Sex-specific prognostic implications of new-onset atrial fibrillation in patients treated with dual chamber pacemakers

Abstract Background Right ventricular pacing induces ventricular dyssynchrony, which over time may result in left ventricular dysfunction, increased left ventricular filling pressures, and ensuing left atrial dilatation, with increased risk of atrial arrhythmias. Atrial fibrillation (AF) prior to device implant is associated with worse prognosis, but the prognostic effects of new-onset AF during pacemaker treatment are less well described. Purpose To describe risk factors, incidence, and prognostic effects of new-onset AF after treatment is initiated with a dual chamber pacemaker. To evaluate mortality and risk of heart failure diagnosis or hospitalisation for heart failure in patients who develop AF, compared to those who do not develop AF. Methods All patients without pre-existing heart failure or atrial fibrillation, who received a dual chamber pacemaker at a large-volume tertiary care center during the period 2005–2020 were included. Data was crossmatched between the national pacemaker registry, the population registry and national disease registries. The primary outcome was 10-year mortality, and the secondary outcome was new-onset heart failure. Results 37127 patients were included in the study, of which 14760 (30%) were female. Median age was 76.4 years [interquartile range, IQR, 68.0–83.1] and the most common indication for pacemaker implant was AV block (57.7%), see Table 1. Overall, 10-year survival was higher for female patients, compared to male patients, p<0.0001 (see Kaplan-Meier curve in Figure 1A). Patients who developed new-onset AF had more comorbidities, were slightly older and a higher percentage were men. During follow-up 3661 (9.9%) developed atrial fibrillation within two years (9.1% of female and 10.3% of male patients, p<0.001), at a median of 291 [88–461] days after implant. In multivariable Cox regression analysis with new-onset AF as time dependent covariable and adjusted for clinically relevant covariables, AF was an independent predictor of higher all-cause mortality (HR 1.43 [1.37–1.49], p<0.0001). Risk factors for new-onset AF included increasing age, male sex, hypertension, malignancy, diabetes, chronic obstructive lung disease, chronic renal disease, and sick sinus syndrome indication (all p<0.01). In separate analyses for men and women, the risk factors and magnitude of odds ratios were the same. Conclusion In patients treated with dual chamber pacemakers due to bradycardia or AV block, development of new-onset AF within two years was associated with a higher 10-year mortality. The risk of developing AF was higher for men, but the negative prognostic effect was more pronounced for women.Figure 1A.-B. K-M survival curves