Treatment pathways for people hospitalised for acute coronary syndrome

This project included 35,784 people, aged between 25 and 84, who had an acute coronary syndrome (ACS) hospitalisation.

Figure 2: Distribution of diagnosis subtype, age group, sex, comorbidities and adverse health outcomes of the ACS cohort

Source: AIHW NIHSI 2010-11 to 2019-20, analysis of NIHSI

1 in 4 people were aged 75–84 years

Around 2 in 3 people in the ACS cohort were men and most people lived in Major cities (61%). Fourteen percent lived in Outer regional, Remote or Very remote areas. Four percent (n=1,359) of the cohort were Aboriginal and Torres Strait Islander (First Nations) people. 

Results for pathways are presented by all demographic factors, were possible, in the supplementary data tables.

1 in 2 people had a diagnosis of NSTEMI

Almost half (48%, n=17,109) of the cohort had a diagnosis of NSTEMI, 29% (n=10,453) were diagnosed with unstable angina and 22% (n=7,853) had a diagnosis of STEMI. Only 1% (n=369) of the cohort had unspecified myocardial infarction (MI).

Almost 1 in 3 had pre-existing CHD

Thirty percent of the cohort had a hospitalisation for CHD in the prior 6 years and 2 in 3 people had used one of the 4 in-scope classes of medicines in the 3 months prior to their hospital admission.

Of the selected comorbidities measured, the most common were hypertension (39%) and diabetes (32%). Seventeen percent had a history of congestive heart failure, and 12% had a diagnosis of renal failure. It is important to note that comorbidity information was obtained from the admitted patient care data only. Therefore, it is likely an underestimate of comorbidities in the cohort.

For details see About this project: Key variables.

12% died during the 3-year follow-up period, and 40% of these deaths were due to CVD causes

One percent of the cohort died within the first 40 days of the follow-up period and five percent of the cohort died during the first-year of the follow-up period. Thirty percent of the cohort had an emergency CVD readmission in the 3-year follow up period. One in 5 (21%) experienced a major adverse cardiac event (MACE) during the 3-year follow up period. A MACE included emergency hospital readmission (or death due to ACS, stroke, or heart failure.

Differences by diagnosis type

Those diagnosed with STEMI were younger and more likely to be men

People with a STEMI diagnosis were younger (29% were 25–54 years), more likely male (76%), and were less likely to have identified comorbidities when compared with the rest of the cohort (18% were 25-54 years, 67% men). For example, around 1 in 3 people with unstable angina, unspecified MI and NSTEMI had a diagnosis of diabetes, compared with 1 in 4 (24%) of people with a STEMI diagnosis. Further, 1 in 4 people with STEMI also had a diagnosis of hypertension, compared with around 43% in the rest of the cohort.

A higher proportion of people with STEMI (62%) visited a cardiologist in the year post hospitalisation when compared to other subtypes. Fifty-six percent of people with unstable angina or NSTEMI, and 47% of people with unspecified MI visited a cardiologist in the year post hospitalisation. 

Around 1 in 2 people with unstable angina had a history of CHD

Those with a diagnosis of unstable angina tended to be older and had a greater proportion with a prior CHD diagnosis (46%) when compared with other subgroups (NSTEMI: 27% and STEMI: 11%).

Four in 5 people with unstable angina had been dispensed an in-scope CVD medicine in the 3 months prior to the index hospital admission. In comparison, around 2 in 3 people with NSTEMI and unspecified MI, and 45% of people with STEMI, had been dispensed in-scope medicines in this period. 

Approximately 1 in 6 people (16%) with NSTEMI died in the 3-year follow-up period

Eight percent of those with STEMI and unstable angina, and 22% of those with unspecified MI, died during the 3-year follow up period. Deaths due to CVD (underlying cause) ranged between 3.4% among those with STEMI and 9.2% among those with unspecified MI.

Emergency CVD readmissions were lowest among those with STEMI (23%) and highest among those with NSTEMI and unstable angina (32%).

1 in 6 people with unspecified MI lived in Outer regional, Remote and Very remote areas

Unspecified MI was the smallest subgroup. More than 2 in 3 (68%) were over 65 years and 5.2% identified as being of Aboriginal and/or Torres Strait Islander origin. The unspecified MI subtype had a higher proportion of people with congestive heart failure (27%) when compared with those with NSTEMI (22%), STEMI and unstable angina (13% in both). 

See S3 in the supplementary data tables for demographic, clinical characteristics in the cohort, by ACS subtype.