White Coat Hypertension in the Very Elderly: Worth Treating?

Henry R. Black, MD


February 28, 2013

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Hi. I am Dr. Henry Black, Clinical Professor of Internal Medicine at the New York University Langone Medical Center and member of the Center for Prevention of Cardiovascular Disease at that institution. I am also a former president of the American Society of Hypertension.

Clinical trials [are usually designed to] answer a question. But sometimes we learn other things from a clinical trial that might not necessarily be what the trial was designed to answer. One of these cases was HYVET (Hypertension in the Very Elderly Trial), which looked at individuals over age 80 years who were clearly shown to have lower mortality, fewer strokes, and less heart failure. (The stroke rate was not quite statistically significant, but the study was stopped 3 years earlier than planned, so we cannot indict the investigators for not showing that [the lower stroke rate outcome] was significant.)

A substudy[1] of this trial looked at so-called "white coat hypertension" in this elderly population. Investigators measured ambulatory blood pressure in a small subgroup of the HYVET participants. They ended up overall with a relatively small number, only about 50 in the placebo group and a similar number in the group [treated with sustained-release indapamide followed by perindopril if necessary].

The investigators were looking to see whether white coat hypertension was as common in older people as some have expected and to learn the prognosis of someone who has white coat hypertension because now recommendations are mixed. Some say we should not treat it because it is just an alerting reaction. Other pretty convincing studies show that white coat hypertension is something we should not ignore. In this small subset of the population, these investigators found that about half of the individuals in HYVET, over the age of 80 years now and relatively healthy, had what was defined as white coat hypertension by currently available measurements.

Investigators very carefully looked at ambulatory blood pressure (ABP) from 8 AM to 8 PM, making the point that older people generally wake up a little earlier, and from 10 PM to 6 AM as well. [They compared this to clinic blood pressure (CBP) measurements to identify] white coat hypertension in more than half of these individuals. And this group seemed to have the same benefit of treatment as those who had sustained hypertension or did not have white coat hypertension. The differences in systolic/diastolic blood pressures in the placebo vs active treatment group were about the same as in the overall study, about 15/6 mm Hg. [The average placebo-active differences in systolic/diastolic blood pressure were 6/5 mm Hg for morning ABP, 8/5 mm Hg for 24-hour ABP, and 13/5 mm Hg for CBP].

This shows the difference between clinical measurements in the office and ambulatory blood pressure monitoring and is another example showing that ambulatory blood pressure monitoring gives us very good information. We should not ignore patients who say that their blood pressures at home are not high, so we do not need to treat them, because white coat hypertensives in this elderly age group benefited just as much as people who had ambulatory monitoring elevations.

Thank you very much.