Arm exercise stress perfusion imaging predicts clinical outcome

Area of Science:

• Cardiology
• Nuclear Cardiology
• Exercise Physiology

Background:

• Treadmill exercise capacity and stress responses are established predictors of adverse cardiovascular events.
• Limited data exist on the prognostic value of arm ergometer stress testing (AXT) in patients with lower extremity disabilities.
• Assessing exercise capacity and cardiac stress is crucial for risk stratification in diverse patient populations.

Purpose of the Study:

• To evaluate the independent incremental value of AXT metrics (METs, hemodynamics, ECG, MPI) in predicting adverse clinical outcomes.
• To assess the predictive power of AXT for all-cause mortality, myocardial infarction (MI), and late coronary revascularization.
• To determine if AXT responses add prognostic information beyond demographic and clinical variables.

Main Methods:

• Prospective cohort study of 186 patients unable to perform leg exercise, undergoing AXT with MPI.
• Patients were followed for a median of 62 months for endpoints including death, MI, and revascularization.
• Statistical analysis adjusted for age and clinical variables to identify independent predictors of outcomes.

Main Results:

• Arm ergometer stress testing (AXT) METs and abnormal myocardial perfusion imaging (MPI) independently predicted mortality.
• A positive AXT electrocardiogram (ECG) predicted myocardial infarction (MI).
• AXT METs, MPI, and positive AXT ECG collectively prognosticated combined death and MI.

Conclusions:

• For high-risk patients with lower extremity limitations, AXT METs are as crucial as MPI for predicting mortality.
• AXT provides independent prognostic value for adverse cardiovascular events in this specific patient group.
• AXT, including ECG and MPI, is a valuable tool for risk stratification when treadmill testing is not feasible.