PRESENTING to a hospital with a catheterisation laboratory can make the difference between life and death for patients with acute coronary syndrome, new Australian research shows.
The study in today’s MJA
was based on a prospective audit of the care provided to consecutive patients with suspected acute coronary syndrome (ACS) admitted to 478 Australian and New Zealand hospitals during a 2-week period in May 2012. (1)
Electronic case reports were used for 4387 patients to collect comprehensive historical and clinical data, including provision of invasive management, medications and in-hospital outcomes.
More than half of patients presented to catheterisation-capable hospitals. These patients were 21% less likely to die within 18 months of hospital presentation compared with those presenting to non-catheterisation-capable hospitals, the study found.
Modelling suggested this difference was largely due to higher rates of timely reperfusion for ST elevation myocardial infarction (STEMI) at catheterisation-capable hospitals, and higher rates of coronary angiography for intermediate to high risk ACS patients.
However, the study authors noted that even at catheterisation-capable hospitals, the proportion of patients who received reperfusion (65.6%) was “less than optimal”.
“Rates of angiography at catheterisation-capable hospitals, transfer rates from non-catheterisation-capable hospitals and access to rehabilitation in all hospitals should be further improved”, they wrote.
The authors estimated that if half of the patients who currently did not receive angiography and secondary prevention strategies including rehabilitation were treated, the annual mortality attributable to ACS in Australia and New Zealand would fall by 11%.
Professor Richard Harper, emeritus director of cardiology at Monash Medical Centre, said the mortality rates in the present study were unexpectedly high — 16.2% for STEMI, 16.3% for non-STEMI and 6.8% for unstable angina.
He noted that an earlier study by the same group involving 24 metropolitan and 15 non-metropolitan Australian hospitals found corresponding 12-month mortality rates of just 8%, 10.5% and 3.3% in 2005‒2007. (2)
“The fact that mortality rates in the current study, which involved many more hospitals, were higher than in the earlier study suggests to me that there must be wide variation in the management of ACS across Australia and that many patients are not getting ideal treatment”, Professor Harper told MJA InSight.
The latest study also showed a lower rate of angiography in 2012 compared with 2005‒2007, he said.
“The message about the importance of early angiography doesn’t seem to be percolating.”
Professor Harper said the latest study strongly supported the policy of ambulances transferring patients with electrocardiographically confirmed ACS or those with a high index of suspicion of ACS to the nearest catheterisation-capable hospital wherever possible.
“If a patient initially ends up at a non-catheterisation capable hospital this study suggests they should be transferred as soon as possible”, he said.
Study coauthor Professor David Brieger, head of coronary care and coronary interventions at Concord Hospital, Sydney, told MJA InSight the latest findings provided a more realistic picture of the current standard of ACS care in Australia than the earlier study, as it included many smaller regional and remote hospitals while the earlier study included only relatively well resourced larger hospitals.
Professor Brieger said the new study emphasised the benefits of invasive therapy, consistent with a retrospective cohort study published last week in the Annals of Internal Medicine
That study, based on nearly 20 000 patients with a first hospitalisation for ACS, found that early invasive treatment of patients reduced the risk of cardiac death compared with conservative invasive management, particularly in patients aged 75 years and older. It also found that an early invasive strategy was most effective in patients admitted directly to an invasive heart centre.
Professor Brieger said a major reason Australian patients inappropriately missed out on early angiography was the “tyranny of distance”, including the difficulties and expense associated with transferring patients to hospitals with angiographic facilities.
Another factor was clinician reluctance to send patients for an invasive procedure because they might “fear the complications of the procedure rather than realising the benefits”, he said.
The MJA study also made an unexpected finding that prescription of antiplatelet and lipid-lowering therapy was not predictive of improved outcomes.
However, Professor Harper said this finding was at odds with the results of many other studies and should not lessen the importance of ensuring all patients receive appropriate anti-atherosclerotic therapy following an ACS event.
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