Atrial high‑rate episodes and risk of major adverse cardiovascular events in patients with dual chamber permanent pacemakers: a retrospective study

Abstract

Patients with atrial high-rate episodes (AHRE) are at higher risk of major adverse cardiovascular events (MACE). The cutoff threshold for AHRE duration for MACE, with/without history of atrial fibrillation (AF) or myocardial infarction (MI), is unknown. A total of 481 consecutive patients with/without history of AF or MI receiving dual-chamber pacemaker implantation were included. The primary outcome was a composite endpoint of MACE after AHRE ≥ 5 min, ≥ 6 h, and ≥ 24 h. AHRE was defined as > 175 bpm (MEDTRONIC) or > 200 bpm (BIOTRONIK) lasting ≥ 5 min. Cox regression analysis with time-dependent covariates was conducted. Patients' mean age was 75.3 ± 10.7 years and 188 (39.1%) developed AHRE ≥ 5 min, 115 (23.9%) ≥ 6 h, and 83 (17.3%) ≥ 24 h. During follow-up (median 39.9 ± 29.8 months), 92 MACE occurred (IR 5.749%/year, 95% CI 3.88-5.85). AHRE ≥ 5 min (HR 5.252, 95% CI 2.575-10.715, P < 0.001) and ≥ 6 h (HR 2.548, 95% CI 1.284-5.058, P = 0.007) was independently associated with MACE, but not AHRE ≥ 24 h. Patients with history of MI (IR 17.80%/year) had higher MACE incidence than those without (IR 3.77%/year, p = 0.001). Significant differences were found between MACE patients with/without history of AF in AHRE ≥ 5 min but not AHRE ≥ 6 h or ≥ 24 h. Patients with dual-chamber pacemakers who develop AHRE have increased risk of MACE, particularly after history of AF or MI.

Figure 1

Receiver-operating characteristic curve analysis of atrial high-rate episodes (minutes) in patients with dual chamber permanent pacemakers with subsequent MACE Atrial high rate episodes (minutes): cutoff value, 5-min; sensitivity, 68.3%; specificity, 65.3%; AUC, 0.662; 95% CI, 0.588–0.736; p < 0.001.

Figure 2

Cox regression event-free survival curves from primary endpoint at 39.9 ± 29.8 months of follow-up based on five subgroups. (A) All patients. (B) Patients without history of AF. (C) Patients with history of AF. (D) Patients without history of MI. E: Patients with history of MI. (AF atrial fibrillation, MI myocardial infarction).