Thrombotic Thrombocytopenic Purpura Associated with Clopidogrel Ticlopidine, an antiplatelet drug, has been widely used to prevent arterial thrombosis. However, its adverse effects, especially thrombotic thrombocytopenic purpura (TTP), have led physicians to prefer clopidogrel, a similar, less toxic antiplatelet thienopyridine. The current report describes 11 cases of TTP in patients who received clopidogrel; all patients were treated with plasma exchange. One patient died despite aggressive therapy. The characteristic autoantibody of TTP was found in two patients.

Sudden Death in Hypertrophic Cardiomyopathy Sudden death is the most feared consequence of hypertrophic cardiomyopathy. This study found that the magnitude of left ventricular hypertrophy, assessed as the maximal left-ventricular-wall thickness on echocardiography, correlated directly with the risk of sudden death. In particular, patients with extreme hypertrophy, who were the youngest patients in the study population, were at substantial long-term risk. The use of implantable cardioverter­defibrillators may be warranted to prevent sudden death in these young patients.

Heritability of Cataracts in Twins Nuclear cataracts are common among elderly people, but little is known about the interplay of genetic and environmental factors in their pathogenesis. In this study of 226 pairs of monozygotic female twins and 280 pairs of dizygotic female twins from 50 to 79 years of age, the scores for nuclear cataract were more highly correlated among monozygotic twins than among dizygotic twins (intrapair correlation, 0.90 vs. 0.57). Heritability accounted for 48 percent of the variance in the cataract score, age for 38 percent, and individual environmental factors for only 14 percent.