Risk of cardiac and ocular toxicity of synthetic antimalarials in rheumatic diseases

Summary

Hydroxychloroquine (HCQ) and chloroquine (CQ) are synthetic antimalarials with a long-term stable position in the therapy of rheumatic diseases. Overall, the low risk of severe HCQ/CQ toxicity mainly includes retinal maculopathy, which has been known for decades, but only sporadic information has been available on cardiac toxicity. Increased attention to the cardiac risk of HCQ/CQ therapy has been prompted by recent reports of severe arrhythmias with prolongation of the corrected QT interval (QTc) during experimental HCQ medication in Covid-19 infection. With HCQ/CQ therapy of rheumatic patients, a risky prolongation of the QTc interval can be expected, especially in patients with comorbidities, especially arrhythmias and heart failure. Long-term treatment with HCQ/CQ can lead to restrictive cardiomyopathy. HCQ/CQ cardiomyopathy is a lysosomal storage disease, which is morphologically characterized by the finding of curved linear myeloid deposits during the examination of an endomyocardial biopsy by the electron microscopy method. HCQ retinal maculopathy, including the bull's eye phenomenon, and magnetic resonance imaging in lysosomal storage cardiomyopathy are demonstrated in the form of short case studies. An analysis of current requirements for optimal control of cardiac and ocular risk during HCQ/CQ therapy for rheumatic diseases and especially during long-term HCQ therapy for systemic lupus erythematosus was performed.

Keywords:

Chloroquine – hydroxychloroquine – toxic retinal maculopathy – QTc-interval prolongation – lysosomal storage cardiomyopathy – rheumatic diceases