Referral patterns of patients presenting with chest pain at two rural emergency departments in Western Australia.

Introduction: Coronary heart disease is the largest single cause of death in Australia. In Western Australia invasive diagnostics and therapies for acute coronary syndromes are only provided in the metropolitan hospitals of Perth. Patients in rural hospitals who need invasive cardiac care have to be transferred to Perth. The aim of our research was to determine which patient factors are associated with referral to advanced cardiac care at metropolitan level and how this compares to Australian guidelines for the management of acute coronary syndromes.

Method: Data was collected from patients presenting with chest pain to the rural emergency department, who were at least 18 years old and had given their consent. Exclusion criteria were chest pain accompanied or precipitated by significant co morbidity and prior enrolment in this study protocol. Socioeconomic and medical information of patients was collected from their medical records. Data was analysed using chi(2) tests, independent sample t-tests and multivariable logistic-regression models (stepwise backwards procedure).

Results: The study included 115 rural patients with chest pain with a mean age of 58 years: 66 (57%) men, 12 (10%) indigenous Australians and 38 (33%) transferred patients. Of all transferred patients 19 (50%) had a positive peak troponin-T, 13 (36%) a high peak creatine kinase (CK) and 12 (32%) persistent ST-elevation on their electrocardiogram, compared with 10 (14%), 12 (17%) and 11 (14%) respectively for non-transferred patients. Chi-square-tests showed significant differences between transfer groups in all three essential initial cardiac investigations and known dyslipidaemia. In multivariate analyses the positive peak troponin-T increased odds of transfer (OR6.40; 95% CI 2.55-16.08). This effect increased after adjustment for gender, serum creatinine and known dyslipidaemia (OR27.61; 95% CI 6.41-119.04). When adjusted for the peak troponin-T, neither ECG with persistent ST-elevation nor high peak CK remained significant. Known dyslipidaemia remained significant and serum creatinine became significant. Gender became significant when adjusted for troponin-T, known dyslipidaemia and serum creatinine.

Conclusions: Peak troponin-T is an independent determinant associated with the transfer to advanced care at metropolitan level, but ECG with persistent ST-elevation and peak CK (other essential initial cardiac investigations) are not. Further investigation of the available and provided cardiac care in rural Western Australia is required.