Table 3.
Randomized Clinical Trials Comparing Conduction System Pacing With Biventricular Pacing in Heart Failure
| Trial | Sample size, No. | No. (%) | Baseline QRS, mean (SD), ms | No. (%) | LVEF, mean (SD), % | Follow-up, mo | Paced QRS duration, mean (SD), ms | LVEF at last follow-up, mean (SD), % | All-cause death, No. (%) | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Female | Ischemic | LBBB | AF | Conduction system pacing | Biventricular pacing | Conduction system pacing | Biventricular pacing | Conduction system pacing | Biventricular pacing | |||||
| His-SYNC,65,66 2019 | 40 | 15 (38) | 26 (65)a | 168 (18) | 25 (62) | 13 (33) | 28 (23 to 34)b | 12 | 125 (22) | 164 (25) | 35 (31 to 45)b | 32 (31 to 40)b | 1 (6) | 1 (4) |
| His-Alternative,67 2021 | 50 | 18 (36) | 11 (22) | 167 (15) | 50 (100) | 0 | 30 (6) | 6 | 131 (20) | 134 (15) | 46 (9) | 43 (7) | 0 | 0 |
| LBBP-RESYNC,68 2022 | 40 | 20 (50) | 0 | 175 (14) | 40 (100) | 0 | 30 (6) | 6 | 131 (12) | 137 (13) | 49 (13) | 46 (9) | 0 | 0 |
| HOT-CRT,69 2023 | 100 | 31 (31) | 39 (39) | 165 (27) | 62 (62) | 34 (34) | 31 (9) | 6 | 137 (20) | 141 (19) | 43 (10) | 39 (10) | 2 (4) | 2 (4) |
| CONSYST-CRT,70 2025 | 134 | 36 (27) | 46 (34) | 175 (22) | 75 (56) | 27 (20) | 28 (7) | 12 | 126 (17) | 131 (13) | 18 (10)c | 17 (11)c | 1 (1.5) | 3 (4.5) |
| CSP-SYNC,71 2025 | 62 | 18 (29) | 20 (32) | 174 (18) | 62 (100) | 0 | 29 (6) | 12 | −33 (−40 to −26)d | −32 (−39 to −25)d | 14 (11 to 17)d | 8 (6 to 11)d | 1 (3) | 0 |
| PhysioSync-HF,72 2026 | 179e | 86 (50) | 22 (13) | 180 (170 to 200)b | 165 (95) | 12 (7) | 26 (22 to 31)b | 12 | 122 (25) | 126 (21) | 35 (12) | 39 (12) | 11 (12.6) | 4 (4.7) |
| HeartSync-LBBP,73 2026 | 200 | 64 (32) | 35 (17) | 168 (18) | 200 (100) | 0 | 28 (4) | 36 | 121 (18) | 137 (16) | 47 (11) | 41 (9) | 2 (2) | 5 (5) |
Abbreviations: AF, atrial fibrillation; LBBB, left bundle-branch block; LVEF, left ventricular ejection fraction.
a
Patients with coronary artery disease at baseline.
b
Median (IQR).
c
Study reported change in LVEF.
d
Study reported mean difference in LVEF from baseline at 6 months with 95% CI.
e
A total of 179 participants were randomized; 6 did not undergo the index procedure for resynchronization (primary analysis, n = 173).