Meta-Analysis of the Relation of Baseline Right Ventricular Function to Response to Cardiac Resynchronization Therapy

Right ventricular (RV) dysfunction has been associated with adverse clinical outcomes in patients with heart failure (HF). Cardiac resynchronization therapy (CRT) improves left ventricular (LV) size and function in patients with markedly abnormal electrocardiogram QRS duration. However, relation of baseline RV function with response to CRT has not been well described. In this study, we aim to investigate the relation of baseline RV function with response to CRT as assessed by change in LV ejection fraction (EF). A systematic search of studies published from 1966 to May 31, 2015 was conducted using PubMed, CINAHL, Cochrane CENTRAL, and the Web of Science databases. Studies were included if they have reported (1) parameters of baseline RV function (tricuspid annular plane systolic excursion [TAPSE] or RVEF or RV basal strain or RV fractional area change [FAC]) and (2) LVEF before and after CRT. Random-effects metaregression was used to evaluate the effect of baseline RV function parameters and change in LVEF. Sixteen studies (n = 1,764) were selected for final analysis. Random-effects metaregression analysis showed no significant association between the magnitude of the difference in EF before and after CRT with baseline TAPSE (β = 0.005, p = 0.989); baseline RVEF (β = 0.270, p = 0.493); baseline RVFAC (β = -0.367, p = 0.06); baseline basal strain (β = -0.342, p = 0.462) after a mean follow-up period of 10.5 months. In conclusion, baseline RV function as assessed by TAPSE, FAC, basal strain, or RVEF does not determine response to CRT as assessed by change in LVEF.