New York (AP) -- Shares of Isle of Capri Casinos Inc. slumped to a multi-year low Monday as an analyst downgraded the casino operator, citing economic concerns and a possible Iowa smoking ban. Ryan Worst of Brean Murray, Carret & Co. expects the St. Louis-based company will continue to look to lower costs, but believes sales growth will be harder to achieve in the next few quarters, which will likely keep the stock from rising much.