My grandmothers were both type II diabetics, controlled mainly with diet for many years, and a lot of the cooking I did for them was quite simple. Many of the things I used to make with them in mind (I used to make extra to freeze so they didn't have to cook) are still in our family dinner rotation.
For main dishes, eggplant thin sliced and dried slightly in the oven - just a few minutes at 250, to remove some of the water so the lasagna doesn't come out runny - makes a lower-carb substitute for noodles in a lasagna and there are a lot of diabetic and heart healthy options for fillings. My favorites are classic ricotta with Italian-style turkey sausage, garlic & onion, and vegetable with eggplant, zucchini/summer squash, carrots, and mushrooms and feta cheese in place of the ricotta (not a 1 to 1 substitution; I use about half as much feta as I would ricotta).
Stir-frys without rice work well too, just a lean meat and an assortment of veggies, nicely seasoned, but be sure to look for low sodium soy sauce if you're doing a soy-based sauce. And of course, simple lean meats - baked chicken, meatloaf made with lean beef, grilled fish, pork roast. You should be able to find a lot of variations on those that are low carb; chili-glazed pork tenderloin, chicken breasts simmered in salsa, etc.
For snacks, it'll depend on his heart-related restrictions. My grandmother loved turkey jerky, but that might be too high in sodium. Tomatoes & mozzarella with a drizzle of an olive-oil based dressing was another favorite. Veggies and dairy-based dips are usually a safe bet but broccoli and other brassicas (kale and cabbage and a few others, IIRC) are generally not recommended for people on blood thinners or anticoagulants because they're high in vitamin K which promotes clotting.