Predictors of rate-adaptive pacing in patients implanted with implantable cardioverter–defibrillator and subsequent differential clinical outcomes

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.

Personalized Rate-Response Programming Improves Exercise Tolerance After 6 Months in People With Cardiac Implantable Electronic Devices and Heart Failure

Background:

Heart failure with reduced ejection fraction (HFrEF) is characterized by blunting of the positive relationship between heart rate and left ventricular (LV) contractility known as the force-frequency relationship (FFR). We have previously described that tailoring the rate-response programming of cardiac implantable electronic devices in patients with HFrEF on the basis of individual noninvasive FFR data acutely improves exercise capacity. We aimed to examine whether using FFR data to tailor heart rate response in patients with HFrEF with cardiac implantable electronic devices favorably influences exercise capacity and LV function 6 months later.

Methods:

We conducted a single-center, double-blind, randomized, parallel-group trial in patients with stable symptomatic HFrEF taking optimal guideline-directed medical therapy and with a cardiac implantable electronic device (cardiac resynchronization therapy or implantable cardioverter-defibrillator). Participants were randomized on a 1:1 basis between tailored rate-response programming on the basis of individual FFR data and conventional age-guided rate-response programming. The primary outcome measure was change in walk time on a treadmill walk test. Secondary outcomes included changes in LV systolic function, peak oxygen consumption, and quality of life.

Results:

We randomized 83 patients with a mean±SD age 74.6±8.7 years and LV ejection fraction 35.2±10.5. Mean change in exercise time at 6 months was 75.4 (95% CI, 23.4 to 127.5) seconds for FFR-guided rate-adaptive pacing and 3.1 (95% CI, −44.1 to 50.3) seconds for conventional settings (analysis of covariance; P =0.044 between groups) despite lower peak mean±SD heart rates (98.6±19.4 versus 112.0±20.3 beats per minute). FFR-guided heart rate settings had no adverse effect on LV structure or function, whereas conventional settings were associated with a reduction in LV ejection fraction.

Conclusions:

In this phase II study, FFR-guided rate-response programming determined using a reproducible, noninvasive method appears to improve exercise time and limit changes to LV function in people with HFrEF and cardiac implantable electronic devices. Work is ongoing to confirm our findings in a multicenter setting and on longer-term clinical outcomes.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02964650.