Relationship between combat-related traumatic injury and ultrashort term heart rate variability in a UK military cohort: findings from the ADVANCE study

Rabeea Maqsood; S Schofield; A N Bennett; A Mj Bull; N T Fear; P Cullinan; A Khattab; C J Boos; ADVANCE study

doi:10.1136/military-2022-002316

Relationship between combat-related traumatic injury and ultrashort term heart rate variability in a UK military cohort: findings from the ADVANCE study

BMJ Mil Health. 2023 Mar 29:e002316. doi: 10.1136/military-2022-002316. Online ahead of print.

Authors

Rabeea Maqsood^{1

2}, S Schofield², A N Bennett^{2

3}, A Mj Bull⁴, N T Fear⁵, P Cullinan², A Khattab⁶, C J Boos^{6

7}; ADVANCE study

Affiliations

¹ Department of Medical Sciences and Public Health, Faculty of Health and Social Sciences, Bournemouth University, Bournemouth, UK rmaqsood@bournemouth.ac.uk.
² National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
³ Academic Department of Military Rehabilitation, Defence Medical Rehabilitation Centre, Loughborough, UK.
⁴ Centre for Blast Injury Studies, Department of Bioengineering, Imperial College London, London, UK.
⁵ Academic Department of Military Mental Health, King's College London, London, UK.
⁶ Department of Medical Sciences and Public Health, Faculty of Health and Social Sciences, Bournemouth University, Bournemouth, UK.
⁷ Department of Cardiology, University Hospitals Dorset NHS Foundation Trust, Poole, UK.

PMID: 36990509
DOI: 10.1136/military-2022-002316

Abstract

Introduction: Combat-related traumatic injury (CRTI) has been linked to an increased cardiovascular disease (CVD) risk. The long-term impact of CRTI on heart rate variability (HRV)-a robust CVD risk marker-has not been explored. This study investigated the relationship between CRTI, the mechanism of injury and injury severity on HRV.

Methods: This was an analysis of baseline data from the ArmeD SerVices TrAuma and RehabilitatioN OutComE (ADVANCE) prospective cohort study. The sample consisted of UK servicemen with CRTI sustained during deployment (Afghanistan, 2003-2014) and an uninjured comparison group who were frequency matched to the injured group based on age, rank, deployment period and role in theatre. Root mean square of successive differences (RMSSD) was measured as a measure of ultrashort term HRV via <16 s continuous recording of the femoral arterial pulse waveform signal (Vicorder). Other measures included injury severity (New Injury Severity Scores (NISS)) and injury mechanism.

Results: Overall, 862 participants aged 33.9±5.4 years were included, of whom 428 (49.6%) were injured and 434 (50.3%) were uninjured. The mean time from injury/deployment to assessment was 7.91±2.05 years. The median (IQR) NISS for those injured was 12 (6-27) with blast being the predominant injury mechanism (76.8%). The median (IQR) RMSSD was significantly lower in the injured versus the uninjured (39.47 ms (27.77-59.77) vs 46.22 ms (31.14-67.84), p<0.001). Using multiple linear regression (adjusting for age, rank, ethnicity and time from injury), geometric mean ratio (GMR) was reported. CRTI was associated with a 13% lower RMSSD versus the uninjured group (GMR 0.87, 95% CI 0.80-0.94, p<0.001). A higher injury severity (NISS ≥25) (GMR 0.78, 95% CI 0.69-0.89, p<0.001) and blast injury (GMR 0.86, 95% CI 0.79-0.93, p<0.001) were also independently associated with lower RMSSD.

Conclusion: These results suggest an inverse association between CRTI, higher severity and blast injury with HRV. Longitudinal studies and examination of potential mediating factors in this CRTI-HRV relationship are needed.

Keywords: cardiology; public health; trauma management.