Atrial Fibrillation Detection During 24-Hour Ambulatory Blood Pressure Monitoring

Atrial Fibrillation Screening During Routine Automated Office, Home, and Ambulatory Blood Pressure Measurement: A Diagnostic Test Accuracy Systematic Review and Meta-Analysis

BACKGROUND

Atrial fibrillation (AF) is often asymptomatic and undiagnosed. As AF and hypertension often coexist, opportunistic AF detection during routine automated blood pressure (BP) measurement appears to be an attractive screening method.

METHODS

A systematic literature search was conducted to identify studies assessing the diagnostic test accuracy of office, home, or 24-hour ambulatory BP measuring devices with AF detection algorithms versus reference electrocardiography. Analyses were performed per participant (AF status based on several BP readings; most office/home devices) or per reading (AF status based on individual readings; all ambulatory devices). A meta-analysis stratified by device type (office/home/ambulatory) was conducted to calculate pooled measures of diagnostic accuracy. Sensitivity/meta-regression analyses were also performed.

RESULTS

Among 3096 records initially retrieved, 23 diagnostic test accuracy studies were included. Data derived from 11 093 individuals (weighted age 69 years, males 56%, hypertensives 79%, diabetics 24%, and AF prevalence 17%) indicated a pooled sensitivity 0.97 (95% CI, 0.92-0.99), specificity 0.93 (95% CI, 0.90-0.95), and accuracy 0.93 (95% CI, 0.89-0.95), with generally consistent results using office, home, or ambulatory BP devices (slightly lower specificity with the latter). The positive and negative predictive values were 0.70 (95% CI, 0.60-0.80) and 0.99 (95% CI, 0.98-1.00), respectively. Sensitivity analyses indicated lower specificity in studies implementing reading versus participant analyses. Most studies presented a low risk of bias and minor applicability concerns.

CONCLUSIONS

There is considerable and consistent evidence suggesting high diagnostic accuracy of AF detection algorithms implemented in automated BP monitors during routine BP measurements in and out of the office. AF diagnosis requires verification (electrocardiography) before treatment is administered.

Blood pressure in atrial fibrillation and in sinus rhythm during ambulatory blood pressure monitoring: data from the TEMPLAR project

The coexistence of hypertension and atrial fibrillation (AF) is common and accounts for a worse prognosis. Uncertainties exist regarding blood pressure (BP) measurements in AF patients by automated oscillometric devices. The Microlife WatchBP 03 AFIB ambulatory BP monitoring (ABPM) device including an AF algorithm with each measurement was used in 430 subjects aged >65 years referred for ABPM and with assumed paroxysmal AF to perform intra-individual comparisons of BP during both AF-indicated and sinus rhythm. Only subjects with >30% of measurements indicating AF and episodes >30 min for assumed AF and for sinus rhythm were included. Mean age was 78 ± 7 years, 43% were male, 77% hypertensive, and 72% were treated. Compared to sinus rhythm, 24-h mean arterial pressure was similar (87.2 ± 9.5 vs 87.5 ± 10.6 mm Hg, p = 0.47), whereas 24-h systolic BP tended to be lower (123.6 ± 13.9 vs 124.7 ± 16.1 mm Hg, p = 0.05) and night-time diastolic BP higher (64.6 ± 10.9 vs 63.3 ± 10.4 mm Hg, p = 0.01) in assumed AF. Diastolic (not systolic) BP variability was higher in AF (p < 0.001). Results were similar with heart rates <90 and ≥90 bpm. In conclusion, this is the first study to use intra-individual comparisons of averaged BP during an ABPM in assumed paroxysmal AF and sinus rhythm. Our results imply that ABPM is feasible and informative also in patients with AF. We also suggest that an AF detection algorithm offers a new approach to evaluate the reliability of averaged BP values in AF compared to SR during an ABPM.

Sensitivity and specificity of automated blood pressure devices to detect atrial fibrillation: A systematic review and meta-analysis of diagnostic accuracy

Background

Atrial fibrillation (AF) is a prevalent and preventable cause of stroke and mortality.

