Sudden Cardiac Death Risk Prediction From QT-RR Adaptation Time Lag Computed From Exercise Stress Test ECG.

Area of Science:

• Cardiology
• Electrocardiography
• Predictive Analytics

Background:

• Sudden cardiac death (SCD) and cardiovascular death (CVD) remain significant health concerns.
• Exercise stress testing (EST) provides valuable cardiovascular data.
• Assessing QT adaptation time may offer novel risk stratification insights.

Purpose of the Study:

• To evaluate QT adaptation time from EST ECGs as a marker for SCD and CVD risk.
• To assess the predicted risk value for any cardiovascular death (CVD).

Main Methods:

• Calculated three ECG-derived QT-RR adaptation time markers: $\check{\tau }_{e}$, $\check{\tau }_{r}$, and $\Delta _{\check{\tau }}$.
• Utilized RR-based and QT-based strategies for marker estimation in 1472 coronary artery disease (CAD) patients from the ARTEMIS study.
• Evaluated the relationship between markers and CAD, SCD, or CVD outcomes over an 8.9-year median follow-up.

Main Results:

• The $\check{\tau }_{r}$ marker, estimated via the RR-based strategy, robustly stratified survivors and victims of SCD or CVD (p=0.022 and p=0.065).
• Multivariable regression models incorporating QT-RR adaptation time from EST recovery (RR-based strategy) predicted SCD and CVD.

Conclusions:

• A prolonged QT-RR adaptation time during EST recovery, using the RR-based strategy, is a predictor of SCD and CVD.
• This ECG-derived marker provides complementary information to existing clinical risk stratification tools.