they are better than regular cigarettes but not smoking at all is best. 

The issue is that though there is evidence that e-cigarettes can cause a variety of health issues, we have not studied the relationship between quantity and risk, so clinically it is difficult to give advice about what it means to be a heavy e-cigarette smoker. I do agree we need to come up with a way to quantify it in order to study these effects. 

So they have done this twice, and both patients have died.. 

Although it does say that they are patients who are so sick they are not eligable for human organ donations anyway. So maybe they are choosing the wrong patients.