Conduction System Pacing Validated for HF With Wide QRS
Seventy patients at a single center with an indication for cardiac resynchronization therapy were randomly assigned in this parallel group, noninferiority trial 1:1 to one or the other pacing modality (n = 35 each). For the primary endpoint of left ventricular activation time (LVAT) shortening, a noninferiority margin of -12 ms was used, measured by electrocardiographic imaging at day 45. Secondary endpoints were measured at 6 months.

Despite the relatively small sample sizes, the CSP and BiVP groups were fairly equivalent in terms of gender (34.3%, 28.6% female, respectively), age (65.7 vs 68.1 years), ischemia (31.4% each), QRS width (177 msec, 178 msec), LBBB (65.7% each), AV block (31.4%, 25.7%), New York Heart Association (NYHA) functional class (I or II: 60%, 57.1%; III: 31.4%, 37.1%; IV: 8.6%, 5.7%), LVEF (27%, 28%), and left ventricular end-systolic volume (148 mL, 125 mL).

Conduction system pacing (CSP) produced the same degree of cardiac resynchronization, ventricular reverse modeling, and similar clinical outcomes as did biventricular pacing (BiVP) in patients with heart failure and wide QRS.