Impedance cardiography and heart rate variability for long-term cardiovascular outcome prediction after myocardial...

Area of Science:

• Cardiology
• Biomedical Engineering
• Clinical Medicine

Background:

• ST-segment elevation myocardial infarction (STEMI) is a critical condition requiring accurate risk stratification.
• Traditional risk assessment methods may not fully capture the complex physiological changes post-STEMI.
• Heart rate variability (HRV) and impedance cardiography (ICG) offer insights into autonomic function and hemodynamics.

Purpose of the Study:

• To evaluate the predictive capability of combined HRV and ICG measures for serious adverse events after STEMI.
• To identify patients at higher risk of all-cause or cardiac mortality within a 5-year period post-STEMI.
• To assess the prediction of secondary outcomes including recurrent ischemia and revascularization needs.

Main Methods:

• A cohort of 213 STEMI patients underwent 24-hour ECG for HRV analysis and thoracic bioimpedance monitoring for ICG immediately after admission.
• Patients were followed up at discharge, 1 year, and 5 years post-STEMI.
• Cox regression analysis was employed to identify predictors of mortality and other adverse events.

Main Results:

• Decreased standard deviation of all normal-to-normal intervals (SDNN) and cardiac power output (CPO) significantly predicted 5-year all-cause mortality (HR, 11.1).
• Reduced SDANN and CPO were significant predictors of 5-year cardiac mortality (HR, 11.05).
• No significant predictive value was found for ICG measures concerning secondary outcomes.

Conclusions:

• Combined assessment of HRV and ICG effectively identifies STEMI patients at increased risk of 5-year all-cause and cardiac mortality.
• Impaired autonomic heart regulation (low HRV) and systolic function (low CPO) are key indicators of elevated risk.
• Integrated analysis of ECG and impedance cardiography enhances risk stratification for adverse outcomes post-STEMI.