An executive from Accretive Health Inc. apologized Wednesday to Minnesotans who were offended by aggressive debt-collection tactics at Fairview hospitals but offered the company's first public defense, saying its mission is to help patients pay their bills and help nonprofit hospitals improve their finances. Accretive Senior Vice President Greg Kazarian came under intense questioning at a field hearing in St. Paul called by U.S. Sen. Al Franken, D-Minn., who said he was troubled not only by the way patients were hounded for payment but by the possibility that Accretive violated the privacy of thousands of Minnesotans.