Midterm effects and clinical benefits of left ventricular vs biventricular pacing in heart failure.

BACKGROUND: Although left ventricular pacing (LVP) leads to a greater acute hemodynamic response than does biventricular pacing (BVP), the long-term effects are diverse. We aimed to assess the efficacy of LVP and BVP in patients undergoing cardiac resynchronization therapy and determine which patients would benefit more from LVP or BVP.

METHODS: Randomized controlled trials that compared left and biventricular pacing were retrieved from MEDLINE and analyzed for changes in cardiac function and dimensions, cardiac resynchronization therapy response, and electromechanical effects.

RESULTS: A total of 811 patients were included from 9 trials. After a mean follow-up, a shorter QRS duration (-40.92 milliseconds; 95% confidence interval [CI], -64.50 to -17.34; P = 0.0007), and improved left ventricular dimensions were observed in the BVP group compared with the LVP group. Moreover, the BVP group had a longer 6-minute hall walk (6MHW) test (37.19 m; 95% CI, 4.72 to 69.67; P = 0.02).

CONCLUSION: Our results indicate that BVP results in a better electromechanical effect and leads to a better 6MHW test. For all other test criteria, LVP showed a benefit equal to that of BVP. Thus, there is currently insufficient evidence to advocate for LV-only pacing.