Many people wonder 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?
For so many of my patients, it seems all we want to do is prescribe medicines for everything. How did we get here?
Less than 100 years ago, half of all deaths in America were from cardiovascular disease (heart attacks and strokes, mainly), yet we had no idea what caused it. Our own President Roosevelt died in 1945 at the age of 63 from a cerebral hemorrhage (stroke caused by bleeding in the brain). Before his death, his blood pressure was recorded as 300/190 mmHg, an astonishingly high blood pressure that would almost certainly have resulted in being admitted to the Intensive Care Unit today. At the time, though, no one knew his stroke was the result of many years of untreated high blood pressure.
A few years after Roosevelt’s death 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.
Meadors and his team chose the town of Framingham, Massachusetts as the location for a new kind of population study, because it was thought to be an “ideal town.” The thinking was to start with a group of people who never had a heart attack, and monitor things such as weight, blood pressure, and some lab values over many years.
If any of the Framingham citizens had a heart attack, their data would get pooled into a database. Once they had enough people who experienced a heart attack, they could then identify what clinical features were common to the people who had heart attacks. So, for example (and this is oversimplified), if a majority of people who had a heart attack also had high blood pressure, this would be called a potential “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 actually 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 the 1960s that medications to lower blood pressure safely were identified. We could then see that treating the hypertension subsequently reduced the incidence of heart attacks.
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!
Subsequent studies showed that when we used medicines and lifestyle changes (what I will 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 that individual’s 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 ideal blood pressure control. Most of these conditions (diabetes and high blood pressure) can get better with weight loss and exercise, but most often medications are still needed.
High blood pressure, for example, is typically a lifelong problem that requires medications to get the pressure 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 help us understand how genetic factors may contribute to heart disease and stroke. I commend these Americans for their selfless contributions. It is because of them that we can all have healthier lives.
*Normal blood pressure is a systolic – top number – less than 120 mmHg! Reference: The Framingham Heart Study and the Epidemiology of Cardiovascular Disease: A Historical Perspective (2014) Lancet March 15; 383 (9921): 999 – 1008.
Photo courtesy of the Framingham History Center.
