Cardiopulmonary Exercise Testing Variables Reflect the Degree of Diastolic Dysfunction in Patients With Heart Failure-Normal Ejection Fraction

PURPOSE: Previous investigations have reported a relationship between variables obtained from echocardiography with tissue Doppler imaging (TDI) and cardiopulmonary exercise testing (CPX) in systolic heart failure (HF) cohorts. The purpose of the present investigation was to perform a comparative analysis between echocardiography with TDI and CPX in patients with HF and normal ejection fraction (NEF). METHODS: Patients with HF-NEF (N = 32) underwent echocardiography with TDI and CPX to determine the following variables: (1) the ratio between mitral early velocity (E) and mitral annular velocity (E'), (2) ejection fraction, (3) left ventricular (LV) mass, (4) left ventricular end systolic volume, (5) peak oxygen uptake ((V) over dotO(2)), (6) ventilatory efficiency, (7) the partial pressure of end-tidal carbon dioxide (PETCO2) at rest and peak exercise, and (8) heart rate recovery at 1 minute (HRR1). RESULTS: Pearson correlation revealed that E/E' was significantly correlated with peak oxygen uptake (r = -0.55, P = .001), the ventilatory efficiency slope (r = 0.60, P < .001), resting PETCO2 (r = -0.39, P = .03), peak PETCO2 (r = -0.50, P = .004), and HRR1 (r = -0.63, P < .001). Left ventricular mass and left ventricular end systolic volume were not correlated with any CPX variable. Ejection fraction was correlated with HRR1 (r = -0.55, P = .001). An HRR1 threshold of less than 16 and/or 16 or more beats per minute (higher value positive) effectively identified subjects with an E/E' > 10 (positive likelihood ratio: 13:2). DISCUSSION: E/E' provides an accurate reflection of LV filling pressure and thus, insight into diastolic function. The results of the present investigation indicate CPX provides insight into cardiac dysfunction in patients with HF-NEF and thus, may eventually prove to be a valuable and accepted clinical assessment.