Moderately Accelerated Pacing in Patients With a Pacemaker and HFpEF

Moderately accelerated pacing was safe and improved quality of life, N-terminal pro–brain natriuretic peptide (NT-proBNP) levels, physical activity, and atrial fibrillation (AF) compared with the standard 60-bpm setting among patients with heart failure with preserved ejection fraction (HFpEF) and pacemakers, according to a study in JAMA Cardiology.

Researchers presented findings from the myPACE (ClinicalTrials.gov Identifier: NCT04721314) trial, which evaluated moderately accelerated pacing in patients with HFpEF for 1 year.

The prospective, blinded, parallel-group, randomized clinical trial recruited patients with American College of Cardiology/American Heart Association stage B and C HFpEF with an ejection fraction of more than 50%. Participants were enrolled from July 2019 to November 2020, with follow-up concluding in December 2021.

The participants completed baseline assessments and were then randomly assigned in a 1:1 ratio to a personalized backup heart rate setting (myPACE) or the nominal 60-bpm setting (usual care) for 1 year. The primary outcome was the change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) score.

A total of 100 patients participated in the study. Of these patients, 52 were in the usual care group and 48 were in the myPACE group. Their median age was 75 (IQR, 69-81) years, 48% were women, and the median H₂FPEF score was 6 (IQR, 5-8). The median baseline pacemaker-recorded heart rate within the previous 6 months was 65 (IQR, 65-70) bpm in the usual care group and 65 (61-70) bpm in the myPACE group. The median programmed rate was 60 (IQR, 60-60) bpm in the usual care group and 75 (IQR, 70-75) bpm in the myPACE group. The resultant median pacemaker-recorded heart rate at 2 years was 65 (IQR, 63-68) bpm in the usual care group and 75 (IQR, 75-80) bpm in the myPACE group.

The mean follow-up was 378 (SD, 83) days. Participants’ mean MLHFQ scores decreased by 0.6 (SD, 9.1) points at 1 month and increased by 3.5 (SD, 10.6) points at 1 year for usual care. MLHFQ scores improved by a mean of 10.9 (SD, 13.7) points at 1 month and 15.0 (SD, 15.5) points at 1 year for the myPACE group. The relative percent change in NT-proBNP levels at 1 month between groups was P =.02.

The median pacemaker-detected daily activity level at baseline was 2.5 (IQR, 2.1-3.9) hours for usual care and 2.6 (IQR, 1.5-3.1) hours for personalized accelerated pacing. At 1 year, daily activity levels were greater with personalized accelerated pacing (median [IQR], 3.1 [2.0-4.3] hours) vs usual care (median [IQR], 2.9 [1.7-4.0] hours; P =.003).

Personalized accelerated pacing reduced the relative risk of device-detected AF by 27% compared with usual care (risk ratio, 0.73; 95% CI, 0.55-0.99; P =.04). With personalized accelerated pacing, 4 participants had 4 adverse events, and with usual care, 11 participants had 17 adverse events.

Study limitations include more than half of the patients had sick sinus syndrome as the primary pacing indication, which may have increased the effect size of the personalized accelerated pacing intervention. Also, although the MLHFQ and NT-proBNP levels are not significantly different, the values are nominally higher in the personalized accelerated pacing group vs usual care. In addition, enrollment stopped early owing to the COVID-19 pandemic.

“The myPACE study supports the concept of heart rate modulation as a therapeutic intervention in HFpEF and provides additional evidence that moderately higher, and not lower, heart rates are beneficial in this complex patient population with an unmet need for therapies addressing underlying hemodynamic and cardiac structural abnormalities,” the investigators wrote.

Disclosure: Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.