Detection of cardiac sarcoidosis using cardiac markers and myocardial integrated backscatter

It is not known whether cardiac markers and cyclic variations of integrated backscatter can be used to detect cardiac sarcoidosis.

We studied 62 patients with sarcoidosis affecting the lung, eyes, skin, or heart (27 patients with cardiac involvement and 35 patients without). The cyclic variation of integrated backscatter and wall thickening was evaluated in the left ventricular anterior septum and posterior wall. Plasma A-type natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) concentrations and serum cardiac troponin T were also determined.

Plasma natriuretic peptide concentrations were higher in the cardiac involvement group (ANP: 15.5 [interquartile range (IQR) 2.5-34.0] vs. 12.0 [10.0-16.5] pg/ml, P=0.25; BNP: 28.6 [5.9-141] vs. 10.1 [4.8-15.4] pg/ml, P=0.049). However, cardiac troponin T concentration was <0.01 ng/ml in all patients. Receiver-operator characteristic (ROC) analysis showed that both ANP and BNP could identify patients with high-degree atrioventricular block, ventricular tachyarrhythmias, or symptomatic heart failure (the areas under the ROC curve were 0.94 and 0.97, respectively). The cardiac involvement group could be distinguished from the noninvolvement group by combining cutoff values for the magnitude of integrated backscatter cyclic variation (5.5 dB) and wall thickening (30%), albeit only for the posterior wall.

Both ANP and BNP are useful markers for identifying patients with sarcoidosis and cardiac complication(s). Moreover, evaluation of integrated backscatter cyclic variation combined with wall thickening may be of help in detecting cardiac involvement in the posterior wall.