Impact of Repeat Myocardial Revascularization on Outcome in Patients With Silent Ischemia After Previous Revascularization
What is the survival of asymptomatic patients with a history of revascularization and myocardial perfusion scintigraphy (MPS)-identified inducible ischemia who undergo either repeat revascularization or receive medical therapy (MT)?
This was a single-site observational study of 769 asymptomatic patients with a history of previous revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI]), and who had ischemia on exercise or adenosine stress MPS. Patients were separated into those undergoing MT (n = 654) and those undergoing revascularization (n = 115). Patients were followed up for a median of 5.7 years for the primary endpoint of all-cause mortality. A Cox proportional hazards model was used to examine the association of post-MPS treatment and all-cause death after adjustment for baseline characteristics and potential confounders.
Mortality with MT and revascularization were 18.3% and 19.1%, respectively (p = 0.84). In a Cox proportional hazards model (adjusted for baseline characteristics and potential confounders), revascularization was not associated with mortality. The authors did not differentiate between revascularization performed with CABG versus PCI.
The authors concluded that there is no survival benefit of repeat revascularization in asymptomatic patients with inducible ischemia on MPS.
While appropriate use criteria support the use of functional testing in asymptomatic patients >5 years after CABG, and such testing is often performed in patients following PCI, the benefit of repeat revascularization as a strategy to treat ‘silent’ ischemia remains uncertain. The limitations of this single-site MPS-based study aside, these findings suggest that repeat revascularization in this patient population does not provide a survival benefit. Should these findings be further validated, they will call into question the routine practice of post-revascularization functional testing in asymptomatic patients.
Keywords: Myocardial Revascularization, Coronary Artery Bypass, Percutaneous Coronary Intervention
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