Lisa Dannenberg

Antiplatelet effects of aspirin in chronic kidney disease patients

Essentials Chronic kidney disease (CKD) patients have a high risk of cardiovascular events. A pharmacodynamic evaluation of the effects of aspirin in 116 patients was carried out. The antiplatelet effects of aspirin are associated with impaired renal function. The optimal antithrombotic regimen in CKD patients must be investigated on a larger scale.

Dabigatran enhances platelet reactivity and platelet thrombin receptor expression in patients with atrial fibrillation.

Essentials Whether or not dabigatran enhances the risk of myocardial infarction is under discussion. We measured platelet reactivity and thrombin receptor expression in dabigatran patients. Platelet reactivity and thrombin receptor expression is enhanced during dabigatran treatment. This should be considered when choosing the optimal direct oral anticoagulant for individuals.

Dipyrone comedication in aspirin treated stroke patients impairs outcome

BACKGROUND >50% of stroke patients rely on analgesic medication to control pain. Aspirin is the mainstay of medical treatment of stroke patients; however analgesic medication with dipyrone impairs aspirin antiplatelet effects ex-vivo. The clinical impact of this impairment is unknown. Therefore, we aimed to determine aspirin antiplatelet effects and neurological outcome in stroke patients with aspirin and dipyrone comedication. METHODS We conducted a prospective cohort study in 41 patients with stroke. Primary outcome was pharmacodynamic response to aspirin in dipyrone treated stroke patients. Secondary outcome was neurological recovery after stroke. Pharmacodynamic response to aspirin was measured using arachidonic acid induced aggregation in light-transmission aggregometry. Neurological outcome was determined three months after stroke onset by telephone interview. RESULTS Patients characteristics were similar in the aspirin-alone group and the aspirin+dipyrone group. Impaired pharmacodynamic response to aspirin occurred in 62% (14/21) of patients with aspirin and dipyrone co-medication. Only 10% (2/20) of aspirin treated patients without analgesic comedication displayed residual platelet reactivity (P=0.001; odds ratio [OR], 18 [95% CI, 3.2-100]). Excellent neurological recovery (measured by three months follow-up modified Rankin Scale<2) was observed in 80% (16/20) of patients in the aspirin-alone group and 48% (10/21) of patients in the aspirin+dipyrone group (P=0.037; OR, 4.4 [95% CI, 1.1-17.7]). CONCLUSIONS Dipyrone comedication in patients with stroke impairs pharmacodynamic response to aspirin. This is associated with worse clinical outcome. Therefore dipyrone should be used with caution in aspirin treated stroke patients. CLINICAL TRIAL REGISTRATION https://clinicaltrials.gov/show/NCT02148939; Identifier: NCT02148939.

Analgesic medication with dipyrone in patients with coronary artery disease: Relation to MACCE

BACKGROUND The non-opioid analgesic dipyrone can trigger life-threatening blood formation disorders. However, it is frequently used, as many patients with coronary artery disease (CAD) rely on non-opioid analgesics to relieve pain. In this study, we investigated the incidence of death, myocardial infarction (MI) or stroke in CAD patients with aspirin and dipyrone comedication as compared to aspirin-alone. METHODS We conducted an observational pilot study in 72 CAD patients with aspirin ± dipyrone comedication in the department of cardiology of the University Hospital Düsseldorf. The primary end point was a composite of death, myocardial infarction (MI) or stroke. The secondary end points were the components of the primary end point. The median follow-up period was 3.2years. RESULTS The primary end point occurred 67% of patients in the aspirin+dipyrone group as compared to 31% in the aspirin-alone group (odds ratio [OR] 4.5, 95% confidence interval [CI] 1.7 to 12.3; P=0.0028;). All-cause mortality was significantly higher in the aspirin+dipyrone group (44%) than the aspirin-alone group (22%; OR 2.8, 95% CI 1.01 to 7.8; P=0.049). Ischemic events (MI and stroke) were more frequent in the aspirin+dipyrone group as compared to the aspirin alone group as well (OR 4, 95% CI 1.1 to 14; P=0.03). CONCLUSION In this hypothesis generating pilot analysis, dipyrone medication in aspirin treated coronary artery disease patients is associated with an increased cumulative incidence of death, MI or stroke as well as all-cause mortality and ischemic events. These data have to be confirmed in larger registries and trials. CLINICAL TRIAL REGISTRATION http://clinicaltrials.gov/ct2/show/NCT01402804; Identifier: NCT01402804; Date of registration: July 25, 2011.

