Editorials
Cardiovascular diseases
Volume 214 - Issue 11

A good report card, but there is room for improving care for patients with myocardial infarction

Author:  John K French

Med J Aust 2021; 214 (11): 512-513. || doi: 10.5694/mja2.51110
Published online: 21 June 2021

Improving systems of care can achieve earlier treatment and increase survival

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Improving systems of care can achieve earlier treatment and increase survival

The report by Nadlacki and colleagues1 on long term outcomes for patients after myocardial infarction provides much needed clarity about progress in care in Australia and New Zealand during 2009‒2015. The next step, well overdue, is a prospective, comprehensive registry based on the current universal definition of myocardial infarction,2 rather than on information derived from administrative data using International Classification of Diseases (ICD) codes. The major advances in terms of technology, pharmacology, and patterns of care for people with myocardial infarction in Australia and New Zealand should not lead to complacency; improvements are still required, at both the systems and local levels, to achieve good quality care for all. For this we need outcomes data for unselected patients with myocardial infarction, as has been collected in New Zealand for almost a decade (ANZACS‐QI)3 and in Sweden for more than two decades (the SWEDEHEART registry).4

There are key differences between ICD diagnosis codes and the universal definition of myocardial infarction, which includes four diagnosis categories: type 1 myocardial infarction, type 2 myocardial infarction (usually non‐ST elevation myocardial infarction, NSTEMI), acute myocardial injury, and chronic myocardial injury.2 The proportions of patients with NSTEMI in the analysis by Nadlacki and colleagues1 (73% of their study population) who had conditions in the latter three diagnostic categories is unknown. This information is important for assessing survival, as late survival rates for people with type 2 myocardial infarction, acute myocardial injury, and chronic myocardial injury are generally lower than for those with type 1 myocardial infarction (STEMI or NSTEMI).5 Whether routine angiography increases survival for people with type 2 myocardial infarction is being evaluated in the National Health and Medical Research Council‐funded ACT‐2 trial.6 However, further studies are needed to establish evidence‐based pharmacotherapies.

Whether coronary imaging leads to better outcomes for patients with myocardial injury should also be evaluated. The relatively low angiography rates for patients with NSTEMI, particularly older patients, reported by Nadlacki and his co‐authors1 may reflect the inclusion of patients with type 2 myocardial infarction, myocardial injury, or major comorbid conditions. Further, 30‒40% of patients with suspected acute coronary syndromes have troponin levels above the upper reference limit because highly sensitive assays measure levels in the low ng/L range, although only a small proportion have myocardial infarctions; most have chronic myocardial injury.7

Local clinical registries have included the selective CONCORDANCE registry, which recruited patients during 2009‒20178 and the acute coronary syndrome (ACS) Snapshot series, which studied fortnights of care in New Zealand in May 2002 and May 2007, and in New Zealand and Australia in May 2012; the medium term outcomes of the 2012 study were reported in this Journal.9

The key short term outcome determinant for patients with STEMI is achieving reperfusion in the infarct‐related coronary artery, or thrombolysis in myocardial infarction flow 3 (TIMI‐3 flow). Reperfusion can be achieved mechanically by primary percutaneous coronary intervention (PCI) or pharmacologically, using fibrinolytic therapy together with antithrombin and antiplatelet agents.10 The late benefits of complete revascularisation have recently been reported in trial and registry studies.11,12

The results of community education campaigns encouraging people to seek care as soon as possible after cardiac symptom onset have been disappointing, although patients with STEMI, in particular, have presented earlier in Australia over the past ten years.13 As fewer than 5% of patients under 65 years of age die within 30 days of first clinical contact for STEMI,14 key messages for the community are that effective cardio‐pulmonary resuscitation should be performed and an ambulance immediately called. Ambulance services in the eastern mainland states of Australia can transmit electrocardiograms (ECGs) of patients with suspected STEMI to clinical reading services developed in various formats during the past decade. For example, the LifeNet ECG transmission system in New South Wales uses the Glasgow algorithm, also employed in many emergency departments, to identify STEMI. If STEMI is confirmed, the ECG reader can immediately call the transmitting paramedic or emergency department to transfer the patient for primary PCI or, if the PCI centre is more than 60 minutes away, to commence fibrinolytic therapy.10

The widespread adoption of pharmacotherapies, both in hospital and for secondary prevention, have significantly improved clinical outcomes. The role of rehabilitation is still somewhat neglected, perhaps because evidence for its utility from randomised clinical trials is limited. Specific groups of patients may have poorer outcomes after myocardial infarction, including culturally and linguistically diverse communities,15 and people in rural or remote areas, although many regional centres now have cardiac catheterisation laboratories that have improved care. Nadlacki and colleagues1 also reported that survival was poorer for women than men, and specific studies of the assessment and treatment of women could improve their outcomes after myocardial infarction.16

Better systems of care can achieve earlier treatment and reduce the number of deaths after myocardial infarction, both out of hospital and overall. The very good outcomes of those who survived to hospital presentation reported by Nadlacki and his colleagues1 indicate that a strong base of cardiology care has been established over the past decade. We now need to build on this with both research and quality assurance studies that can be translated into enhanced care.

 

Author

  • John K French1,2,3
  • 1. Liverpool Hospital, Sydney, NSW
  • 2. Ingham Institute for Applied Medical Research, Western Sydney University, Sydney, NSW
  • 3. University of New South Wales, Sydney, NSW

Correspondence: j.french@unsw.edu.au

Competing interests

No relevant disclosures.

References

Linked content

  • MJA Research: Long term survival after acute myocardial infarction in Australia and New Zealand, 2009‒2015: a population cohort study

  • InSight+: Work to be done to improve heart attack survival rates

Provenance: Commissioned; externally peer reviewed.

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