Patienter med hjertesygdomme såsom angina, kongestionshjertesvigt eller arrhytmia skal følges tæt, hvis deres kliniske tilstand bliver forværret ved behandling med interferon beta- 1a.
Patients with cardiac disease, such as angina, congestive heart failure or arrhythmia, should be closely monitored for worsening of their clinical condition during initiation of therapy with interferon beta-1a.