*Jerry Lee  received an MPhil in Epidemiology as a Gates Cambridge Scholar and is now a second year medical student at Duke University. He is currently funded by the American Heart Association to conduct statins research with Dr Michael Pencina. Picture credit: "Crestor Tablets (rosuvastatin)" by Mk2010 - Own work. Licensed under CC BY-SA 4.0 via Wikimedia Commons.
Cardiovascular disease (CVD) is the leading cause of death in the world. Over the past three years, the major European, American, and British cardiology societies have tried preventing CVD by releasing new guidelines on drugs called statins, which were met with considerable controversy. Some of this controversy has now been clarified with two studies published in the Journal of the American Medical Association (JAMA), though many questions still remain.
The controversy comes from the number of people recommended for statin treatment. In the United States, almost half of the adult population would be eligible for lifelong statin treatment, with comparable numbers estimated for European and British populations.
In other words, if these guidelines were implemented in full effect, statins would be the most prescribed drugs in the world.
In the first JAMA article, 2,435 participants were followed for nine years and assessed for heart attacks, coronary heart disease and stroke. In the second study, the authors determined how much the new guidelines would cost compared to how many years of life they would save. The conclusions were that the guidelines were more effective at preventing CVD and death, better at identifying patients who were more likely to have CVD and cheaper to implement than many other interventions.
In an accompanying editorial, two prominent cardiovascular epidemiologists noted: "There is no longer any question as to whether to offer treatment with statins for patients for primary prevention, and there should now be fewer questions about how to treat and in whom."
Effective, targeted, and cheap. What's not to like?
...Not so fast. My lab at the Duke Clinical Research Institute, headed by Dr Michael Pencina, published the original equations used to calculate CVD risk and the estimations of statin eligibility under the American guidelines, and among our group, there is general agreement that yes, more people are likely to be treated with therapeutic benefit and at reasonable costs. Very importantly, the guidelines do represent a crucial shift towards personalising a patient's risk for CVD events and mortality.
However, I would also emphasise caution - if nothing else than because the implications of these results are staggering. As a future doctor, I am essentially urged to recommend daily, lifelong medication for up to two thirds of adults, many of whom may never have a heart attack for the rest of their lives and many of whom will experience the debilitating side effects of muscle damage and fatigue. Furthermore, as a profession we seem to have concluded that patients will never adhere to the lifestyle recommendations of diet and exercise and have instead decided to use chronic medications for largely preventable conditions - an astounding defeat for public health.
There are several other concerns, such as the exact risk threshold that should determine statin eligibility; the reliance on mainly white study participants (African Americans, for example, are known to have physiological differences, such as salt sensitivity, that affect cardiovascular health); and the possibility of financial conflicts of interest. However, these criticisms are relatively minor when compared to the fact that these studies are not randomised clinical trials, but retrospective studies and simulations - hardly the gold standard for deciding the treatment plan for millions of people.
Frankly, I'm surprised at how quickly these guidelines have caught on. Last year during my cardiovascular pharmacology course, we regularly used the "risk calculator" recommended by the guidelines to determine statin prescriptions; just last week, I shadowed a family doctor who pulled up the risk calculator during a patient visit to determine her patient's statin eligibility. (It should be noted that on the same day, I also met a patient who experienced the side effects associated with statins use.)
At the very least, there is a significant proportion of US doctors who use these guidelines in everyday practice. Although the evidence so far has supported the widespread use of statins to reduce CVDs, I would only re-emphasise the importance of caution in the US and elsewhere: statins eligibility is not a closed case just yet and it may take some time before we fully understand how statins can be best prescribed.