Direct His/LBB Pacing as an Alternative to Biventricular Pacing in Patients With HFrEF and a Typical LBBB
View Full PaperWhy the trial?
His bundle pacing offers more physiological ventricular activation than biventricular pacing, but randomised evidence in heart failure patients needing resynchronisation is limited to small studies. HIS Alternative II compared the two strategies head-to-head.
Does conduction system pacing (CSP-CRT) improve left ventricular end-systolic volume compared to biventricular pacing in patients with symptomatic heart failure, LVEF ≤35%, and LBBB?
Population
150 patients with symptomatic HF, LVEF <=35%, and typical LBBB (Strauss criteria)
Comparison
His/LBB conduction system pacing vs biventricular pacing
Design
Randomized 1:2 (BiV:CSP) noninferiority trial
Follow-up
6 months
Key result
Conduction-system pacing (His/LBB) was noninferior to biventricular pacing for reducing left ventricular end-systolic volume (35% vs 34% reduction) in patients with heart failure and typical LBBB.
Authors
Electrophysiology · Copenhagen University Hospital
What do you think the place is for CSP in heart failure patients who are candidates for CRT?
HIS Alternative II co-authorElectrophysiology · Copenhagen University Hospital
Looking forward to discussing HIS Alternative II with this community.
HIS Alternative II co-author
this is an interesting first take. A well done study but limited by duration of follow up and sample size. It does seem to indicate when the procedure is well done, actually both procedures well done there may not be that much difference between both techniques.
His/LBB pacing was noninferior to biventricular pacing for LVESV reduction (35% vs 34%).
| Outcome | His/LBB | BiV |
|---|---|---|
| Relative LVESV reduction at 6 months | -35% +/- 22% | -34% +/- 22% |
| Primary endpoint · difference 0.9% (95% CI -6.0 to 7.8); noninferior (P<0.01), not superior (P=0.80) | ||
| LVEF increase | +14% +/- 8% | +14% +/- 9% |
| Secondary outcome · no significant difference | ||
| 6-minute walk distance change | +37 +/- 53 m | +24 +/- 48 m |
| Secondary outcome · improvement in both arms | ||
Design limitations
The primary endpoint is echocardiographic remodeling over only 6 months, and 15 patients (15%) in the conduction-system-pacing arm crossed over to biventricular pacing at implantation (vs 1 the other way).
Statistical certainty
Small trial (150 patients); adverse-event rates beyond crossover are not reported in the record.
Does conduction system pacing (CSP-CRT) improve left ventricular end-systolic volume compared to biventricular pacing in patients with symptomatic heart failure, LVEF ≤35%, and LBBB?
In patients with HFrEF and LBBB, conduction system pacing is noninferior to biventricular pacing for improving left ventricular end-systolic volume and functional outcomes.
Absolute Event Rate: 35% vs 34%
Vinther et al. (2026) conducted an RCT in Heart failure with reduced ejection fraction and typical left bundle branch block. Conduction-system pacing (His bundle or left bundle branch) vs. Biventricular pacing was evaluated on Change in left ventricular end-systolic volume. Conduction-system pacing (His/LBB) was noninferior to biventricular pacing for reducing left ventricular end-systolic volume (35% vs 34% reduction) in patients with heart failure and typical LBBB.
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