Age and Outcomes in ST-Segment Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention: Findings From the APEX-AMI Trial

Study Questions:

What is the association between age and clinical and procedural characteristics, in-hospital complications, and cardiovascular events through 90 days among ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI)?

Methods:

The investigators analyzed data from 5,745 patients in the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial from July 13, 2004, through May 11, 2006. Age was analyzed continuously and according to three groups: younger than 65 years old (n = 3,410), 65-74 years old (n = 1,358), 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. Multivariable Cox proportional hazards models were used to develop a predictive model for 90-day mortality.

Results:

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 primary PCI, 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 old, 65-74 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).

Conclusions:

The authors concluded that age is the strongest predictor of 90-day mortality in STEMI patients undergoing primary PCI.

Perspective:

The study suggests that age remains the most powerful determinant of outcome in STEMI patients undergoing primary PCI, such that for every decade increase in age, there was a more than twofold increase in the adjusted hazard of 90-day mortality. Older patients tend to have lower rates of acute procedural success and more postinfarction complications. Additional efforts and studies to attenuate this risk and understand reperfusion factors that increase age-associated outcomes are indicated.

Keywords: Outcome Assessment, Health Care, Pulmonary Disease, Chronic Obstructive, Myocardial Infarction, Heart Failure, Hypertension, Percutaneous Coronary Intervention


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