Review of Hydroxychloroquine Cardiotoxicity: Lessons From the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) pandemic has popularized the usage of hydroxychloroquine and chloroquine (HCQ/CQ) as treatments for COVID-19. Previously used as anti-malarial and now commonly used in rheumatologic conditions, preliminary in vitro studies have demonstrated these medications also have anti-viral properties. Retinopathy and neuromyopathy are well recognized complications of using these treatments; however, cardiotoxicity is under-recognized. This review will discuss the implications and cardiotoxicity of HCQ/CQ, their mechanisms of action, and their utility in COVID-19.

Early clinical trials demonstrated a modest benefit of HCQ in COVID-19, causing a push for the usage of it. However, further large multi-center randomized control centers, demonstrated no benefit, and even a trend towards worse outcomes. The predominant cardiac complication observed with HCQ in COVID-19 was cardiac arrhythmias and prolonging of the QT interval. However, with chronic usage of HCQ/CQ, the development of heart failure (HF) and cardiomyopathy (CM) can occur. Although, most adverse cardiac events related to HCQ/CQ usage in COVID-19 were secondary to conduction disorders given the short duration of treatment, HCQ/CQ can cause CM and HF, with chronic usage. Given the insufficient evidence, HCQ/CQ usage in COVID-19 is not routinely recommended, especially with novel therapies now being developed and used. Additionally, usage of HCQ/CQ should prompt initial cardiac evaluation with ECG, and yearly monitoring, with consideration for advanced imaging if clinically warranted. The diagnosis of HCQ/CQ cardiomyopathy is important, as prompt cessation can allow for recovery when these changes are still reversible.