Heart Failure in Vulnerable Populations: The Emerging Evidence of Methamphetamine-Associated Cardiomyopathy

Abstract

Heart failure is a significant and growing cause of disease in the developed world with substantial cost and morbidity associated with it. This review focuses on methamphetamine-associated cardiomyopathy (MACM) as an increasingly recognized cause of heart failure. MACM is increasingly recognized worldwide. Prevalence of MACM in heart failure hospital admissions has been increasing in the western USA. Risk factors for development of MACM include male sex, hypertension, and alcohol use disorder. MACM is associated with severe left ventricular dysfunction, greater heart failure symptom burden, and younger age of presentation than non-ischemic controls. Improvement of ejection fraction has been seen with guideline-directed therapy and methamphetamine cessation. EF improvement is correlated with lack of evidence of chronicity on transthoracic echocardiography and extent of fibrosis on endomyocardial biopsy. Limited studies show white and Māori patients are most often affected, though race/ethnicity has not been shown to be an independent risk factor in the development of MACM. MACM represents a subset of heart failure that affects predominantly young men, and tends to present with severely reduced ejection fraction and significant symptom burden. There is evidence that ejection fraction can be improved in patients without extensive cardiac fibrosis or evidence of cardiomyopathy chronicity on imaging in the setting of abstinence and medical therapy. In this context, methamphetamine use is a modifiable risk factor in the development of heart failure that would likely benefit from early intervention, though larger longitudinal studies are needed.