Background: Cardiac sarcoidosis is associated with mortality and adverse cardiovascular outcome, especially in patients with late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). CMR derived left ventricular global longitudinal strain (GLS) and parametric mapping analysis are recent techniques allowing comprehensive non-invasive assessment of myocardial deformation and diffuse fibrosis/inflammation. However, their prognostic value for risk stratification in patients with cardiac sarcoidosis remains unknown.
Methods: A total of 69 consecutive patients, who underwent clinically indicated CMR for suspected cardiac sarcoid involvement and gave informed consent were included. The median follow-up was 10 years. Pre-defined endpoints were 1) death, 2) ventricular tachycardia (VT) or non-sustained VT, 3) device implantation, and 4) hospitalisation. Follow-up rate was 92.8% for primary endpoint (death) and 81.2% for all endpoints.
Results: Study participants were on average 51 ± 10.6 years old (59% male). During the follow-up period, 23 adverse events (including 9 deaths) occurred (33.3%). Patients with LVEF <60%, and those with abnormal parametric mapping (defined as abnormal T1 and/or extracellular volume (ECV) and/or T2) demonstrated worse overall survival (log rank: x2= 11.2, p< 0.001 and x2= 5.97, p=0.014 respectively). LVEF <60%, the presence of LGE, abnormal global parametric mapping as well as abnormal GLS (defined as GLS> -16%) were all associated with an adverse outcome (Table). A prognostic 4-point-score comprising these four CMR parameters demonstrated a moderate ability for predicting adverse events (AUC 0.731 (0.599-0.863), p= 0.001).
Conclusion: Our data suggest that among patients with suspected cardiac sarcoidosis not only LGE and LVEF but also parametric mapping and GLS may enhance the prognostic ability of CMR. These data support the necessity of future larger studies to further evaluate these predictors of an adverse outcome.
