Myocardial Injury and Cardiac Reserve Limitation in Heart Failure with Preserved Ejection Fraction

Abstract

Background Cardiac reserve is depressed in patients with heart failure and preserved ejection fraction (HFpEF). The mechanisms causing this are poorly understood. We tested the hypotheses that myocardial injury might contribute to the hemodynamic derangements and cardiac reserve limitations that are present in HFpEF. Methods Subjects with HFpEF (n=38) and controls without HF (n=20) underwent cardiac catheterization, echocardiography, and expired gas analysis at rest and during exercise. Markers of cardiomyocyte injury (high sensitivity troponin T), central hemodynamics, ventricular function, and determinants of cardiac oxygen supply-demand balance were measured. Results Compared to controls, troponins were more than two-fold higher in subjects with HFpEF at rest and during exercise (p Conclusions Limitations in left ventricular functional reserve and the hemodynamic derangements that develop secondary to these limitations during exercise in HFpEF are correlated with the severity of cardiac injury, assessed by plasma levels of troponin T. Further study is warranted to determine the mechanisms causing myocyte injury in HFpEF, the potential role of ischemia, and to identify and test novel interventions targeted to these mechanisms.