Comparison of epidemiology, treatments and outcomes of ST segment elevation myocardial infarction between young and elderly patients.

BACKGROUND

With an ageing population, there is a need to understand the relative risk/benefit of interventions for elderly ST segment elevation myocardial infarction (STEMI) patients. The primary aim of this study was to compare epidemiology, treatments and outcomes between young and elderly STEMI patients. Our secondary aim was to determine the cut-off age when the benefits of primary percutaneous coronary intervention (PCI) were less pronounced.

METHODS

Data were collected by the Singapore Myocardial Infarction Registry. Patients were categorised into young (age <65 years) and elderly STEMI (age ≥65 years) patients.

RESULTS

We analysed 14 006 STEMI cases collected between January 2007 and December 2014; 33.9% were elderly STEMI patients. Elderly STEMI patients had longer median door to balloon (73 vs 64 min, P<0.001) time and were less likely to receive PCI (proportion difference=-23.6%, 95% CI -25.3 to -22.0). In the absence of PCI, elderly STEMI patients had a higher mortality within 30 days (elderly: HR 1.65, 95% CI 1.36 to 1.99, P<0.001; young: HR 1.10, 95% CI 0.79 to 1.54, P=0.573) and 1 year (elderly: HR 1.83, 95% CI 1.57 to 2.14, P<0.001; young: HR 1.41, 95% CI 1.09 to 1.83, P=0.009) of admission. The 1 year survival benefit of PCI started to decline after the age of 65 years.

CONCLUSION

Elderly STEMI patients were less likely to receive PCI and had longer door to balloon times. Survival benefit of PCI decreased after the age of 65 years, with the decline most evident from age 85 years onwards. The risks of PCI need to be weighed carefully against its benefits, especially in very elderly patients.