COOK spaghetti according to package instructions until al dente; DRAIN, RESERVING 1 cup pasta water.
Meanwhile, in a large skillet over medium heat, MELT butter.
ADD garlic; STIR until fragrant; ADD asparagus, COOKING until just tender, 4 to 5 minutes; REMOVE from skillet.
DRIZZLE shrimp with olive oil; ADD to skillet; COOK, STIRRING until pink, about 3 minutes moreSEASON with salt and pepper.
RETURN asparagus to skillet with shrimp; ADD lemon juice, lemon slices, Parmesan and heavy cream; let SIMMER until thickened.
ADD cooked spaghetti; TOSS until coated; ADD pasta water as needed until sauce is creamy.
Per Serving (excluding unknown items): 549 Calories; 13g Fat (22.0% calories from fat); 37g Protein; 70g Carbohydrate; 3g Dietary Fiber; 202mg Cholesterol; 330mg Sodium. Exchanges: 4 1/2 Grain(Starch); 3 1/2 Lean Meat; 0 Vegetable; 1/2 Fruit; 0 Non-Fat Milk; 2 Fat.