Automatic Blood Pressure Monitor Accurately Detects AF

Abstract

Automatic blood pressure screening with a blood pressure monitor can accurately detect new cases of atrial fibrillation (AF) among older populations, according to a recent U.S. study. Long-term residents of skilled nursing facilities frequently have multiple risk factors for strokes due to AF, and studies have shown that screening for AF may allow residents the opportunity to begin treatment that lowers their risk for stroke. The American Heart Association and the British National Institute for Health and Care Excellence (NICE) both recommend AF screening for residents 65 years and older in primary care clinics. NICE specifically recommends the Microlife WatchBP Home A (BPM-AF), an automatic blood pressure monitor that can detect AF when set to a triple-reading mode. Results from past studies have shown that the monitor has a sensitivity of 95% and specificity of 90% for detecting AF. In 2016 Joseph Wiesel, MD, and Thomas J. Salomone, DrNP, FNP, conducted a pilot program to assess the efficacy of the BPM-AF monitor for AF screening among long-term residents at an SNF in the northeastern United States. Their results, published in the American Journal of Cardiology [July 24, 2017; doi: 10.1016/j.amjcard.2017.07.016], showed that the BPM-AF identified 9 residents with possible AF out of 101 residents screened. In five of those residents the AF was confirmed by a 12-lead electrocardiogram (ECG), and in two of the remaining four it was confirmed using an immediate 30-second single-lead ECG. Overall, 113 residents of extended care units who were 65 and older were eligible to participate, and a total of 101 residents were screened. The average age of the screened residents was 77.7 years, and men made up 52% of the cohort. Residents with dementia, using a ventilator, or housed in short-term rehabilitation were excluded, as were residents with previously diagnosed AF, those who had a pacemaker or a defibrillator, and those who were unavailable or uncooperative. The investigators used the BPM-AF in the automatic three-sequential-reading mode, as recommended for AF screening and maximum blood pressure accuracy. If the BPM-AF detected possible AF, the nurse on the unit would request a standard 12-lead ECG as per routine practice. All 12-lead ECGs in the study were interpreted by a board-certified cardiologist who provided routine ECG readings for the facility. When the investigators could not perform a 12-lead ECGs until several days after an abnormal BPM-AF reading, they immediately collected a backup with a 30-second single-lead ECG handheld device. In the cases where the resident’s delayed 12-lead ECG did not show AF, a board-certified cardiologist interpreted the 30-second single-lead ECG result. The residents with AF confirmed by either the 12-lead ECG or the immediate single-lead ECG were considered to have AF. With one screening BMP-AF reading and a routine confirmatory 12-lead ECG, the incidence of new AF was 4.9%. Including the residents whose AF was confirmed by an immediate 30-second single-channel ECG, the incidence rate increased to 6.9%. The false-positive rate was 2%. The investigators noted that their AF detection rates were significantly higher than the 1.61% rate obtained via systematic screening using one ECG in participants 65 and older from a general outpatient medical population (BMJ 2007;335:383–388) and the 1.2% incidence rate recorded for ECG screening among 75-year-old community residents (Circulation 2013;127:930–937). “Residents of skilled nursing facilities may be at particularly high risk of undiagnosed AF and would benefit from routine screening for AF,” wrote Drs. Wiesel and Salomone. They also noted that “given the high prevalence of previously undiagnosed AF found in this study, expanding the criteria for AF screening to include younger skilled nursing facility residents may be appropriate.” Braxton Poe is a freelance writer in the Philadelphia area. We certainly have the technology to do widespread screening for asymptomatic atrial fibrillation in our nursing home residents. Considering the prevalence of risk factors for stroke that would make them good candidates for anticoagulation, this may become the standard of care. However, we need to consider burdens vs. benefits, and allow our patients or their decision-makers to make informed decisions about whether such screening is appropriate for an individual patient. If patients are at excessively high risk for bleeding or falls, or if they have substantially limited life expectancy, then perhaps it is of no benefit to know that they may be experiencing AF since anticoagulation would be relatively contraindicated. Antiarrhythmic medications could be considered for some. And for others, nonpharmacological interventions such as radiofrequency ablation might be considered. As long as we keep the individual patient’s goals of care and specific medical profile in mind, this technology has the potential to prevent many strokes. —Karl Steinberg, MD, CMD, HMDC Editor in Chief