Santa Rosa-based Arterial Vascular Engineering Inc.’s shares...

Santa Rosa-based Arterial Vascular Engineering Inc.’s shares rose 18% after analysts touted prospects for the company’s new heart stent. Shares rose $8.75 to close at $56.63 on Nasdaq. After attending a heart conference in Washington last week, analysts said the company’s new stent, used to prop open clogged heart arteries, could provide major competition to market leader Johnson & Johnson. Sales of J&J;’s Palmaz-Schatz stent dominate the $800-million U.S. market for the devices. Arterial Vascular’s stent can do things that currently approved models cannot, including penetrate tough, calcified arteries, analysts said. U.S. Food and Drug Administration approval of the device is expected late this year or early next, analysts said. . . . Boston-based records-storage company Iron Mountain Inc. agreed to acquire Pleasanton-based Arcus Group Inc. for about $160 million, the latest in a series of acquisitions made to beef up its services for backing up and storing computer data.