QRS-based assessment of myocardial damage and adverse events associated with cardiac sarcoidosis

Background Cardiac sarcoidosis (CS) generates myocardial scar and arrhythmogenic substrate. CS diagnosis according to the Japanese Ministry of Health and Welfare guidelines relies, among others, on cardiac magnetic resonance imaging with late gadolinium enhancement (CMR-LGE). However, access to CMR-LGE is limited. The electrocardiography-based Selvester QRS score has been validated for identifying myocardial scar in ischemic/nonischemic cardiomyopathy, but its efficacy has not been tested to evaluate CS. Objective The purpose of this study was to examine whether the QRS score can be applied to CS. Methods CS-associated myocardial scar was assessed by both CMR-LGE and QRS scoring in patients with extra-CS (n = 59). Results Of 59 patients, 35 (59%) were diagnosed with CS according to the Japanese Ministry of Health and Welfare guidelines. QRS-estimated scar mass positively correlated with that quantified by CMR-LGE (signal intensity ≥2SD above the reference; r = 0.68; P < .001). Receiver operating characteristic curves demonstrated optimal cutoffs of 9% CMR-LGE scar and 3-point QRS score to identify patients with CS. The areas under the curves of CMR-LGE and the QRS score were not significantly different (0.83 and 0.78, respectively; P = .27); both methods demonstrated similar diagnostic performance. A QRS score of ≥3 led to a higher incidence of CS-associated adverse events (death/fatal arrhythmia/heart failure hospitalization) than did a QRS score of