Battling rising hypertension in children: 5 tools

FDR (here signing the Declaration of War against Japan, 1941) died from a stroke caused by years of hypertension. Millions of U.S. children could meet the same fate - unless we act now.

While many of us recall that President Franklin Delano Roosevelt had polio, few remember that he died in 1945 from another cause: stroke. The sentiment of his physician — that it “had come out of the clear sky” — reflected the prevailing view that heart attack and stroke were bolts from the blue that doctors could act on only after the event.

But a few mavericks challenged this “salvage” paradigm, establishing the Framingham Heart Study in 1948 to identify predictors of cardiovascular events. One leading maverick, Dr. William Kannel, who passed away last month, coined the term “risk factors” to describe these predictors. Acting on the insight that controlling risk factors could prevent cardiovascular disease saved the lives of more than 150,000 Americans from heart disease alone between 1980 and 2000.

Judging by the surviving medical records, Roosevelt’s stroke may have been preventable with treatment for one such risk factor, hypertension. How different would the world have been had his persistent high blood pressure been treated?

The world is different now, not all for the better. High blood pressure has been attacking more and more children over the last 30 years, as documented by the government-sponsored National Health and Nutrition Examination Survey. This change over such a short time is likely a consequence of changing dietary habits, food environments and activity levels. The relative proportion of children with elevated BP varies by age, sex, ethnicity and weight, with obese adolescent boys having a 950 percent greater risk than young kids of normal weight. A recent study of more than 15,000 young adults showed that nearly 1 in 5 twenty-somethings have high blood pressure – predicting an avalanche of heart attack, heart failure and stroke at younger and younger ages.

Yet hypertension in children often goes undiagnosed. A study of more than 14,000 well-child visits at a Midwestern pediatric center  found that 75 percent of children with high blood pressure were missed.

At the same time, a substantial proportion, if not the majority, of children referred to our hypertension clinics turn out not to be persistently hypertensive. Our resources are not being applied efficiently.

The good news is that we already have the tools to fight back. Here are 5 steps we’re pursuing in our own practice at Children’s Hospital Boston.

1. Standardize blood pressure measurement: Perhaps because high blood pressure used to be such a rare problem, many practitioners are out of practice in optimal BP measurement. Our Preventive Cardiology program and the Renal Hypertension program have developed an interdisciplinary refresher course on manual and machine BP measurement in a variety of patient care venues, hoping to foster better adherence to optimal BP measurement guidelines.

2. Help practitioners recognize high blood pressure: Abnormal BP cutffs in children depend on age, sex and height, requiring busy clinicians to negotiate elaborate charts containing 476 normal values – here’s just a portion of it:

Click to enlarge. For full chart: http://www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.pdf

We are developing an electronic-medical-record-based solution to help with this ponderous task.

3. Verify that high blood pressure is persistent: Doctors make kids nervous, which raises BP during medical encounters. Since BP medications don’t fix anxiety, we want to limit treatment to children who truly have persistent high BP. We are using remote 24-hour blood pressure monitors to verify that high BP is persistent, an approach demonstrated in studies in Pediatrics and, most recently, in The Lancet to enhance proper diagnosis and reduce unnecessary tests in children and adults.

4. Treat high blood pressure by modifying lifestyle: Since high blood pressure in kids is partly due to poor eating and activity habits, it can be successfully reversed with diet and exercise. These powerful interventions can have synergistic effects, reducing cholesterol, blood sugar and excess weight as well.

5. Prevent hypertension: While treating hypertension lowers the added risk for cardiovascular disease, it may not reduce the added risk to zero. If treating isn’t enough, how about preventing hypertension before it ever starts? We are using cutting-edge research techniques and equipment proven at the Framingham Heart Study to investigate biophysical, biochemical and lifestyle predictors of hypertension. We hope to leverage these “risk factors for risk factors” to prevent hypertension from even occurring — just as we address hypertension to prevent stroke or heart attack.

Rigorous medical scientists showed us that hypertension causes death and disability. While not in time for President Roosevelt, we now have the tools to fight cardiovascular disease by modifying risk factors. As the government launches the Million Hearts initiative to prevent 1 million heart attacks and strokes, we should remember that the fight must begin in childhood. If we follow the example of Kannel and his pioneering colleagues, it’s a fight we can win.

Justin Zachariah, MD, MPH, is a Preventive Cardiologist at Children’s Hospital Boston interested in preventing atherosclerotic heart disease in children with and without congenital heart disease. He is the first pediatric cardiologist to train at the NHLBI’s Framingham Heart Study.