Cardiomyopathy in patients with type 1 tyrosinemia, and the effect of nitisinone treatment on cardiomyopathy

Abstract

Purpose: This study aimed to retrospectively evaluate the frequency of cardiomyopathy and its response to routinely used nitisinone treatment in patients with tyrosinemia type 1.
 Materials and Methods: Participants of this descriptive cross-sectional study were Tyrosinemia Type 1 patients who were under the care of a single metabolic unit. The primary outcome of the study was “presence of abnormal echocardiographic findings” at diagnosis and the impact of nitisinone treatment on the detected findings.
 Results: Of the 54 patients enrolled in the study, 21 (38.9%) were female and 33 (61.1%) were male. 41 patients were evaluated using echocardiography at the time of diagnosis. 9 (21.9%) of them had hypertrophic cardiomyopathic alterations varying in severity. In the follow-up period, second echocardiographic examinations revealed improvements in cardiac alterations while on nitisinone treatment. Thirteen patients dropped out of follow-up. Of the remaining 41 patients, 10 (24.4%) patients died in the follow-up period, whereas 31 (75.6%) remained alive. Plasma aspartate aminotransferase (AST), total bilirubin, and direct bilirubin concentrations were significantly higher in patients witj normal cardiac evaluation.
 Conclusion: Echocardiographic examination should be done in all tyrosinemia type 1 patients including those with an absence of cardiac manifestations. The presence of cardiomyopathy may indicate a poor prognosis. Nitisinone is found to have a positive impact on cardiomyopathy in patients with type 1 tyrosinemia.