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Atrial fibrillation, the world’s most common arrhythmia, is a leading risk factor for stroke, a disease striking nearly 1.6 million Indians annually. Early detection and management of atrial fibrillation is a promising opportunity to prevent stroke but widespread screening programs in limited resource settings using conventional methods is difficult and costly.
The objective of this study is to screen people for atrial fibrillation in rural western India using a US Food and Drug Administration-approved single-lead electrocardiography device, Alivecor.
Residents from 6 villages in Anand District, Gujarat, India, comprised the base population. After obtaining informed consent, a team of trained research coordinators and community health workers enrolled a total of 354 participants aged 50 years and older and screened them at their residences using Alivecor for 2 minutes on 5 consecutive days over a period of 6 weeks beginning June, 2015.
Almost two-thirds of study participants were 55 years or older, nearly half were female, one-third did not receive any formal education, and more than one-half were from households earning less than US $2 per day. Twelve participants screened positive for atrial fibrillation yielding a sample prevalence of 5.1% (95% CI 2.7-8.7). Only one participant had persistent atrial fibrillation throughout all of the screenings, and 9 screened positive only once.
Our study suggests a prevalence of atrial fibrillation in this Indian region (5.1%) that is markedly higher than has been previously reported in India and similar to the prevalence estimates reported in studies of persons from North America and Europe. Historically low reported burden of atrial fibrillation among individuals from low and middle-income countries may be due to a lack of routine screening. Mobile technologies may help overcome resource limitations for atrial fibrillation screening in underserved and low-resource settings.
Atrial fibrillation is the world’s most common cardiac arrhythmia and, if untreated, increases the risk of stroke by upwards of five-fold [
Here we report findings of a study to screen people for atrial fibrillation in rural western India using a US Food and Drug Administration (FDA)-approved single-lead ECG device, Alivecor, to overcome traditional constraints of dysrhythmia screening [
Residents from 6 different villages in Anand District, Gujarat, India, comprised the base population. These 6 villages were randomly selected from a list of 30 villages where our community health workers are present. Trained research coordinators worked with the community health workers who were familiar with the layout of their respective villages and enrolled 60 participants from each village. Villages in India are typically organized by occupation-based colonies (fariyahs), and an equal number of participants were recruited from all fariyahs. The residents of every third house in each fariyah were approached for enrollment through the use of a systematic random sample. After obtaining informed consent, a team of trained research coordinators and community health workers enrolled a total of 355 participants aged 50 years and older to participate in the study.
The study included two components: (1) screening using FDA-approved single-lead ECG device, Alivecor, and (2) collection of pulse data to develop an automated arrhythmia detection mobile app that can be used in low-resource settings [
The Alivecor device malfunctioned for two weeks, and therefore 120 participants from two villages were not screened for atrial fibrillation using Alivecor and were excluded from this study. Study staff uploaded ECG and pulse check recordings to a secure, Web-accessible Research Electronic Data Capture study database. Because pulse data were collected with the intention of developing an arrhythmia detection app based on the results of this pilot study, our outcome of atrial fibrillation was determined based solely on the ECG results from the FDA-approved Alivecor device. A board-certified cardiologist reviewed all ECG tracings for participants who had abnormal rhythm findings based on the automated Alivecor algorithm (
A randomly selected 20% subsample of normal ECG tracings were reviewed by two trained study staff members, and discordant readings were adjudicated by the study cardiologist. Thus, a board-certified cardiologist reviewed the ECG tracings of all participants who were determined to have positive screening findings for the presence of atrial fibrillation. The study received institutional review board approval from the University of Massachusetts Medical School and HM Patel Center for Medical Care and Education. Descriptive statistics were utilized to describe the characteristics of study participants. Sociodemographic and comorbid factors were compared across different age groups using Fisher exact tests. Prevalence rates of atrial fibrillation were calculated in a standard manner with accompanying 95% confidence intervals. Given the limited sample size in our pilot investigation and the use of the Alivecor ECG as the source for gold standard measurement, we did not calculate performance measures.
Community health worker screening a study participant for atrial fibrillation using a single-lead ECG device.
Adjudication of atrial fibrillation screening results.
Almost two-thirds of study participants were 55 years or older, nearly half were female, one-third did not receive any formal education, and more than one-half were from households earning less than US $2 per day (
Twelve participants screened positive for atrial fibrillation yielding a sample prevalence of 5.1% (95% CI 2.7-8.7) (
Only one participant had persistent atrial fibrillation throughout all of the screenings; 9 screened positive only once. The cumulative prevalence of atrial fibrillation in this population according to increasing number of screenings is presented in
The first screening only identified 7 participants with a positive screen for atrial fibrillation. The remaining 5 participants who screened positive for atrial fibrillation were identified at the fourth screening. A comparison of the 235 participants included in the analyses, with the 120 excluded participants, revealed no meaningful differences between the two groups (see
Sociodemographic, lifestyle, and health characteristics of 234 participants from rural Gujarat, India, screened for arrhythmias, stratified by age groups.
