Factors associated with use of percutaneous coronary intervention among elderly patients presenting with ST segment elevation acute myocardial infarction (STEMI): Results from the ISACS-TC registry

Background: A substantial proportion of elderly with ST segment elevation myocardial infarction (STEMI) do not undergo percutaneous coronary intervention (PCI). We sought to investigate factors associated with the decision not to perform coronary angiography at admission in these patients.

Methods: We evaluated 1315 STEMI patients aged ≥75years old enrolled in the International Survey of Acute Coronary Syndromes in Transitional Countries (ISACS TC) registry between October 2010 and February 2015. They were compared with 6667 patients aged <75years old enrolled in the registry in the same time frame.

Results: Elderly patients were less likely to undertake invasive coronary evaluation compared with younger patients (62.1% vs. 78.9; p<0.001%). In the older group there were a lower proportion of patients presenting <12h after symptom onset (66.5% vs.76.9%, p<0.001), and a higher prevalence of comorbidities. Few elderly were treated with current recommended evidence based treatments (aspirin, clopidogrel, heparins, beta-blocker, statins, and ACE-inhibitors). Logistic analysis adjusted for age and sex showed that older age was associated with underuse of coronary angiography (OR 0.46, 95% CI: 0.41-0.53, p<0.001). Clinical factors that were associated with underuse of angiography in patients over 75 were: female sex (OR: 0.77), presence of comorbidities (OR: 0.91), anemia (OR: 0.44) and late hospital admission (OR: 0.89).

Conclusions: In the ISACS-TC, more than one third of the elderly with STEMI did not undergo coronary angiography at admission. Sex, comorbidities, and late hospital admission were independent factors associated with the underuse of PCI in these patients.