The Relationship Between Daily Atrial Tachyarrhythmia Burden From Implantable Device Diagnostics and Stroke Risk: The TRENDS Study

Background—It is unknown if brief episodes of device-detected atrial fibrillation (AF) increase thromboembolic event (TE) risk. Methods and Results—TRENDS was a prospective, observational study enrolling patients with ≥1 stroke risk factor (heart failure, hypertension, age ≥65 years, diabetes, or prior TE) receiving pacemakers or defibrillators that monitor atrial tachycardia (AT)/AF burden (defined as the longest total AT/AF duration on any given day during the prior 30-day period). This time-varying exposure was updated daily during follow-up and related to TE risk. Annualized TE rates were determined according to AT/AF burden subsets: zero, low (<5.5 hours [median duration of subsets with nonzero burden]), and high (≥5.5 hours). A multivariate Cox model provided hazard ratios including terms for stroke risk factors and time-varying AT/AF burden and antithrombotic therapy. Patients (n=2486) had at least 30 days of device data for analysis. During a mean follow-up of 1.4 years, annualized TE risk (including transient ischemic attacks) was 1.1% for zero, 1.1% for low, and 2.4% for high burden subsets of 30-day windows. Compared with zero burden, adjusted hazard ratios (95% CIs) in the low and high burden subsets were 0.98 (0.34 to 2.82, P=0.97) and 2.20 (0.96 to 5.05, P=0.06), respectively. Conclusions—The TE rate was low compared with patients with traditional AF with similar risk profiles. The data suggest that TE risk is a quantitative function of AT/AF burden. AT/AF burden ≥5.5 hours on any of 30 prior days appeared to double TE risk. Additional studies are needed to more precisely investigate the relationship between stroke risk and AT/AF burden.

[1]  Palle Petersen,et al.  Ximelagatran vs warfarin for stroke prevention in patients with nonvalvular atrial fibrillation: a randomized trial. , 2005, JAMA.

[2]  D. Levy,et al.  Independent risk factors for atrial fibrillation in a population-based cohort. The Framingham Heart Study. , 1994, JAMA.

[3]  A. Gillis,et al.  Accuracy of Atrial Tachyarrhythmia Detection in Implantable Devices with Arrhythmia Therapies , 2004, Pacing and clinical electrophysiology : PACE.

[4]  Rahul Mehra,et al.  Comparison of continuous versus intermittent monitoring of atrial arrhythmias. , 2006, Heart rhythm.

[5]  V. Fuster,et al.  ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation , 2001 .

[6]  Susan Regan,et al.  Major Hemorrhage and Tolerability of Warfarin in the First Year of Therapy Among Elderly Patients With Atrial Fibrillation , 2007, Circulation.

[7]  A. Castellanos,et al.  Clinical Utility of Intraatrial Pacemaker Stored Electrograms to Diagnose Atrial Fibrillation and Flutter , 2001, Pacing and clinical electrophysiology : PACE.

[8]  Stephen S. Cha,et al.  Secular Trends in Incidence of Atrial Fibrillation in Olmsted County, Minnesota, 1980 to 2000, and Implications on the Projections for Future Prevalence , 2006, Circulation.

[9]  Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials. , 1994, Archives of internal medicine.

[10]  Massimo Santini,et al.  Monitored atrial fibrillation duration predicts arterial embolic events in patients suffering from bradycardia and atrial fibrillation implanted with antitachycardia pacemakers. , 2005, Journal of the American College of Cardiology.

[11]  M. Joffe,et al.  History-adjusted marginal structural analysis of the association between hemoglobin variability and mortality among chronic hemodialysis patients. , 2008, Clinical journal of the American Society of Nephrology : CJASN.

[12]  Yuchiao Chang,et al.  Anticoagulation therapy for stroke prevention in atrial fibrillation: how well do randomized trials translate into clinical practice? , 2003, JAMA.

[13]  Salim Yusuf,et al.  Incidence of stroke in paroxysmal versus sustained atrial fibrillation in patients taking oral anticoagulation or combined antiplatelet therapy: an ACTIVE W Substudy. , 2007, Journal of the American College of Cardiology.

[14]  Anticoagulation therapy for stroke prevention in atrial fibrillation: how well do randomized trials translate into clinical practice? , 2003 .

[15]  李永军,et al.  Atrial Fibrillation , 1999 .

[16]  C. Israel,et al.  Long-term risk of recurrent atrial fibrillation as documented by an implantable monitoring device: implications for optimal patient care. , 2004, Journal of the American College of Cardiology.

[17]  Martha J. Radford,et al.  Validation of Clinical Classification Schemes for Predicting Stroke: Results From the National Registry of Atrial Fibrillation , 2001 .

[18]  G. Lamas,et al.  Atrial High Rate Episodes Detected by Pacemaker Diagnostics Predict Death and Stroke: Report of the Atrial Diagnostics Ancillary Study of the MOde Selection Trial (MOST) , 2003, Circulation.

[19]  Christopher E Hilker,et al.  Rationale and design of a prospective study of the clinical significance of atrial arrhythmias detected by implanted device diagnostics: The TRENDS study , 2006, Journal of Interventional Cardiac Electrophysiology.

[20]  J. Halperin,et al.  Stroke with intermittent atrial fibrillation: incidence and predictors during aspirin therapy. Stroke Prevention in Atrial Fibrillation Investigators. , 2000, Journal of the American College of Cardiology.