Age-adjusted modification of the Duke Treadmill Score nomogram

Area of Science:

• Cardiology
• Preventive Medicine
• Medical Informatics

Background:

• The Duke Treadmill Score (DTS) is a validated tool for assessing cardiovascular risk in patients undergoing exercise stress tests.
• However, the current DTS does not incorporate patient age, a potentially significant prognostic factor.
• This study investigated the impact of age on the predictive accuracy of the DTS.

Purpose of the Study:

• To evaluate if incorporating age enhances the prognostic power of the Duke Treadmill Score.
• To develop a modified DTS nomogram that includes age for improved cardiovascular risk stratification.

Main Methods:

• A cohort of 1,759 male veterans referred for exercise testing between 1997 and 2006 was analyzed.
• Cox survival analysis was employed to assess the significance of age and DTS in predicting cardiovascular mortality.
• A new nomogram was constructed by integrating age into the existing DTS framework.

Main Results:

• Both age and the DTS were significant predictors of cardiovascular mortality (P ≤ .002).
• The age-DTS model demonstrated superior predictive performance, with an area under the ROC curve of 0.80 compared to 0.76 for the DTS alone (P < .001).
• An age-adjusted DTS nomogram showed that younger patients (e.g., 30 years) had a substantially lower cardiovascular mortality risk than older patients (e.g., 70 years) at the same DTS level.

Conclusions:

• An age-adjusted DTS nomogram provides enhanced prognostic accuracy for average annual cardiovascular mortality compared to the DTS alone.
• The proposed nomogram requires external validation and future extension to include female patients.