0
selected
-
1.
Inhaled nitric oxide to control platelet hyper-reactivity in patients with acute submassive pulmonary embolism.
Kline, JA, Puskarich, MA, Pike, JW, Zagorski, J, Alves, NJ
Nitric oxide : biology and chemistry. 2020;:20-28
-
-
Free full text
-
Abstract
BACKGROUND We test if inhaled nitric oxide (NO) attenuates platelet functional and metabolic hyper-reactivity in subjects with submassive pulmonary embolism (PE). METHODS Participants with PE were randomized to either 50 ppm NO + O2 or O2 only for 24 h with blood sampling at enrollment and after treatment; results were compared with healthy controls. Platelet metabolic activity was assessed by oxygen consumption (basal and uncoupled) and reactivity was assessed with agonist-stimulated thromboelastography (TEG) and fluorometric measurement of agonist-stimulated cytosolic [Ca++] without and with pharmacological soluble guanylate (sGC) modulation. RESULTS Participants (N = 38 per group) were well-matched at enrollment for PE severity, comorbidities as well as TEG parameters and platelet O2 consumption. NO treatment doubled the mean plasma [NO3-] (P < 0.001) indicating successful delivery, but placebo treatment produced no change. After 24 h, neither TEG nor O2 consumption parameters differed significantly between treatment groups. Platelet cytosolic [Ca++] was elevated with PE versus controls, and was decreased by treatment with cinaciguat (an sGC activator), but not riociguat (an sGC stimulator). Stimulated platelet lysate sGC activity was increased with PE compared with controls. CONCLUSIONS In patients with acute submassive PE, despite evidence of adequate drug delivery, inhaled NO had no major effect on platelet O2 consumption or agonist-stimulated parameters on TEG. Pharmacological activation, but not stimulation, of sGC effectively decreased platelet cytosolic [Ca++], and platelet sGC activity was increased with PE, confirming the viability of sGC as a therapeutic target.
-
2.
Comparison of the pharmacodynamic effects of ranolazine versus amlodipine on platelet reactivity in stable patients with coronary artery disease treated with dual antiplatelet therapy : The ROMAN (RanOlazine vs. aMlodipine on platelet reactivity in stable patients with CAD treated with dual ANtiplatelet therapy) study.
Pelliccia, F, Greco, C, Gaudio, C, Rosano, G, Vitale, C, Marazzi, G, Rollini, F, Angiolillo, DJ
Journal of thrombosis and thrombolysis. 2015;(3):331-9
Abstract
Amlodipine, commonly used for relief of ischemic symptoms in coronary artery disease (CAD), may affect clopidogrel-induced antiplatelet effects. It remains unknown if ranolazine, an antianginal drug that constitutes a pharmacologic alternative to calcium channel blockade, interferes with clopidogrel-induced antiplatelet effects. The aim of the ROMAN study was to compare the pharmacodynamic effects of ranolazine versus amlodipine on platelet reactivity in clopidogrel treated patients with CAD. A prospective, randomized, cross-over, open-label study conducted in a total of 210 CAD patients on aspirin (100 mg/q.d.) and clopidogrel (75 mg/q.d.) 1 month following percutaneous coronary intervention. Patients were randomly assigned to amlodipine (10 mg p.d., n = 105) or ranolazine (750 mg b.i.d., n = 105) for 15 days, and after a 1-week wash-out period, crossed-over treatment for 15 days. P2Y12 reaction units (PRU) were assessed at baseline and after each treatment sequence. High on-treatment platelet reactivity (HPR) was defined as a PRU > 208. Amlodipine was associated with higher PRU than ranolazine (182 ± 75 vs. 167 ± 64, p = 0.028). As compared with baseline, PRU increased significantly after treatment with amlodipine (p = 0.018), but was not different after ranolazine therapy (p = 0.871). Changes in platelet reactivity following amlodipine therapy appeared to depend on baseline HPR status, as PRU levels significantly increased only among HPR subjects. In stable CAD patients treated with dual antiplatelet therapy after PCI, concomitant treatment with amlodipine, but not ranolazine, interferes with clopidogrel-induced antiplatelet effects.
-
3.
