Reversible peripartum cardiomyopathy in a patient with prior exposure to interferon

Peripartum cardiomyopathy creates complications for 1 in 3000 to 4000 pregnant women in the US. As this rare condition is associated with a high mortality rate (50% to 85%), it has been investigated to define the possible associated causes. Several factors including hypertension, nutritional and dietary discrepancies, and, recently, myocarditis are being implicated, but the mechanism of cardiac injury is yet to be discovered. Here we present an interesting case of possible interferon-induced reversible peripartum cardiomyopathy. The patient, with a diagnosis of chronic myelogenous leukemia, had been given interferon for 6 years. The therapy was discontinued when she became pregnant, and later she presented with symptoms of heart failure 6 weeks after her c-section. Interferon is an immunomodulating agent and used as an antiviral and an anticancer agent. Interferon-related dilated cardiomyopathy has been described as a rare side effect of the drug, the mechanism of which is unknown. There is compelling data supporting the fact that both peripartum cardiomyopathy and interferon-related cardiomyopathy are autoimmune disorders; so it is suggested that interferon therapy given in the past can have an additive effect in causing dilated cardiomyopathy. It is therefore advisable to follow closely those pregnant patients; who received interferon therapy in the past, for symptoms of cardiac failure, as there can be synergistic action between interferon and pregnancy causing dilated cardiomyopathy.