Multiscale Entropy of the Heart Rate Variability for the Prediction of an Ischemic Stroke in Patients with Permanent Atrial Fibrillation.
BACKGROUND
Atrial fibrillation (AF) is a significant risk factor for ischemic strokes, and making a robust risk stratification scheme would be important. Few studies have examined whether nonlinear dynamics of the heart rate could predict ischemic strokes in AF. We examined whether a novel complexity measurement of the heart rate variability called multiscale entropy (MSE) was a useful risk stratification measure of ischemic strokes in patients with permanent AF.


RESULTS
We examined 173 consecutive patients (age 69 ± 11 years) with permanent AF who underwent 24-hour Holter electrocardiography from April 2005 to December 2006. We assessed several frequency ranges of the MSE and CHA2DS2-VASc score (1 point for congestive heart failure, hypertension, diabetes, vascular disease, an age 65 to 74 years, and a female sex and 2 points for an age ≥ 75 years and a stroke or transient ischemic attack). We found 22 (13%) incident ischemic strokes during a mean follow up of 3.8-years. The average value of the MSE in the very-low frequency subrange (90-300 s, MeanEnVLF2) was significantly higher in patients who developed ischemic strokes than in those who did not (0.68 ± 0.15 vs. 0.60±0.14, P<0.01). There was no significant difference in the C-statistic between the CHA2DS2-VASc score and MeanEnVLF2 (0.56; 95% confidence interval, 0.43-0.69 vs. 0.66; 95% confidence interval, 0.53-0.79). After an adjustment for the age, CHA2DS2-VASc score, and antithrombotic agent, a Cox hazard regression model revealed that the MeanEnVLF2 was an independent predictor of an ischemic stroke (hazard ratio per 1-SD increment, 1.80; 95% confidence interval, 1.17-2.07, P<0.01).


CONCLUSIONS
The MeanEnVLF2 in 24-hour Holter electrocardiography is a useful risk stratification measure of ischemic strokes during the long-term follow-up in patients with permanent AF.
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Eiichi
E
Watanabe
Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan.
Ken
K
Kiyono
Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Junichiro
J
Hayano
Educational Physiology Laboratory, Graduate School of Education, University of Tokyo, Tokyo, Japan.
Yoshiharu
Y
Yamamoto
Department of Neurosurgery, Fujita Health University School of Medicine, Toyoake, Japan.
Joji
J
Inamasu
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Mayumi
M
Yamamoto
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Tomohide
T
Ichikawa
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Yoshihiro
Y
Sobue
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Masehide
M
Harada
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Yukio
Y
Ozaki
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation; D003920:Diabetes Mellitus / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory / Q000379:methods; D019277:Entropy; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D002546:Ischemic Attack, Transient / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology* / Q000503:physiopathology*