Late gadolinium enhancement-cardiovascular magnetic resonance as a predictor of response to cardiac resynchronization therapy in patients with ischaemic cardiomyopathy

AIM: To determine whether myocardial scarring, quantified using late gadolinium enhancement-cardiovascular magnetic resonance (LGE-CMR), predicts response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS: A total of 45 patients with ischaemic cardiomyopathy [age 67.1 +/- 10.4 years (mean +/- SD)] underwent assessment of 6 min walking distance (6MWD) and quality of life (QoL) before and after CRT. Scar size (percentage of left ventricular mass), location, and transmurality were assessed prior to CRT using LGE-CMR. Responders (survived for 1 year with no heart failure hospitalizations, and improvement by >or=1 NYHA classes or >or=25% 6MWD) had a higher left ventricular ejection fraction (P = 0.048), smaller scars (or=51% transmurality (P = 0.002). Scar size correlated negatively with change in 6MWD (r = -0.54, P <0.001) and positively with changes in QoL scores (r = 0.35, P = 0.028). Responder rates in patients with or=33% scar (82 vs. 35%, P <0.01). Responder rates in patients with scar transmurality or=51% (89 vs. 46%, P <0.01). Among the patients with posterolateral scars, a transmurality value of >or=51% was associated with a particularly poor response rate (23%), compared with scars with or=33%, a transmurality >or=51%, and pacing over a posterolateral scar are associated with a suboptimal response to CRT.