Myocardial degradation and left bundle branch block predict conversion to low ejection fraction in heart failure with preserved systolic function.

The authors prospectively investigated whether left bundle branch block (LBBB) and myocardial degradation as indicated by elevated troponin T (tnT) predict the phenomenon of systolic conversion to low ejection fraction (EF <or=40%) in patients with nonsignificant coronary disease and heart failure with preserved systolic function (HFPSF) (initial EF >40%). Thirty consecutive patients with HFPSF were included and followed over a 4-year interval. A follow-up EF assessment was performed in 25 patients. Six of 15 patients with tnT >or=0.01 ng/mL demonstrated systolic conversion to low EF on follow-up, while none of the 10 patients with tnT <0.01 ng/mL experienced this phenomenon (P=.03). Five of the 6 converters presented with LBBB, while only 1 of the 19 nonconverters had this abnormality (P=.0007). Four of the 6 converters had an initial EF >50%. Myocardial degradation and LBBB predicted systolic conversion in HFPSF patients with nonsignificant coronary disease.