Australia has seen improvements in access to early reperfusion and medical therapies for patients with ST elevation myocardial infarction (STEMI) over the last 17 years but no improvement in mortality rates.
An analysis of combined data for 4110 STEMI patients from the GRACE and CONCORDANCE coronary care registries has shown welcome gains between 1999 and 2016 in door-to-balloon times and provision of evidence-based therapies such as antiplatelet agents and statins.
But despite reductions in in-hospital adverse events and readmissions for revascularisation there was no reduction in in-hospital mortality or mortality within six months, according to the analysis published in Heart, Lung and Circulation.
Between 1999 and 2016 there were changes in several areas of STEMI management:
- Reduction in time taken to access medical care from symptom onset of 1.48 to 1.21 hours
- Median door-to-primary PCI time decreased by 11 minutes (95 to 84 minutes).
- Improved adherence to medical therapies with increases in prescribing of statins, aspirin including antiplatelets, beta blockers and ACE/ARB drugs.
- Decrease in in-hospital adverse events such as heart failure and recurrent ischaemia.
- Decrease in readmissions for unplanned revascularisation (odds ration 6.7 for 1999 vs 2016).
The report authors said studies in other countries had shown that improved access to reperfusion for STEMI patients reduced mortality.
The lack of improvement in STEMI mortality rates seen with the GRACE and CONCORDANCE registry data might reflect Australia’s unique geographical factors, they suggested, given one in three patients live in rural areas and do not meet the 90 minute threshold for mortality benefit for primary PCI.
The benefits of shorter door-to-balloon times may also have been masked by a survivor cohort effect due to improving care systems, they added.
“That is, we are now treating patients such as late presenters who in earlier years may have died outside hospital and therefore not been included in the registry,” they said.