Pre-hospital risk assessment in suspected non-ST-elevation acute coronary syndrome: A prospective observational study

Background:Pre-hospital risk stratification of non-ST-elevation acute coronary syndrome (NSTE-ACS) by the complete HEART score has not yet been assessed. We investigated whether pre-hospital risk stratification of patients with suspected NSTE-ACS using the HEART score is accurate in predicting major adverse cardiac events (MACE).Methods:This is a prospective observational study, including 700 patients with suspected NSTE-ACS. Risk stratification was performed by ambulance paramedics, using the HEART score; low risk was defined as HEART score <= 3. Primary endpoint was occurrence of MACE within 45 days after inclusion. Secondary endpoint was myocardial infarction or death.Results:A total of 172 patients (24.6%) were stratified as low risk and 528 patients (75.4%) as intermediate to high risk. Mean age was 53.9 years in the low risk group and 66.7 years in the intermediate to high risk group (p<0.001), 50% were male in the low risk group versus 60% in the intermediate to high risk group (p=0.026). MACE occurred in five patients in the low risk group (2.9%) and in 111 (21.0%) patients at intermediate or high risk (p