 Shares of Boston Scientific Corp. BSX, 0.78 dropped 4.4 in premarket trading Wednesday, after the medical devices company missed third-quarter profit expectations but topped on revenue, and provided a mixed full-year outlook. Net income fell to 174 million, or 12 cents a share, from 405 million, or 28 cents a share, in the year-ago period, compared with previously provided guidance for net earnings per share of 20 cents to 24 cents. 