Management and clinical outcomes in patients with heart failure and high burden of right ventricular pacing, a nationwide registry-based study

Background Right ventricular pacing (RVP) is an established treatment in patients with atrioventricular block (AVB). However, a high burden of RVP may impair cardiac function, particularly in patients with pre-existing heart failure (HF). The aim of this study was to describe the characteristics and outcomes of patients with HF, irrespective of ejection fraction, by comparing those with high burden of RVP to those without. Methods Patients with a first recorded diagnosis of HF between January 2011 and December 2021 (index date) were identified from the Swedish National Patient Register and linked with several national registries, including the Swedish ICD and pacemaker registry. The exposed group included patients with assumed high burden of RVP at the HF diagnosis, defined as complete AVB as the main indication for pacemaker (PM) or implantable cardiac defibrillator (ICD) implantation). The unexposed group consisted of patients without device therapy at HF diagnosis or assumed low burden of RVP. Baseline characteristics and clinical outcomes were compared. Cox proportional hazard models were used to identify variables associated with subsequent upgrading to cardiac resynchronization therapy (CRT). In addition, a sensitivity analysis was performed comparing exposed patients with a subgroup of unexposed patients who had a PM or ICD at the time of HF diagnosis but without complete AVB. Results Among 220,752 patients with a first diagnosis of HF, 22,415 had a PM (88%) or an ICD (12%). Of these, 5,558 (25%) were classified as exposed to a high burden of RVP. The exposed group had a higher risk of cardiovascular death (HR 1.08 95% CI: 1.03-1.13) and first HF hospitalisation (HR 1.25 95% CI: 1.19-1.30) compared with the unexposed group, figure 1. During a median follow-up of 1.9 years, 637 exposed patients (11,5%) were upgraded to CRT, corresponding to an upgrading rate of 48 per 1000 person-year. Older age (HR 0.31 95% CI: 0.25-0.39) and hypertension (HR 0.83 95% CI: 0.69-0.99) were independently associated with a lower probability CRT upgrade, whereas male sex (HR 1.83 95% CI: 1.5-2.23) and higher educational level (HR 1.13 95% CI: 1.01-1.26) were associated with increased likelihood of upgrade. Conclusion A high burden of RVP in patients with HF is associated with increased risk of HF hospitalization and CV death. Despite this, few patients are upgraded to CRT, highlighting the need for improved identification and management of patients who may benefit from advanced pacing strategies.