Related Experiment Videos
Prognostic value of the Duke treadmill score in the elderly
Jennifer M F Kwok1, Todd D Miller, David O Hodge
1Division of Cardiovascular Diseases and Department of Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Insights
The Duke treadmill score is less effective for risk stratification in patients aged 75 and older. This score poorly predicts cardiac events in the elderly, unlike in younger individuals.
Area of Science:
- Cardiology
- Geriatric Medicine
- Diagnostic Test Performance
Background:
- The Duke treadmill score is a standard tool for risk stratification in coronary artery disease (CAD).
- Its prognostic value may be diminished in elderly individuals (≥75 years) due to higher CAD prevalence, severity, and reduced exercise tolerance.
Purpose of the Study:
- To evaluate the effectiveness of the Duke treadmill score for risk stratification in patients aged 75 years or above.
- To test the hypothesis that the score's prognostic utility decreases in this elderly population.
Main Methods:
- A cohort of 247 patients aged ≥75 years was compared with 2,304 patients <75 years.
- All symptomatic patients underwent exercise thallium testing and were followed for >6.5 years.
- Cox regression analysis assessed the Duke score's association with cardiac death, myocardial infarction (MI), and late revascularization.
Main Results:
- In patients ≥75 years, the Duke score poorly stratified risk; 68% were intermediate risk with 86% seven-year cardiac survival (p=0.45).
- The score did not significantly predict cardiac death or MI in the elderly, but did predict total cardiac events (including revascularization).
- In the control group (<75 years), the Duke score was highly predictive of all outcomes (p=0.0001).
Conclusions:
- The Duke treadmill score effectively predicts cardiac survival in younger patients but not in those aged 75 and older.
- Most elderly patients were classified as intermediate risk, with even the low-risk elderly group experiencing significant annual cardiac mortality (2%).
Objectives:
The purpose of this study was to test the hypothesis that the Duke treadmill score works less well for risk stratification in patients age 75 years or above.
Background:
Although the Duke treadmill score is generally effective for risk stratification, its prognostic value in the elderly may be limited because they have a higher prevalence of coronary artery disease (CAD), more severe CAD and a lower exercise tolerance.
Methods:
The study population consisted of 247 patients age 75 years or above, and the control population consisted of 2,304 patients below 75 years of age. All patients were symptomatic, had undergone exercise thallium testing between 1989 and 1991 and were followed for a median of >6.5 years. The Cox regression model was used to test the association of the Duke score (utilized both as a continuous variable and using previously published risk group cutoffs) with outcomes (cardiac death, nonfatal myocardial infarction [MI], late revascularization).
Results:
Using the Duke score to risk-stratify the elderly, 26% were in the low risk group, 68% were in the intermediate risk group and 6% were in the high risk groups; seven-year cardiac survival was 86%, 85% and 69%, respectively (p = 0.45). There was also no significant association between these Duke score risk groups and all other outcome end points in the elderly. The Duke score as a continuous variable did not predict cardiac death (p = 0.43) or cardiac death or MI (p = 0.42), but did predict total cardiac events (which included late revascularization) (p = 0.0027). For the control population, more patients (55%) were in the low risk group, and the Duke score (as a continuous variable or in risk groups) was highly predictive of all end points (p = 0.0001).
Conclusions:
The Duke score predicted cardiac survival in younger patients but not in patients age 75 years or above. The majority of the elderly were classified as intermediate risk by the Duke score. Only a minority of the elderly were classified as low risk, but this group still had an annual cardiac mortality of 2%/year.