As I could see from this passage ("The AED equipment is the automated external defibrillator and they say that the drone would be able to carry this equipment to the scene; equipped with instructions for those standing by on how they can use it to help those who need the assistance following their attack."), the drone relies on other people being around the person with the heart attack. But it is unknown whether there are such people and how much they would be able to follow the instructions. So probably the usefulness of the drone is that it gets there faster. But the ambulance would still be needed, for now at least.
I imagine that, if the person has a device that monitors their heart rate, that device could automatically signal the hospital at the time of the heart attack, or even a little bit before it (assuming the heart has recognizable behavior before it has an attack). So the drone would get there even if there is no one around the attack victim to call the hospital. And the drone could make sounds to call the attention of people nearby. And the software system could message/call the person's relatives/friends who are registered as emergency contacts.
So much unutilized potential...