what is the central idea of this paragraph ?

Question

Artificial hemoglobin was tested in human patients. Unfortunately, there were problems. The altered protein was associated with an increased risk of heart attack and death. It was argued that artificial hemoglobin could still be used to rescue critically injured patients who might otherwise die without immediate blood replacement. [...] The U.S. Food and Drug Administration (FDA) has decided that, at least for the time being, no artificial hemoglobin will be given to human patients.

Answer 1

The central idea of this paragraph is that while artificial hemoglobin was tested in human patients and showed potential to save critically injured patients, it was associated with an increased risk of heart attack and death, leading the FDA to halt its use in patients for the time being.