age groups, and the trends differed significantly between different echo variables, normal echocardiographic cutoff values should be differentially applied based on age and gender.

Pharmacodynamic Effect of Cilostazol Plus Standard Clopidogrel Versus Double-Dose Clopidogrel in Patients With Type 2 Diabetes Undergoing Percutaneous Coronary Intervention

OBJECTIVE To determine the effect of adding cilostazol (100 mg b.i.d.) to standard-dose clopidogrel (75 mg/d) (TRIPLE) compared with double-dose clopidogrel (150 mg/d) (DOUBLE) and the influence of the cytochrome P450 (CYP2C19*2/*3, CYP3A5*3)and ATP-binding cassette subfamily B1(ABCB1 C3435T) genetic polymorphisms in type 2 diabetes (T2DM) patients. RESEARCH DESIGN AND METHODS T2DM patients were treated with TRIPLE (n = 41) or DOUBLE (n = 39) after percutaneous coronary intervention. Conventional aggregometry and VerifyNow were performed at baseline and at 30 days. The primary end point was absolute change in 20-μM ADP-induced maximal platelet aggregation (ΔMPA20) between baseline and switching values. RESULTS TRIPLE versus DOUBLE showed greater ΔMPA20 (22.9 ± 11.6 vs.12.7 ± 15.5%; difference, 10.2% [95% CI 4.2–16.3]; P < 0.001). Carriage of one (β coefficient, −5.4%; P = 0.162) and two CYP2C19 loss-of-function allele(s) (−8.3%; P = 0.007) were associated with lower ΔMPA20 in DOUBLE–treated patients, but not in TRIPLE-treated patients. CONCLUSIONS Among T2DM patients, adding cilostazol achieves greater platelet inhibition compared with clopidogrel (150 mg/d), which is not influenced by genetic polymorphisms.

Normal 2-Dimensional Strain Values of the Left Ventricle: A Substudy of the Normal Echocardiographic Measurements in Korean Population Study

Background It is important to understand the distribution of 2-dimensional strain values in normal population. We performed a multicenter trial to measure normal echocardiographic values in the Korean population. Methods This was a substudy of the Normal echOcardiogRaphic Measurements in KoreAn popuLation (NORMAL) study. Echocardiographic specialists measured frequently used echocardiographic indices in healthy people according to a standardized method at 23 different university hospitals. The strain values were analyzed from digitally stored images. Results Of a total of 1003 healthy participants in NORMAL study, 2-dimensional strain values were measured in 501 subjects (265 females, mean age 47 ± 15 years old) with echocardiographic images only by GE echocardiographic machines. Interventricular septal thickness, left ventricular (LV) posterior wall thickness, systolic and diastolic LV dimensions, and LV ejection fraction were 7.5 ± 1.0 mm, 7.4 ± 1.0 mm, 29.9 ± 2.8 mm, 48.9 ± 3.6 mm, and 62 ± 4%, respectively. LV longitudinal systolic strain (LS) values of apical 4-chamber (A4C) view, apical 3-chamber (A3C) view, apical 2-chamber (A2C) view, and LV global LS (LVGLS) were −20.1 ± 2.3, −19.9 ± 2.7, −21.2 ± 2.6, and −20.4 ± 2.2%, respectively. LV longitudinal systolic strain rate (LVLSR) values of the A4C view, A3C view, A2C view, and LV global LSR (LVGLSR) were −1.18 ± 0.18, −1.20 ± 0.21, −1.25 ± 0.21, and −1.21 ± 0.21−s, respectively. Females had lower LVGLS (−21.2 ± 2.2% vs. −19.5 ± 1.9%, p < 0.001) and LVGLSR (−1.25 ± 0.18−s vs. −1.17 ± 0.15−s, p < 0.001) values than males. Conclusion We measured LV longitudinal strain and strain rate values in the normal Korean population. Since considerable gender differences were observed, normal echocardiographic cutoff values should be differentially applied based on sex.

Protective effect of cilostazol against doxorubicin-induced cardiomyopathy in mice

Doxorubicin (Dox) is an effective anti-cancer drug, but its use is limited because of its adverse effect of inducing irreversible dilated cardiomyopathy. Cilostazol (Cilo), a potent phosphodiesterase III inhibitor, has been reported to have an anti-inflammatory effect. Here, we investigated whether Cilo has a protective effect against Dox-induced cardiomyopathy (DIC). Mice were randomly divided into four groups: saline control, Dox (15 mg/kg), Dox (15 mg/kg) plus Cilo (50mg/kg), and Cilo (50mg/kg). The results showed that the coadministration of Dox and Cilo significantly enhanced left-ventricular systolic function compared with Dox alone. In addition, Cilo treatment significantly reduced Dox-induced perivascular fibrosis, collagen concentration, and connective growth factor expression in the heart. Also, Cilo administration markedly reduced Dox-induced levels of serum B-type natriuretic peptide, dysferlin, high-mobility group protein B1, Toll-like receptor 4, nuclear factor-κB p65, and cyclooxygenase-2. Furthermore, Cilo treatment significantly reduced Dox-induced oxidative stress by lowering the translocation of Nrf2 into the nucleus and the expression of NQO1, heme oxygenase 1, and superoxide dismutase-1. Our results suggest that Cilo may be a potential antifibrotic, antioxidative, and anti-inflammatory drug for DIC.

