People age 80 and over who have high blood pressure live
longer if they receive drugs to lower it, a new study finds. While that
statement might seem obvious, medical opinion has been unclear on the advisability
of treating hypertension in the very elderly.
Some research has failed to show benefits from reducing blood pressure in such people, and other studies have even associated high blood pressure with longer survival in the group.
“That association probably didn’t reflect that low blood pressure was bad for you,” says Nigel Beckett, a geriatrician at Imperial College London. Reducing high blood pressure consistently benefits people in other age groups. More likely, people with low blood pressure didn’t live as long because they also had cancer, dementia, heart problems or other conditions that depressed their blood pressure, he says.
Nevertheless, many physicians have hesitated to treat high blood pressure in very elderly people who are in otherwise good health. These doctors have worried that medication might not only affect survival, but might also induce sudden drops in pressure that can lead to fainting and falls, a major risk at this age.
To sort it out, Beckett and an international team of scientists recruited 3,845 people age 80 or older who had high blood pressure. They randomly assigned half to receive medication to lower blood pressure and the others to get placebos. Participants lived in Europe, Australia, China and Tunisia. Their average age was 84.
The volunteers entered the trial with average blood pressure readings of a whopping 173 over 91 while sitting down. During the study, those getting medication saw their readings drop to an average of 143 over 78, while those getting the placebo pills dipped slightly, hovering around 158 over 84.
The team reports in the May 1 New England Journal of Medicine that people getting medication were 21 percent less likely to die during the study. People getting the drugs were less likely to experience heart failure compared with those getting placebos and were somewhat less likely to have strokes or to die from them.
In 2007, a committee of scientists monitoring the trial halted it. Patients had participated for an average of two years at that point, but the accumulated data suggested that continuing to give people placebos would be unethical.
Based on the study, doctors should reassess how they treat some elderly patients, says John Kostis, a cardiologist at the RobertWoodJohnsonMedicalSchool of the University of Medicine and Dentistry of New Jersey, in New Brunswick. “The average physician may not pay attention to studies, but this will be included in all the lectures that people give on hypertension,” he says. New information often takes a year or two to permeate through the medical community, Kostis says.
Giving medication for high blood pressure in the very old will remain a case-by-case decision, Kostis says. Some people who experience bad side effects from the drugs might not be good candidates, he says. Beckett’s team excluded people from the study if they had had cancer, a recent bleeding stroke or dementia, or if they required nursing care. These weakened individuals might face risks from lowered blood pressure.
But while reducing high blood pressure may not be recommended for especially frail people over 80, Beckett says, doctors might still prescribe drugs for some people who have health problems in addition to high blood pressure. Some volunteers in this study had a history of stroke caused by a blood clot in the brain, the most common type. Others had diabetes or heart disease.
Roughly two-thirds of people over age 65 have high blood pressure, and some studies show that proportion rises to three-fourths in people over 85, a growing segment of the population in Western countries.
High blood pressure increases the risk of stroke and heart disease at any age, Kostis says. It’s highly unlikely that the benefits of controlling high blood pressure suddenly stop when you turn 80, he concludes.