on December 2, 2008
Published online before print December 2, 2008, doi: 10.1161/CIRCEP.108.795351
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Original Article |
Incidence of Atrial Fibrillation in Relation to Changing Heart Rate Over Time in Hypertensive Patients: The LIFE Study
1 Weill Cornell Medical College, New York, NY;
2 The Heart Center, Rigshospitalet, Copenhagen, Denmark;
3 University of Oslo, Ullevål Hospital, Oslo, Norway; University of Michigan, Ann Arbor, MI;
4 University of Michigan, Ann Arbor, MI;
5 Umeå University, Umeå, Sweden;
6 Sahlgrenska University Hospital/Östra, Göteborg, Sweden;
7 Merck Research Labs, West Point, PA;
8 Helsinki University Central Hospital, Helsinki, Finland;
9 Merck & Co., Inc., North Wales, PA
10 E-mail: pokin{at}med.cornell.edu
Background—Onset of atrial fibrillation (AF) has been linked to changes in autonomic tone, with increasing heart rate (HR) immediately prior to AF onset in some patients suggesting a possible role of acute increases in sympathetic activity in AF onset. Although losartan therapy and decreasing ECG left ventricular hypertrophy (LVH) are associated with decreased AF incidence, the relationship of HR changes over time to development of AF has not been examined.
Methods and Results—HR was evaluated in 8,828 hypertensive patients without AF by history or on baseline ECG in the LIFE Study. Patients were treated with losartan- or atenolol-based regimens and followed with serial ECGs annually which were used to determine HR and ECG LVH by Cornell product and Sokolow-Lyon voltage criteria. During mean follow-up of 4.7±1.1 years, new-onset AF occurred in 701 patients (7.9%). Patients with new AF had smaller decreases in HR to last in-treatment ECG or last ECG prior to AF (-2.7±13.5 vs -5.2±12.5 bpm), whether on losartan- (-0.4±13.5 vs -2.2±11.7 bpm) or atenolol-based treatment (-5.3±12.8 vs -8.3±12.6 bpm, all p<0.001). In univariate Cox analyses, higher HR on in-treatment ECGs was associated with an increased risk of new-onset AF, with a 15% greater risk of AF for every 10 bpm higher HR (95% CI 8-22%). In alternative analyses, persistence or development of a HR
84 (upper quintile of baseline HR) was associated with a 46% greater risk of developing AF (95% CI 19-80%). After adjusting for treatment with losartan vs atenolol, baseline risk factors for AF, baseline and in-treatment systolic and diastolic pressure and the known predictive value of baseline and in-treatment ECG LVH for new AF, higher in-treatment HR remained strongly associated with new AF with a 19% higher risk for every 10 bpm higher HR (95% CI 10-28%) or a 61% increased rate of AF in patients with persistence or development of a HR84 (95% CI 27-104%, all p<0.001).
Conclusion—Higher in-treatment HR on serial ECGs is associated with an increased likelihood of new-onset AF, independent of treatment modality, blood pressure lowering and regression of ECG LVH in patients with essential hypertension.
Key Words: electrocardiography • fibrillation • heart rate • hypertension • hypertrophy
Related Articles
Circ Arrhythm Electrophysiol 2008 1: 321-323.
Circ Arrhythm Electrophysiol 2008 1: 344-353.
Circ Arrhythm Electrophysiol 2008 1: 327-336.
This article has been cited by other articles:
 |
|
 |
|
  R. Gopinathannair, R. M. Sullivan, and B. Olshansky Slower Heart Rates for Healthy Hearts: Time to Redefine Tachycardia? Circ Arrhythm Electrophysiol, December 1, 2008; 1(5): 321 - 323. [Full Text] [PDF]
|
|