Aetna Life Insurance Co. on Wednesday appealed a lower court's decision to throw out fraud allegations in a lawsuit against the North Cypress Medical Center, a hospital that prides itself on its hotel-like amenities. The insurance company wasted little time after U.S. Senior District Judge Kenneth Hoyt ruled that there was no merit in Aetna's allegations that North Cypress Medical Center had committed common law fraud, health care fraud or misrepresented medical billing records, in a decision he issued last week.