Objective To investigate whether time from onset of heart failure signs and/or symptoms (ie, progression to stage C/D heart failure) until implantation affects reverse remodelling and clinical outcome after cardiac resynchronisation therapy (CRT).

Design Cohort study of consecutive CRT patients, implanted between 1 October 2008 and 30 April 2011.

Setting Single tertiary care centre (Ziekenhuis Oost-Limburg, Genk, Belgium).

Patients Consecutive CRT patients (n=172; 71±9 years), stratified into tertiles according to the time since first heart failure signs and/or symptoms at implantation.

Main outcome measures Change in left ventricular dimensions, New York Heart Association (NYHA) functional class and freedom from all-cause mortality or heart failure admission.

Results Baseline renal function was better in patients implanted earlier after emerging heart failure symptoms (estimated glomerular filtration rate=73±20 vs 63±23 vs 58±26 ml/min/1.73 m² for tertiles, respectively). After 6 months, decreases in left ventricular end-diastolic/systolic diameter and improvement in NYHA functional class were similar among tertiles. Freedom from all-cause mortality or heart failure admission was better in patients with early implantation (p value=0.042). However, this was not the case in patients with preserved renal function (p value=0.794). Death from progressive heart failure was significantly more frequent in patients implanted later in their disease course.

Conclusions Reverse left ventricular remodelling after CRT is not affected by the duration of heart failure. However, clinical outcome is better in patients implanted earlier in their disease course, which probably relates to better renal preservation.