Feasibility and reproducibility of exercise echocardiography in patients with chronic heart failure

In recent years several studies have shown that exercise echocardiography has
potentially added clinical value as compared to resting echocardiography as a
tool for the evaluation of patient with chronic heart failure (CHF). Potential
clinical applications that have arisen include grading of the severity of
valvular disease (mitral regurgitation), assessment of prognosis, and
prediction and assessment of the effects of cardiac resynchronization therapy
in CHF patients. Currently, however, exercise echocardiography is poorly
implemented in daily clinical practice.

Although several studies showed good intra- and interobserver variability of
exercise echocardiography variables in selected populations of CHF patients,
data on its feasibility are lacking. Moreover, no data exist on the
reproducibility of potentially relevant exercise echocardiography variables
such as left ventricular ejection fraction (LVEF), the severity of mitral
regurgitation and myocardial tissue motion.

* To establish the feasibility (i.e. % of measurements with sufficient quality
for analysis) of exercise echocardiography in CHF patients, focusing on left
ventricular function (LVEF), myocardial tissue motion (intra- and
interventricular dyssynchrony) and the severity of mitral regurgitation.
* To determine the day-to-day reproducibility of these variables

The study is designed as a prospective observational study, including stable
patients with stable CHF. Patients are requested to visit the hospitals 3
times. During the first visit patients undergo a routine clinical examination,
followed by an incremental symptom limited exercise test with respiratory gas
analysis . During the second and third visit (after 7 days and 9-14 days
respectively) echocardiography is performed on an echocardiography stress
table in a left lateral supine position. Measurements are performed at rest and
subsequently during exercise using four 2-minute exercise bouts, respectively
at 30%, 60% and 90% of the ventilatory threshold, and halfway between the
ventilatory threshold and peak VO2. Images are stored for off line analysis by
an experienced cardiologist blinded for the patient number and test order.

There are no direct benefits for individual participants other than additional
information / insight into their disease based on the results of the exercise
tests. On a population level, the results of this study may contribute to a
wider implementation of exercise echocardiography which may improve the
clinical assessment and therapy selection in CHF patients. No adverse effects
of cycle exercise testing performed by CHF patients, nor for supine exercise
testing during echocardiography have been reported in literature. Testing
sessions are supervised by an experienced physician.