Revisiting cardiac safety of hydroxychloroquine in rheumatological diseases during COVID-19 era: Facts and myths

Severe acute respiratory syndrome coronavirus 2 has spread across the globe affecting more than 10 million people as of August 2020. With the pandemic spreading at such an alarming rate, a lot of efforts are in the process of identification of an effective treatment at it’s earliest. Hydroxychloroquine (HCQ) is such a drug that is being studied as a repurposed agent, although the early results are still inconclusive. However, an important adverse effect that has raised concerns in the recent times is its possible cardiac toxicity, mainly the ‘QT,’ prolongation in electro-cardiogram, which has created a sense of apprehension for its use in traditional indications like rheumatological conditions. In decades of HCQ use by rheumatologists, this cardiac toxicity was rarely ever seen. So, what is different in the current coronavirus disease 2019 (COVID-19) era? This review outlines various studies on HCQ reporting cardiac adverse events in patients with rheumatic diseases as well as, in patients with COVID-19 infection. In addition, two important observations were noticed; first, the doses that have been used in the current COVID-19 scenario are much higher than what are used in rheumatology. Second, COVID-19 infection may by itself lead to intrinsic cardiac abnormalities, which is probably acting as a confounder. Most of the available and credible data suggest that HCQ is a safe drug, including the RECOVERY trial stating no cardiotoxicity by HCQ. This review reinforces the safety profile of HCQ in a data-driven manner and addresses the concerns of the physicians. However, its cautious use in those with pre-existing cardiac abnormalities cannot be overemphasized.