Maybe to yearly visits.
Yes to heartworm pills. Heartworms will kill a dog. They're difficult and expensive to treat, and you have to keep the dog still /not excited for the months they're on the treatment. And after all that, the treatment may or may not work. Prevention is so much easier.
Heartworms are also super-easy to get. We just adopted our new puppy in November, and essentially ALL the adult dogs at the rescue had heartworms. Having just lost a dog who had significant special needs /needed much medical treatment, I just wasn't willing to take on a new dog with heartworms.