Improvement of propionic acidemia-associated dilated cardiomyopathy through nutritional adjustment and heart failure...

Propionic acidemia (PA) is a known cause of secondary dilated cardiomyopathy (DCM). However, little is known about how diet and heart failure treatment impact long-term cardiac outcomes in adult PA patients. We report the successful treatment of metabolic disease and secondary DCM-associated heart failure in a 20-year-old male patient with neonatal-onset PA and intellectual disability. At age 19 years, echocardiography had revealed DCM without impaired cardiac contractility. At age 20 years, he developed heart failure, presumably from a common cold infection, and was hospitalized. Acute heart failure treatment improved his symptoms, leading to discharge, but they worsened again, necessitating re-admission. He then was discharged only after successfully adding carvedilol and pimobendan to his medication. Six weeks later, however, he developed hyperammonemia with elevated serum propionyl carnitine and decreased free carnitine levels. He received acute phase treatment for this metabolic crisis and his diet therapy was readjusted, including by reducing natural protein. In the following 5 years, while continuing and slightly adapting heart failure medication and dietary regimens, the patient's cardiac function stably improved and his diuretic dose could be reduced. Our findings support that careful diet therapy and modulation of heart failure medication can improve cardiac function in PA patients with DCM.

Neonatal-onset propionic acidemia (PA) tends to be the most severe form of PA and life-threatening metabolic disease. Even if the impact of the disease can be ameliorated by adapting the diet, later in life these patients often develop symptoms such as intellectual disability, metabolic crises, and dilated cardiomyopathy (DCM), as observed in this case. This case demonstrates that heart failure medication and dietary therapy can help protect against metabolic disease and DCM-associated heart failure in an adult patient with neonatal-onset PA.