Say “fat in the bloodstream” and most people think of cholesterol. But there’s another type of fat shouldn’t be ignored: triglycerides. High triglycerides can increase the risk of having a heart attack. Existing drugs lower triglycerides, but aren’t that good at preventing heart attacks. That’s why a report on a new way to lower triglycerides, published in today’s New England Journal of Medicine, is generating some excitement among cardiologists. The new approach uses weekly injections of “antisense oligonucleotides,” or ASOs. These are pieces of DNA that short-circuit the liver’s production of triglycerides. The NEJM report shows that ASOs can reduce triglyceride levels by as much as 70%. Keep in mind that this was a phase 2 trial, which is designed to test whether a drug does what it is supposed to do (in this case, lower a person’s triglyceride levels). Larger, longer-term studies will be needed to see whether ASOs actually reduce the risk of heart disease, and what sorts of side effects they cause.