Introduction:
In patients with suspected cardiac sarcoidosis, a definitive diagnosis of the condition can only be made in the presence of non-caseating granuloma on histological examination of myocardial tissue with no alternative cause identified. However, endomyocardial biopsy (EMB) has a low sensitivity - attributed to the focal nature of the disease - with a reported yield of <25% in patients with a clinical diagnosis of sarcoidosis. We hypothesized that late gadolinium enhancement (LGE) characteristics on cardiovascular magnetic resonance imaging (CMR) would be associated with the diagnostic yield of EMB for suspected cardiac sarcoidosis.
Methods:
We studied 52 patients with suspected cardiac sarcoidosis that underwent both CMR and EMB and investigated associations between the EMB yield and LGE CMR characteristics: presence of LGE, presence of LGE in the septum, presence of LGE on the right ventricular (RV) side of the septum, extent of LGE, and extent of LGE on the RV side of the septum. The extent of LGE was measured using the 5SD method. The extent of LGE on the RV side of the septum was measured by tracing the RV border of the septum on all short-axis LGE images, and expressed as a percent of the total RV border with LGE.
Results:
Of 52 patients, non-caseating granulomas were noted in 9 (17.3%). Comparison of the markers between patients with and without positive EMB is provided. Receiver Operating Characteristic (ROC) analyses showed the largest area under the curve (AUC) for the extent of LGE on the RV side of the septum (0.92). A cut-off of >14.7% of LGE on the RV side of the septum had a sensitivity of 100% and specificity of 79% to predict the yield of EMB.
Conclusions:
In patients with suspected cardiac sarcoidosis undergoing EMB, the presence of LGE has 100% sensitivity but a low specificity for predicting the yield of EMB. Among LGE characteristics, the extent of LGE on the RV side of the septum has the highest AUC, and a cut-off of >14.7% predicts a positive EMB with 100% sensitivity and 79% specificity. LGE CMR characteristics can help improve the yield of EMB in patients with suspected CS.
Cardiac magnetic resonance imaging with T2 mapping for the monitoring of acute heart transplant rejection in patients with problematic endomyocardial biopsy: in anticipation of new recommendations