Age group (%) | ||||||
N | 50-55 | 55-65 | 65+ | |||
Femaleb | 140 | 71.4 | 55.0 | 56.3 | .09 | |
.19 | ||||||
None | 70 | 30.7 | 27.0 | 35.1 | ||
10thgrade or less | 129 | 50.0 | 59.6 | 58.4 | ||
More than 10thgrade | 29 | 19.4 | 13.5 | 6.5 | ||
Works for pay | 60 | 45.8 | 29.9 | 9.1 | <.001 | |
.03 | ||||||
Less than $1 | 71 | 33.9 | 28.1 | 31.7 | ||
$1-$2 | 62 | 14.5 | 31.5 | 31.7 | ||
$2-$4 | 53 | 37.1 | 20.2 | 15.2 | ||
More than $4 | 44 | 14.5 | 20.2 | 21.5 | ||
Smoking history | 37 | 7.9 | 14.3 | 11.3 | 0.25 | |
Chew tobacco | 58 | 33.3 | 22.0 | 21.3 | 0.03 | |
Hypertension | 87 | 27.0 | 34.1 | 48.8 | 0.02 | |
Diabetes | 20 | 9.5 | 5.5 | 11.3 | 0.37 | |
Hypercholesterolemia | 21 | 4.8 | 8.8 | 12.5 | 0.30 |
aFisher exact test.
bOne participant had completed the screening and thus was included in the analyses but did not respond to the questionnaire.
cBased on a conservative exchange rate of 1 USD = 60 INR for 2015 calendar year.
Characteristics of 12 atrial fibrillation positive cases identified by a cardiologist review of single-lead ECG recording.
Gender | Age | Index positivea | # positiveb | Smoking | Hypertension | |
1 | Female | 50-55 | 3 | 1/3 | No | No |
2 | Female | 55-60 | 1 | 1/3 | No | No |
3 | Female | 60-65 | 1 | 5/5 | No | No |
4 | Female | 60-65 | 1 | 2/5 | No | Yes |
5 | Female | 75-80 | 1 | 1/4 | No | Yes |
6 | Female | 80-85 | 1 | 3/4 | No | No |
7 | Male | 50-55 | 3 | 1/3 | Yes | Yes |
8 | Male | 55-60 | 1 | 1/1 | Yes | No |
9 | Male | 60-65 | 1 | 1/1 | No | Yes |
10 | Male | 70-75 | 4 | 1/5 | Yes | No |
11 | Male | 75-80 | 3 | 1/3 | No | Yes |
12 | Male | 75-80 | 4 | 1/5 | No | Yes |
aRefers to the number of screening when atrial fibrillation was first recognized.
bRefers to the total number of positive screenings for a given participant.
Cumulative prevalence of atrial fibrillation by number of screenings.
Screening number | Cumulative prevalence (95% CI) |
1 | 3.0 (1.2-6.1) |
2 | 3.0 (1.2-6.1) |
3 | 4.3 (2.1-7.7) |
4 | 5.1 (2.7-8.7) |
5 | 5.1 (2.7-8.7) |
Our study suggests a prevalence of atrial fibrillation in this Indian region (5.1%) that is markedly higher than has been previously reported in India and similar to the prevalence estimates reported in studies of persons from North America and Europe [
Current understanding of the global epidemiology of atrial fibrillation is dependent on robust surveillance systems and high quality community-based studies, but there remains a paucity of such investigations outside of North America and Europe, particularly in countries with less developed health systems [
Recently, there has been increased attention in North America and Europe to leverage mobile technology for the screening of persons with undetected atrial fibrillation [
The findings of our study need to be interpreted with appropriate caution given several concerns and limitations. First, this study is based on a relatively small sample size of 235 participants. Therefore, we have presented information about sample sizes and accompanying 95% confidence intervals to demonstrate the range of possible prevalence estimates consistent with the variability observed in our data. Second, we did not perform a gold standard 12-lead ECG to confirm our positive screening findings. It is important to note, however, that Alivecor devices are FDA-approved and are widely used by cardiologists in diverse clinical settings [
In conclusion, our study has two important implications: (1) mobile technologies may help overcome resource limitations for screening adults for atrial fibrillation in underserved and low-resource settings and (2) serial screening for atrial fibrillation enhances the ability to identify persons at risk for atrial fibrillation.
Comparison of sociodemographic, lifestyle, and health characteristics of participants that were excluded versus included in the study.
electrocardiogram
US Food and Drug Administration
We thank Ms Nada Esa, Ms. Dharti Patel, Ms Ami Brahmbhatt, and Mr Utsav Patel for supporting data collection efforts. We are grateful to Dr. Jay Himmelstein and the Office of Health Policy and Technology at the University of Massachusetts Medical School for supporting our research.
AS received support from the National Center for Advancing Translational Sciences (TL1-TR001454), and JA received support from the National Institute on Minority Health and Health Disparities (P60-MD006912-05). DDM’s time was supported by KL2RR031981, 1R15HL121761-01A1, 1UH2TR000921-02, and 1R01HL126911-01A1 from the National Heart, Lung, and Blood Institute.
The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
DDM discloses equity stakes or consulting relationships with Flexcon, Bristol-Myers Squibb, Mobile Sense, ATRIA, and Boston Biomedical Associates. He has also received research funding from Sanofi Aventis, Otsuka Pharmaceuticals, Philips Healthcare, Biotronik, and Pfizer.