Aim

This systematic review and meta-analysis aimed to investigate the sensitivity and specificity of office and out-of-office automated blood pressure (BP) devices to detect AF.

Methods

Diagnostic studies, extracted from databases such as Ovid Medline and Embase, on AF detection by BP device(s), electrocardiography, and reported sensitivity and specificity, were included. Screening of abstracts and full texts, data extraction, and quality assessment were conducted independently by two investigators using Covidence software. The sensitivity and specificity of the BP devices were pooled using a random-effects model.

Results

Sixteen studies including 10,158 participants were included. Only a few studies were conducted in primary care (n = 3) or with a low risk of bias (n = 5). Office BP devices, which utilised different algorithms to detect AF, had a sensitivity and specificity of 96.2 and 94%, respectively. Specificity was reduced when only one positive result was considered among consecutive BP measurements. Only a few studies (n = 3) investigated out-of-office BP. Only one study (n = 100) suggested the use of ≥79 and ≥26% of positive readings on 24-h ambulatory BP measurements to detect AF and paroxysmal AF, respectively.

Conclusions

Office BP devices can be used clinically to screen for AF in high-risk populations. Clinical trials are needed to determine the effect of AF screening using office BP devices in reducing stroke risk and mortality. Further studies are also required to guide out-of-office use of BP devices for detecting paroxysmal AF or AF.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022319541, PROSPERO CRD42022319541.

24-hour ambulatory blood pressure telemonitoring in patients at risk of atrial fibrillation: results from the TEMPLAR project

Hypertension is the most common risk factor for atrial fibrillation (AF). The ability to screen for potential AF during blood pressure (BP) measurement may be a valuable tool for early AF detection. This study evaluated the frequency of irregular pulse rates suggestive of AF in subjects undergoing ambulatory BP monitoring (ABPM) and compared the characteristics of patients at low risk of presumed AF vs. those at high risk. ABPM recordings were obtained in 4419 subjects aged ≥65 years visiting 304 community pharmacies, with clinically validated automated monitors equipped with an algorithm for detecting possible AF episodes during BP measurement. Subjects with <30% of the readings suggestive of AF were categorized as having a low risk of AF, and those with ≥30% of readings were classified as high risk. A total of 531 subjects (12.0%) were categorized as having a high risk of AF, with the risk increasing with advancing age. Subjects at high risk of AF had lower average systolic BP, higher average diastolic BP and pulse rate (PR), increased BP and PR variabilities, and blunted sleep-associated reductions in BP and PR. In repeated recordings, the reliability of the AF detection algorithm per se was good (kappa 0.476, p = 0.0001; intraclass correlation coefficient 0.56, p = 0.0001). Simultaneous BP measurement and screening for potential AF by ABPM in elderly people in clinical practice may help improve BP control and the detection of subjects at high risk of AF. However, a finding of presumed AF must always be confirmed by an electrocardiogram (ECG).

Screening for Atrial Fibrillation in the Older Population: A Randomized Clinical Trial

Importance

Atrial fibrillation (AF) is a major cause of preventable strokes. Screening asymptomatic individuals for AF may increase anticoagulant use for stroke prevention.

Objective

To evaluate 2 home-based AF screening interventions.

Design, Setting, and Participants

This multicenter randomized clinical trial recruited individuals from primary care practices aged 75 years or older with hypertension and without known AF. From April 5, 2015, to March 26, 2019, 856 participants were enrolled from 48 practices.

Interventions

The control group received standard care (routine clinical follow-up plus a pulse check and heart auscultation at baseline and 6 months). The screening group received a 2-week continuous electrocardiographic (cECG) patch monitor to wear at baseline and at 3 months, in addition to standard care. The screening group also received automated home blood pressure (BP) machines with oscillometric AF screening capability to use twice-daily during the cECG monitoring periods.

Main Outcomes and Measures

With intention-to-screen analysis, the primary outcome was AF detected by cECG monitoring or clinically within 6 months. Secondary outcomes included anticoagulant use, device adherence, and AF detection by BP monitors.

