T he benchmark for demonstrating the effectiveness of a therapeutic intervention for coronary artery disease is widely accepted as a reduction in mortality or major adverse cardiac outcomes. In medicine, however, many therapies that do not prolong life are routinely practiced and considered appropriate. There has been tremendous interest in research on the comparative effectiveness of clinical practices since Title VIII of the American Recovery and Reinvestment Act of 2009.1 Over 1 billion of federal funds was authorized to conduct research in clinical outcomes, effectiveness, and appropriateness of health-related services and procedures. Federal support of research in this arena was, in part, intended to control healthcare costs. If a therapy, for example, is found to have no or little benefit then it will not be practiced and cost will be reduced. In reality, the relationship between quality and cost is much more complicated.2 The interventional cardiology community has been scrutinized for the use of percutaneous coronary intervention (PCI) in stable ischemic heart disease (SIHD). This is largely related to claims of overuse and studies showing no reduction in death or myocardial infarction (MI) when compared with medical therapy alone. The crucial question is what outcomes should be measured to demonstrate the effectiveness of PCI? In patients with acute coronary syndromes, outcomes of death and MI are relevant because of a high short-term risk of these events. Whereas in SIHD the goal of PCI is symptom relief and health status outcomes need to be measured in additional to other clinical outcomes. Presented is the evidence for the effectiveness of PCI according to clinical indication of the procedure.
PCI to Reduce Major Adverse Cardiac EventsIn patients with acute coronary syndromes, there is no dispute about the effectiveness of PCI for reducing major adverse cardiac events. In ST-segment-elevation MI, reperfusion with either primary PCI or thrombolytic therapy reduces mortality when compared with conservative management. Several randomized clinical trials in the balloon angioplasty and stent era compared primary PCI with thrombolytic therapy. A metaanalysis of 23 trials, 12 with stents, showed that compared with thrombolytic therapy primary PCI reduces mortality, reinfarction, and stroke.3 In high-risk non-ST-segment-elevation MI acute coronary syndromes, a routine invasive strategy including PCI of culprit lesions is more effective for reducing the risk of death or MI than a selective strategy of revascularization only for demonstrable ischemia. 4 There is no direct evidence that PCI can reduce mortality in patients with SIHD, however, there is reason to think that there is the potential. Studies of patients undergoing noninvasive risk stratification show a relationship between ischemia burden and mortality, and a reduced risk of mortality associated with revascularization. In an observational study of 10 627 patients without previous MI or coronary revascularization referred for myocardial perfusion str...