Home-based BP monitoring is on the rise
October 2021 – Repertoire Magazine
You may have seen alarming headlines last September about a decline in blood pressure control in recent years. Authors of a study in the Journal of the American Medical Association reported that the proportion of the population with controlled blood pressure dropped to 43.7% in 2017-2018. It had increased from 31.8% in 1999-2000 to 48.5% in 2007-2008, and remained stable through 2013-2014 (53.8%). And the decline preceded the pandemic, when in-office visits (and in-person BP checks) dropped precipitously.
Some experts argue with the study’s methodology, but hypertension is of concern to all. Educating people about the risks of hypertension and how to avoid or monitor it remains Public Health Step No. 1. Making sure that health professionals in doctors’ offices take blood pressure readings correctly is Step No. 2.
But increasingly, home BP monitoring is becoming Step No. 3. Ambulatory blood pressure monitoring continues to be the gold standard, but at-home units, including wearables, are playing a bigger role in BP monitoring today.
Home monitoring
Even as far back as 2008, there existed widespread agreement on the efficacy of home blood pressure monitoring. “It is recommended that [home blood pressure monitoring] should become a routine component of BP measurement in the majority of patients with known or suspected hypertension,” read a Joint Scientific Statement from the American Heart Association, American Society of Hypertension, and Preventive Cardiovascular Nurses Association.
In 2017 and 2018, guidelines by the American College of Cardiology/American Heart Association and European Society of Cardiology/European Society of Hypertension recommended the use of out-of-office blood pressure measurements to confirm the diagnosis of hypertension and avoid white coat hypertension (said to occur when blood pressure readings at the doctor’s office are higher than they are in other settings, including the home).
Self-monitored BP could prevent false-positive diagnoses of about 420 patients in a population of 1,000, and avert unnecessary treatment of some 221 people per 1,000, reported the authors of a study published this summer in PLOS One. “When scaled to the U.S. population, adoption of SMBP would prevent nearly 16.5 million FP [false-positive] diagnoses, and 8.2 million unnecessary treatments,” the authors wrote.
“Self-monitoring should be the primary mode of measuring blood pressure,” says Issam Moussa, M.D., MBA, professor and head of the Department of Clinical Sciences at the Carle Illinois College of Medicine at the University of Illinois. White coat hypertension is one reason, says Moussa, who is co-chair of the American College of Cardiology’s Digital Health and Devices Work Group. The second reason is that BP is most accurately gauged over the course of multiple measures, not just one office reading. “Self-monitoring is essential,” he says.
Tom Schwieterman, M.D., vice president of clinical affairs and chief medical officer for Midmark, says that studies have demonstrated that at-home BP – despite a relative lack of control over the way the blood pressure measurement is taken (which is a key consideration) – is a valid measurement that helps identify key aspects of BP control, including identifying individuals with false-negative or false-positive BP elevation at the clinical point of care.
“For false negatives, some patients may have ‘masked hypertension,’ where the BP measurement is artifactually normal at their provider’s office, but high at home,” Schwieterman told Repertoire in an email. “For false-positives, patients may have had their BP taken incorrectly or have ‘white-coat hypertension,’ where the healthcare environment induces short-term elevations that are absent when BP is taken in the comfort of the home.
“It is also useful to employ home readings to monitor patients during the third or fourth decade of life to see if they are trending toward unhealthy BP elevations between visits, which can be spaced years apart if there are no pre-existing issues,” he adds. “Wearables, home monitors and even pharmacy devices can be very useful in determining where a ‘patient lives’ with respect to their real-life BP. This can make a big difference in what pharmaceuticals are used, what doses are needed, and even when those medications should be taken.”
Ambulatory BP monitoring devices remain the gold standard in determining the true pattern and level of elevation for patients with BP issues (high or low), Schwieterman says. “With very little human intervention and the unique opportunity to achieve BP measurements while the patient is asleep or even driving, an ABPM unit captures rich serial data that is useful to correctly map the true physiology.”
Even so, he sees wearables as becoming a normal part of a patient’s home-care routine and a data contribution to every doctor visit. “It is that valuable.”
All in the wrists
Thirteen years ago, the most commonly used home-based monitors were those placed on the upper arm and self-inflating. But the use of wrist monitors was already growing, used by 22% of patients who owned monitors at the time, according to the 2008 Joint Statement from the American Heart Association, American Society of Hypertension, and Preventive Cardiovascular Nurses Association.
Today, consumers can find wearables and fitness trackers on Amazon, though these are not certified medical devices. One significant example of the technology stepping up comes from a recent update to the Samsung Health Monitor app, reports TechRadar. The update allows the user to use the PPG (photoplethysmography) sensor already in the Samsung Galaxy Watch 3 or Galaxy Watch Active to take a blood
pressure reading.
Medical professional organizations such as the American College of Cardiology are embracing home-based wearables for blood pressure control. In June 2020, ACC and Heartbeat Health, a New York City-based virtual care company, announced a smartphone program in which key metrics – e.g., BP changes or volume status in heart failure – are transmitted in real-time to cloud-based artificial intelligence engines, which flag potential health risks for clinicians.
“To truly transform cardiovascular care and improve heart health, we must incorporate data, remote patient monitoring and outcome tracking in an easy-to-use format both the patient and the physician can use to inform shared decision-making,” John Rumsfeld, MD, PhD, FACC, ACC chief science and quality officer and chief innovation officer, was quoted as saying. “Wearable health monitoring devices have evolved rapidly over the last five to 10 years and are now widely available; COVID-19 is a catalyst to push remote patient monitoring into the virtual care workflow.”
