A new algorithm for optimization of rate-adaptive pacing improves exercise tolerance in patients with HFpEF.

Abstract

To develop an algorithm for optimization of rate-adaptive pacing settings in heart failure patients with preserved ejection fraction (HFpEF) and permanent cardiac pacing. This is a prospective randomized controlled study. A total of 54 patients with HFpEF, permanent atrial fibrillation (AF), and VVIR pacing were randomized to an intervention group with optimization of rate-adaptation parameters by using cardiopulmonary exercise testing (CPET) and pacemaker stress echocardiography (PASE), and to a control group with conventional programming. CPET, 6-min walk test (6-mwt), echocardiography (echo), Duke Activity Status Index (DASI), and Minnesota questionnaire (MLHFQ) were performed at baseline and after 3 months. PASE was used to exclude exercise-induced ischemia and to determine safe upper sensor rate. Pacing parameters were corrected to achieve optimal heart rate increments of 3-6bpm for 1mL/min/kg of VO2 (oxygen uptake). After 3 months, the intervention group demonstrated significant improvement of VO2 peak by 1.64±1.6mL/min/kg, anaerobic threshold by 1.33±1.3mL/min/kg, exercise time by 170±98s, 6-mwt distance by 75±63m (P<.0001 for all), DASI by 5.23 points (P=.009), MLHFQ-score (reduction by 9 points, P<.0001), and echo parameters (decrease in LA volume from 108 (84; 132) to 95 (85; 130) mL, P=.026; E/e' from 11.7±3.2 to 10.4±2.9, P=.025; systolic pulmonary artery pressure (SPAP) from 44±14 to 39±12mm Hg, P= .001) compared to the control group. An algorithm incorporating CPET and PASE for optimal programming of rate-adaptation parameters is a valuable tool to improve exercise capacity in HFpEF patients with permanent AF and VVIR pacing who remain exercise intolerant after conventional programming.