Results

Of the 856 participants, 487 were women (56.9%); mean (SD) age was 80.0 (4.0) years. Median cECG wear time was 27.4 of 28 days (interquartile range [IQR], 18.4-28.0 days). In the primary analysis, AF was detected in 23 of 434 participants (5.3%) in the screening group vs 2 of 422 (0.5%) in the control group (relative risk, 11.2; 95% CI, 2.7-47.1; P = .001; absolute difference, 4.8%; 95% CI, 2.6%-7.0%; P < .001; number needed to screen, 21). Of those with cECG-detected AF, median total time spent in AF was 6.3 hours (IQR, 4.2-14.0 hours; range 1.3 hours-28 days), and median duration of the longest AF episode was 5.7 hours (IQR, 2.9-12.9 hours). Anticoagulation was initiated in 15 of 20 patients (75.0%) with cECG-detected AF. By 6 months, anticoagulant therapy had been prescribed for 18 of 434 participants (4.1%) in the screening group vs 4 of 422 (0.9%) in the control group (relative risk, 4.4; 95% CI, 1.5-12.8; P = .007; absolute difference, 3.2%; 95% CI, 1.1%-5.3%; P = .003). Twice-daily AF screening using the home BP monitor had a sensitivity of 35.0% (95% CI, 15.4%-59.2%), specificity of 81.0% (95% CI, 76.7%-84.8%), positive predictive value of 8.9% (95% CI, 4.9%-15.5%), and negative predictive value of 95.9% (95% CI, 94.5%-97.0%). Adverse skin reactions requiring premature discontinuation of cECG monitoring occurred in 5 of 434 participants (1.2%).

Conclusions and Relevance

In this randomized clinical trial, among older community-dwelling individuals with hypertension, AF screening with a wearable cECG monitor was well tolerated, increased AF detection 10-fold, and prompted initiation of anticoagulant therapy in most cases. Compared with continuous ECG, intermittent oscillometric screening with a BP monitor was an inferior strategy for detecting paroxysmal AF. Large trials with hard clinical outcomes are now needed to evaluate the potential benefits and harms of AF screening.

Trial Registration

ClinicalTrials.gov Identifier: NCT02392754.

Blood pressure measurement in atrial fibrillation: review and meta-analysis of evidence on accuracy and clinical relevance

: Atrial fibrillation (AF) often coexists with hypertension in the elderly and multiplies the risk of stroke and death. Blood pressure (BP) measurement in patients with AF is difficult and uncertain and has been a classic exclusion criterion in hypertension clinical trials leading to limited research data. This article reviews the evidence on the accuracy of BP measurement in AF performed using different methods (office, ambulatory, home) and devices (auscultatory, oscillometric) and its clinical relevance in predicting cardiovascular damage. The current evidence suggests the following: (i) Interobserver and intra-observer variation in auscultatory BP measurement is increased in AF because of increased beat-to-beat BP variability and triplicate measurement is required; (ii) Data from validation studies of automated electronic BP monitors in AF are limited and methodologically heterogeneous and suggest reasonable accuracy in measuring SBP and a small yet consistent overestimation of DBP; (iii) 24-h ambulatory BP monitoring is feasible in AF, with similar proportion of errors as in individuals without AF; (iv) both auscultatory and automated oscillometric BP measurements appear to be clinically relevant in AF, providing similar associations with intra-arterial BP measurements and with indices of preclinical cardiac damage as in patients without AF, and predict cardiovascular events and death; (v) Screening for AF in the elderly using an AF-specific algorithm during routine automated office, home or ambulatory BP measurement has high diagnostic accuracy. In conclusion, in AF patients, BP measurement is important, reliable, and clinically relevant and should not be neglected in clinical research and in practice.

