Caritas Christi Health Care representatives said Ascension Health of St. Louis remains committed to investing in the six-hospital chain, which is owned by the Archdiocese of Boston. The Caritas representatives said the chain is still planning to refinance its existing debt of about $250 million, and that Ascension will buy $100 million of additional bonds to pay for expansions and new equipment. The finance deal is expected to proceed when conditions improve in the credit markets, said the representatives.