Amiodarone-induced thyroid dysfunction in a tertiary center in south Brazil

Amiodarone, used in the treatment of cardiac arrhythmias, is associated with thyroid dysfunction. No reports exist on its frequency in southern Brazil, nor studies evaluating the usefulness of clinical scores to diagnose thyroid abnormalities in these patients. This study aimed at determining the prevalence of amiodarone-induced thyroid dysfunction in a representative sample from a tertiary center, to study the conditions associated to this dysfunction and to evaluate the reliability of clinical scores of hypo and hyperthyroidism. One hundred ninety-five amiodarone users were submitted to a clinical and laboratory evaluation. Of these, 2.1 percent were hyperthyroid, 25.1 percent hypothyroid and 9.2 percent had only a high T4. Considering thyroid dysfunction variables researched, thyroid autoimmunity was positively associated (OR 4.8; p= 0.02), and male gender had a trend to a positive association (OR 1.86; p= 0.06). Clinical scores were highly sensitive for hyperthyroidism (100 percent), but not for hypothyroidism (8 percent). The low prevalence of amiodarone-induced hypothyroidism suggests that this specific region is iodine-sufficient. All patients receiving chronic amiodarone therapy should be checked for clinical scores for hyperthyroidism and laboratory evaluation should be performed, as a screening for thyroid dysfunction, especially if they are male or have positive microsomal antibodies.

Momento ideal para a endarterectomia de carótida após um AVC recente / Timing of carotid endarterectomy after a recent stroke

Vários estudos prospectivos de escolha aleatória confirmaram a eficácia da endarterectomia de carótida na prevenção de novos acidentes vasculares cerebrais (AVC) em pacientes sintomáticos com estenose grave na carótida. Entretanto, o timing da endarterectomia ainda é controverso. A cirurgia precoce pode estar associada à hemorragia intracerebral e à extensão do infarto inicial. A cirurgia tardia pode expor o paciente à recorrência do AVC e à oclusão da artéria carótida. Os estudos que avaliaram o intervalo de tempo para a endarterectomia são retrospectivos e não randomizados. Na ausência de um estudo prospectivo randomizado comparando endarterectomia precoce e tardia, uma abordagem para se interpretar os resultados das séries cirúrgicas é a comparação destes com a história natural do AVC isquêmico. Os autores descrevem os argumentos em favor da cirurgia precoce, a história natural do AVC isquêmico e os fatores de risco associados ao AVC no perioperatório da endarterectomia.

Recent randomized clinical trials have confirmed the role of carotid endarterectomy in the prevention of a second stroke in patients with a recent stroke and severe carotid stenoses. However, the timing of the operation is still controvertial. Early surgery has been associated with cerebral hemorrhage and infarct extension. Delayed endarterectomy exposes the patient to recurrent stroke and carotid occlusion. The clinical studies addressing this problem are retrospective and nonrandomized. In the absence of a prospective randomized trial comparing early and late surgery, one approach to interpreting the surgical studies is to compare them with the natural history of stroke. The authors describe the rationale for early surgery, the natural history of ischemic strokes and the risk factors associated with perioperative strokes in patients undergoing endarterectomy.