Accelerated Bachmann bundle area pacing for atrial resynchronization in patients with non-obstructive hypertrophic cardiomyopathy and heart failure with preserved ejection fraction: A randomized crossover trial.

BACKGROUND

Inter-atrial block (IAB) can contribute to the worsening of diastolic dysfunction in heart failure with preserved ejection fraction (HFpEF).

OBJECTIVE

To determine the effects of accelerated Bachmann bundle area pacing (BBAP) in symptomatic patients with non-obstructive hypertrophic cardiomyopathy (nHCM), HFpEF, and IAB.

METHODS

Prospective, randomized, patient-blinded crossover study in symptomatic patients with nHCM, HFpEF, and IAB. Patients were recruited during 2021-2024 for dual-chamber implantable cardioverter defibrillator (ICD) implantation. Patients with successful BBAP were randomized to dual-chamber rate-responsive pacing (DDDR 70/min) or no pacing (VVI 30/min) for 4 weeks. After a washout period of 4 weeks, they were crossed over to the other arm for 4 additional weeks. In addition, a historical cohort of nHCM patients with an atrial lead in the right atrial appendage pacing (RAAP) were programmed to DDDR 70/min for 12 weeks. The primary end point was a change in N-terminal pro-brain natriuretic peptide (NT-proBNP). Secondary end points included 6-minute walk distance, functional class, diastolic filling parameters, and daily diuretic requirement.

RESULTS

Of 46 patients recruited, 42 patients had successful BBAP and were randomized (age 46.2 ± 7.2 years, 82.6% men). BBAP significantly reduced the N-terminal pro-brain natriuretic peptide (NT-proBNP), compared with no pacing (-116.4 ± 22.1 vs -8.1 ± 6.2, P = .008) and RAAP (-116.4 ± 22.1 vs -27.1 ± 12.6, P = .021). BBAP also led to an improvement in all the secondary end points. Compared with the historical cohort of RAAP, BBAP was associated with a significant reduction in NT-proBNP levels (-116.4 ± 22.1 vs -27.1 ± 12.6, P = .021) and all secondary end points.

CONCLUSION

Among patients with nHCM, HFpEF, and an IAB, accelerated BBAP was found to reduce the NT-proBNP and was accompanied by an improvement in the diastolic function and exercise capacity.