Impact of a regionalised clinical cardiac support network on mortality among rural patients with myocardial infarction

Abstract

OBJECTIVE: To evaluate the impact of the regionalised Integrated Cardiovascular Clinical Network (ICCNet) on 30-day mortality among patients with myocardial infarction (MI) in an Australian rural setting. DESIGN, SETTING AND PATIENTS: An integrated cardiac support network incorporating standardised risk stratification, point-of-care troponin testing and cardiologist-supported decision making was progressively implemented in non-metropolitan areas of South Australia from 2001 to 2008. Hospital administrative data and statewide death records from 1 July 2001 to 30 June 2010 were used to evaluate outcomes for patients diagnosed with MI in rural and metropolitan hospitals. MAIN OUTCOME MEASURE: Risk-adjusted 30-day mortality. RESULTS: 29 623 independent contiguous episodes of MI were identified. The mean predicted 30-day mortality was lower among rural patients compared with metropolitan patients, while actual mortality rates were higher (30-day mortality: rural, 705/5630 [12.52%] v metropolitan, 2140/23 993 [8.92%]; adjusted odds ratio [OR], 1.46; 95% CI, 1.33-1.60; P< 0.001). After adjustment for temporal improvement in MI outcome, availability of immediate cardiac support was associated with a 22% relative odds reduction in 30-day mortality (OR, 0.78; 95% CI, 0.65-0.93; P= 0.007). A strong association between network support and transfer of patients to metropolitan hospitals was observed (before ICCNet, 1102/2419 [45.56%] v after ICCNet, 2100/3211 [65.4%]; P< 0.001), with lower mortality observed among transferred patients. CONCLUSION: Cardiologist-supported remote risk stratification, management and facilitated access to tertiary hospital-based early invasive management are associated with an improvement in 30-day mortality for patients who initially present to rural hospitals and are diagnosed with MI. These interventions closed the gap in mortality between rural and metropolitan patients in South Australia.