The study revealed an innovative cuffless blood pressure monitor

A study led by a Brigham researcher evaluated a novel device that automatically measures blood pressure at the wrist, generating hundreds of readings over days, which could help clinicians determine cardiovascular risk and improve hypertension treatment

High blood pressure, the leading risk factor for death worldwide, affects one in two adults. Only a quarter of people with hypertension have their blood pressure under control, highlighting the need for innovative blood pressure control strategies. The study, conducted by a researcher at Brigham and Women’s Hospital, founder of the Mass General Brigham health system, evaluated a cuffless monitor that uses optical sensors to continuously and efficiently record blood pressure without disrupting a patient’s life. Study published in Frontiers in medicinehighlights the promising advances in hypertension diagnosis, risk assessment and management that can be achieved through the use of cuffless devices.

“Successful treatment of hypertension depends on the ability for patients to easily and reliably obtain blood pressure measurements outside the traditional physician’s office,” said corresponding author Naomi Fisher, M.D., of the Division of Endocrinology, Diabetes and Hypertension at Brigham and Women’s Hospital. “Cuffless devices have the potential to revolutionize the treatment of hypertension. They provide significantly more readings than traditional devices, both day and night, which can help confirm the diagnosis of hypertension and guide drug dosage.”

Medical guidelines increasingly recommend the inclusion of home blood pressure monitoring in the diagnosis and treatment of hypertension. This is because isolated blood pressure readings taken in a clinic can be inaccurate: some people have blood pressures that tend to rise in the medical setting (“white coat hypertension”), while others have normal blood pressures at the time of testing despite readings of hypertension at home (“masked hypertension”).

Time in target range (TTR) describes how often a patient’s blood pressure remains within the normal range and is emerging as a promising measure of cardiovascular risk. However, TTR requires more frequent blood pressure readings, which can be obtained by patients wearing traditional blood pressure cuffs, which can be inconvenient, cumbersome, and sometimes inconvenient for patients.

Fisher, who designed and conducted the study, worked with co-authors from Swiss biotechnology company Aktiia SA to analyze more than 2.2 million blood pressure readings from 5,189 people in Europe and the United Kingdom who wore a cuffless wrist monitor manufactured by Aktiia. The Aktiia device collected an average of 29 readings per day, a significant increase over the number of blood pressure readings patients typically take with home devices (guidelines recommend four readings per day, which is more than most patients measure). Over 15 days, researchers obtained an average of 434 readings from each patient.

By calculating TTR over a 15-day period, investigators were able to risk stratify participants by the percentage of readings within the target range and compare these classifications with classifications generated by traditional measurement patterns, using 24-hour or weekly daytime monitoring schedules. They found that traditional methods misclassified 26 and 45 percent of patients, respectively, compared to the reference TTR. They found that continuous monitoring for seven days was required to achieve at least 90% accuracy in classifying hypertension risk, a frequency of measurement only possible with cuffless monitors.

Although the cuffless device studied here has not been approved by the U.S. Food and Drug Administration, it has been validated in numerous studies and is available for sale over the counter in Europe and the United Kingdom. Work is ongoing to evaluate and establish standards for such devices in the US.

“For the first time, we can collect continuous blood pressure readings outside the office using a cuffless device and use that data to calculate a new metric, time in target range, that shows great promise as a predictor of risk,” Fisher said. “The use of cuffless devices has the potential to change the paradigm of blood pressure monitoring and hypertension treatment.”

Authorship: Fisher’s co-authors on the article are Tiago P. Almeida, David Perruchoud, Jay Shah, and Josep Sola.

Disclosures: Fisher is a consultant for Aktiia SA. Almeida, Perruchoud, Shah and Sola are employees of Aktiia SA.

Financing: No financial support was received for this research.

Cited article: Fisher, N.D. et al. “Optimizing Blood Pressure Target Range Assessment: Lessons from a Large-Scale Study with Cuffless Continuous Monitoring” Frontiers in Medicine DOI: 10.3389/fmed.2024.1396962

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