Letter by Joshi Regarding Article, “Optimal Medical Therapy With or Without Percutaneous Coronary Intervention to Reduce Ischemic Burden: Results From the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) Trial Nuclear Substudy”
To the Editor:
The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) nuclear substudy demonstrates that when added to optimal medical therapy, percutaneous coronary intervention reduces the extent of ischemia demonstrated with noninvasive testing and that patients with a reduction in ischemia have an improved prognosis.1 These findings are difficult to reconcile with the overall COURAGE trial results.2 Objective evidence of ischemia was necessary for enrolment in COURAGE; either percutaneous coronary intervention did not consistently cause in a reduction in ischemia, or a reduction in ischemia alone did not confer a prognostic benefit. It would also be worth knowing if there were differences between patients with and without a major reduction in ischemia in the nuclear substudy. In particular, did patients without a reduction in ischemia have worse left ventricular function due to predominantly fixed perfusion defects? As the authors state, the nuclear substudy should be considered an exploratory analysis only, and as such not definitive proof that a reduction in ischemic burden is sufficient justification for percutaneous coronary intervention in stable coronary disease.
Shaw LJ, Berman DS, Maron DJ, Mancini GBJ, Hayes SW, Hartigan PM, Weintraub WS, O'Rourke RA, Dada M, Spertus JA, Chaitman BR, Friedman J, Slomka P, Heller GV, Germano G, Gosselin G, Berger P, Kostuk WJ, Schwartz RG, Knudtson M, Veledar E, Bates ER, McCallister B, Teo KK, Boden WE; COURAGE Investigators. Optimal medical therapy with or without percutaneous coronary intervention to reduce ischemic burden: results from the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial nuclear substudy. Circulation. 2008; 117: 1283–1291.
Boden WE, O'Rourke RA, Teo KK, Hartigan PM, Maron DJ, Kostuk WJ, Knudtson M, Dada M, Casperson P, Harris CL, Chaitman BR, Shaw L, Gosselin G, Nawaz S, Title LM, Gau G, Blaustein AS, Booth DC, Bates ER, Spertus JA, Berman DS, Mancini GB, Weintraub WS; COURAGE Trial Research Group. Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med. 2007; 356: 1503–1516.