Novel role of platelet reactivity in adverse left ventricular remodelling after ST-segment elevation myocardial infarction: The REMODELING Trial

The role of platelet-leukocyte interaction in the infarct myocardium still remains unveiled. We aimed to determine the linkage of platelet activation to post-infarct left ventricular remodelling (LVR) process. REMODELING was a prospective, observational, cohort trial including patients (n = 150) with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. Patients were given aspirin plus clopidogrel therapy (600 mg loading and 75 mg daily). Platelet reactivity (PRU: P2Y12 Reaction Units) was assessed with VerifyNow P2Y12 assay on admission. Transthoracic echocardiography was performed on admission and at one-month follow-up. The primary endpoint was the incidence of LVR according to PRU-based quartile distribution. LVR was defined as a relative ≥ 20 % increase in LV end-diastolic volume (LVEDV) between measurements. Adverse LVR was observed in 36 patients (24.0 %). According to PRU quartile, LVR rate was 10.8 % in the first, 23.1 % in the second, 27.0 % in the third, and 35.1 % in the fourth (p = 0.015): the optimal cut-off of PRU was ≥ 248 (area under curve: 0.643; 95 % confidence interval: 0.543 to 0.744; p = 0.010). LVR rate also increased proportionally according to the level of high sensitivity-C reactive protein (hs-CRP) (p = 0.012). In multivariate analysis, the combination of PRU (≥ 248) and hs-CRP (≥ 1.4 mg/l) significantly increased the predictive value for LVR occurrence by about 21-fold. In conclusion, enhanced levels of platelet activation and inflammation determined the incidence of adverse LVR after STEMI. Combining the measurements of these risk factors increased risk discrimination of LVR. The role of intensified antiplatelet or anti-inflammatory therapy in post-infarct LVR process deserves further study.

Influence of platelet reactivity on BARC classification in East Asian patients undergoing percutaneous coronary intervention. Results of the ACCEL-BLEED study.

An increasing body of data suggests that East Asian patients have differing risk profiles for both thrombophilia and bleeding compared with Western population. This study was designed to evaluate the relationship of bleeding to platelet function in East Asians undergoing percutaneous coronary intervention (PCI). Patients who had undergone uneventful PCI (n= 301) were prospectively enrolled and bleeding events were evaluated during dual antiplatelet therapy (DAPT) with aspirin and clopidogrel. Platelet function was measured during hospitalisation and at 30-day follow-up by light transmittance aggregometry (LTA) and vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) assay. During 30-day follow-up, 29.2 % of patients (n= 88) experienced post-discharge Bleeding Academic Research Consortium (BARC) complications (24.6 % and 7.0 % of BARC type 1 and 2, respectively). Patients presenting with acute myocardial infarction had fewer episodes of type 1 BARC bleeding (odds ratio: 0.41; 95 % confidence interval: 0.22 to 0.76; p= 0.005). The cut-off of low platelet reactivity (LPR) (20 µM ADP-induced platelet aggregation ≤ 46.1 %; platelet reactivity index ≤ 45.1 %) was the independent determinant of type 2 BARC bleeding (odds ratio: 3.55 and 4.44; p= 0.009 and 0.002, respectively). The first 30-day BARC bleeding episodes were associated with an increased rate of subsequent premature DAPT discontinuation during one-year follow-up (4.7 % vs 11.4 %; odds ratio: 2.60; 95 % confidence interval: 1.04 to 6.50; p= 0.035). In conclusion, among East Asians, mild bleeding episodes are common early after PCI and are associated with premature DAPT discontinuation. Type 2 BARC bleeding episodes are associated with LPR cut-offs measured at 30 days post-discharge.

Effects of Peroxisome Proliferator-Activated Receptor-δ Agonist on Cardiac Healing after Myocardial Infarction

Peroxisome proliferator-activated receptor-delta (PPAR-δ)-dependent signaling is associated with rapid wound healing in the skin. Here, we investigated the therapeutic effects of PPAR-δ-agonist treatment on cardiac healing in post-myocardial infarction (MI) rats. Animals were assigned to the following groups: sham-operated control group, left anterior descending coronary artery ligation (MI) group, or MI with administration of the PPAR-δ agonist GW610742 group. GW610742 (1 mg/kg) was administrated intraperitoneally after the operation and repeated every 3 days. Echocardiographic data showed no differences between the two groups in terms of cardiac function and remodeling until 4 weeks. However, the degrees of angiogenesis and fibrosis after MI were significantly higher in the GW610742-treated rats than in the untreated MI rats at 1 week following MI, which changes were not different at 2 weeks after MI. Naturally, PPAR-δ expression in infarcted myocardium was highest increased in 3 day after MI and then disappeared in 14 day after MI. GW610742 increased myofibroblast differentiation and transforming growth factor-beta 2 expression in the infarct zone at 7 days after MI. GW610742 also increased bone marrow-derived mesenchymal stem cell (MSC) recruitment in whole myocardium, and increased serum platelet-derived growth factor B, stromal-derived factor-1 alpha, and matrix metallopeptidase 9 levels at day 3 after MI. PPAR-δ agonists treatment have the temporal effect on early fibrosis of infarcted myocardium, which might not sustain the functional and structural beneficial effect.