Pressure-Cooker Buffalo Shrimp Mac & Cheese

In a 6-qt. electric pressure cooker, combine the first 7 ingredients; stir in macaroni. Lock lid; close pressure-release valve. Adjust to pressure-cook on high for 3 minutes. Allow pressure to naturally release for 4 minutes, then quick-release any remaining pressure. , Select saute setting and adjust for medium heat. Stir in shredded cheeses, shrimp, blue cheese and hot sauce. Cook until heated through, 5-6 minutes. Just before serving, stir in chives, parsley and, if desired, additional hot sauce.