This award seat from Miami (MIA) to London Heathrow (LHR) is pricing at 57,500 AAdvantage miles in business class. You'll also need to pay $738 in taxes and fees, which is standard for premium cabin awards to the UK due to carrier surcharges.
For context, business class awards on this route typically run around 115,000 miles through American's program. At 57,500 miles, you're looking at a redemption that's about 50% below what you'd normally expect to pay. That's a solid value if you have the miles sitting in your account.
One important note: there's only a single seat available at this price. That makes this a better fit for solo travelers rather than families booking together. If you need multiple seats, it's worth searching nearby dates to see if similar availability opens up.
Before booking, double-check your AAdvantage balance covers the miles and confirm the taxes fit your budget. The $738 in fees is worth factoring into your overall cost calculation.
How to book
Search for award availability and complete your booking directly through American Airlines: https://www.aa.com/booking/choose-flights/1