番茄社区

Lower-contact solutions for QT monitoring of hospitalized COVID-19 patients taking hydroxychloroquine (Plaquenil) and azithromycin are being developed, both pragmatically and with trials underway to prove their utility.

Those drugs may carry risk of potentially fatal QTc prolongation, requiring typically twice daily checks. Standard cardiac telemetry for this measurement requires staff exposure and consumes personal protective equipment, both problematic.

While gold standard 12-lead telemetry is still preferred because it offers the possibility of real-time response to any problems that a technician is watching for, circumstances have necessitated creative solutions, said David Chang, MD, of Northwell Health, North Shore University Hospital in Manhasset, New York.

The surge of cases there in early March quickly burned through capacity for placing patients who needed telemetry on floors that could support it, and the number of telemetry monitors wasn't sufficient to keep up with the demand at the large hospital, Chang noted.

So, the electrophysiology department turned to the four-lead MCOT Patch mobile cardiac telemetry patch system, which is FDA cleared for outpatient monitoring.

Over the course of a single week, they used the device to treat 117 consecutive COVID-positive patients on hydroxychloroquine (44% were also on azithromycin, and 34% got at least one additional QT prolonging medication) for whom there were no telemetry monitors.

The device as used replaced ECGs after baseline, with twice daily QTc measurements that were summarized into reports or sent to an electrophysiologist if urgent with a 3- to 5-minute turnaround time.

Chang's group reported in the Journal of the American College of Cardiology that the device triggered urgent alerts for 15.4% of patients based on a QTc over 500 ms (five cases) or any arrhythmia (largely rapid ventricular response). One patient had to be taken off hydroxychloroquine after three days when the device showed QTc prolongation from 460 to 565 ms.

"I don't think this is a complete possible replacement for telemetry, but it can help out in certain situations," Chang said.

His group cautioned that the device was never approved to measure QTc for patients with atrial fibrillation or flutter, QRS >160 ms, and T-wave <5% of the peak QRS amplitude. Also, the study included only a healthy population from a cardiac standpoint, they noted. "The MCOT must be used with caution in patients with significant cardiac disease."

Another strategy for less severe COVID-19 cases, the AliveCor KardiaMobile 6L electrocardiogram device has been used for its in non-invasive monitoring for QT prolongation at Thomas Jefferson University Hospital in Philadelphia.

The hospital was already prescribing the device to selected outpatients when the COVID-19 crisis struck, Daniel Frisch, MD, an electrophysiologist there, told 番茄社区. "It really took the pandemic to consider the option of moving this type of product to the inpatient setting."

COVID-positive patients starting hydroxychloroquine, azithromycin, or both who are able to use the device independently without a clinician needing to enter the room have been provided these six-lead devices by the hospital.

The device could fill a need for patients requiring intermittent ECG monitoring, particularly QT monitoring, "but for whom we're trying to be as contactless as possible," Frisch said.

However, "we're rolling in slowly," he said. "It's not a replacement for live telemetry. We need that for moment-to-moment monitoring of patients, particularly on our cardiology wards. ... Until everyone is comfortable with this plan, we are still doing redundant ECGs to make sure we are getting the same quality of information and same measurements, and so far it's been the same."

AliveCor announced it is offering a on ECGs from its KardiaMobile 6L, either in-hospital or at home, with data going directly from the clinician platform to an independent diagnostic testing facility for calculation and rapid return to front-line care providers.

Such automatic measurement would extend the number of people able to look at tracings to get a sense of dangerous cardiac rhythms beyond just the cardiologists on the team, he noted. "It would save resources and does save resources in that regard."

Right now, KardiaMobile 6L devices are recommended for single-patient use only. "I'm speaking to our infection control in the hospital, but the company has made it clear to us that these are one shot deals for the particular patient. So we're not pursuing use in multiple patients," Frisch noted. "Cost could become an issue."

By contrast, Chang's group did sterilize and reuse the MCOT Patch devices after patients were done with telemetry.

As evidence continues to roll in, Frisch expressed hope that the KardiaMobile devices could become even more useful. "The QT monitoring is the first step, not the last step. I'm hopeful it will pave the way for monitoring of every ECG interval going forward. It would be nice to know PR duration, QRS duration, things of that nature."

Another strategy being tried for QTc and arrhythmia monitoring in COVID-19 patients is the Cardiologs AI platform to analyze smartwatch ECG data.

A at the University Hospital of Marseilles, France, is underway to remotely monitor COVID-19 patients during hydroxychloroquine and azithromycin treatment. The study will use the Withings Move ECG Watch linked to Cardiologs' AI platform, which has FDA clearance for QT interval analysis and arrhythmia diagnostics. Daily ECG readings analyzed by the software will be compared to gold standard ECG.

However, even if hydroxychloroquine and azithromycin don't ultimately pan out for COVID-19 treatment, there's still likely to be a role for such monitoring, noted Chang.

"COVID patients are still at great risk for other cardiac issues because of inflammation of heart cells -- myocarditis, for instance. We're getting a lot of calls nowadays for help managing these patients with conduction and other problems from inflammation of the heart," he said. "If we have to manage these patients by going in the room and interacting with them in person, that's putting healthcare workers at risk."

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