Abstract
STUDY OBJECTIVE: To determine whether risk stratification in the out-of-hospital setting could identify patients with chest pain who are at low and high risk to avoid admission or aid direct transfer to cardiac centers.
METHODS: Paramedics prospectively enrolled patients with suspected acute coronary syndrome without diagnostic ST-segment elevation on the ECG. The History, ECG, Age and Risk Factors (HEAR) score was recorded contemporaneously, and out-of-hospital samples were obtained to measure cardiac Troponin I (cTnI) level on a point-of-care device, to allow calculation of the History, ECG, Age, Risk Factors, and Troponin (HEART) score. HEAR and HEART scores less than or equal to 3 and greater than or equal to 7 were defined as low and high risk for major adverse cardiac events at 30 days.
RESULTS: Of 1,054 patients (64 years [SD 15 years]; 42% women), 284 (27%) experienced a major adverse cardiac event at 30 days. The HEAR score was calculated in all patients, with point-of-care cTnI testing available in 357 (34%). A HEAR score less than or equal to 3 identified 32% of patients (334/1,054) as low risk, with a sensitivity of 84.9% (95% confidence interval [CI] 80.7% to 89%), whereas a score greater than or equal to 7 identified just 3% of patients (30/1,054) as high risk, with a specificity of 98.7% (95% CI 97.9% to 99.5%). A point-of-care HEART score less than or equal to 3 identified a similar proportion as low risk (30%), with a sensitivity of 87.0% (95% CI 80.7% to 93.4%), whereas a score greater than or equal to 7 identified 14% as high risk, with a specificity of 94.8% (95% CI 92.0% to 97.5%).
CONCLUSION: Paramedics can use the HEAR score to discriminate risk, but even when used in combination with out-of-hospital point-of-care cTnI testing, the HEART score does not safely rule out major adverse cardiac events, and only a small proportion of patients are identified as high risk.
| Original language | English |
|---|---|
| Pages (from-to) | 575-588 |
| Number of pages | 14 |
| Journal | Annals of Emergency Medicine |
| Volume | 77 |
| Issue number | 6 |
| Early online date | 27 Apr 2021 |
| DOIs | |
| Publication status | Published - Jun 2021 |
Bibliographical note
The authors acknowledge the invaluable contribution of all the participating Scottish Ambulance Service paramedics and technicians and the support of the regional and national Scottish Ambulance Service managerial structures; the involvement of numerous medical, nursing, reception, and portering staff within the Emergency Department of Aberdeen Royal Infirmary; and the assistance of Gary Robinson, Chaloner Chute, and Susan Scotland from the DHI.Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article as per ICMJE conflict of interest guidelines (see www.icmje.org). The authors have stated that no such relationships exist. The study was supported financially by the Digital Health & Care Institute (DHI), Scotland and by the National Health Service Grampian Endowment Fund. Samsung provided the point-of-care devices and test discs and the University of Aberdeen contributed to the design and administration of the study. Dr. Cooper was supported by a National Research Scotland Clinical Research Fellowship . Prof. Mills and Dr. Lee are supported by the British Heart Foundation through the Butler Senior Clinical Research Fellowship ( FS/16/14/32023 ) and a Clinical Research Training Fellowship ( FS/18/25/33454 ), respectively.
Trial registration number: UIN 2671