Treatment with His-bundle (His)-pacing cardiac resynchronization therapy (CRT) offered a clinical improvement in patients with heart failure (HF) by 6 months, including better improvement in left ventricular ejection fraction (LVEF) and lower end-systolic volumes than biventricular pacing cardiac resynchronization therapy (BiV-CRT), according to study results in Current Treatment Options in Cardiovascular Medicine.
Patients in this study had symptomatic HF, LVEF ≤35%, and left bundle branch block (LBBB) (N=50). The investigators randomly assigned these patients to either His-CRT (n=19) or BiV-CRT (n=31) and examined outcomes over a 6-month follow-up period.
A total of 7 patients in the His-CRT group crossed over from His-pacing to left ventricular (LV)-pacing at implantation whereas 1 patient in the BiV-CRT arm crossed over from LV-pacing to His-pacing. Approximately 72% of patients randomly assigned to His-CRT achieved His-corrective pacing.
At 6-month follow-up, the LVEF increased by 17%±8% in the His-CRT arm vs 13%±6% in the BiV-CRT group (P =.053). The investigators observed improvements in both arms with regard to clinical and physical parameters, with no significant differences between either treatment group.
In contrast, pacing thresholds were significantly higher for His-CRT at implantation (1.8 V±1.2 V vs 1.2 V±0.8 V; P <.01) as well as at the 6-month follow-up (2.3 V±1.4 V vs 1.4 V±0.5 V; P <.01). In a comparison between His-CRT and BiV-CRT arms, the per-protocol, 6-month LVEF was higher (48%±8% vs 42%±8%; P =.014) and the lower end-systolic LV volume was lower (65 mL±22 mL vs 83 mL±27 mL; P =.02) with His-CRT.
Limitations of this study included its single-center design and small sample size, as well as the predominance of patients with nonischemic cardiomyopathy.
According to these findings, the investigators wrote that “His-pacing correcting LBBB holds promise as a feasible alternative to biventricular pacing in selected heart failure patients.”
Chatterjee NA, Heist EK. Cardiac resynchronization therapy-emerging therapeutic approaches. Curr Treat Options Cardiovasc Med. 2018;20(3):20. doi:10.1007/s11936-018-0614-2