Background and objectives .– Proportion of non-responders to cardiac resynchronization therapy (CRT) is high (≥ 30%). Echocardiography has been recently shown to predict a CRT-induced improvement in heart failure with a 6 months follow-up. We aimed to verify whether a combination of echographic criteria before CRT is still predictable at a 2-year follow-up.

Methods .– Fifty-five patients with left ventricular ejection fraction < 35% (20 ischaemic, 35 idiopathic), mean age 70.4 ± 10.9 years old, NYHA class III-IV, QRS duration ≥120 ms, were resynchronized. Before implantation, various echographic parameters of dyssynchrony were evaluated: atrioventricular dyssynchrony (AVD), defined by LV filling time/RR < 40%; interventricular dyssynchrony (IVD), defined by a difference between left and right pre-ejection delay > 40 ms. Various criteria of intraventricular dyssynchrony: overlap between inferolateral or anterolateral end-systole and mitral valve opening (Cazeau); aortic pre-ejectional delay (APED) > 140 ms; using tissue Doppler imaging (TDI) in 4 and 2 apical chambers view, maximum difference time to onset (electrosystolic delay) or maximum difference time to peak (electromechanical delay) > 60 ms.

Responders were defined as clear functional improvement and absence of heart failure hospitalization. We then evaluated sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of isolated and combined pre-CRT echographic parameters.

Results .– The follow-up was 22.6 ± 6.2 months, and 72% of patients were considered as responders. Three patients died. Prediction of CRT response was poor using 1 echographic criterion, independent of the criterion (Se 24%; Sp 43%; PPV 53%; NPV 42%); combination of 2 criteria was better (Se 30%; Sp 86%; PPV 85%; NPV 49%), while various combinations of 3 criteria were highly specific:

– APED + IVD + Cazeau (Se 29%; Sp 100%; PPV 100%; NPV 8%);

– APED + AVD + TDI (Se 24%; Sp 100%; PPV 100%; NPV 33%);

– IVD + TDI + AVD (Se 30%; Sp 100%; PPV 100%; NPV 35%);

– APED + Cazeau + AVD (Se 11%; Sp 100%; PPV 100%; NPV 30%);

– AVD + Cazeau + TDI (Se 8%; Sp 100%; PPV 100%; NPV 29%).

Conclusion .– Echocardiography is highly predictive of CRT-induced functional improvement at long-term follow-up, if a combination of 3 pre-implant criteria is used.