Diagnostic accuracy of a novel cuffless self-blood pressure monitor for atrial fibrillation screening in the elderly

Blood pressure (BP) monitors equipped with atrial fibrillation (AF) detection algorithm are attractive screening tools for AF in elderly hypertensives. This study assessed the diagnostic accuracy of a novel cuffless pocket-size self-BP monitor (Freescan, Maisense) equipped with an AF detection algorithm, which displays results for the detection of "AF" or "Arrhythmia" during routine BP measurement. Subjects aged >65 years or 60-65 years with hypertension, diabetes, or cardiovascular disease were subjected to BP measurements using the Freescan device with simultaneous continuous Holter electrocardiography (ECG) monitoring. Readings with device notification "Instability" (29%) or "Error" (20%) were discarded. Data from 136 subjects with five valid Freescan BP measurements were analyzed (age 73.8 ± 7.1 years, males 63%, treated hypertensives 88%, AF in ECG 21%). Analysis of 680 Freescan readings vs ECG revealed specificity 99%, sensitivity 67%, and diagnostic accuracy 93% for AF diagnosis. When the "Arrhythmia" notification was considered as AF diagnosis, the sensitivity was improved (93%, 96%, and 93%, respectively). Analysis of AF diagnosis in subjects (diagnosis defined as at least three of five readings indicating "AF" or "Arrhythmia") revealed specificity, sensitivity, and diagnostic accuracy for AF detection at 94%, 100%, and 95%, respectively. These data suggest that the Freescan cuffless device could be used as a useful screening tool for AF detection during routine self-measurement of BP in the elderly.

Validation of the modified Microlife blood pressure monitor in patients with paroxysmal atrial fibrillation

AIMS

Undiagnosed atrial fibrillation (AF) accounts for 6% of all strokes, therefore early detection and treatment of the arrhythmia are paramount. Previous research has illustrated that the Microlife WatchBPO3 AFIB, an automated blood pressure (BP) monitor with an inbuilt AF algorithm, accurately detects permanent AF. Currently, limited data exist on whether the modified BP monitor is able to detect paroxysmal AF (PAF). Therefore, this study aims to assess the accuracy of the Microlife WatchBPO3 AFIB monitor to detect PAF against a pacemaker reference standard over a 24-h period.

METHODS AND RESULTS

Forty-eight patients with a pacemaker implanted for sick sinus syndrome and previously documented fast AF participated. Sensitivity of the atrial pacemaker lead was set to allow detection of signals of ≥ 0.5 mV. Patients engaged in their normal daily routine whilst wearing the modified BP monitor. The modified BP monitor demonstrated an overall sensitivity of 76.0% and specificity of 80.8% for detecting PAF. This sensitivity and specificity increased to 100% and 83.1%, respectively, for patients that achieved more than 80% successful BP readings. Compared to day-time readings, night-time readings also demonstrated a lower proportion of movement artefact (14.4% vs. 3.4%), and therefore, a higher sensitivity and specificity of 100% and 84.9%, respectively, for detecting PAF.

CONCLUSION

The Microlife WatchBPO3 AFIB device has an acceptable diagnostic accuracy to detect PAF; however, movement artefact affects the accuracy of the readings. This modified BP monitor may potentially be useful as a screening tool for AF in patients at high risk of developing stroke.

Blood pressure measurement in special populations and circumstances

According to the established validation protocols, a typical validation study of a blood pressure (BP) monitor includes general population adults with normal or elevated BP. It is recognized, however, that the automated (oscillometric) BP monitors may have different accuracy or uses in some special populations compared with adults in the general population. Thus, an automated BP monitor with proven accuracy in a general population of adults may not be accurate in a special population, and therefore separate validation is needed. Recognized special populations deserving separate validation are those for which there is theoretical, and also clinical evidence, that the accuracy of BP monitors in these groups differs from that in the general population. Young children, pregnant women (including those with preeclampsia), individuals with arm circumference >42 cm, and patients with atrial fibrillation are regarded as special populations. Adolescents, individuals older than 80 years, and patients with end-stage renal disease or diabetes mellitus have also been considered as possible special groups, but there is still inadequate evidence of altered accuracy of BP monitors in these subjects. Validation studies should be performed in special populations and evaluated separately after the BP-measuring device has successfully undergone a validation study in a general population (unless the test device is intended only for a special population). This article discusses issues relating to the measurement of BP and the diagnosis of hypertension in selected special populations, as well as in low-resource settings, where a simplified yet efficient evaluation strategy is necessary.