To understand the influence of age on treatment and outcomes, we analyzed the largest group of patients 75 years or older with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention (PPCI) in a clinical trial.
We analyzed data from 5745 patients in the Assessment of Pexelizumab in Acute Myocardial Infarction trial from July 13, 2004, through May 11, 2006. Age was analyzed continuously and according to 3 groups: younger than 65 years (n = 3410), 65 to 74 years old (n = 1358), and 75 years or older (n = 977). The main outcome measures were 90-day mortality and the composite of congestive heart failure, shock, or death at 90 days.
Older patients had higher rates of hypertension, chronic obstructive lung disease, previous angina, and prior revascularization. Also notable in these patients were higher Killip class, less angiographic success after PPCI, and less ST-segment resolution with higher rates of in-hospital clinical events, including mechanical, electrical, and bleeding complications. There was less use of short-term adjunctive medications but similar use of discharge medications in older compared with younger patients. Ninety-day mortality rates were 2.3%, 4.8%, and 13.1%; composite outcome rates were 5.9%, 11.9%, and 22.8% for patients younger than 65 years, 65 to 74 years old, and 75 years or older, respectively. After multivariable adjustment, age was the strongest independent predictor of 90-day mortality (hazard ratio, 2.07 per 10-year increase; 95% confidence interval, 1.84-2.33).
Older patients have lower rates of acute procedural success and more postinfarction complications. Age is the strongest predictor of 90-day mortality in ST-segment elevation myocardial infarction patients undergoing PPCI. Despite implementing PPCI for ST-segment elevation myocardial infarction in older patients, early risk remains high, necessitating continued focus on improving outcomes in this vulnerable population.