Jamie G Cooper1, James Ferguson2, Lorna A Donaldson3, Kim M M Black4, Kate J Livock4, Judith L Horrill4, Elaine M Davidson5, Neil W Scott6, Amanda J Lee6, Takeshi Fujisawa7, Kuan Ken Lee8, Atul Anand8, Anoop S V Shah9, Nicholas L Mills10. 1. Emergency Department, Aberdeen Royal Infirmary, Aberdeen, United Kingdom; Department of Applied Medicine, University of Aberdeen, Aberdeen, United Kingdom. Electronic address: jamie.cooper2@nhs.scot. 2. Emergency Department, Aberdeen Royal Infirmary, Aberdeen, United Kingdom; Department of Applied Medicine, University of Aberdeen, Aberdeen, United Kingdom. 3. Scottish Ambulance Service, Gyle Square, Edinburgh, United Kingdom. 4. Emergency Department, Aberdeen Royal Infirmary, Aberdeen, United Kingdom. 5. Department of Clinical Biochemistry, Aberdeen Royal Infirmary, Aberdeen, United Kingdom. 6. Medical Statistics Team, University of Aberdeen, Aberdeen, United Kingdom. 7. BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom; BHF Cardiovascular Biomarker Laboratory, University of Edinburgh, Edinburgh, United Kingdom. 8. BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom. 9. BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom; Usher Institute, University of Edinburgh, Edinburgh, United Kingdom. 10. BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom; BHF Cardiovascular Biomarker Laboratory, University of Edinburgh, Edinburgh, United Kingdom; Usher Institute, University of Edinburgh, Edinburgh, United Kingdom.
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.
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.