Can Technology Silence a Silent Killer?

Telemonitoring of high blood pressure improves patients' care and could lower health costs

Often referred to as a silent killer because it doesn't exhibit any warning signs, high blood pressure-or hypertension-affects one in five Canadians. Half will be afflicted at the age of 65, and the risks increase as we get older. Ninety percent of Canadians will develop high blood pressure during their lifetime.

Left untreated, high blood pressure causes atherosclerosis and hardening of the arteries over the long term. This can lead to strokes, heart disease, vision loss, dementia, and kidney failure. University of Alberta researcher Dr. Raj Padwal believes that helping patients monitor and better manage their high blood pressure to avoid such dire consequences can help reduce the costs to the heath system that happen when high blood pressure goes unchecked. He also hopes to help patients and doctors get better readings to avoid over or under medicating patients.

"A major complication of hypertension is stroke," says Dr. Padwal. "We know that proper control of blood pressure will reduce the risk of having one. Stroke is very costly because it incapacitates people and their level of care must go up, dramatically in many cases. Stroke can impact people in the prime of their lives, and you can well imagine the burden on the health care system if someone suffers a stroke and then spends decades in a nursing home."

Typically, patients manage their high blood pressure with medication that is given based on accurate readings of their blood pressure. Getting accurate readings, however, is more difficult than it sounds. Everything from testing in a clinical setting to patient and doctor biases can skew the numbers.

Dr. Padwal and his team are conducting a study that uses digital technology to increase the accuracy of blood pressure readings and makes it possible for those readings to be done at home. The study is funded by the eHealth Innovations Partnership Program (eHIPP) and Alberta Innovates.

Real-time blood pressure management

Dr. Padwal and his team will start with seniors in assisted living facilities because the remote technology makes sense for patients who can't get to their clinic easily. Participants will take their blood pressure readings four times a day for a week; the readings will be transmitted via Bluetooth to a secure website. This data will be averaged and interpreted by a pharmacist who can adjust the patient's medication accordingly.

"The best way to properly measure high blood pressure is to wear an ambulatory monitor for 24 hours, but that's very cumbersome," says Dr. Padwal. "We think that if a case manager telemonitors the readings in real time, blood pressure is going to be much better controlled. High pressure is going to be lowered and low pressure avoided with properly dosed medication."

Getting rid of error, stress and bias

Dr. Padwal's digital technology also helps avoid something he describes as the 'white-coat' phenomenon that can lead to inaccurate readings. "The worst setting to do blood pressure measurements is in the clinic," he says. "In 95 percent of the people being managed for high blood pressure, office readings are inaccurate up to about 40 percent of the time, most often because a person's blood pressure spuriously goes up when he or she is in the clinic to see their physician."

Patients can also make errors while taking readings at home because they have poor information about how to properly monitor their own blood pressure and they don't always record the right numbers.

"Maybe the patient takes ten readings and eight of them are elevated, and they only report two to you," says Dr. Padwal. "And you think this patient is controlled when they are really not." It works the other way as well. Sometimes patients are very anxious and they think they are going to have a cardiovascular event, and they want their blood pressure lower. "They actually want more medication. It's not as common, but it happens," he says. "And so you really are often not getting a very accurate picture when you say, go buy a home monitor, do some monitoring, and then come and give me the readings."

Dr. Padwal's remote monitoring technology avoids all these errors and biases and makes it easier for the patient. "The nice thing about the system we're testing is that it has been designed so that all seniors have to do is really what they already do, and the rest of it is automated," he says.

What the future holds for e-health technology

If his research confirms what he believes it will, telemonitoring could find its way into many people's homes in the future. "We firmly believe it is the way to go," he says. "As long as you can do it easily, cheaply, in the background, and as long as you can get those readings to a place where physicians can quickly and easily access them, I think it will revolutionize care in many ways."

Dr. Padwal anticipates enrollment for the study to begin in July 2016.