Recently published news from the ESCAPE randomized trial to reduce hypertension is good: practitioners helped patients reduce high blood pressure with a multifaceted, yet simple, intervention. Can American doctors take some lessons from this French clinical trial?
To understand high blood pressure, it's important to know what blood pressure readings mean. Blood pressure is typically recorded as a ratio of two numbers, with the systolic number written above the diastolic number, such as 115 / 75 mm Hg (millimeters of mercur. The systolic number (shown on top) indicates the pressure (measured in millimeters of mercury, using a sphygmomanometer) on the arteries during systole, which is when the heart beats (during the contraction of the heart muscle). The diastolic number (shown on the bottom) indicates the pressure on the arteries during diastole, which is when the heart muscle rests between beats.
Both numbers matter. The American Heart Association (AHA) offers the following guidelines for blood pressure, with the caveat that unusually low numbers warrant a doctor's attention: normal blood pressure is a systolic number below 120 and a diastolic number below 80; prehypertension is a systolic number between 120 and 139 or a diastolic number between 80 and 89; stage 1 hypertension is a systolic number between 140 and 159 or a diastolic number between 90 and 99; stage 2 hypertension is a systolic number above 160 or a diastolic number above 100, with a "hypertensive crisis" indicated by a systolic number above 180 or a diastolic number above 110. Emergency medical care is needed in a hypertensive crisis.
More than one-third of American adults (33.5%) have high blood pressure, or hypertension. Since high blood pressure is linked to a higher incidence of heart attack, stroke, and kidney disease, it is important to prevent the development of this condition and to work to remedy it if one does develop it. The AHA recommends eight areas of practice to prevent hypertension: improved diet, regular physical activity, a healthy weight, stress management, tobacco avoidance, proper use of any prescribed medication, low to zero alcohol consumption, and hot tub safety.
The ESCAPE trial was a "two-year, pragmatic, randomized cluster controlled trial" that took place in France. What makes it different from many clinical trials is that the intervention was aimed at doctors rather than patients. Eleven medical colleges were enrolled in the "usual care" group, and 12 into the intervention group. Patients were ages 45 to 75; had been treated for hypertension for at least six months, but did not yet have any signs of cardiovascular disease; and had at least two additional cardiovascular risk factors, such as having been a smoker within the past three years. The doctors in the intervention group were given a day-long seminar about reducing hypertension, a reliable electronic blood pressure measurement device, and a six-page brochure about blood pressure targets and hypertension reduction strategies to keep on their desks over the next two years. Every six months during the trial, the doctors in the intervention group were asked to spend a full office visit discussing the patients' blood pressure numbers and advising them about blood pressure management strategies. Although the specifics of each discussion were not scripted, doctors were instructed to mention diet, exercise, medication, and smoking cessation.
At the end of the two-year trial, significantly more patients in the intervention group achieved their blood pressure targets. The Framingham-Anderson score for coronary risk was also reduced by a statistically significantly greater margin in the intervention group. The study authors note that this is impressive, given that blood pressure targets and Framingham-Anderson scores improved in the "usual care" (control) group as well, possibly due to the "Hawthorne effect" of changing one's behavior when one knows one is participating in a study. The authors also note that the simplicity of the intervention -- providing training and instruction only to doctors -- was possible because in France, unlike in other countries, general practitioners (GPs) do not have nurses, assistants, nutritionists, or psychologists in their offices.
Given the recent editorial in the New England Journal of Medicine asking for specialized training for physicians to equip them to deal with the obesity epidemic, it seems that the medical community may be receptive to interventions such as ESCAPE. Perhaps when all doctors know what to say about preventing and treating chronic disease, and are told how often to say it, patients will benefit.