Many people ask me about how physicians know when to treat certain medical problems. For example, how do we decide what high blood pressure is? How did we figure out how to treat high blood pressure? How long do we have to treat it?
There’s no better way to explain our thought process than to tell the story about how we figured out these questions. To many people, it seems all doctors want to do it prescribe medicines for blood pressure, cholesterol, diabetes–so many medicines! How did we get here?
Believe it or not, about 100 years ago, we had no idea why Americans were dying of cardiovascular disease (heart attacks and strokes, mainly), yet nearly half of all deaths in this country were related to cardiovascular disease. In fact, President Roosevelt died in 1945 at the age of 63 from a cerebral hemorrhage (bleeding in the brain) caused by a blood pressure recorded at 300/190 mmHg, an astonishingly high blood pressure that would almost certainly lead to someone being admitted to the Intensive Care Unit today. At the time, no one knew that this his death was the result of many years of untreated high blood pressure.
A few years later in 1948 his successor, President Harry S. Truman, signed the “National Heart Act,” a new law developed to figure out what caused cardiovascular disease. A physician and Public Health officer, Gilcin Meadors, was given the task to lead this new endeavor.
He and his team chose the town of Framingham, Massachusetts as the location for a new kind of population study in the field of epidemiology. The idea was to start with a group of people who had never had a heart attack. Then, they monitored things such as weight, blood pressure and some lab values, and followed the participants over many years. If any of the Framingham residents had a heart attack, their data would be pooled into a database.
Once enough people had experienced a heart attack, the researchers could identify the clinical features those people had in common. So, for example (and this is way over-simplified), if a majority of people who had a heart attack also had high blood pressure, this would be called a “risk factor” for having a heart attack.
This project was started in 1947, and ten years later the first major study was published. The researchers found that people who had hypertension (defined then as a blood pressure >/= 160/95 *) were 4 times more likely to have a heart attack. Even so, it wasn’t until 1964 that medications to lower blood pressure safely were identified.
Other conditions that were found to be associated with heart attacks included diabetes mellitus, high cholesterol, and smoking. Ironically, before we knew smoking caused heart attacks the very first budget for the Framingham Heart Study included ashtrays for the doctors and nurses!
Studies performed as a result of this work showed that when we used medicines and lifestyle changes (what I call interventions) to treat diabetes, hypertension, and obesity, we could reduce the likelihood of people having a heart attack.
The results from the Framingham Heart Study also led to the development of risk calculators that allow us to determine the likelihood of a patient having a heart attack in the next ten years. From this information, we can tailor interventions that help reduce the risk of having a heart attack.
Your doctor will work with you to find the interventions that are most appropriate for you, but it’s important that you monitor how you feel and how well that intervention works for you at home. We know from many other studies since Framingham that, even with the most ideal lifestyle changes (stopping smoking, weight loss, increase exercise), it may take two to three medications before we can achieve the best blood pressure control.
Most of these conditions can get better with things like weight loss and exercise, but many don’t go away completely. High blood pressure, for example, is most often a lifelong problem that requires medications to get the value in the normal range*. But we know that all of these efforts will reduce the likelihood that you will have a heart attack, and that’s our goal.
The Framingham Heart Study is still active, with third and fourth generation Framingham residents involved to learn about genetic factors that may contribute to heart disease and stroke. I commend these Americans for their selfless contributions–it is because of them that we can help you live healthier lives.
*Normal blood pressure is a systolic - top number - less than 120 mmHg!