1Universitätsklinikum Ulm Klinik für Innere Medizin II Ulm, Deutschland
Background: The diagnostic and prognostic performance of phasic atrial function by Cardiac Magnetic Resonance (CMR) is increasingly recognized in various cardiac conditions. Although cardiac sarcoidosis (CS) is known to be associated with increased mortality, most studies have focused only on the ventricular involvement and the significance of atrial dysfunction in CS has not been previously reported. Purpose: We aimed to assess indices of left atrial (LA) and right atrial (RA) function based on phasic volumes and longitudinal atrial strain measured using CMR in patients with extracardiac biopsy proven sarcoidosis.
Methods and results: 102 consecutive patients with biopsy-proven sarcoidosis and suspected cardiac involvement were dichotomized according to the presence of left ventricular late gadolinium enhancement (LV-LGE) and compared to an age- and sex matched cohort of 72 healthy subjects. LV-LGE consistent with CS was present in 36% of the sarcoidosis patients. Compared to healthy subjects, sarcoidosis patients presented significant impaired left atrial conduit and reservoir function: LA total ejection fraction (EF) 47.9±5.9% vs. 60.4±4.9%, p<0.001, LA passive EF 31.4±6.1% vs. 40.7±4.7 %, p<0.001, LA reservoir strain 20.9±5.4% vs. 32.3 ±6.8%, p<0.001, LA conduit Strain 13.9±6.0 % vs. 20.3±4.6%, p<0.001, not only when LV-LGE was present, but also in patients without LV-LGE, while the LA booster function remained preserved. Maximal LA volume indices were not significantly different between subgroups, whereas the minimal and pre-contractile LA volume indices were significantly higher in sarcoidosis patients. Only the RA conduit function showed abnormalities in sarcoidosis patients compared to healthy control (RA passive EF 30.6±5.6% vs. 36.9±7.4 %, p<0.001, RA conduit strain 16.6±5.2% vs. 21.0±6.1 %, p<0.001, RA conduit strain rate 1.3±0.4 s-1 vs. 1.9±0.4 s-1) while the RA reservoir and booster functions were not reduced. Correlations between atrial functional parameters and baseline symptoms were weak.
Conclusion: Bi-atrial phasic dysfunction represents an important cardiac phenotype in patients with sarcoidosis irrespective of the presence of LV-LGE. Compared with healthy controls, sarcoidosis patients have LA reservoir and conduit dysfunction as well as RA conduit dysfunction before atrial enlargement. CMR-FT identifies bi-atrial dysfunction and deformation at an early subclinical stage in patients with sarcoidosis.