Percutaneous coronary intervention (PCI) is well established as an effective treatment option for reducing angina in patients that have symptomatic coronary artery disease (CAD) and reducing mortality in patients who have acute myocardial infarction with ST-segment elevation or in patients who are deemed to have high-risk acute coronary syndromes without ST-segment elevation.1 This has led to widespread use of PCI in patients with stable coronary artery disease despite treatment guidelines that advocate an initial approach with intensive medical therapy, a reduction of risk factors, and lifestyle intervention (known as optimal medial therapy).2 In 2004, more than 1 million coronary stent procedures were performed in the United States, with approximately 85% of all PCI procedures undertaken electively in patients with stable CAD.1
The COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive druG Evaluation) trial studied whether the addition of PCI to optimal medical therapy (OMT) provided any mortality and morbidity benefit to patients with stable CAD.3 The trial was a multi-center, randomized study of 2,287 patients with objective evidence of myocardial ischemia and significant coronary disease. Patients were assigned to either PCI with OMT (n=1149) or OMT alone (n=1138). Patients with persistent Canadian Cardiovascular Society (CCS) class IV angina, a markedly positive stress test (defined as substantial ST-segment depression or hypotensive response during stage 1 of the Bruce protocol), refractory heart failure or cardiogenic shock, an ejection fraction of less than 30%, revascularization within the previous 6 months, or coronary anatomy not suitable for PCI were excluded from the study. The primary end point was all-cause mortality or nonfatal MI. Secondary endpoints included death alone, hospitalization for ACS, a composite of death, MI, or stroke, and a composite of death, MI, stroke, or hospitalization for ACS.
The 4.6-year cumulative primary-event rates were 19.0% in the PCI group and 18.5% in the medical-therapy group. There were no significant differences between the PCI group and the medical-therapy group in the composite of death, myocardial infarction, and stroke, hospitalization for ACS, or myocardial infarction. Despite no improvement in mortality, the results are consistent with previous results that PCI is effective at relieving angina. However, a subsequent study assessing quality-of-life concluded that patients who undertake PCI with OMT versus OMT alone provided a small benefit in symptom relief that disappeared after 36 months.4
In a pre-specified subset analysis, the COURAGE investigators evaluated the effects of PCI + OMT versus OMT in older patients with CAD.5 A total of 1,381 patients (60%) were < 65 years of age (mean 56 ± 6 years) and 904 patients (40%) were ≥ 65 years of age (mean 72 ± 5 years). The ability to achieve treatment goals (LDL-cholesterol, blood pressure, diet, exercise, and angina-free status) did not differ by age group or treatment allocation. There was an increased risk of death or myocardial infarction (MI) in the older cohort (p<0.001) but similar rates were seen in MI, stroke, and hospitalization for unstable angina. There was no evidence that an initial PCI + OMT strategy was superior to OMT in decreasing these adverse cardiovascular outcomes or in achieving an angina-free status.
The results of the COURAGE trial and the elderly substudy should reassure clinicians that an initial strategy of OMT in patients with stable CAD is acceptable. The addition of PCI does not prevent “hard” clinical outcomes such as death or MI. OMT is as effective in decreasing cardiovascular events in the elderly as in patients ≤ 65 years. It is hard to substantiate PCI as an initial strategy in most elderly patients with stable coronary artery disease.