TNNI3 and congestive heart failure: In advanced stage (non-CMI treated) HCM, and other causes of chronic heart failure, a deteriorating LVEF is associated with a rise in concentrations of both NT-proBNP and hs-cTnI.8,23,24 Results from SEQUOIA-HCM suggest that in the small number of patients who had an LVEF <50%, a reduction (rather than an increase) was generally seen in NT-proBNP and hs-cTnI.