Introduction
Sarcoidosis is a multisystem granulomatous disease of unknown etiology
characterized by noncaseating granulomas in involved
organs.1 Cardiac
involvement in sarcoidosis occurs in 20-27% of cases in the United
States and may be as high as 58% in Japan.2 Cardiac
sarcoidosis (CS) manifestations include various types of tachy- and
brady-arrhythmias, left ventricular (LV) systolic dysfunction, and
sudden death, and it is increasingly recognized for its poor prognosis.3-6Corticosteroids are widely used as
the first-line immunosuppressants for patients with CS, especially in
patients who have active inflammation in the myocardium. However,
patients with CS are sometimes not diagnosed in the early stage of the
disease (e.g. during pacemaker or implantable cardioverter defibrillator
[ICD] implantations for atrioventricular block or ventricular
arrhythmias), and later are diagnosed with CS due to a cardiac function
decline.7 For those patients,
it is not well known which
therapeutic strategy should come first, corticosteroids therapy or an
upgrade to CRT therapy from a pacemaker or ICD. Generally, the clinical
response and long-term survival have been less favorable in patients
undergoing CRT upgrades than de novo implantations.8However, the pathophysiology of CS greatly differs from that of other
cardiomyopathies, and corticosteroid therapy would have a potential to
affect the clinical response and long-term prognosis. Thus, in the
present study, we investigated the echocardiographic response and
long-term prognosis in patients with non-ischemic cardiomyopathy (NICM)
who underwent CRT upgrade therapy and analyzed the impact of the timing
of the initiation the corticosteroid therapy on the clinical outcomes in
patients with CS.