Importance of ventricular longitudinal function in chronic heart failure

Despite its immediate relevance, cardiopulmonary exercise testing (CPET) is infrequently performed in the presence of chronic heart failure (CHF). Previous studies of patients suffering from CHF have found a closer correlation between exercise capacity and measurements of diastolic than systolic ventricularfunction. We examined the correlation between echocardiographic measurements and (i) results of CPET and (ii) cardiovascular prognosis.

We performed resting two-dimensional echocardiograms and CPET in 140 patients with CHF (mean age = 61 ± 13 years, 111 men). The underlying heart disease was ischaemic in 48 patients (34%). They were followed for a mean of 38 months (range 28-52). The mean left ventricular (LV) ejection fraction (EF) was 30 ± 9% and peak VO₂ 17.2 ± 6.5 mL/kg/min. LVEF correlated weakly with peak VO₂ (r = 0.21), while systolic and early diastolic LV longitudinal function correlated best [early diastolic peak velocity at the mitral annulus (E'): r = 0.38; global longitudinal strain (GLS): r = -0.4; P <0.001 for both]. By multiple variable regression analysis, the best prediction of peak VO₂ was derived from a model based on age, mitral annulus end-diastolic peak velocity (A'), GLS, right ventricular (RV) systolic strain, and left atrial systolic strain (r² = 0.57; P <0.0001). The two best independent predictors of adverse cardiovascular events at 28 months were GLS (odds ratio 1.31, P <0.001; prognostic cut-off = -8%) and RV systolicstrain (odds ratio 1.05, P =0.01; prognostic cut-off = -22%).

Resting RV and LV longitudinal functions were reliable predictors of adverse cardiovascular events and correlated moderately with, but not took to the place of, CPET measurements.