The prognostic role of exercise echocardiography in heart failure

Gradual impairment of exercise tolerance is the commonest sign of heart failure (HF). Little is known as to which cardiac contributors of poor exercise capacity carry an independent prognostic information in HF.

We investigated the prognostic role of exercise echocardiography (ex-echo) in HF patients.

We studied 85 consecutive, symptomatic HF patients (66 males, mean age 62.5 ± 11.8 [range 21-83] years, mean left ventricular ejection fraction [LVEF] 27.2 ± 9.5%). The end-point was all-cause mortality. During the follow-up period (mean 43 ± 21 months) 21 patients died. Resting echocardiography and ex-echo, with the simultaneous measurement of peak oxygen uptake (VO(2peak)), was performed in each patient using a semi-supine ergometer (20 W, 2-min increments). Apart from conventional assessment of systolic and diastolic function (EF, E/A, DT, IVRT) or right ventricular systolic pressure (RVSP), tissue Doppler imaging was used for the assessment of LV and RV peak velocity (IVV) as well as acceleration during isovolumic contraction (IVA), peak velocity during ejection phase (S'), peak early diastolic velocity (E'), peak late diastolic velocity (A'), and ratio of early diastolic mitral/tricuspid velocity to peak early diastolic velocity (E/E').

Patients who died were significantly older, had lower exercise capacity, more advanced HF, greater impairment of baseline systolic function, higher baseline pulmonary artery systolic pressure, and most importantly a lack of improvement in EF, diastolic function, and further increase of RVSP during exercise. Out of all echocardiographic parameters, only peak stress EF (x(2) 6.1; p = 0.01), baseline and peak exercise RVSP (x(2) 12.5 and c(2) 18.7; p 〈 0.001; respectively), and mitral E/E' ratio (x(2) 8.9; p 〈 0.01) were univariate predictors of prognosis and remained independently prognostic when adjusted for age and sex but were eliminated from the model by NT-proBNP.

During exercise, more severe systolic and diastolic dysfunction with the elevation of pulmonary arterial pressure is more prevalent in HF patients who have a poorer outcome. The estimation of common parameters such as EF, RVSP and E/E' using ex-echo, provides prognostic information in HF.