Background: The HEART Pathway combines a History Electrocardiogram Age Risk factor (HEAR) score and serial troponins to risk stratify patients with acute chest pain. However, it is unclear whether patients with HEAR scores of 0-1 require troponin testing. The objective of this study is to measure the major adverse cardiac event (MACE) rate among patients with 0-1 HEAR scores and determine whether serial troponin testing is needed to achieve a miss rate
Methods: A secondary analysis of the HEART Pathway Implementation Study was conducted. HEART Pathway risk assessments (HEAR scores and serial troponin testing at 0 and 3 hours) were completed by providers on adult patients with chest pain from three US sites between 11/2014 and 1/2016. MACE (the composite of cardiac death, myocardial infarction (MI) and coronary revascularization) at 30 days was determined by health records, insurance claims, and death index. The proportion of patients with HEAR scores of 0-1 diagnosed with MACE within 30 days was calculated. The impact of troponin testing on patients with HEAR scores of 0-1 was determined using net reclassification.
Results: During the study period, providers completed HEART Pathway assessments on 4986 patients. HEAR scores of 0-1 occurred in 9.0% (448/4986) of patients with 1.6% (82/4986) and 7.3% (366/4986) of patients scored as 0 and 1, respectively. Among these patients, MACE at 30 days occurred in 0.4% (2/448; 95%CI 0.1-1.6%) with 0 cardiac deaths, 2 MIs, and 0 revascularizations. In patients with a HEAR score of 0, the MACE rate was 0% (0/82; 95%CI 0-4.4%) while 0.5% (2/366; 95%CI 0.1-2.0%) of patients with a HEAR score of 1 had MACE. The 2 patients with MI both had chest pain in the setting of cocaine use and neither required revascularization during their hospitalizations. No patients with a HEAR score of 0 had elevated troponin testing while 9 patients with HEAR scores of 1 had elevated troponin measures. The addition of troponin testing to patients with HEAR 0-1 correctly reclassified the 2 patients diagnosed with MI but was also elevated among 7 patients without MACE, yielding a net reclassification index of 0.3% (95%CI 0.2-0.5%).
Conclusion: These data suggest that patients with HEAR scores of 0 and 1 represent a very-low-risk cohort. In this very-low-risk group, troponin testing was not needed in order to achieve a low missed MACE rate.