Management of Acute Coronary Syndromes in Patients in Rural Australia

Abstract

Treatment of ST-segment elevation myocardial infarction (STEMI) in rural settings involves thrombolysis followed by transfer to a percutaneous coronary intervention-capable hospital. The first step is accurate diagnosis via electrocardiography (ECG), but one-third of all STEMI incidents go unrecognized and hence untreated. OBJECTIVE To reduce missed diagnoses of STEMI. DESIGN, SETTING, AND PARTICIPANTS This cluster randomized clinical trial included 29 hospital emergency departments (EDs) in rural Australia with no emergency medicine specialists, which were randomized to usual care vs automatically triggered diagnostic support from the tertiary referral hospital (management of rural acute coronary syndromes [MORACS] intervention). Patients presenting with symptoms compatible with acute coronary syndromes (ACS) were eligible for inclusion. The study was conducted from December 2018 to April 2020. Data were analyzed in August 2021.INTERVENTION Triage of a patient with symptoms compatible with ACS triggered an automated notification to the tertiary hospital coronary care unit. The ECG and point-of-care troponin results were reviewed remotely and a phone call was made to the treating physician in the rural hospital to assist with diagnosis and initiation of treatment. MAIN OUTCOMES AND MEASURESThe proportion of patients with missed STEMI diagnoses.RESULTS A total of 6249 patients were included in the study (mean [SD] age, 63.6 [12.2] years; 48% female). Of 7474 ED presentations with suspected ACS, STEMI accounted for 77 (2.0%) in usual care hospitals and 46 (1.3%) in MORACS hospitals. Missed diagnosis of STEMI occurred in 27 of 77 presentations (35%) in usual care hospitals and 0 of 46 (0%) in MORACS hospitals (P < .001). Of eligible patients, 48 of 75 (64%) in the usual care group and 36 of 36 (100%) in the MORACS group received primary reperfusion (P < .001). In the usual care group, 12-month mortality was 10.3% (n = 8) vs 6.5% (n = 3) in the MORACS group (relative risk, 0.64; 95% CI, 0.18-2.23). Patients with missed STEMI diagnoses had a mortality of 25.9% (n = 7) compared with 2.0% (n = 1) for those with accurately diagnosed STEMI (relative risk, 13.2; 95% CI, 1.71-102.00; P = .001). Overall, there were 6 patients who did not have STEMI as a final diagnosis; 5 had takotsubo cardiomyopathy and 1 had pericarditis. There was no difference between groups in the rate of alternative final diagnosis. CONCLUSION AND RELEVANCEThe findings indicate that MORACS diagnostic support service reduced the proportion of missed STEMI and improved the rates of primary reperfusion therapy. Accurate diagnosis of STEMI was associated with lower mortality.

Improving the Detection of ST-Segment Elevation Myocardial Infarction in Rural Settings

“…Dee et al 4 address the question of whether a centralized tertiary-hospital-based decision-support service for patients presenting to rural hospitals with symptoms suggestive of acute coronary syndrome (ACS) might prevent missed STEMI diagnoses. The authors conducted a cluster randomized clinical trial involving 29 hospitals in New South Wales, Australia, whose emergency departments (EDs) had no emergency medicine specialists.…”

“…Further, accurate STEMI diagnosis resulted in higher rates of initiation of primary reperfusion and was associated with lower mortality. 4 The strengths of the study include the cluster randomized methods and the low-cost, easily adaptable, and scalable intervention. Although the study findings are limited by low patient sample sizes in each trial arm and by an apparent imbalance in the number of STEMI patients across the intervention and control hospitals, it highlights an important aspect of rural-urban health care disparity and raises crucial questions regarding how the findings can be translated into policy decisions for the care of acute cardiovascular conditions in the rural setting.…”

“…These 3 approaches are not mutually exclusive and, in practice, successful models should integrate the 3 in a complementary way, as was done in this intervention. 4 Although the study did not collect data to ascertain if recognition of STEMI by rural clinicians improved over time, the education of clinicians within rural hospitals that were randomized to the intervention and the telephone consultations and feedback con-stitute a form of community outreach that may explain the profound nature of the results, and could contribute to sustaining study gains over time.…”

“…Growing gaps in urban-rural cardiovascular inequity suggest that both policy and clinical interventions are needed. The study by Dee et al 4 provides an example of what we might hope to achieve for rural patients with cooperation and coordination across geographies.…”

“…The study demonstrates that a centralized diagnostic support service can significantly reduce the proportion of missed STEMI. Further, accurate STEMI diagnosis resulted in higher rates of initiation of primary reperfusion and was associated with lower mortality . The strengths of the study include the cluster randomized methods and the low-cost, easily adaptable, and scalable intervention.…”