Abstract 214: Determinants of Cardiac Rehabilitation Referral Following Acute Myocardial Infarction In Australia

Background: Despite the known benefits of cardiac rehabilitation (CR) and widespread endorsement of its use, CR is vastly underutilised, with less than 30% of eligible patients participating in a CR program after a cardiac event. The current study assessed the factors independently associated with referral to CR following acute myocardial infarction (AMI). Methods: The CR referral rate and factors associated with referral were assessed among all consecutive patients undergoing coronary angiography for AMI and surviving to hospital discharge, attending South Australian public hospitals from January 2012 [[Unable to Display Character: &#8211;]] December 2013. Data was maintained by the Coronary Angiogram Database of South Australia (CADOSA), a comprehensive registry compatible with the NCDR ® CathPCI ® Registry. Results: Among 3,212 patients undergoing angiography for AMI, CR referral occurred in 1,530 patients (48%). Compared to patients without CR referral, these patients were younger (62±13 vs. 64±14, p<0.01) and less likely to be female (25% vs. 34%, p<0.01). Following age-adjusted analysis, the cardiovascular risk factors were similar between CR referral and non-CR referral patients including: diabetes (29% vs. 30%, p>0.5), hypertension (61% vs. 64%, p>0.5), and dyslipidaemia (59% vs. 60%, p>0.5), but CR referral patients were more likely to be active smokers (40% vs. 33%, p<0.01). CR referral patients were less likely to have additional comorbidities including current dialysis (0.9% vs. 2.2%, p<0.01) and cerebrovascular disease (6.0% vs. 8.8%, p<0.01). In multivariable analyses, factors associated with increased CR referral were (c statistic 0.68): presentation with ST-elevation MI (STEMI) (1.4, 1.2-1.7, p<0.01), undergoing percutaneous coronary intervention (PCI) following angiography (1.6, 1.4-1.9, p<0.01) and younger age (1.0, 0.98-1.0, p<0.01). Prior CABG (0.6, 0.5-0.8, p<0.01) and absence of significant coronary artery disease, defined by stenosis <50%, (0.2, 0.1-0.3, p<0.01) were associated with decreased referral. Lastly, secondary prevention therapies were more often prescribed at discharge in patients with CR referral compared to patients without referral including: aspirin (93% vs. 82%, p<0.01), beta-blockers (64% vs. 61%, p<0.05), statin (92% vs. 78%, p<0.01), and ACE-inhibitor/angiotensin receptor blocker (84% vs. 74%, p<0.01). Conclusion: This study highlights a significant disparity in cardiovascular care with approximately half of AMI patients not referred to CR, despite it being a key performance measure. STEMI presentation, younger age and undergoing PCI are associated with increased referral. Alarmingly, AMI patients not referred to CR are also less likely to receive other guideline-based therapies. Increased physician awareness about the benefits of CR is required and initiatives to overcome barriers to referral may improve the delivery of evidence-based care.