Self-monitoring linked to greater BP reductions than in-clinic management

Self-monitoring was more useful than in-clinic blood pressure measurements for titrating antihypertensive medication, according to a randomized trial published online Feb. 27 in The Lancet. After one year, patients who underwent self-monitoring interventions showed significantly lower systolic blood pressures than those who were randomized to normal care.

Lead researcher Richard McManus, PhD, MBBS, and colleagues divided 1,182 participants equally between three groups: self-monitoring, self-monitoring with telemonitoring or usual care (blood pressure taken in the clinic). The average age of the study population was 67 and all individuals were hypertensive with blood pressure above 140/90 mm Hg.

Participants assigned to the self-monitoring groups were asked to check their blood pressure twice each morning for the first week of every month. Their physicians used those readings to guide medication dosage.

Those self-monitoring alone mailed their results to clinicians, while those in the telemonitoring group sent their results via text message. These text results also filtered through an algorithm that alerted participants if they sent insufficient readings, reminded them to contact their practice if blood pressure was off target and sent the readings to the clinicians via a secure web page, where they could view the mean BP for the week, abnormally high or low readings and a graphical display of BP measurements.

Practitioners reviewed these two groups’ readings each month and saw patients in the normal care group as often as they wanted.

After 12 months, average systolic blood pressures were 137 in the self-monitoring group, 136 in the telemonitoring group and 140.4 in the usual care group. Compared to normal care, the risk-adjusted mean differences were 3.5 mm Hg lower in the self-monitoring group and 4.7 mm Hg lower in the telemonitoring group.

Importantly, the blood pressure targets for clinicians were 5/5 mg Hg lower for home monitoring versus in-clinic, consistent with international guidelines.

“Self-monitoring, with or without telemonitoring, when used by general practitioners to titrate antihypertensive medication in individuals with poorly controlled blood pressure, leads to significantly lower blood pressure than titration guided by clinic readings,” McManus et al. reported. “With most general practitioners and many patients using self-monitoring, it could become the cornerstone of hypertension management in primary care.”

The authors said their trial wasn’t powered to detect the difference in cardiovascular outcomes, but the self-monitoring interventions would be expected to reduce the risk of stroke by 20 percent and the risk of coronary heart disease by 10 percent given the differences in blood pressure.

Retention wasn’t significantly different between the groups—83 percent in both intervention groups and 88 percent in the usual care cohort. McManus and coauthors noted the telemonitoring group developed the strongest antihypertensive care plan, both in terms of taking more medications and at the highest daily doses.

“Although not significantly different from each other at 12 months, blood pressure in the group using telemonitoring for medication titration became lower more quickly (at 6 months) than those self-monitoring alone, an effect which is likely to further reduce cardiovascular events and might improve longer term control.”

Even though the group who self-monitored alone benefitted from the intervention, the researchers noted sending results by mail and processing data manually could be a logistical hurdle that would be hard to overcome in a non-study setting.

A telemonitoring approach with complementary web-based support could be the best solution, they wrote, hinting that a future study will further support it as the best of all three options.

“An economic analysis and qualitative study will follow this work and will be important in understanding the place of telemonitoring over and above self-monitoring in the management of hypertension,” McManus and colleagues wrote.

In a related editorial, Ernst. R. Rietzschel, MD, PhD, and Marc L. De Buyzere, MSc—both with University Hospital Ghent in Belgium—highlighted a 2014 JAMA study which demonstrated patients could self-titrate antihypertensive medication with similar results as the intervention groups in McManus et al.’s trial.

Given the data overload clinicians are confronted with in this digital age, the editorialists suggested physicians cede some control of hypertension management.

“Should not the driver's seat be co-chaired by health literate patients and dedicated professionals from allied fields? Could it be a valuable option to empower patients whenever possible, introducing them to self-titration and self-initiation of antihypertensive drug therapy? Such an option would be controversial and not devoid of risks but could be a worthwhile and future-proof strategy,” Rietzschel and De Buyzere wrote.

The Belgian authors said this approach could use physicians as a centralized expert focused on population health. It could address doctor shortages, they wrote, and be “equally applicable” to low-income countries where there are often high rates of undiagnosed and untreated hypertension.