Exercise testing in asymptomatic patients after revascularization: are outcomes altered?

Area of Science:

• Cardiology
• Diagnostic Imaging
• Preventive Medicine

Background:

• Exercise echocardiography (ExE) is considered inappropriate for asymptomatic patients early after coronary revascularization (2 years post-PCI, 5 years post-CABG).
• The appropriateness of later ExE testing and the impact of treatment responses on outcomes remain uncertain.
• This study investigates if ExE-identified risk predictors can guide interventions to improve outcomes in asymptomatic patients post-revascularization.

Purpose of the Study:

• To determine if exercise echocardiography (ExE) can identify asymptomatic patients with previous coronary revascularization who are at increased risk.
• To assess if interventions based on ExE findings can alter outcomes in these patients.
• To evaluate the association between ExE-detected ischemia and cardiac mortality.

Main Methods:

• Exercise echocardiography (ExE) was performed on 2105 asymptomatic patients (mean age 64 years) with prior percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery.
• Ischemia was defined as new or worsening wall motion abnormality.
• Patients were followed for a mean of 5.7 years for cardiac mortality, with Cox proportional hazard models used to assess the association of ischemia with survival.

Main Results:

• Ischemia was identified in 13% of patients (262/2105); only 34% (88/262) underwent subsequent revascularization.
• Mortality (4.6%) was associated with ischemia in both early and late testing groups (HR 2.10, P=.04).
• Clinical and stress testing findings, not echocardiographic features, were the main outcome predictors. Patients without diabetes, with normal ejection fraction, and normal exercise capacity had fewer events. High-risk patients did not benefit from repeated revascularization.

Conclusions:

• Asymptomatic patients identified as high-risk by ExE after coronary revascularization do not appear to benefit from repeated revascularization.
• The study suggests that the appropriateness of ExE testing in this population warrants careful consideration from a health economic perspective.
• Clinical and stress test data are more predictive of outcomes than ExE findings alone.