Low level exercise echocardiography helps diagnose early stage heart failure with preserved ejection fraction: a study of echocardiography versus catheterization

Increased left ventricular end-diastolic pressure (LVEDP) with exercise is an early sign of heart failure with preserved left ventricular ejection fraction (LVEF). The abnormal exercise increase in LVEDP is nonlinear, with most change occurring at low-level exercise. Data on non-invasive approach of this condition are scarce. Our objective was assessing E/e' to estimate low level exercise LVEDP using a direct invasive measurement as the reference method. Sixty patients with LVEF > 50 % prospectively underwent both exercise cardiac catheterization and echocardiography. E/e' was measured at rest and during low-level exercise. Abnormal LVEDP was defined as > 16 mmHg. Patients with a history of coronary artery disease and/or abnormal LV morphology were classified as having apparent cardiac disease (CD). Thirty-four (57 %) patients had elevated LVEDP only during exercise. Most of the change in LVEDP occurred since the first exercise level (25 W). There was a correlation between LVEDP and septal E/e' at rest and during exercise. Lateral E/e' and E/average e' ratio had worse correlations with LVEDP. In the whole population, exercise septal E/e' at 25 W had the best accuracy for abnormal exercise LVEDP, area under curve (AUC) = 0.79. However, while low-level exercise septal E/e' had a high accuracy in CD patients (n = 26, AUC = 0.96), E/e' was not linked to LVEDP in patients without CD (n = 34). Low-level exercise septal E/e' is valuable for predicting abnormal exercise LVEDP in patients with preserved LVEF and apparent CD. However, this new diagnosis approach appears not reliable in patients with normal LV morphology and without coronary artery disease.