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Heart rate fragmentation and brain MRI markers of small vessel disease in MESA
Susan R Heckbert1,2, Paul N Jensen1,3, Guray Erus4
1Cardiovascular Health Research Unit, University of Washington, Seattle, Washington, USA.
Insights
Heart rate fragmentation, a measure of heart rate regulation, is linked to small vessel disease in the brain. This finding suggests its potential as a biomarker for vascular brain injury.
Area of Science:
- Cardiology
- Neurology
- Medical Imaging
Background:
- Heart rate (HR) fragmentation indices assess HR regulation breakdown, linked to atrial fibrillation and cognitive impairment.
- The association between HR fragmentation and brain magnetic resonance imaging (MRI) markers of small vessel disease remains unexplored.
Purpose of the Study:
- To investigate the relationship between HR fragmentation indices and brain imaging markers of small vessel disease.
Main Methods:
- Analysis of 606 stroke-free participants from the Multi-Ethnic Study of Atherosclerosis (mean age 67).
- Derivation of HR fragmentation indices, including percentage of inflection points (PIP), from sleep study recordings.
- Examination of PIP in relation to white matter hyperintensity (WMH) volume, white matter fractional anisotropy (FA), and microbleeds using 3-Tesla brain MRI data collected 7 years later.
Main Results:
- Higher PIP was significantly associated with greater WMH volume (14% increase per SD, P=0.02).
- Higher PIP was significantly associated with lower white matter FA (-0.09 SD per SD, P=0.03).
Conclusions:
- HR fragmentation is associated with markers of small vessel disease in the brain.
- Automatic measurement of HR fragmentation from ambulatory electrocardiogram devices may serve as a valuable biomarker for vascular brain injury.
Introduction:
Heart rate (HR) fragmentation indices quantify breakdown of HR regulation and are associated with atrial fibrillation and cognitive impairment. Their association with brain magnetic resonance imaging (MRI) markers of small vessel disease is unexplored.
Methods:
In 606 stroke-free participants of the Multi-Ethnic Study of Atherosclerosis (mean age 67), HR fragmentation indices including percentage of inflection points (PIP) were derived from sleep study recordings. We examined PIP in relation to white matter hyperintensity (WMH) volume, total white matter fractional anisotropy (FA), and microbleeds from 3-Tesla brain MRI completed 7 years later.
Results:
In adjusted analyses, higher PIP was associated with greater WMH volume (14% per standard deviation [SD], 95% confidence interval [CI]: 2, 27%, P = 0.02) and lower WM FA (-0.09 SD per SD, 95% CI: -0.16, -0.01, P = 0.03).
Discussion:
HR fragmentation was associated with small vessel disease. HR fragmentation can be measured automatically from ambulatory electrocardiogram devices and may be useful as a biomarker of vascular brain injury.