Platelet function testing: dead or alive

Essentials Pharmacodynamic response to antiplatelet medication is heterogeneous. Platelet reactivity to dual antiplatelet therapy was analyzed by three platelet function assays. The prevalence of high and low platelet reactivity differed significantly between assays. Future trials are needed to determine the best assay to analyze platelet function.

Thromboxane Formation Assay to Identify High On-Treatment Platelet Reactivity to Aspirin

Platelet inhibition by aspirin is indispensable in the secondary prevention of cardiovascular events. Nevertheless, impaired aspirin antiplatelet effects (high on-treatment platelet reactivity [HTPR]) are frequent. This is associated with an enhanced risk of cardiovascular events. The current gold standard to evaluate platelet hyper-reactivity despite aspirin intake is the light-transmittance aggregometry (LTA). However, pharmacologically, the most specific test is the measurement of arachidonic acid (AA)-induced thromboxane (TX) B2 formation. Currently, the optimal cut-off to define HTPR to aspirin by inhibition of TX formation is not known. Therefore, in this pilot study, we aimed to calculate a TX formation cut-off value to detect HTPR defined by the current gold standard LTA. We measured platelet function in 2,507 samples. AA-induced TX formation by ELISA and AA-induced LTA were used to measure aspirin antiplatelet effects. TX formation correlated nonlinearly with the maximum of aggregation in the AA-induced LTA (Spearmans rho R = 0.7396; 95% CI 0.7208-0.7573, p < 0.0001). Receiver operating characteristic analysis and Youdens J statistics revealed 209.8 ng/mL as the optimal cut-off value to detect HTPR to aspirin with the TX ELISA (area under the curve: 0.92, p < 0.0001, sensitivity of 82.7%, specificity of 90.3%). In summary, TX formation ELISA is reliable in detecting HTPR to aspirin. The calculated cut-off level needs to be tested in trials with clinical end points.

SeQuent Please vs. Pantera Lux drug coated balloon angioplasty in real life: Results from the Düsseldorf DCB registry

BACKGROUND In-stent restenosis (ISR) is still a major concern in interventional cardiology. Drug coated balloon (DCB) angioplasty has been shown to be a promising option in treatment of ISR. However heterogeneity of different DCBs in suppression of neointimal growth has been described in a porcine model of coronary ISR. Therefore, in this registry analysis, we compared two frequently used paclitaxel eluting DCBs, the SeQuent Please and the Pantera Lux DCB. METHODS 571 patients were treated with DCB angioplasty at the Heinrich-Heine University Düsseldorf between 2009 and 2012. Follow-up was conducted during ambulatory care at our department. Major adverse cardiac events (death, myocardial infarction [MI] and target lesion revascularization) were registered during hospitalization and follow-up. RESULTS Patient characteristics, prior diseases, clinical presentation, ejection fraction, procedural success and lost-for-follow-up did not differ between patients treated with the SeQuent Please and. The Pantera Lux DCB. MACE during hospital course were similar as well (Pantera Lux: 6 patients [1.6%] vs. SeQuent®Please: 3 patients [1.5%], relative risk 1.06, 95% confidence interval 0.3-4.2, P=0.93). Event free survival was significantly longer in patients treated with the Pantera Lux DCB as compared to SeQuent Please DCB (Hazard ratio: 0.65, 95% confidence interval 0.43-0.98; P value of log-rank test: 0.0405). CONCLUSION MACE free survival was longer in Pantera Lux DCB treated patients as compared to SeQuent Please treated patients. This finding has to be confirmed in future clinical trials.

