A randomized comparison of His bundle pacing versus right ventricular pacing: Effect on left ventricular function and biomarkers of collagen metabolism

Abstract

BACKGROUND: Right ventricular pacing (RVP) can result in pacing-induced cardiomyopathy (PICM). It is unknown whether specific biomarkers reflect differences between His bundle pacing (HBP) and RVP and predict a decrease in left ventricular function during RVP. AIMS: To compare the effect of HBP and RVP on the LV ejection fraction (LVEF) and to study how they affect serum markers of collagen metabolism. METHODS: Ninety-two high-risk PICM patients were randomized to HBP or RVP. Their clinical characteristics, echocardiography, and serum levels of TGF-β1, MMP-9, ST2-IL, TIMP-1, and Gal-3 were studied before and six months after pacemaker implantation. RESULTS: Fifty-three patients were randomized to HBP and 39 patients to RVP. HBP failed in 10 patients, which crossed over to the RVP group. Patients with RVP had significantly lower LVEF compared to HBP after six months of pacing (-5% and -4% in as-treated and intention-to-treat analysis, respectively). Levels of TGF-β1 after 6 months were lower in HBP than RVP (mean difference -6 ng/ml; P = 0.009) and preimplant Gal-3 and ST2-IL levels were higher in RVP patients with a decline in the LVEF >= 5% compared to those with a decline of < 5% (mean difference 3 ng/ml and 8 ng/ml; P = 0.02 for both). CONCLUSION: In high-risk PICM patients, HBP was superior to RVP in providing more physiological ventricular function, as reflected by higher LVEF and lower levels of TGF-β1. Among RVP patients, LVEF declined more in those with higher baseline Gal-3 and ST2-IL levels than those with lower levels.