Frontiers in Cardiovascular Medicine · Oct 30, 2026
Device-detected new-onset atrial fibrillation after dual-chamber pacemaker implantation in patients with sick sinus syndrome under managed ventricular pacing: a risk nomogram from the 3-month landmark
By Jinmei Xie, Chenghua Shan, Yingjun Xiao et al.
BackgroundNew-onset atrial fibrillation (NOAF) is common after dual-chamber pacemaker implantation, but existing prediction models were derived from mixed populations of patients with sick sinus syndrome (SSS) and atrioventricular block and included heterogeneous pacing strategies.MethodsIn this single-centre retrospective cohort study, consecutive patients with SSS who received a first permanent Medtronic dual-chamber pacemaker with managed ventricular pacing (MVP) enabled as the default strategy were screened. Patients with atrial fibrillation or an atrial high-rate episode (AHRE) within 3 months after implantation were excluded, and prediction time started at this 3-month landmark, with atrial pacing percentage (AP%) and ventricular pacing percentage (VP%) measured at that visit. Patients implanted in 2015–2021 formed the development cohort (n = 322), and those implanted in 2022–2025 formed a temporal validation cohort (n = 121) reserved exclusively for validation. Twenty-six candidate predictors were assessed by univariable and multivariable Cox regression with backward Akaike information criterion (AIC) selection. Internal validation repeated the complete model-building procedure within 2,000 bootstrap samples. Temporal performance was assessed using discrimination and calibration at 1, 2 and 3 years after the landmark.ResultsNOAF occurred in 90 of 322 development patients (28.0%) during a median follow-up of 41.6 months [interquartile range (IQR), 13.7–80.1], and in 28 of 121 temporal validation patients (23.1%) during a median follow-up of 30.5 months (IQR, 8.8–45.9). Age (hazard ratio [HR] per year, 1.043; 95% confidence interval [CI], 1.019–1.067), maximum P-wave duration (Pmax; HR per 10 ms, 1.200; 95% CI, 1.085–1.326), left atrial volume index (LAVi; HR per 1 mL/m2, 1.051; 95% CI, 1.030–1.073), AP% > 50% (HR, 1.845; 95% CI, 1.198–2.840) and VP% > 40% (HR, 1.898; 95% CI, 1.045–3.446) were independently associated with NOAF. The apparent C-index was 0.735; repeating the complete model-building procedure within 2,000 bootstrap samples gave a mean optimism of 0.036 and an optimism-corrected C-index of 0.6992. In temporal validation the C-index was 0.769 (95% CI, 0.639–0.873) and cumulative/dynamic AUC values were 0.753, 0.881 and 0.916 at 1, 2 and 3 years after the landmark. Calibration-in-the-large was −0.17, 0.24 and 0.35 and calibration slopes were 0.90, 0.99 and 0.98 at 1, 2 and 3 years, respectively. The 1-year calibration estimate remained least precise, with only five NOAF events by 1 year in the validation cohort.ConclusionIn patients with SSS who remained free of atrial arrhythmia through the 3-month post-implantation landmark, a five-variable landmark model showed moderate optimism-corrected discrimination in the development cohort and promising same-centre temporal validation performance, particularly at 2 and 3 years after the landmark. The limited number of validation events, particularly at 1 year, warrants cautious interpretation. Prospective multicentre external validation is required before clinical implementation.