1. Quit smoking. According to one source, it takes the average smoker between 7 and 10 tries to actually quit. So keep trying and don't get discouraged.
2. Stop pigging out. Portion control becomes more important as you get older. Your metabolism slows down, and it's a lot easier to gain weight. So get out of the habit of eating whatever you want, and pay more attention to calories.
3. Start exercising. Getting 30 to 45 minutes of exercise a day is one of the best things you can do for your heart. Just make sure your workout includes a warmup and a cool-down. It's more important in your 40's than it is in your 20's.
4. Figure out how to manage your stress. Too much of it is bad for you in more ways than one. But it's impossible to avoid, so you just have to find a way to deal with it.
5. Stop isolating yourself. It's easy to stay home and do nothing now that everyone has high-speed Internet and a huge TV. But it can catch up with you. People who keep socializing tend to live longer.
And a study in 2016 found that if you're lonely or isolated, you're about 30% more likely to develop heart issues.