Hypertension predicts major adverse cardiac events after discharge from the emergency department with unspecified chest pain.

Abstract

To investigate the incidence of major adverse cardiac events (MACEs) after discharge from the emergency department (ED) with unspecified chest pain and the predictive value of cardiovascular risk factors included in HEART score. This was a register-based retrospective cohort study including all patients discharged with the diagnosis 'unspecified chest pain' from Swedish EDs between 2006-2013. Diagnosis and drug prescriptions were collected from national registers and the association to the occurrence of MACE was studied with logistic regression and category-free net reclassification improvement (cNRI). Out of 74,329 included patients 619 (0.8%) experienced MACE within 30 days of discharge from the ED. Hypertension (odds ratio (OR) 4.74, 95% confidence interval (CI) 4.02-5.59), diabetes mellitus (3.76, 3.10-4.57), hyperlipidaemia (1.92, 1.51-2.44), and earlier cardiovascular disease (CVD) were all associated with MACE. The addition of hypertension to a risk factor model improved net reclassification (cNRI 53%, 95% CI 29-67%). The variables age (A) (1 point OR 7.01, 95% CI 4.79-10.26, 2 points OR 23.57, 95% CI 16.35-33.97) and risk factors (R) (1 point OR 3.76, 95% CI 3.05-4.63, 2 points OR 10.94, 95% CI 8.96-13.38) in HEART score were both independently associated with MACE with a combination area under the curve (AUC) of 0.8. MACE after discharge with unspecified chest pain is uncommon and associated with a diagnosis of hypertension and other cardiovascular risk factors. Our findings support the use of risk factors in HEART score. The relation between age and MACE was not linear and our data indicates that the lower cut-off value for age in HEART score should be adjusted downwards.