Combined impact of paced QRS duration and right ventricular pacing burden on heart failure admission: Identifying clinical progression to stage C/D in pacemaker recipients

Background Right ventricular (RV) pacing-induced dyssynchrony can lead to progressive left ventricular (LV) dysfunction. Although a decline in LV ejection fraction (LVEF) after pacemaker implantation is common, the transition to symptomatic heart failure (HF) requiring hospitalization (HF admission; HFA) represents a more clinically meaningful progression to Stages C/D. Objective To determine whether paced QRS duration (pQRS) and RV pacing burden (RVp) independently or jointly predict HFA in pacemaker recipients followed with remote monitoring. Methods We retrospectively analyzed 200 pacemaker recipients actively followed with remote monitoring. pQRS at implantation and RVp during follow-up were evaluated as markers of baseline electrical dyssynchrony and cumulative pacing exposure. The primary endpoint was HFA, and the secondary endpoint was all-cause mortality. Results During a median follow-up of 4.5 years, 27 patients (13.5%) developed HFA. Patients with HFA had longer pQRS (171±18 vs. 156±20 ms, p <0.001) and higher RVp (median 99% vs. 38%, p =0.002). In a multivariable Cox model, both pQRS ≥168 ms (HR 2.98, p=0.011) and RVp ≥20% (HR 7.16, p =0.009) and age independently predicted HFA. Neither pQRS nor RVp predicted all-cause mortality, which was associated only with age. Conclusion PQRS and RVp jointly identify patients at high risk of progression from clinical to symptomatic HF (Stages C/D). While mortality in this population is primarily age-driven, HFA reflects a modifiable consequence of pacing-related dyssynchrony. Combined assessment of pQRS and RVp may facilitate early identification of high-risk patients who could benefit from closer monitoring or alternative pacing strategies.