(Karen Garloch, kgarloch@charlotteobserver.com) Novant Health has signed a letter of intent to merge with Prince William Health System of Manassas, Va.. It's the first time that Winston-Salem-based Novant has affiliated with an out-of-state system. As part of the agreement, Novant has pledged more than $200 million to help meet the growing health needs in western Prince William County, where the population is projected to grow more than 20 percent in the next two years.Both Novant and Prince William are regional, not-for-profit health systems.“We chose to affiliate with Novant because of our shared vision and commitment to high quality community-based healthcare delivery,” said Michael Schwartz, president and CEO of Prince William Health System.