February 11, 2008Circulation1,611 citations
Optimal Medical Therapy With or Without Percutaneous Coronary Intervention to Reduce Ischemic Burden
Key Result
Adding percutaneous coronary intervention to optimal medical therapy resulted in a greater reduction in ischemic myocardium (−2.7% vs. −0.5%, P <0.0001).
Structured PICO
Does adding PCI to OMT reduce ischemic burden in patients with stable CAD and ischemia?
P
Population
Patients with medically stable coronary artery disease (CAD) with ≥70% stenosis in at least 1 major epicardial coronary artery and myocardial perfusion single photon emission computed tomography (MPS) ischemia
I
Intervention
Percutaneous coronary intervention (PCI) added to optimal medical therapy (OMT)
C
Comparator
Optimal medical therapy (OMT) alone
O
Outcome
≥5% reduction in ischemic myocardium at follow-upsurrogate
In patients with stable CAD, adding PCI to optimal medical therapy resulted in a significantly greater reduction in myocardial ischemia compared to medical therapy alone.
Limitations
- Substudy sample size was not powered to examine differences in clinical outcomes
- Risk adjustment attenuated comparative differences for clinical outcomes
- Observational nature of the outcome associations
Abstract
Background— Extent and severity of myocardial ischemia are determinants of risk for patients with coronary artery disease, and ischemia reduction is an important therapeutic goal. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) nuclear substudy compared the effectiveness of percutaneous coronary intervention (PCI) for ischemia reduction added to optimal medical therapy (OMT) with the use of myocardial perfusion single photon emission computed tomography (MPS). Methods and Results— Of the 2287 COURAGE patients, 314 were enrolled in this substudy of serial rest/stress MPS performed before treatment and 6 to 18 months (mean=374±50 days) after randomization using paired exercise (n=84) or vasodilator stress (n=230). A blinded core laboratory analyzed quantitative MPS measures of percent ischemic myocardium. Moderate to severe ischemia encumbered ≥10% myocardium. The primary end point was ≥5% reduction in ischemic myocardium at follow-up. Treatment groups had similar baseline characteristics. At follow-up, the reduction in ischemic myocardium was greater with PCI+OMT (−2.7%; 95% confidence interval, −1.7%, −3.8%) than with OMT (−0.5%; 95% confidence interval, −1.6%, 0.6%; P <0.0001). More PCI+OMT patients exhibited significant ischemia reduction (33% versus 19%; P =0.0004), especially patients with moderate to severe pretreatment ischemia (78% versus 52%; P =0.007). Patients with ischemia reduction had lower unadjusted risk for death or myocardial infarction ( P =0.037 risk-adjusted P =0.26), particularly if baseline ischemia was moderate to severe ( P =0.001 risk-adjusted P =0.08). Death or myocardial infarction rates ranged from 0% to 39% for patients with no residual ischemia to ≥10% residual ischemia on follow-up MPS ( P =0.002 risk-adjusted P =0.09). Conclusions— In COURAGE patients who underwent serial MPS, adding PCI to OMT resulted in greater reduction in ischemia compared with OMT alone. Our findings suggest a treatment target of ≥5% ischemia reduction with OMT with or without coronary revascularization.