Homocysteine is a novel risk factor for suboptimal response of blood platelets to acetylsalicylic acid in coronary artery disease: a randomized multicenter study.
Karolczak, K, Kamysz, W, Karafova, A, Drzewoski, J, Watala, C
Pharmacological research. 2013;:7-22
Abstract
The incomplete inhibition of platelet function by acetylsalicylic acid (ASA), despite the patients are receiving therapeutic doses of the drug ('aspirin-resistance'), is caused by numbers of risk factors. In this study we verified the idea that plasma homocysteine (Hcy) contributes to 'aspirin-resistance' in patients with coronary artery disease (CAD) and with or without type 2 diabetes mellitus (T2DM). A cross-designed randomized controlled intervention study has been performed (126 CAD pts incl. 26 with T2DM) to determine whether increasing ASA dose from 75mg to 150mg daily may result in the increased antiplatelet effect, in the course of four-week treatment. Platelet response to collagen (coll) or arachidonic acid (AA) was monitored with whole blood aggregometry, plasma thromboxane (Tx), and Hcy levels were determined immunochemically. The ASA-mediated reductions in platelet response to coll (by 12±3%) or AA (by 10±3%) and in plasma Tx (by 20±9%; p<0.02 or less) were significantly greater for higher ASA dose and significantly correlated with plasma Hcy, which was significantly lower in "good" ASA responders compared to "poor" responders (p<0.001). Higher plasma Hcy appeared a significant risk factor for blood platelet refractoriness to low ASA dose (OR=1.11; ±95%CI: 1.02-1.20, p<0.02, adjusted to age, sex and CAD risk factors). Hcy diminished in vitro antiplatelet effect of low ASA concentration and augmented platelet aggregation (by up to 62% (p<0.005) for coll and up to 15% (p<0.005) for AA), whereas its acetyl derivative acted oppositely. Otherwise, Hcy intensified antiplatelet action of high ASA. Hyperhomocysteinaemia may be a novel risk factor for the suppressed blood platelet response to ASA, and homocysteine may act as a specific sensitizer of blood platelets to some agonists. While homocysteine per se acts as a proaggregatory agent to blood platelets, its acetylated form is able to reverse this effect. Thus, these findings reveal a possibly new challenging potential of the acetylating properties of ASA therapy.
-
4.
Alterations in platelet function and cell-derived microvesicles in recently menopausal women: relationship to metabolic syndrome and atherogenic risk.
Jayachandran, M, Litwiller, RD, Lahr, BD, Bailey, KR, Owen, WG, Mulvagh, SL, Heit, JA, Hodis, HN, Harman, SM, Miller, VM
Journal of cardiovascular translational research. 2011;(6):811-22
-
-
Free full text
-
Abstract
A woman's risk for metabolic syndrome (MS) increases at menopause, with an associated increase in risk for cardiovascular disease. We hypothesized that early menopause-related changes in platelet activity and concentrations of microvesicles derived from activated blood and vascular cells provide a mechanistic link to the early atherothrombotic process. Thus, platelet functions and cellular origin of blood-borne microvesicles in recently menopausal women (n = 118) enrolled in the Kronos Early Estrogen Prevention Study were correlated with components of MS and noninvasive measures of cardiovascular disease [carotid artery intima medial thickness (CIMT), coronary artery calcium (CAC) score, and endothelial reactive hyperemic index (RHI)]. Specific to individual components of the MS pentad, platelet number increased with increasing waist circumference, and platelet secretion of ATP and expression of P-selectin decreased with increasing blood glucose (p = 0.005) and blood pressure (p < 0.05), respectively. Waist circumference and systolic blood pressure were independently associated with monocyte- and endothelium-derived microvesicles (p < 0.05). Platelet-derived and total procoagulant phosphatidylserine-positive microvesicles, and systolic blood pressure correlated with CIMT (p < 0.05), but not with CAC or RHI. In summary, among recently menopausal women, specific platelet functions and concentrations of circulating activated cell membrane-derived procoagulant microvesicles change with individual components of MS. These cellular changes may explain in part how menopause contributes to MS and, eventually, to cardiovascular disease.
-
5.
