Late Gadolinium Enhancement and Prognosis in Cardiac Sarcoidosis
What is the prognostic value of myocardial late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI) in patients with known or suspected cardiac sarcoidosis?
This was a meta-analysis of studies from the medical literature with at least 1 year of prognostic data. Co-primary endpoints were: 1) mortality from any cause, and 2) the composite of all-cause death and arrhythmogenic events (including ventricular arrhythmia, implantable cardioverter-defibrillator [ICD] shock, and sudden cardiac death).
Ten studies were identified in the literature with a total of 760 patients and a mean follow-up of 3 years. Nearly all patients (95%) had proven extracardiac sarcoidosis and 21.6% had proven cardiac involvement. The prevalence of LGE was strongly correlated with mean ejection fraction (R = 0.95, p < 0.001). Patients with LGE had a substantially increased risk of both all-cause mortality (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1-8.2; p < 0.03) and the composite of arrhythmogenic events and mortality from any cause (OR, 10.7; 95% CI, 4.1-27.9; p < 0.0001) compared to those without LGE. Generally, the ORs were higher in studies with populations with better preserved left ventricular ejection fraction (LVEF). The annualized rate of the composite of arrhythmogenic events and mortality was 11.9% in those with LGE compared with 1.1% in those without (p < 0.0001).
In patients with established extracardiac or cardiac sarcoidosis, LGE on cardiac MRI is associated with markedly worse prognosis.
These data further solidify the scientific rationale for performing cardiac MRI in patients with confirmed extracardiac sarcoidosis and suspected cardiac involvement. It is clear that patients with suspected cardiac sarcoidosis without LGE and with preserved LVEF are at low risk and therefore appear to be unlikely to benefit from ICD therapy. However, there are several important remaining questions. For example, which patients with preserved or relatively preserved LVEF who do have LGE would benefit from ICD therapy? The lack of patient-level data and subgroup analyses in this study does not explore this important question. Finally, because LGE may represent scar, inflammation, or some combination of these two, the interplay of medical therapy and device therapy is an important unanswered question.
< Back to Listings