Effectiveness of rate-adaptive pacing on patients with chronotropic incompetence: Systematic review and meta-analysis of randomized controlled trials

Background: Rate-adaptive pacing (RAP) complements heart rate (HR) responses in patients with cardiac pacing devices and chronotropic incompetence, although improvements in exercise capacity have varied across reported studies. The purpose of this study was to evaluate the effectiveness of the RAP mode across different clinical settings. Methods: A systematic review and meta-analysis were conducted according to PRISMA guidelines. MEDLINE and EMBASE databases were searched through May 2024. Randomized controlled trials comparing RAP-on with RAP-off modes in patients with chronotropic incompetence were included. Outcomes related to exercise capacity, such as peak oxygen uptake (VO2), exercise duration, and patient-reported outcomes (PROs), were analyzed. Results: Twelve trials with a total of 1199 patients were included. The meta-analysis showed that RAP-on significantly improved peak VO2 (mean difference [MD]: 1.35 ml/kg/min, 95 % confidence interval [CI]: 0.47 to 2.23) and exercise duration (MD:0.74 min, 95 % CI: 0.14 to 1.33) with augmenting peak HR (MD: 19 bpm, 95 % CI: 13 to 26) during cardiopulmonary exercise tests. The effectiveness of RAP on exercise capacity blunted particularly in patients with heart failure (HF) (MD: 0.36 ml/kg/min, 95 % CI: −0.88 to 1.60) compared with those without HF (MD: 1.95 ml/kg/min, 95 % CI: 0.66 to 3.23). PROs showed no significant improvement with RAP-on except for one study including non-HF. Conclusions: RAP-on mode significantly enhances exercise capacity in patients with chronotropic incompetence, however, the benefits are less pronounced in patients with concomitant HF. In patient with HF, careful assessment is crucial to identify potential need for advanced therapeutic approach following the RAP-on pacing.