Publications (66) View all
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Article: Prothrombotic Changes in Diabetes Mellitus.
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ABSTRACT: Although our understanding of vascular pathology has greatly improved in recent years, the cellular and molecular mechanisms underlying the enhanced thrombotic propensity in type 2 diabetes mellitus (T2DM) remain incompletely characterized. Detrimental interactions between activated vascular cells (i.e., platelets, leukocytes, endothelial cells) and the vulnerable atheromatous plaque are a major determinant of the increased atherothrombotic burden in T2DM patients. Endothelial damage and accelerated senescence, impairment of the endothelial progenitor cell repair system, plaque neovascularization and inflammation, decreased clearance of detrimental molecules within the plaque, and increased expression of matrix metalloproteinases may collectively contribute to intraplaque hemorrhage and subsequent rupture. Notably, recent data demonstrates the central importance of the tissue factor-microparticle-mediated pathway in diabetic thrombophilia and cardiovascular complications. Acting as detrimental amplifiers of various biological responses (including thrombogenicity and plaque remodeling), microparticles have also emerged as a key marker of global vascular damage in T2DM patients. Available evidence suggests that targeting the tissue factor-microparticle pathway may be a promising approach for reducing the burden of the atherosclerotic complications of diabetes.Seminars in Thrombosis and Hemostasis 04/2013; · 4.52 Impact Factor -
Article: Impaired platelet P2Y12 inhibition by thienopyridines in chronic kidney disease: mechanisms, clinical relevance and pharmacological options.
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ABSTRACT: Patients with chronic kidney disease (CKD) represent an increasing proportion of the population undergoing percutaneous coronary intervention (PCI) and up to 40% of the patients treated for acute coronary syndrome (ACS). Several studies and registries in the setting of ACS and elective PCI have reported a negative association between CKD and mortality, stent thrombosis, post-procedural ischaemic events and bleeding events. Pharmacological inhibition of the adenosine diphosphate receptor by thienopyridines or ticagrelor and disruption of the cyclooxygenase pathway by aspirin constitute the current standards of care to prevent thrombotic complications following stent-based PCI. In CKD patients, the avoidance of anti-platelet therapy may be driven by the lack of clinical trial data to support its efficacy, by errors or omissions, or by a reluctance to use this therapy in a population characterized by its enhanced bleeding risk. However, there is growing evidence to suggest that a severely decreased glomerular filtration rate per se, independent of the presence of diabetes mellitus, is an important determinant of high residual platelet reactivity under a clopidogrel maintenance dose. Recent reports have emphasized that the impact of impaired platelet inhibition by thienopyridines is of paramount importance in CKD patients, with an enhanced mortality rate in low-responder patients. Pharmacodynamic studies indicate the phosphodiesterase 3 inhibitor, cilostazol, the third generation thienopyridine prasugrel and the reversible P2Y12 antagonist ticagrelor to be potent strategies to overcome this biological resistance. In clinical practice, platelet function testing should be considered in CKD patients undergoing PCI, especially in those who experience thrombotic events despite dual therapy. Newer agents should be contemplated in patients who display higher residual platelet aggregability after standard treatment. Among these, the non-thienopyridine P2Y12 receptor antagonist ticagrelor, which does not require biotransformation, could be the drug of choice in CKD patients with ACS. In this population, ticagrelor has been found to reduce mortality and ischaemic events with an acceptable bleeding risk.Nephrology Dialysis Transplantation 03/2013; · 3.40 Impact Factor -
Article: Takotsubo and Takotsubo-like syndrome: A common neurogenic myocardial stunning pathway?
International journal of cardiology 10/2012; · 7.08 Impact Factor -
Article: Pharmacological approaches to reperfusion therapy.
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ABSTRACT: Despite the fact that numerous clinical trials investigating infarct size have been completed over the last two to three decades, the methods for treating lethal reperfusion injury efficiently have only become established very recently. After several years of accumulating evidence in experimental preparations that lethal reperfusion injury might exist, the description of the phenomenon of ischaemic post-conditioning in animal models has fully convinced us of the existence and importance of irreversible myocardial damage occurring after reflow. Transfer to the clinics was possible in small phase II trials, provided care was taken to assess the determinants of infarct size and, most importantly, to consider the timing of drug administration with respect to the time of reflow. Technical questions remain to be resolved regarding the assessment of the area at risk in the difficult setting of emergency care for reperfusion therapy. Nevertheless, convincing pharmacological trials are being performed that mark the start of a new era that will, in the future, improve the prognosis of patients with ST-segment elevation myocardial infarction through the prevention of lethal myocardial reperfusion injury. At present, while erythropoietin and adenosine have not proved efficient for alleviation of lethal reperfusion injury, a significant benefit has been reported for cyclosporin and exenatide. New pharmacological agents need to be identified and tested in phase II trials. In the meantime, clinical outcome studies are currently being conducted for cyclosporin.Cardiovascular research 04/2012; 94(2):246-52. · 5.80 Impact Factor -
Article: Association of estimated GFR with platelet inhibition in patients treated with clopidogrel.
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ABSTRACT: The reasons that decreased glomerular filtration rate (GFR) might alter the clinical efficacy of clopidogrel are poorly understood. In this study, we sought to evaluate whether decreased GFR alters platelet response to clopidogrel in patients receiving a maintenance dose of clopidogrel (75 mg/d for at least 8 days). 126 consecutive patients categorized by estimated GFR: stages 1-2 (>60 mL/min/1.73 m(2); n = 29), stage 3a (45-59 mL/min/1.73 m(2); n = 21); stage 3b (30-44 mL/min/1.73 m(2); n = 26), stage 4 (15-29 mL/min/1.73 m(2); n = 14), and stage 5 (<15 mL/min/1.73 m(2); n = 36) were prospectively enrolled. Residual platelet reactivity, defined in the VASP (Vasodilator Stimulated Phosphoprotein) flow cytometry test as platelet reactivity index (PRI) ≥61% and in the VerifyNow turbidimetric-based assay as a value >235 PRU (adenosine diphosphate receptor reaction units) or percentage of platelet inhibition <15%. We examined factors associated with low response to clopidogrel using logistic regression. A significant relationship between estimated GFR, PRI, PRU, and percentage of inhibition was found. The prevalence of residual platelet reactivity was highest in patients with GFR stage 5. PRI ≥61% occurred in 52.8% of patients with stage 5 versus 30.8% of stage 3b and 24.1% of stages 1-2 (P = 0.1). PRU >235 was found in 63.6% of patients with stage 5 versus 36.8% of stage 3b and 17.2% of stages 1-2 (P = 0.005). Inhibition <15% affected 66.7% of patients with stage 5 versus 21.1% of stage 3b and 17.2% of stages 1-2 (P < 0.001). In the multivariable model, GFR stage 5 (adjusted prevalence ratio [PR], 3.10; 95% CI, 1.23-9.43; P = 0.02), and obesity (adjusted PR, 1.92; 95% CI, 1.34-2.23; P = 0.004) were the sole predictors of residual platelet reactivity. Interference of hemodialysis with the pharmacokinetics of clopidogrel could not be excluded. GFR stage 5 is associated with substantial impairment of platelet inhibition independently of diabetes mellitus.American Journal of Kidney Diseases 03/2012; 59(6):777-85. · 5.43 Impact Factor
