Clinical and Electrocardiographic Predictors of a Positive Response to Cardiac Resynchronization Therapy in Advanced Heart Failure

Meta-Analysis of the Usefulness of Change in QRS Width to Predict Response to Cardiac Resynchronization Therapy

“…The heterogeneity test showed significant differences among the subgroups (80.5% and 73.4%, respectively). However, we did not find significant differences in studies 8,9,11,13 measuring postimplantation QRSd after a certain follow-up period compared with studies 7,10,12,14e18 measuring QRSd immediately after CRT device implantation (À19.37 The American Journal of Cardiology (www.ajconline.org) vs À19.31 ms) without any heterogeneity among the individual studies (I 2 ¼ 0%). In addition, the sensitivity analysis showed that heterogeneity across studies was reduced when we excluded the study by Lecoq et al 9 where the inclusion criteria for QRSd was at least 150 ms (I 2 ¼ 33%) or the study by Zhang et al 18 that enrolled only patients with dilated cardiomyopathy (I 2 ¼ 31%), without changing the overall effect.…”

“…In the present analysis, we clearly demonstrated that QRSd shortening predicts both clinical and echocardiographic response. In Alonso 1999 Survival with significantly improved symptoms (at least 1 class down) and exercise tolerance (at least 10% increase on baseline in peak VO 2 ) for at least 6 months Molhoek 2004 Those patients who improved at least 1 class NYHA classification score after 6 months of CRT Lecoq 2005 Patients were classified at 6 months as responders to CRT if they were alive, they had not been re-hospitalized for management of CHF, and the NYHA class had decreased by 1 point, and/or peak VO 2 or 6 min hall-walk increased by > 10% Boriani 2006 A reduction > 15% of LVESV Lellouche 2007 (1) no cardiovascular death, (2) no hospitalization for decompensated HF, and (3) ! 1 point decrease in NYHA functional class.…”

Native QRS narrowing reflects electrical reversal and associates with anatomical reversal in cardiac resynchronization therapy

“…Lecoq et al investigated the association between ΔQRSd and clinical response to CRT. They revealed that 95 % of responders and 60 % of non-responders exhibited QRS narrowing on biventricular pacing ECG [19]. In our patient cohort, 53.2 % of responders and 18.5 % of non-responders had native QRS narrowing post-CRT.…”

“…Alonso et al first reported a shorter QRS duration in responders than in non-responders on biventricular pacing ECG [21]. Lecoq et al revealed that the amount of abbreviation in paced QRS duration positively associated with therapeutic response to CRT [19]. Additionally, Serdoz et al found that more than 40 ms reduction in paced QRS duration could predict hyper-response independently [12].…”

“…Accumulating evidences indicated that QRS narrowing after initiation of biventricular pacing also predicted beneficial outcomes to CRT [12,[18][19][20]. Abbreviation in QRS duration on biventricular pacing ECG was taken as a sign of rectification on electrical asynchrony produced directly by CRT.…”