Impact of Repeat Myocardial Revascularization on Outcome in Patients With Silent Ischemia After Previous Revascularization

Study Questions:

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)?

Methods:

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.

Results:

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.

Conclusions:

The authors concluded that there is no survival benefit of repeat revascularization in asymptomatic patients with inducible ischemia on MPS.

Perspective:

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.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery

Keywords: Myocardial Revascularization, Coronary Artery Bypass, Percutaneous Coronary Intervention


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