Aspirin Inhibits Platelet-Derived Sphingosine-1-Phosphate Induced Endothelial Cell Migration

Background: Aspirin plays a crucial role in the prevention of cardiovascular diseases. We previously described that aspirin has effects beyond inhibition of platelet aggregation, as it inhibited thrombin-mediated release of sphingosine-1-phosphate (S1P) from human platelets. S1P is a bioactive lipid with important functions on inflammation and apoptosis. In endothelial cells (EC), S1P is a key regulator of cell migration. In this study, we aimed to analyze the effects of aspirin on platelet-induced EC migration. Methods: Human umbilical EC migration was measured by Boyden chamber assay. EC migration was induced by platelet supernatants of thrombin receptor-activating peptide-1 (AP1) stimulated platelets. To investigate the S1P receptor subtype that promotes EC migration, specific inhibitors of S1P receptor subtypes were applied. Results: S1P induced EC migration in a concentration-dependent manner. EC migration induced by AP1-stimulated platelet supernatants was reduced by aspirin. S1P1 receptor inhibition almost completely abolished EC migration induced by activated platelets. The inhibition of S1P2 or S1P3 receptor had no effect. Conclusion: Aspirin inhibits EC migration induced by activated platelets that is in part due to S1P and mediated by the endothelial S1P1 receptor. The clinical significance of this novel mechanism of aspirin action has to be investigated in future studies.

Plasma sphingosine-1-phosphate concentrations are associated with systolic heart failure in patients with ischemic heart disease

OBJECTIVE Sphingosine-1-Phosphate (S1P) is a bioactive sphingolipid with important functions in immunity, inflammation and cardiovascular biology. S1P is associated with prevalence and severity of coronary artery disease and myocardial infarction. However, its relevance in ischemic cardiomyopathy is unknown. We aimed to investigate associations of plasma S1P and other sphingolipids with the extent of heart failure in patients with ischemic heart disease. METHODS AND RESULTS 74 patients with ischemic heart disease were investigated in this observational study. Plasma concentrations of S1P, C16 ceramide and sphingomyelin (SM) were measured using liquid chromatography/tandem mass-spectrometry and associated with objective (echocardiography) and subjective (dyspnea) signs of heart failure. Plasma S1P and SM but not C16 ceramide concentrations were negatively associated with left ventricular ejection fraction (LVEF) and dyspnea (ranked by New York Heart Association; LVEF: S1P standardized coefficient beta: -0.25; 95%CI: -273 to -13nM, p=0.03; SM beta: -0.24; 95%CI: -16,310 to -413nM, p=0.04; NYHA: S1P beta: -0.3; 95%CI: -174 to -26nM, p=0.009; SM beta: -0.46; 95%CI: -13,462 to -5013nM, p<0.001). ROC analysis revealed that S1P and SM predicted impaired LVEF with optimal cut-off levels below 843nM and 77μM, respectively. CONCLUSION S1P is associated with the impairment of LVEF and dyspnea. Considering the major effects of S1P on cardiac and vascular functions in experimental models, we put forward the hypothesis that S1P is causally involved in the pathophysiology of heart failure. Interfering pharmacologically with S1P receptors may have an impact on ischemic cardiomyopathy.

Malondialdehyde Assay in the Evaluation of Aspirin Antiplatelet Effects

Aspirin is essential in secondary prevention of patients after myocardial infarction and with coronary artery disease. However, impaired pharmacodynamic response to aspirin is frequent (high on-treatment platelet reactivity [HTPR]). This leads to an enhanced prevalence of cardiovascular events and to an impaired clinical outcome. The current specific assays to evaluate aspirin antiplatelet effects are complex, time-consuming and demand for a high laboratory expertise. Therefore, we developed a potentially bedside assay based on the determination of malondialdehyde (MDA). MDA is a by-product of the thromboxane (TX) formation, which is synthesized in equimolar concentrations. In this study, we compared this MDA assay to the conventional assays in determination of pharmacodynamic aspirin response. For this, aspirin antiplatelet effects were measured in 22 healthy individuals and 63 aspirin treated patients using TX B2 formation enzyme-linked antibody assay, arachidonic acid induced light transmission aggregometry (LTA) and the new fluorometric MDA assay. In patients, MDA levels correlated well with TX formation (R = 0.81; 95% CI 0.69–0.88; p < 0.001) and LTA (R = 0.84; CI 0.74–0.91; p < 0.001). Receiver operating characteristic analyses revealed that the MDA assay does detect HTPR to aspirin sufficiently (area under the curve: 0.965; p < 0.001). The optimal cut-off was > 128 nmol/L (sensitivity of 100%, specificity of 91%). The new MDA assay is reliable in detecting HTPR. It is highly specific in the evaluation of antiplatelet effects by aspirin. This promising and potential bedside assay needs to be evaluated in clinical practice.