Exercise Capacity and the Force Frequency Relationship in Multi-Point Versus Single-Point Pacing: A Randomized Trial

Quadripolar left ventricular (LV) epicardial leads capable of multipoint pacing (MPP) may have an advantage over conventional bipolar leads for delivering cardiac resynchronization therapy (CRT) by stimulating the lateral LV wall from two distinct locations simultaneously.

We aimed to determine the acute and longer-term effects of MPP compared with single-point pacing (SPP) on LV contractility and exercise capacity in individuals with heart failure with reduced ejection fraction receiving CRT.

Participants were enrolled into a randomized crossover study with echocardiographic assessment of the comparative effects of acute MPP and SPP on LV contractility and cardiopulmonary exercise testing at 6-weeks and 6-months following device implantation. Participants were then randomized in a parallel-group study to either MPP or SPP for further 6-months.

Twenty-three participants (mean age 73 years [95% confidence interval: 69, 78], 91% male, 91% New York Heart Association [NYHA] class II, LV ejection fraction 31.3% [27.4, 35.1]) were included. At resting heart rates, LV contractility was significantly higher with MPP compared to SPP (2.29 mmHg/mL/m² [1.74, 2.84] vs. 2.03 [1.58, 2.47]; p = 0.019). However, it was not different between MPP and SPP at higher heart rates or at 6-months, and there were no differences in exercise performance between MPP and SPP at any point including following 6 months of chronic treatment.

Although CRT with MPP resulted in improved LV contractility at resting heart rates acutely post implantation, it did not translate into consistent mechanistic or patient-orientated benefits in the short or longer-term.