Increased platelet inhibition after switching from maintenance clopidogrel to prasugrel in patients with acute coronary syndromes: results of the SWAP (SWitching Anti Platelet) study.
Angiolillo, DJ, Saucedo, JF, Deraad, R, Frelinger, AL, Gurbel, PA, Costigan, TM, Jakubowski, JA, Ojeh, CK, Effron, MB, ,
Journal of the American College of Cardiology. 2010;(13):1017-23
Abstract
OBJECTIVES The objective was to evaluate the pharmacodynamic response of switching patients on maintenance phase clopidogrel therapy after an acute coronary syndrome (ACS) to prasugrel. BACKGROUND Prasugrel P2Y(12) receptor blockade is associated with greater pharmacodynamic platelet inhibition and reduction of ischemic complications compared with that of clopidogrel in ACS patients undergoing percutaneous coronary intervention. The pharmacodynamic effects of switching patients during maintenance phase clopidogrel therapy after an ACS event to prasugrel are unknown. METHODS The SWAP (SWitching Anti Platelet) study was a phase 2, multicenter, randomized, double-blind, double-dummy, active-control trial. After a run-in of daily open-label clopidogrel 75 mg with aspirin therapy for 10 to 14 days, patients were randomly assigned to 1 of the following 3 treatments: placebo loading dose (LD)/clopidogrel 75 mg maintenance dose (MD), placebo LD/prasugrel 10 mg MD, or prasugrel 60 mg LD/10 mg MD. Platelet function was evaluated at 2 h, 24 h, 7 days, and 14 days using light transmittance aggregometry, VerifyNow P2Y(12) assay, and vasodilator-stimulated phosphoprotein phosphorylation. RESULTS A total of 139 patients were randomized, of whom 100 were eligible for analysis. Maximum adenosine diphosphate-induced platelet aggregation (20 μM) by light transmittance aggregometry at 1 week (primary end point) was lower after prasugrel MD compared with clopidogrel MD (41.1% vs. 55.0%, p < 0.0001), and was also lower in the prasugrel LD+MD group compared with clopidogrel MD (41.0% vs. 55.0%, p < 0.0001). At 2 h, a prasugrel LD resulted in higher platelet inhibition compared with the other regimens. Similar results were found using light transmittance aggregometry with 5 μM adenosine diphosphate, VerifyNow P2Y(12), and vasodilator-stimulated phosphoprotein phosphorylation assays. CONCLUSIONS For patients receiving maintenance clopidogrel therapy after an ACS event, switching from clopidogrel to prasugrel is associated with a further reduction in platelet function by 1 week using prasugrel MD or within 2 h with the administration of a prasugrel LD. (A Pharmacodynamic Comparison of Prasugrel [LY640315] Versus Clopidogrel in Subjects With Acute Coronary Syndrome Who Are Receiving Clopidogrel [SWAP]; NCT00356135).
-
6.
The platelet function dose-response to abciximab during percutaneous coronary revascularization is variable.
Casterella, PJ, Kereiakes, DJ, Steinhubl, SR, Raymond, RE, Kottke-Marchant, K, Patel, K, Mueller, M, Rosenthal, M, Moliterno, DJ, Teirstein, PS
Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions. 2001;(4):497-504
Abstract
The platelet function dose-response to incremental abciximab (Reopro, Eli Lilly/Centocor, Indianapolis, IN) bolus dosing during percutaneous coronary intervention (PCI) was evaluated in 85 patients using a point-of-service platelet function assay. Patients received incremental bolus doses of abciximab at 10- to 20-min intervals; platelet function was measured at 10-min intervals during dosing. The percentage of patients achieving > or = 80% inhibition of platelet function after 50%, 75%, and 100% of a standard abciximab bolus was 40%, 87%, and 95%, respectively. There were no significant associations between the platelet function dose-response to abciximab and age, weight, platelet count, hematocrit, heparin dose, peak activated clotting time, thienopyridine use prior to PCI, gender, cigarette smoking, diabetes mellitus, or clinical syndrome. This study demonstrated significant interpatient variability in platelet function dose-response to abciximab with a substantial proportion (87%) of patients achieving high-level platelet function inhibition with less than the standard abciximab bolus dose.