Incremental Prognostic Value of Exercise Stress Testing in Primary Prevention

Area of Science:

• Cardiology
• Preventive Medicine
• Clinical Risk Assessment

Background:

• The Reynolds Risk Score (RRS) incorporates traditional risk factors, family history, and C-reactive protein for cardiovascular (CV) event prediction.
• Assessing the incremental prognostic value of functional capacity when added to the RRS is crucial for primary prevention strategies.

Purpose of the Study:

• To evaluate whether incorporating functional capacity measures, specifically % age-gender predicted metabolic equivalents (%AGP-METs) and heart rate recovery (HRR), improves the prognostic accuracy of the RRS for future CV events in asymptomatic adults.
• To determine the incremental predictive value of exercise capacity added to the RRS for identifying individuals at higher risk of CV events.

Main Methods:

• A prospective observational cohort study involving 3,964 asymptomatic adults without prior CV disease.
• Baseline assessments included RRS calculation, treadmill stress testing to determine %AGP-METs achieved and HRR, and measurement of C-reactive protein and family history.
• Outcomes (death and myocardial infarction) were tracked over a median follow-up of 7.3 years, with findings validated in separate derivation and validation cohorts.

Main Results:

• Higher RRS, lower %AGP-METs achieved, and abnormal HRR were independently associated with an increased risk of longer-term CV events in multivariable survival analysis (p <0.01).
• Adding %AGP-METs to the RRS resulted in a significant continuous net reclassification improvement of 0.79 (p <0.01) for predicting longer-term events.
• Specific cutoffs (RRS >3 and %AGP-METs <110%) identified individuals with increased event risk, consistent across derivation and validation groups.

Conclusions:

• The addition of exercise capacity (%AGP-METs and HRR) to the Reynolds Risk Score provides significant incremental prognostic value for cardiovascular event prediction in primary prevention.
• Integrating functional capacity assessment into risk models enhances the ability to stratify individuals at risk, guiding more effective preventive interventions.
• These findings support the routine use of exercise testing parameters alongside established risk scores for comprehensive cardiovascular risk assessment in asymptomatic populations.