Imaging-guided cardiac resynchronization therapy: A meta-analysis of randomized controlled trials

Background: Among patients with heart failure and left ventricular (LV) dysfunction despite guideline directed medical therapy, cardiac resynchronization (CRT) is an effective technology to reverse LV remodeling. Given that a large portion of patients are non-responders, alternatives to traditional LV-lead placement have been explored. A promising alternative is image targeted placement of an LV-lead to latest mechanically activated segment without scar. Methods: Electronic database search for randomized controlled trials (RCTs) that evaluated the imaging-guided LV-lead placement on clinical, echocardiographic, and functional outcomes. The primary outcome was a composite of mortality and heart failure hospitalization. The secondary outcomes included CRT responders, New York Heart Association (NYHA), 6-minute walk test, Minnesota Living with Heart Failure Questionnaire (MLHFQ), and ejection fraction (EF) changes. Results: Analysis included 4 RCTs of 691 patients with an average follow-up of 2 years (age 69.5 ± 10.3 years, 76% males, 54% ischemic cardiomyopathy, 81% with NYHA classes III/IV, and EF of 24.4% ± 8). The most common site for LV-lead paced segment was the anterolateral segment (45%) and at mid-LV (49%). Compared with the control, imaging-guided LV-lead placement was associated with a significant reduction of the primary outcome (hazard ratio [HR] = 0.60; 95% CI = 0.40–0.88; p =.01), higher CRT responders (odd ratio [OR] = 2.10; p <.01), more NYHA improvements by ≥1 (OR = 1.89; p =.01), increased 6MWT (mean difference [MD] = 25.78 feet; p <.01), and lower MLHFQ (MD = -4.04; p =.04), without significant differences in the LVEF (p =.08). Conclusions: In patients undergoing CRT, imaging-guided LV-lead placement was associated with improved clinical, echocardiographic, and functional status.