TNNI3 and Arrhythmia: Primary endpoints were 6-month relative decline in left ventricular global longitudinal strain (ΔLVGLS%) and change in left ventricular ejection fraction (ΔLVEF); secondary endpoints included 3-month measures, LVEF and LVGLS, CTRCD incidence [LVEF<50% or ΔLVGLS%>15% or elevated high-sensitivity cardiac troponin I (hs-cTnI)/N-terminal pro-B-type natriuretic peptide (NT-proBNP)], and severe arrhythmias.