The headline seems bogus but the article says that "naturally occurring coronary heart attacks due to atherosclerosis are virtually non-existent in other mammals." Atherosclerosis is the cause of only "one-third of deaths worldwide due to cardiovascular disease" so other causes could still apply to other mammals. For example, "chimp heart attacks were due to an as-yet unexplained scarring of the heart muscle."

Of course we can give rabbits atherosclerosis by giving them high cholesterol from a diet they don't eat in the wild. But in humans, "in roughly 15 percent of first-time cardiovascular disease events (CVD) due to atherosclerosis, none of these [risk] factors apply," where risk factors include "blood cholesterol, physical inactivity, age, hypertension, obesity and smoking."

So the study explores a possible reason for that.

The important animals are other apes and primates, when considering the evolution of disease. If none of them have it but humans do, then it likely came about recently. This means that it has independently evolved in humans and other animals (like rodents) that may have it. Makes for a misleading headline, though.

Ya, rabbits can die of heart attack if you startle them