Prospective randomized trial of conduction system pacing vs right ventricular pacing for patients with atrioventricular block; Prague CSP trial

Abstract

Background: Conduction system pacing (CSP) replaces right ventricular pacing (RVP) in bradycardia patients.

Objective: To compare CSP vs RVP in patients with pacemaker indication due to atrioventricular conduction disease.

Methods: This study randomized patients to CSP or RVP in 1:1 ratio and followed them for 12 months. CSP received either His bundle pacing or left bundle branch area pacing; The primary end point was a change in the left ventricular ejection fraction (LVEF). The combined composite clinical end point consisted of cardiovascular death, cardiac resynchronization therapy upgrade, or hospitalization for heart failure.

Results: Of 249 patients, 125 were randomized to RVP and 124 to CSP; there were no differences between clinical parameters. In CSP, 10 patients received His bundle pacing, 96 left bundle branch area pacing, 15 deep septal pacing, and 3 RVP. Procedural and fluoroscopy times were longer in CSP vs RVP (63 vs 40 and 7 vs 3 minutes; P < .001). In the intention-to-treat analysis, the LVEF decline in CSP was smaller than RVP (-2% vs -4%, P = .03), and a LVEF decrease ≥ 10% occurred more often in RVP 19 (16%) than CSP 6 (5%), P = .01. There was no difference in the composite clinical outcome between RVP and CSP (9 vs 4, P = .15). There was also no difference in procedural complications (9 in RVP vs 2 in CSP, P = .09).

Conclusion: In patients with severe conduction disease, CSP led to a smaller LVEF decline than RVP after 1 year of pacing. Both pacing methods had similar rates of clinical end points and procedural complications.

Keywords: Conduction system pacing; His bundle pacing; Left bundle branch pacing; Randomized trial; Right ventricular pacing.