Modalities of ventricular pacing for cardiac resynchronization therapy in patients with heart failure: a meta-analysis and systematic review

INTRODUCTION This meta-analysis evaluated 14 studies which compared clinical and functional outcomes after different cardiac resynchronization therapy (CRT) modalities. MATERIAL AND METHODS Relevant studies were selected from the Medline, PubMed, Cochrane, and Google Scholar databases until June 27th, 2016. We analyzed and compared the clinical outcomes (peak O2 consumption and LVEF) and functional outcomes (6-min walk distance and quality of life (SF-36)) of HF patients who received different CRT modalities with outcomes in patients who received conventional univentricular therapy. RESULTS There was no significant difference in post-treatment 6-min walking distance between the biventricular (BiV) and left/right univentricular (LUV/RUV) groups (standardized difference in means = 0.049, 95% CI: -0.119 to 0.217, p = 0.566), or between the BiV and triventricular (TriV) groups (standardized difference in means = 0.035, 95% CI: -0.270 to 0.340, p = 0.822). Peak O2 consumption was comparable between BiV and LUV/RUV groups (standardized difference in means = 0.306, 95% CI: -0.002 to 0.614, p = 0.052). Patients in the TriV group had a significant improvement in LVEF compared to the BiV group (standardized difference in means = 0.647, 95% CI: 0.313 to 0.982, p < 0.001). CONCLUSIONS TriV CRT is an attractive alternative to univentricular or BiV pacing for heart failure patients. It is necessary to conduct further large randomized trials to validate our present data.