Long-term cardiovascular outcomes and mortality with enzyme replacement therapy in patients with mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (MPS II) is a rare multisystemic lysosomal disorder in which cardiac issues can lead to serious dysfunction and an increased risk of fatal cardiac failure. However, studies on major adverse cardiac event (MACE) outcomes in MPS II are lacking. This study evaluated the cardiovascular outcomes and impact of enzyme replacement therapy (ERT) in patients with MPS II in South Korea. In this national cohort study, utilizing data from the National Health Insurance Database, we evaluated 127 patients with MPS II over a 14-year period to investigate the effects of ERT on MACE and all-cause mortality. We tracked MACE incidence, defined by hospitalizations for cardiovascular events, from diagnosis and adjusted the hazard ratios for MACE using Cox modeling. Over an average follow-up period of 7.3 years, we identified 16 cases of MACE among patients (17.35 per 1000 person-years; 95% confidence interval, 10.74-26.83). Patients receiving ERT exhibited a significantly lower incidence of MACE than untreated patients, with cumulative incidences showing a marked difference of 8.3 years. Notably, initiating ERT at earlier stages post-diagnosis was associated with improved outcomes, underscoring the importance of timely treatment. The key risk factors for MACE included specific arrhythmias, a history of invasive procedures, and depression. Early ERT significantly reduced MACE risk and increased survival in patients with MPS II. This underscores the importance of prompt treatment initiation and comprehensive care to address key risk factors and advocates for an expanded therapeutic strategy to enhance MPS II outcomes.