ABSTRACT
Background
Post-stroke autonomic nervous dysfunction measured with heart rate variability (HRV) is correlated with the traditional risk factors and poor outcome. This study aimed to investigate the association between HRV and infarct locations, etiology subtypes, and neurological functional outcomes in patients with acute ischemic stroke (AIS).
Methods
In this prospective observational study, 186 consecutive patients were assigned to four major stroke severity categories based on the National Institutes of Health Stroke Scale score (NIHSS) and the modified Rankin Scale score (mRS): mild (NIHSS 0–4) stroke, moderate (NIHSS 5–14) stroke, ‘favorable’ (mRS 0–2) group, and ‘unfavorable’ (mRS 3–5) group. HRV time domain parameters were applied to evaluate the autonomic function of patients within 1 week after admission. All patients were classified into different etiology subtypes based on the TOAST (modified Trial of ORG 10172 in Acute Stroke Treatment) classification. The association of HRV with stroke location, etiology subtypes, neurological outcome was explored for all participants. Univariate and multivariate analyses were applied to explore the prediction value of HRV.
Results
160 participants had large artery atherosclerotic infarction (LAA), 61 had right internal carotid artery system infarction (R-ICA), and 61 had vertebrobasilar artery system infarction (VB). Root-mean-square of differences (RMSSD) of adjacent RR intervals and the proportion calculated by dividing the interbeat interval differences >50 ms (pNN50) in patients of VB group was significantly lower than those of patients in R-ICA group (P < 0.01). HRV parameters in the LAA group was significantly lower than non-LAA group (P < 0.01). At discharge, significant lower HRV presented in the unfavorable group and moderate group (P < 0.05). After logistic univariate and multivariate analysis, lower SDNN (OR = 1.019; 95% CI = 1.003–1.035; p= 0.021) was independently associated with unfavorable mRS and higher NIHSS at discharge (OR = 1.013; 95%CI = 1.003–1.024; p= 0.015). Only SDNN showed predictive value for mRS≥3 (OR = 1.012; 95%CI = 1.002–1.022; p= 0.016) at 1 year.
Conclusions
HRV measured after admission is related to the AIS infarction basin, TOAST subtypes, and neurological outcomes at discharge suggesting a possible role for HRV in evaluating AIS and identifying high-risk patients.
Acknowledgments
We thank our colleagues on Dr Wang’s research team and physicians in the Department of Neurology in Beijing Tiantan Hospital. MZ was responsible for writing the manuscript. LG conceived of the study design and provided critical review of the manuscript. JP C provided critical review of the manuscript. YW conceived of the study design and provided critical review of the manuscript. All authors approved the final version of the manuscript. We also thank all the patients and their families involved.
Disclosure statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Statement of ethics
All participants (or their legal representative) have given their written informed consent. The protocol was approved by the Ethics Committee of the participating hospital.
Additional information
Funding
Notes on contributors
Mengxi Zhao
Mengxi Zhao, a post-graduate of Capital Medical University, is now undertaking clinical practice and research in Beijing Tiantan Hospital directed by Dr. Yilong Wang.
Ling Guan
Ling Guan is currently the Committee Member in Cerebral Small Vessel Disease Professional Committee of Beijing Neurology Association researching on Autonomic Nervous System and stress, ischemic stroke, and neurocardiology.
Jean-Paul Collet
Jean-Paul Collet is the professor, senior scientist of University of British Columbia, mainly focuses on Autonomic Nervous System and stress research, cognitive research and brain science.
Yilong Wang
Yilong Wang is the director of science and technology department of Beijing Tiantan Hospital Affiliated to Capital Medical University, mainly researches on ischemic cerebrovascular disease and cerebral small vessel disease.