Duration of atrial high-rate episodes and CHA₂DS₂-VASc score to predict cardiovascular and cerebrovascular events in patients with dual chamber permanent pacemakers

Background: Patients with atrial high-rate episodes (AHRE) have a high risk of cardiovascular and cerebrovascular events (CCE); however, the optimal cut-off threshold for AHRE duration and the prediction power of AHRE with CHA₂DS₂-VASc score is unknown. Methods: We enrolled 355 consecutive patients undergoing dual chamber pacemaker implantations. The primary endpoint was subsequent CCE after AHRE ≥ 30 seconds, 1 minute, 2 minutes, 5 minutes, 6 hours, and 24 hours. AHRE was defined as >175 bpm (Medtronic, Dublin, Ireland) or >200 bpm (Biotronik, Berlin, Germany) lasting ≥30 seconds. Multivariate Cox regression analysis with time-dependent covariates was used to determine the variables associated with higher risks of CCE. Results: The average age of the patients was 75.6 ± 11.3 years, and 162 patients (45.6%) developed AHRE ≥ 30 seconds, 145 (40.8%) ≥1 minute, 125 (35.2%) ≥2 minutes, 107 (30.1%) ≥5 minutes, 55 (15.5%) ≥6 hours, and 37 (10.4%) ≥24 hours. During follow-up (mean 42.1 ± 31.2 months), 145 CCE occurred in 107 patients (incidence rate 11.64/100 patient-years, 95% CI 9.99-13.70). The optimal AHRE cut-off value was 1 minute (sensitivity, 57.9%; specificity, 66.0%; area-under-the-curve, 0.631; 95% CI, 0.563–0.698; p < 0.001). Multivariate Cox regression analysis demonstrated that all categories of AHRE duration were independently associated with CCE. The occurrence of CCE increased with AHRE ≥30 seconds and CHA₂DS₂-VASc score ≥2 (males) or ≥3 (females). Conclusion: Patients with dual chamber pacemakers who develop AHRE ≥ 30 seconds have an increased risk of CCE. The combination of AHRE duration ≥30 seconds and CHA₂DS₂-VASc score ≥2 (males) or ≥3 (females) is a useful risk-stratification predictor for subsequent CCE.