Antiplatelet Therapy for Long-Term Management of Patients with Mechanical Aortic Prostheses.

BACKGROUND: A mechanical aortic prosthesis (MAP) may cause platelet activation secondary to shear forces, and the release of adenosine diphosphate (ADP). This platelet-mediated event may lead to arterial embolism. Traditionally, warfarin has been used to treat such cases, although this anticoagulant has no inhibitory effects on platelets. The study aim was to determine if antiplatelet agents could prevent thromboembolic events in patients with a MAP. METHODS: Since 2001, a total of 265 patients (average age 64.5 ± 12.0 years), each of whom received a MAP with or without additional aortic surgery, was followed at the authors' institution. Patients received a loading dose of clopidogrel or prasugrel + asprin 325 mg and tested for platelet inhibition. The maintenance dose was 75 mg clopidogrel or 10 mg prasugrel + 81 mg aspirin. Platelet reactivity was tested, using two different methods, after one month and at six-month intervals thereafter. RESULTS: The average follow up was 47.3 ± 44.3 months; total follow up was 11,688.8 months [974 patient-years (pt-yr)]. Over a 16-year period 51 patients died, primarily from myocardial infarction. Twelve patients had strokes (1.2%/pt-yr); of these patients, 10 had discontinued the antiplatelet medication (and were receiving warfarin). One patient was nonresponsive to clopidrogel and another (a compliant patient) was never tested. Strokes were not observed in compliant patients who responded to antiplatelet agents. Thirteen patients had gastrointestinal bleeding, four required transfusion, and three died due to cerebral aneurysms. CONCLUSIONS: Platelet-mediated thromboembolism following MAP installation can be treated with antiplatelet agents. The 16-year results of the present study suggested that antiplatelet agents can reduce thromboembolic events in patients with MAP. Strokes can be prevented in patients with MAP if treated with the correct antiplatelet agent, if the patient responds to the agent employed and is strictly compliant.

Initial experience with dual antiplatelet thromboprophylaxis using clopidogrel and aspirin in patients with mechanical aortic prostheses.

BACKGROUND AND AIM OF THE STUDY: The aortic mechanical prosthesis (AMP) generates shear stress and causes erythrocyte fragmentation with ADP release that leads to platelet activation, the cause of thromboembolism. Thromboprophylaxis with the antiplatelet agents clopidogrel and aspirin (Clop-ASA) should reduce thromboembolic events in patients receiving an AMP. METHODS: Over an eight-year period at the authors' institutions, a total of 135 patients underwent aortic valve replacement (AVR), with or without concomitant thoracic aortic procedures, and received Clop-ASA as thromboprophylaxis. Platelet reactivity was measured using the Verify Now system. Thromboelastography was commenced in August 2006, and patients were followed at six-month intervals, with echocardiography and assessment of platelet reactivity. RESULTS: The total follow up was 4,776 months (equivalent to 398 patient-years (pt-yr)); the average follow up was 35.4 +/- 25 months. During follow up, 18 patients (13.3%) died, eight from coronary artery disease and three from valve-related causes. Five patients (3.7%; 1.2%/pt-yr) had bleeding complications, but none experienced valve thrombosis. Two patients (1.5%; 0.5%/pt-yr) had a transient ischemic attack (TIA); one of these occurred in a patient who discontinued Clop-ASA, and the other in a responder to Clop-ASA. Seven patients (5.2%; 1.7%/pt-yr) had strokes, one of which occurred at 48.5 months after AVR. Of the remaining six patients who had a stroke, one was a non-responder to clopidogrel and five had stopped taking Clop-ASA. The incidence of strokes before using the Accumetrics and TEG devices was 2.5% per pt-yr, but only 1.0% per pt-yr thereafter. CONCLUSION: Thromboprophylaxis in patients with AMP receiving Clop-ASA seems to be effective. Patients had a low incidence of bleeding, TIA and ischemic stroke, and no valve thrombosis. The use of assays to determine platelet reactivity helped to identify those patients who were resistant to clopidogrel, hyporesponders, and poorly compliant patients. Notably, the incidence of strokes after implementing assays to monitor platelet reactivity was reduced. Deaths were due primarily to myocardial infarction, and none of the deaths was anticoagulant-related. Patients receiving Clop-ASA should undergo routine testing of platelet reactivity, and also continue antiplatelet therapy so as to reduce the risk of ischemic stroke.

Demencia en la enfermedad de Pick

Se realizó una revisión somera sobre la demencia presenil y los conceptos actuales según la clasificación internacional de los trastornos mentales y del comportamiento (CIE-10) y el Manual de Estadística y Diagnóstico de los desórdenes mentales DSM-IV. Se presenta un caso de una paciente de la tercera década de vida que comenzó con un cuadro clínico depresivo ansioso, recibió tratamiento con antidepresivo y 8 meses después aparecen las manifestaciones neurológicas de la enfermedad. Al inicio trastornos de la marcha y más tarde rigidez muscular, temblores, dificultad para hablar, pérdida de memoria y otras alteraciones de la conducta. Se realiza diagnóstico diferencial con la enfermedad de Alzheimer, la demencia en la enfermedad de Creutzfeldt-Jakob y tumores cerebrales de la región frontal.

A brief review of presenile dementia and of the current concepts according to the international classification of mental and behaviour disorders (ICD-10) and to the Manual of Statistics and Diagnosis of Mental Disorders (DSM-IV) is made. The case of an aged patient that began with a clinical picture of anxiety and depression, received treatment with antidepressants and 8 months later had neurological manifestations is reported. At the beginning she had walk disorders and afterwards muscular rigidity, tremor, difficulty to speak, memory loss and other behaviour alterations. The differential diagnosis is made with Alzheimer's disease, dementia in Jakob-Creutzfeld disease and brain tumors of the frontal region.