Treatment group and results for patients with non-LBBB QRS morphology who did or did not receive CRT
| Study | Intervention group | Control group | Follow-up | Outcomes |
|---|---|---|---|---|
| MADIT-CRT5 15 20 | CRT-D and OMT | ICD and OMT | Median 5.6 years | Death: Non-LBBB: adjusted HR 1.57 (1.03–2.39), p=0.04 HF event: Non-LBBB: adjusted HR 1.13 (0.80–1.60), p=0.48 HF event or death: Non-LBBB: adjusted HR 1.27 (0.94–1.73), p<0.001 |
| CARE-HF1 18 | CRT-P and OMT | OMT alone | 29.4 months | All-cause mortality or HF hospitalisation with baseline RBBB: HR 0.81 (0.52−1.28). |
| COMPANION2 | OMT with CRT-P or CRT-D | OMT alone | 12 months | Composite events non-LBBB: 0.86 (0.63–1.17), p=0.34. |
| RAFT4 12 | CRT-D | ICD alone | 40 months | Cardiovascular mortality: RBBB 11 (16.2%) vs 19 (20.4%), HR 0.83 (0.39–1.74), p=0.617 NIVCD 19 (17.9%) vs 20 (19.8%), HR 0.81 (0.43–1.51), p=0.500 Calculated pooled non-LBBB: HR 0.82 (0.51−1.32) HF hospitalisation: RBBB 17 (25.0%) vs 20 (21.5%), HR 1.24 (0.65–2.36), p=0.518 NIVCD 32 (30.2%) vs 29 (28.7%), HR 1.00 (0.60–1.66), p=0.999 Calculated pooled non-LBBB: HR 1.09 (0.73−1.62) All-cause mortality or HF hospitalisation: RBBB 28 (41.2%) vs 42 (45.2%), HR 0.98 (0.61–1.58), p=0.930 NIVCD 48 (45.3%) vs 40 (39.5%), HR 1.08 (0.71–1.65), p=0.790 Calculated pooled non-LBBB: HR 1.03 (0.75–1.42) |
| REVERSE6 14 | CRT-D (CRT on) | CRT-D (CRT off) | 24 months | Death or first HF hospitalisation: RBBB: 0.083 (0.01–0.69) NIVCD: 0.60 (0.22–1.65) Calculated pooled non-LBBB: HR 0.50 (0.11−2.29). |
CRT-D, cardiac resynchronisation therapy defibrillator; CRT-P, cardiac resynchronisation therapy pacemaker; HF, heart failure; ICD, implantable cardioverter-defibrillator; LBBB, left bundle branch block; OMT, optimal medical therapy; RBBB, right bundle branch block; NIVCD, non-specific intraventricular conduction delay.