There’s now emerging evidence that what matters even more than age are preexisting conditions. According to a new report from the CDC published on March 31, 73% of people hospitalized for the novel coronavirus had at least one preexisting condition. Even more striking, 94% of all people who died from the virus had an underlying chronic illness, the most common being diabetes, chronic lung disease, and cardiovascular disease.

Older people are more likely to have chronic health problems than younger individuals, which contributes to the age skew seen in deaths and severe cases. But according to an April 1 report from Kaiser Health News, there are still 41.4 million U.S. adults under the age of 65 who are at risk of developing a serious Covid-19 infection because of preexisting conditions…

It turns out that many deaths caused by respiratory infections, including influenza, are a result of damage to the heart, not the lungs, and Covid-19 appears to be no different. A recent study published in the Journal of the American Medical Association showed that among people hospitalized for the coronavirus, those with high levels of a protein called troponin — a sign of heart muscle damage — had a 61% death rate compared to a 9% death rate in people with normal troponin levels, regardless of underlying cardiovascular problems.