Coat the inside of a 3-1/2- or 4-quart slow cooker with cooking spray. Drain two of the cans of diced tomatoes (do not drain remaining can). In the prepared cooker, stir together drained and undrained tomatoes, the artichoke hearts, and garlic.
Cover and cook on low-heat setting for 6 to 8 hours or on high-heat setting for 3 to 4 hours. Stir in whipping cream; let stand about 5 minutes to heat through.
Meanwhile, cook pasta according to package directions; drain. Serve sauce over hot cooked pasta. If desired, top with olives and/or cheese. Makes 6 servings.