Blood clots that develop in the large veins of the calf can kill if they break off and travel up to the heart. That’s what is called a pulmonary embolism, the killer of some 100,000 Americans every year. Now there’s evidence that statin drugs for lowering cholesterol, and thereby preventing clogging of the arteries in the heart (thus lowering heart attack risk), may also lower the risk of clots developing in the veins, and dramatically so.
But don’t demand a statin drug prescription from your internist just yet. You have to understand your own statistical risk first.
According to a major study of 18,000 patients, as reported in the New York Times, the patients who took the potent statin drug Crestor (rosuvastatin) had a 43 percent lower risk of blood clots in the leg veins than patients who took a placebo pill in the same study.
That’s an impressive number. But more revealing, perhaps, is the actual number of patients that percentage represents. In the 18,000 patients, only 94 developed blood clots — 34 in the group taking Crestor and 60 in those taking the dummy pill, thus the 43 percent difference. But the overall risk is so small that no responsible doctor would recommend people take a statin drug long-term to prevent blood clots in the legs, UNLESS you have some specific high risk for such blood clots — such as a history of having them in the past.
This blog has made a similar point with other “breakthrough” reports on drugs — actually on the same study with the same drug, when it reported in late 2008 that Crestor might reduce heart attack risk even in patients without high cholesterol. You have to count the actual numbers of patients affected and understand where you fit, before you can make an intelligent commitment to long-term use of a drug. This issue is discussed in more depth in my book, The Life You Save: Nine Steps to Finding the Best Medical Care — and Avoiding the Worst.