Home blood pressure monitors show mixed results

Home blood pressure monitors may be useful to some older adults who've suffered a stroke, but little help to others, a new study suggests.

Researchers found that overall, home monitors did not help stroke sufferers get a better handle on their blood pressure over one year.

The exception, though, was patients whose blood pressure was poorly controlled at the study's start - meaning it was above the standard high blood pressure cutoff of 140/90 mm Hg.

In that case, patients given a home monitor cut an average of 11 points from their systolic blood pressure (the top number in a blood-pressure reading). That compared with just under five points among patients who were not given the devices.

That's a meaningful difference, said Hayden B. Bosworth, a professor of medicine at Duke University in Durham, North Carolina, who was not involved in the study.

The lack of overall benefit in the study doesn't mean stroke patients shouldn't use blood pressure monitors, according to Bosworth, who studies ways to improve people's management of high blood pressure and other chronic conditions.

"It may be a matter of finding the right people to give them to," he said.

Sally M. Kerry, the lead researcher on the study, said that many people who've had a stroke are "very motivated" to prevent another. So they may already be doing their best to keep their numbers under control.

"The main issue seems to be with those who already have relatively well-controlled blood pressure. Home monitoring is unlikely to improve this, although people do find it reassuring," Kerry, a researcher at Queen Mary, University of London in the UK, said in an email.

She and her colleagues report their findings in the Canadian Medical Association Journal.

Past studies have found that home monitoring may aid blood pressure control. A 2010 review of 37 clinical trials found that overall, people who used monitors shaved a few extra points from their blood pressure. They were also more likely to cut down on medication compared with patients who stuck with traditional doctor's office measurements.

The new study focused on patients who'd recently had a stroke - a group, Bosworth noted, that hasn't really been studied when it comes to home blood pressure monitoring. He said that's probably in part because there is no real consensus on what stroke survivors' blood pressure levels should be.

Kerry's team randomly assigned the patients to either stick with standard care only or get a home monitor - along with instructions on how to use it and periodic phone calls from a nurse to check on how they were doing.

Over the next year, the results were mixed. Among the patients who didn't seem to benefit were those who'd been left disabled by their stroke. Home monitors showed no effects on their blood pressure, while non-disabled patients cut about four points using a monitor.