Table 4

Effect of QRS Morphology and CRT Response

Trial (Ref. #)LBBBNon-LBBBRBBBIVCDPrimary Endpoint
COMPANION (3)CRT-D and CRT-P better than OPTCRT-D and CRT-P better than OPT (includes RBBB, IVCD)NRNRDeath or all-cause hospitalization
CARE-HF (2,20)CRT associated with favorable outcomeNACRT associated with unfavorable outcomeNRDeath or unplanned cardiovascular hospitalization
MADIT-CRT (17)HR: 0.47 (95% CI: 0.37–0.61); p < 0.001HR: 1.24 (95% CI: 0.85-1.81); p = 0.257HR: 0.99 (95% CI: 0.55–1.79); p = 0.969HR: 1.44 (95% CI: 0.88–2.36); p = 0.143)Death or nonfatal HF event
MADIT-CRT long-term analysis, LBBB patients only (21)
(N = 1,281)
0.59 (0.43–0.80); p < 0.0011.57 (1.03–2.39) 0.04 (includes RBBB, IVCD)NRNRAll-cause mortality
REVERSE (18)OR: 0.530 (0.35-0.81); p = 0.0034OR: 0.27 (0.10–0.77)0.083 (0.01–0.69)0.79 (0.40–1.57)Clinical composite score
RAFT (42)HR: 0.640 (95% CI: 0.524–0.781); p < 0.001HR: 0.986 (95% CI: 0.695–1.399); p = 0.937HR: 0.890 (95% CI: 0.530–1.494); p = 0.659HR: 1.116 (95% CI: 0.666–1.815); p = 0.657Death or HF hospitalization

NR = not recorded; RBBB = right bundle branch block; other abbreviations as in Tables 1 and 2.

  • For all non-LBBB, p = 0.21.