Discussion
This was the first study to investigate the impact of the corticosteroid therapy on the efficacy of an upgrade to CRT therapy in patients with CS. Previous studies showed that a high echocardiographic response to CRT therapy was associated with a good long-term prognosis.9, 10
The present study demonstrated that the echocardiographic response to an upgrade to CRT was lower in patients with CS than in those with other etiologies of NICM. The patients with CS who had taken corticosteroids before the upgrade to CRT (group 1) demonstrated the lowest echocardiographic response. However, the cumulative freedom from hospitalizations from worsening heart failure and cardiovascular death did not significantly differ between the patients with CS and those with other etiologies. In particular, the group 1 patients presented with the lowest cardiovascular death and hospitalizations.