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38 Heart rate variability and pre-hospital risk stratification of chest pain patients
  1. Chu En Ting1,
  2. Nan Liu2,3,
  3. Zhi Xiong Koh4,
  4. Dagang Guo4,
  5. Janson Cheng Ji NG4,
  6. Swee Han Lim4,
  7. Marcus Eng Hock Ong4,5
  1. 1Duke-NUS Medical School, Singapore
  2. 2Health Services Research Centre, Singapore Health Services, Singapore
  3. 3Centre of Quantitative Medicine, Duke-NUS Medical School, Singapore
  4. 4Department of Emergency Medicine, Singapore General Hospital, Singapore
  5. 5Health Services and Systems Research, Duke-NUS Medical School, Singapore


Aim Assessment of chest pain patients often requires extensive investigations, while existing risk-scores are designed for use in Emergency Departments (ED). We aim to develop a risk score for chest pain patients in pre-hospital settings and ambulances by utilising heart rate variability (HRV), a rapid, non-invasive reflection of cardiac stress states.

Method This study analysed 902 chest pain cases presenting to Singapore General Hospital (SGH) ED between 2010 and 2015. The data was divided into a model derivation set (616 cases, 32% meeting outcomes) and a validation set (286 cases, 28.7% meeting outcomes). HRV Prediction Model (HRV-PM) for 30 day Major Adverse Cardiac Events (MACE) was derived using backward-stepwise logistic regression. HEART, TIMI and GRACE scores were used as comparators for the HRV-PM.

Results In the derivation set, 66.9% of patients were male, with a mean (SD) age of 60.71 (12.97). HRV-PM encompasses 9 parameters: 6 HRV variables (triangular interpolation of normal-to-normal intervals, total power, very-low/low/high-frequency power, approximate entropy), and 3 ECG variables (ST-elevation, ST-depression, Q-wave). Validation of HRV-PM shows similar performance to HEART for 30 day MACE prediction with Area Under Receiver-Operating-Curve (AUC) of 0.737 (95% CI: 0.673 to 0.800) versus 0.739 (95% CI: 0.679 to 0.799). The addition of 1 set of troponin results in HRV-PM improves the AUC to 0.749 (95% CI: 0.686 to 0.813), thereby outperforming HEART.

Conclusion HRV-PM is a simple, non-invasive test demonstrating comparable performance with HEART without need of blood-tests. We hope to validate and apply HRV-PM for assessment of chest pain patients by EMS in pre-hospital settings including ambulances.

Conflict of interest None

Funding None

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