Leadless left ventricular endocardial pacing for cardiac resynchronization therapy: A systematic review and meta-analysis

BACKGROUND Leadless left ventricular (LV) endocardial pacing to achieve cardiac resynchronization therapy (CRT) is a novel procedure for treatment of patients with dyssynchronous heart failure. Current evidence is limited to observational studies with small patient numbers. OBJECTIVE The purpose of this systematic review and meta-analysis was to assess the safety and efficacy of leadless LV endocardial pacing. METHODS A literature search was conducted through PubMed, EMBASE, and Cochrane databases. Mean differences (MDs) in New York Heart Association (NYHA) functional class and LV ejection fraction (LVEF) from baseline to 6 months postprocedure were combined using a random effects model. Heterogeneity was evaluated using the Cochrane Q test, I-2, meta-regression, and sensitivity analysis. Funnel plots were constructed to detect publication bias. RESULTS Five studies with 181 patients were included in the final analysis. Procedural success rate was 90.6%. Clinical response rate was 63%, with mean improvement in NYHA functional class of 0.43 (MD-0.43; 95% confidence interval [CI] -0.76 to -0.1; P < .01), with high heterogeneity (P<.001; I-2 - 81.1%). There was a mean increase in LVEF of 6.3% (MD 6.3; 95% CI 4.35-8.19; P<.001, with low heterogeneity (P=0.84; I-2, 0.001%). The echocardiographic response rate was 54%. Procedure-related complication and mortality rates were 23.8% and 2.8%, respectively. CONCLUSION The efficacy of leadless LV endocardial pacing for CRT supports its use as a second-line therapy in patients in whom standard CRT is not possible or has been ineffective. Improvements in safety profile will facilitate widespread uptake in the treatment of these patients.