Progressive Fibrosis in Hydroxychloroquine Cardiomyopathy Mimicking Hypertrophic Cardiomyopathy and Cardiac...

Early recognition of hydroxychloroquine cardiotoxicity is crucial given its potential reversibility; however, the diagnosis can be complicated by imaging findings that overlap with other infiltrative cardiomyopathies, including cardiac amyloidosis.

A 62-year-old woman with systemic lupus erythematosus on hydroxychloroquine therapy (>15 years, cumulative dose: >2000 g) presented with progressive heart failure. Serial cardiac magnetic resonance imaging performed over 5 years showed evolution from extensive myocardial fibrosis (37%) to infiltrative cardiomyopathy. Technetium-99m-pyrophosphate scintigraphy demonstrated diffuse myocardial uptake. Endomyocardial biopsy confirmed hydroxychloroquine cardiotoxicity and the absence of amyloid involvement by Congo red staining.

This case documents the 5-year imaging evolution of hydroxychloroquine cardiotoxicity, representing a rare cause of false-positive pyrophosphate scintigraphy.

Hydroxychloroquine cardiotoxicity should be considered when pyrophosphate scintigraphy is positive in patients with long-term exposure. Early recognition (before extensive fibrosis develops) is critical, as the likelihood of recovery diminishes with advanced disease.