Using an outcomes-based approach to identify candidates for risk stratification after exercise treadmill testing

Area of Science:

• Cardiology
• Nuclear Medicine
• Preventive Cardiology

Background:

• Cardiac risk stratification is crucial for managing patients with suspected coronary artery disease.
• Treadmill testing is a common initial diagnostic tool, but further risk assessment is often needed for intermediate-risk patients.

Purpose of the Study:

• To develop and evaluate a hierarchical risk stratification strategy for patients undergoing treadmill testing.
• To determine the utility of stress tomographic myocardial perfusion imaging in refining risk assessment for intermediate-risk patients.

Main Methods:

• A prospective study of 3,620 medically treated patients with a 2.5% mortality rate.
• Utilized clinical and treadmill test data, including Duke Treadmill Scores (DTS).
• Employed Cox proportional hazards models and Kaplan-Meier survival analysis.

Main Results:

• Annual cardiac death rates were 0.4%, 1%, and 1% for low, intermediate, and high DTS groups, respectively.
• For intermediate DTS patients, multivariate analysis identified the number of ischemic/infarcted territories and DTS as significant predictors of cardiac death.
• Patients with defects on myocardial perfusion imaging showed significantly worse survival within 1 year.

Conclusions:

• Stress myocardial perfusion imaging effectively stratifies cardiac risk in symptomatic patients with intermediate treadmill test scores.
• This approach allows for efficient patient management by guiding further diagnostic and therapeutic decisions.
• Exercise nuclear scans are valuable for intermediate-risk patients identified by treadmill testing.