Our study found that, as compared with medical therapy alone, late PCI of occluded infarct arteries provided a marginal clinical advantage in cardiac physical functioning at 4 months that was not sustained. In addition, medical therapy alone resulted in both lower cumulative medical costs and higher quality-adjusted life expectancy out to 2 years, with no empirical trends suggesting that longer term follow-up might reveal a reversal of these patterns. Combined with the previously reported lack of advantage of PCI with respect to the primary endpoint of OAT, these data do not support the common practice of routine PCI in stable post-MI patients with an occluded IRA.2
Additional QOL comparisons showed only that PCI patients had less exertional angina and dyspnea at 4 months, and that the angina difference attenuated by 12 months, while the dyspnea difference was sustained through 24 months. The significance of these subjective differences is unclear since, except at the 4-month follow-up, they did not affect the activities patients reported they were able to do.
Comparison of our results with the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial is instructive.13
COURAGE found that routine PCI resulted in small incremental benefits in both angina symptoms and physical limitations at 3 months over medical therapy alone. By 12 months, the differences in physical limitations were no longer significant, and the differences in anginal symptoms had attenuated by about 50%. The Trial of Invasive versus Medical Therapy in Elderly Patients (TIME) also compared invasive therapy versus medicine, but enrolled elderly patients (mean age 80 years) with refractory angina.14
While both treatment groups improved over the first 6 months, the invasively treated group had larger improvements in angina and general health perceptions. However, at a median of 3.1 years, the advantage of the invasive treatment had disappeared.15
Thus, our study adds to the evidence that in a variety of clinical situations involving stabilized coronary artery disease patients, a strategy of routine revascularization adds only a modest early advantage in symptoms and functional status that is not maintained. Given that this modest QOL benefit was produced at a cost of over $7000 per patient, our cost-effectiveness analysis found that this strategy was not economically attractive. The COURAGE cost-effectiveness analysis came to a similar conclusion, estimating that the cost per additional quality-adjusted life-year with PCI versus medical therapy alone was around $288,000.16
Several caveats apply to our work. First, sample sizes for both the QOL and economic substudies were considerably smaller than initially planned, due to the enrollment in the parent study of patients outside North America. While the QOL substudy sample differed from the main OAT population in some baseline measures, the differences were clinically small and unlikely to have affected our conclusions. Sensitivity analysis for the economic substudy suggests that a substantively different result would have been unlikely even if we had included all OAT patients in the analysis. Because treatment was not masked, we cannot rule out biases in QOL responses and changes in patterns of care resulting from knowledge of treatment assignment.
In summary, PCI of a persistently occluded infarct artery at 3 to 28 days post infarction provided clinically marginal improvement in physical functioning relative to medical therapy alone but this effect was not sustained at 1 year or beyond. In addition, PCI was more expensive than medical therapy alone out to 2 years, and the small symptom benefits observed were insufficient to make PCI an economically attractive strategy in OAT-eligible patients.