Smartphone-Based ECG Device Could Play Role in Primary Care

Wearable devices and smartphone-based apps are becoming ever more popular for patients who want a personalized tool to track their CV metrics. But a new study takes a different tack, asking: could these technologies play a role in the doctor’s office?

At 10 Dutch general practices, researchers found that the KardiaMobile (AliveCor) with single-lead ECG functionality, which is already commercially available, can accurately diagnose A-fib or atrial flutter, as well as other rhythm abnormalities, but is less sensitive for conduction abnormalities.

“The findings from the present study are therefore highly relevant for primary care physicians because the smartphone-operated ECG device operates as a point-of-care test and allows for immediate rhythm assessment during a symptomatic episode,” said lead author Jelle Himmelreich, MD, MSc (Amsterdam UMC, the Netherlands). “Moreover, our findings support patients’ use of the device at home as a one-lead event recorder, provided that the ECG readings are assessed by a cardiologist.”

When clinicians suspect an arrhythmia in a symptomatic patient, 12-lead ECG is the gold standard, the investigators note in their paper published in the September/October issue of the Annals of Family Medicine. “Unfortunately, in primary care, performing 12-lead ECG can be cumbersome, particularly during house visits, and it is not available at every practice. . . . The availability of an unobtrusive, handheld ECG device is likely to lower the logistical threshold for performing ECG and may therefore improve detection of relevant arrhythmias in primary care.”

But for Dhanunjaya Lakkireddy, MD (HCA Midwest Health, Overland Park, KS), who commented on the study for TCTMD, this tool is one of many in existence that, while convenient, has no infrastructure yet built for housing the data that will be generated by at-home use. “Until we really develop the necessary systems around it, this is data deluge and it is basically insane to really think that somehow these devices are going to just creep in and everybody is just going to start using them left and right and all of a sudden the data is going to be revolutionized,” he said.

“On average, each of these patients can generate anywhere from 100 to 200 strips in a week,” Lakkireddy continued. “That's close to 20,000 rhythm strips that would be generated by just 100 patients. . . . Who’s going to check those emails? Who’s going to clean them up? Who’s going to be accountable for reviewing them, databasing them? The current healthcare system that we work in does not have the capability to embrace this at this stage.”

Indeed, the data deluge is on the minds of many cardiologists, as recently reported by TCTMD.

KardiaMobile for Physicians?

For the study, the researchers included 214 patients who were assigned to 12-lead ECG for a nonacute indication by a local primary care physician. Half of these patients had symptoms, including 44.4% of those who reported palpitations.

All patients were assessed with the following: single-lead ECG recorded by KardiaMobile then read by the device’s A-fib detection algorithm, the same single-lead ECG read instead by three cardiologists, and standard 12-lead ECG read by the cardiologists. According to the 12-lead ECG readings, 23, 44, and 28 patients had A-fib or atrial flutter, any rhythm abnormality, and any conduction abnormality, respectively.

While the cardiologists were able to identify all 23 cases of A-fib or atrial flutter, the smartphone-integrated algorithm only picked up 20, resulting in a sensitivity of 87.0% and specificity of 97.9%. KardiaMobile had lower but good sensitivity (90.9%) and specificity (93.5%) for identifying the secondary endpoint of any rhythm abnormality, but for any conduction abnormality the sensitivity and specificity were 46.4% and 100%, respectively. False positives of any rhythm abnormality were all attributed to misclassified ectopic beats.

“To our knowledge, this is the first study to validate the KardiaMobile device for both AF and common non-AF ECG abnormalities against simultaneously performed 12-lead ECG in a primary care population,” the authors write.

“These results may be relevant for primary care physicians because they are encouraged to perform proactive case identification in asymptomatic patients with elevated risk of developing AF (eg, via pulse palpation followed by ECG),” Himmelreich and colleagues suggest. “Here, the single-lead ECG device could be a valuable point-of-care tool for at-risk patients for whom traveling to the practice for standard 12-lead ECG is too cumbersome or for primary care physicians who do not possess a 12-lead ECG device.”

‘Data Deluge’

Lakkireddy admitted there is clinical significance to this paper, but said “there’s nothing earth-shattering that they’ve proven.” The results are “reasonable in terms of [the device’s] quality and the confidence we can have in it in correlating with the 12-lead ECG,” he said. “It’s not the greatest, but I think it’s acceptable because it's less expensive and [offers] the patient convenience factor.”

What needs to happen next is to first understand that many patients are not capable of using smartphone-operated devices on their own, according to Lakkireddy. “So this is not something that can be universally given to everybody. Even people who have these smartphones [and] can use them, we need to teach them how to use it, how to upload it, and all of that,” he said.

Also, he said, potentially artificial intelligence should be better harnessed to “enable us to clean up a significant amount of this data—sort of cull the wheat from the chaff—and then be able to consolidate and concentrate the main important data so that it's easy for healthcare professional teams to manage.”

Lakkireddy said his team is currently working on a project of this nature. “It is going to basically reduce the data deluge and make it more effective,” he said. “We have made substantial progress on this front, and all of the work will be coming out soon.”