Usefulness of Additional ECG Indicators for Prognosis Prediction in Patients With Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is characterized by variability in ventricular repolarization and depolarization due to sarcoid granulomas. The T-wave peak to end (Tp-e)/QT ratio and fragmented QRS complex (fQRS), which are markers of repolarization dispersion and depolarization abnormality, respectively, predict arrhythmic risk in cardiac conditions. However, their prognostic value in CS remains uncertain. This study aimed to assess the association between the Tp-e/QT ratio and fQRS presence with prognosis and arrhythmic risk in CS patients through a Japanese nationwide survey. This multicenter retrospective cohort study used data from a nationwide survey on CS conducted from 2014 to 2016 in Japan. The authors categorized CS patients based on Tp-e/QT ratios and fQRS presence. They assessed a composite of all-cause mortality and ventricular arrhythmia events as primary outcomes, and a composite of cardiac-related deaths (heart failure and sudden death) and ventricular arrhythmia events as secondary outcomes. Among 227 CS patients (151 women, median follow-up: 1,286 days), grouped by Tp-e/QT ratios (cutoff value: 0.232) and fQRS presence, higher Tp-e/QT ratios and fQRS indicated poorer prognosis. Multivariable analysis revealed high Tp-e/QT (HR: 3.01; P = 0.002), fQRS (HR: 2.48; P = 0.012), past ventricular tachycardia, and left ventricular ejection fraction (LVEF) ≤35% as independent adverse outcome predictors. These electrocardiograph indicators were also significant in CS patients with LVEF >35% (Tp-e/QT > 0.232: HR: 3.62; P = 0.011; fQRS: HR: 3.38; P = 0.022). High Tp-e/QT ratios and fQRS presence in CS patients suggest worse prognosis, particularly with LVEF >35%, highlighting their importance in early-stage arrhythmic risk. (Investigation of Fixation Behavior During Perimetry Test; UMIN000018393).