Impact of socioeconomic status on risk factors, treatment and clinical outcomes in patients undergoing percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction.

Abstract

Background: Low socioeconomic status (SES) has been shown to be associated with worse cardiovascular outcomes, potentially due to a higher prevalence of cardiac risk factors. We sought to determine whether SES impacts on reperfusion time, clinical outcomes and adherence to secondary prevention therapy in STEMI patients undergoing PCI.

Method: We prospectively collected data on 5665 consecutive STEMI PCI patients between 2005 and 2015 in the multi-centre Melbourne Interventional Group registry. Patients were categorised into SES quintiles using the Index of Relative Socioeconomic Disadvantage system – a score allocated to each postcode based on factors like educational level, employment status and vehicle ownership by the Australian Bureau of Statistics using 2011 census data.

Results: Lower SES patients were more likely to be obese, have diabetes, currently smoke, present to a non-PCI capable hospital and receive thrombolysis (all p≤0.01). Among primary PCI patients, door-to-balloon times were similar in all SES groups (p = NS). Drug-eluting stent use was higher in the higher SES groups (p < 0.01). Despite these differences, adjusted 30-day and 12-month mortality and MACE were similar across SES groups (p = NS). At 12 months after PCI, lower SES patients had higher rates of ongoing smoking (p < 0.01) but there were no differences in use of guideline-indicated medications across SES groups (p = NS).

Conclusion: Lower SES patients have more comorbidities and are less likely to have timely access to a PCI-capable hospital resulting in more thrombolysis. Despite this, their outcomes are similar to higher SES patients, likely due to robust systems of care for STEMI in Victoria.