COVID-19 Resource Center

COVID-19 Resource Center

Disclosures: Gasperetti and Schiavone report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
September 25, 2020
2 min read

Short-term COVID-19 treatment with hydroxychloroquine may not confer arrhythmia risk

Disclosures: Gasperetti and Schiavone report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

Hydroxychloroquine may be safe for the short-term treatment of patients with COVID-19 who were chosen for therapy after undergoing risk assessment, researchers found.

Researchers observed modest QTc prolongation with hydroxychloroquine, but no deaths associated with arrhythmias, according to the study published in Europace.

Source: Adobe Stock.

“The message is that hydroxychloroquine is safe from a cardiac point of view when adequate risk assessment is performed,” Marco Schiavone, MD, cardiology fellow at Luigi Sacco Hospital at the University of Milan, told Healio. “Basically, ECG should be monitored with repeated QT and QTc measurement on admission and during administration of hydroxychloroquine, hydroxychloroquine seems safe from an arrhythmic point of view.”

In April, the FDA issued a safety alert warning health care professionals and patients to avoid the use of hydroxychloroquine and chloroquine outside of hospital or clinical trial settings due to potential increased risk for serious heart-related adverse events and death.

COVID-19 in different care settings

In this multicenter cohort study, Alessio Gasperetti, MD, cardiology fellow at University Hospital Zurich, and colleagues analyzed data from 649 patients (mean age, 62 years; 46% men) with COVID-19 who were treated at seven institutions from March 10 to April 10. Patients were enrolled from three different settings: home management (n = 126), medical ward management (n = 495) or ICU management (n = 28).

Marco Schiavone

“The most important thing that our paper adds to the knowledge base is that those are patients from different clinical settings,” Schiavone said in an interview. “It was important to monitor the safety of hydroxychloroquine in these settings because other studies that have been published so far on this topic do not have data on home treatment and cardiac safety of hydroxychloroquine.”

All patients underwent ECG baseline assessment within 5 days before the first dose of hydroxychloroquine and then at 36 to 72 hours after the first dose or at least 96 hours after the first dose. ECGs were used to assess QT-associated and QT-independent arrhythmic events, in addition to QT/QTc prolongation. Overall and arrhythmic morality were also analyzed throughout the study.

After the first dose of hydroxychloroquine, 358 ECGs were obtained at 36 to 72 hours and 404 ECGs were obtained at 96 hours or later.

Researchers observed a QT/QTc interval prolongation (P < .001), although the increase was modest (+13 ms). The greatest determinants of QT/QTc prolongation was QT/QTc length at baseline and fever at admission (P = .001). No deaths were reported related to arrhythmias.

Overall major ventricular arrhythmias occurred in 1.1% of patients, which were not related to QT or hydroxychloroquine therapy.

Different clinical settings did not affect QT-related arrhythmias and QT/QTc prolongation, although non-QT-related arrhythmias were more common in patients treated in an ICU setting.

Additional research

“Other research that is needed in this area should be focused on the efficacy of hydroxychloroquine,” Schiavone told Healio. “Some [studies] have been published, but it’s not enough to understand the efficacy of hydroxychloroquine in COVID-19 in the different stages of the disease.”

For the latest news on COVID-19 including case counts, information about the global public health response and emerging research, please visit the COVID-19 Resource Center on Healio.

For more information:

Marco Schiavone, MD, can be reached at