The liver is one of the most complex organs in the human body. It is responsible for a wide spectrum of toxin breakdown and chemical synthesis. The heart only needs to pump blood, though it’s uptime is very impressive. If your liver stops working you won’t die immediately but if your heart stops working your body will be starved of oxygen in mere minutes. Ultimately though what the heart does is mechanical and simple.
Most politicians in the West don’t actually care about humanitarian issues in China. That has almost nothing to do with why we don’t play nice.