Echocardiographic measures of acute haemodynamic response after cardiac resynchronization therapy predict long-term clinical outcome.

Abstract

Although acute haemodynamic improvement in response to cardiac resynchronization therapy (CRT) is reflective of a favourable cardiac contractile response, there is limited information regarding not only its ability to predict long-term clinical outcome but also cardiac-substrate-specific differences in the prognostic value of this measure. Fifty-three heart failure patients (69 +/- 11 years) with low left ventricle ejection fraction (LVEF) (22 +/- 6%), wide QRS (169 +/- 31 ms), and indications for CRT were included. There were no significant differences in age, New York Heart Association (NYHA) class, medications, QRS width, or LVEF between ischaemic (n = 37) and non-ischaemic (n = 16) groups. Echocardiograms were performed within 24 h of implantation with device OFF and ON. Acute haemodynamic response was measured as LV dP/dt derived from the CW Doppler of mitral regurgitation. Percentage change in dP/dt was used to classify patients: high- (HR: DeltadP/dt > 25%) or poor-responders (PR: DeltadP/dt <or= 25%). Clinical response to CRT was defined by a combined endpoint of hospitalizations and all-cause mortality at 12 months. HR group had a significantly better outcome compared to the PR group (P-value = 0.004) irrespective of the aetiology of the cardiomyopathy. Echocardiographic assessment of the acute haemodynamic response to CRT predicts long-term clinical outcome in both ischaemic and non-ischaemic cardiomyopathy.