Abbott Seeks Foothold in Stent Business  CHICAGO (Reuters) - Abbott Laboratories Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=ABT.N target=/stocks/quickinfo/fullquote"&gt;ABT.N&lt;/A&gt; is  betting \$1 billion in deals and the start of a new clinical  trial will finally get Wall Street to focus on its  cardiovascular device business.