Ouch. I've had popcorn husks stuck in between my teeth, but never had an infection because of it and certainly never tried to remove one with wire or a nail! Good old floss usually does the job.
Keep in mind that before we undergo open heart surgery we need a "dental clearance". It was explained to me by the surgeon that infections in the mouth that go untreated can quickly move to the heart and do major damage there. With that in mind, it's not difficult to see why this man's heart was damaged by an untreated infection in his mouth..
Not much to add, except that since the US health authorities have, in the last couple of years, moved antibiotic cover for valvers to the "optional" category, be sure to impress upon your dentist how YOU feel about it. They can prescribe, they just don't "have to."
My dentist and I are in full agreement - 600 mg of clindamycin prior to any invasive dental procedure. I have cleaning performed 4 times a year. The good side effect of this is that I have (knock on wood) had minimal to no dental issues (other than replacing some worn crowns) for the past 10 years or so.