In June 2021, ACC and cliexa, a Denver-based start-up focused on remote patient monitoring, collaborated to launch a home health monitoring program called cliexa-Pulse, which allows clinicians to track symptoms, medications and daily activity for the management of hypertension, atrial fibrillation, heart failure and other cardiovascular conditions.
The limits
Wearables may be improving every day, but some believe more study is necessary. The American Heart Association currently recommends that blood pressure readings be taken only from the upper arm. Other places, like the wrist or finger, might not be as accurate, according to the AHA. In a recent TechRadar article, Ghalib Janjua, a lecturer in electronic and electrical engineering at Robert Gordon University, Scotland, warned that cuffless monitors are limited in accuracy and require calibration against the sphygmomanometer devices.
Says Moussa, “If we could demonstrate that wearables are as reliable as traditional cuff devices, they would be preferred, because the patient could get blood pressure any time, including during exercise. But studies need to demonstrate their reliability.”
And, as with so many IoT devices, there’s the challenge of integrating the influx of patient-generated data into the physician practice’s workflow, so the information is actionable.
“This is a critical concern, as physicians have no shortage of data available to make decisions,” says Schwieterman. “Today’s workflow in a typical office does not provide adequate time nor methods of data review for chronic patients to allow this important clinical activity.
“With the rise of value-based care reimbursement, where financial success for the clinical team is tied to success in disease care, and because of its centrality to both clinical and financial success, I do anticipate future workflow priorities changing to create time in the day for these activities. As of today, however, this shift has not occurred, and most clinicians are doing the best they can to review self-reported data, often while the patient is in the exam room for a checkup or during a telehealth visit.”
Clinicians are still the key
Million Hearts® 2022 is a national initiative co-led by the Centers for Disease Control and Prevention and the Centers for Medicare & Medicaid Services whose goal is to prevent 1 million heart attacks and strokes within five years. The program holds that self-monitoring of blood pressure + clinical support = lower hypertension rates, and it recognizes physician practice “Champions” that have used the program to improve their patients’ health.
According to the initiative’s leaders, public education campaigns can encourage patients to monitor their blood pressure at home, but clinician support is critical for empowering patients, training them on proper measurement techniques, monitoring home readings, and providing timely advice on medication titrations and lifestyle changes.
Sidebar – 1
The JAMA study in perspective
In September 2020, authors of a study in the Journal of the American Medical Association reported that the proportion of the population with controlled blood pressure dropped to 43.7% in 2017-2018. It had increased from 31.8% in 1999-2000 to 48.5% in 2007-2008, and remained stable through 2013-2014 (53.8%). Experts believe the study must be put in its proper context.
The reported decrease in BP control was anticipated, says Tom Schwieterman, M.D., vice president of clinical affairs and chief medical officer for Midmark. In December 2013, the eighth Joint National Committee (JNC 8) recommended higher BP goals for some adults compared with the previous guidelines, he told Repertoire in an email. “Five authors of the new guideline predicted the reported decrease, noting that the higher BP goal would result in reduced intensity of antihypertensive medication use. Under the later guideline, certain populations were determined to need more strict BP goals to achieve optimal clinical outcomes. In many respects, this shift incurred a higher percentage of individuals deemed not in control by the new standard.
“Despite it having been expected, I do think that having less than 50% control, no matter the guideline used, is cause for alarm.”
Issam Moussa, M.D., MBA, professor and head of the Department of Clinical Sciences at the Carle Illinois College of Medicine at the University of Illinois, warns that studies done retrospectively, as the one reported in JAMA, are always subject to limitations. In this case, patients were seen only one time.
“One of the main premises [of blood pressure measurement] is, there needs to be multiple visits,” said Moussa, who is co-chair of the American College of Cardiology’s Digital Health and Devices Work Group. “I don’t believe the results of this study are definitive enough to build an unequivocal conclusion.” Other factors were at play as well, including the fact that the definition of what constitutes hypertension changed during the study period.
“Having said that, we know that blood pressure control varies among different populations, regions, health insurance plans, compliance, patient profiles, and treating institutions.”
Sidebar – 2
Seven steps for self BP measurement
The American Medical Association recommends that physicians implement seven steps to improving self blood pressure measurement (SMBP) among their patients:
1. Identify patients suited for SMBP (e.g., those with an existing diagnosis of hypertension, or those suspected of having it).
2. Make sure patients have automated, validated devices with appropriately sized upper arm cuffs. (Use the US Blood Pressure Validated Device Listing and self-measured blood pressure
cuff selection.)
3. Educate patients on proper preparation and positioning before taking measurements, as well the need to rest one minute between measurements.
4. Instruct the patient to conduct SMBP monitoring whenever BP assessment is desired. Provide instructions on the frequency and duration of monitoring and the number of measurements to take each day. Determine when and how patients will share results back to care team.
5. Compute and document average SMBP measures received from patients for monitoring period.
6. Interpret results, then initiate, intensify or continue treatment.
7. Document treatment and follow-up plans and communicate to patients. Confirm their agreement and understanding.
Source: American Medical Association, www.ama-assn.org/system/files/2020-06/7-step-smbp-quick-guide.pdf