Computed Tomography-Estimated Right Ventricular Function and Exercise Capacity in Patients with Continuous-Flow Left...

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Left ventricular assist devices (LVADs) are crucial for end-stage heart failure management.
• Assessing right heart function and its relationship with exercise capacity in LVAD patients is vital for optimizing outcomes.
• Four-dimensional cardiac computed tomography (4D CCT) offers advanced visualization of cardiac structures and function.

Purpose of the Study:

• To evaluate right heart chamber sizes and systolic function using 4D CCT in LVAD recipients.
• To determine the association between right ventricular and right atrial systolic function and exercise capacity (peak oxygen uptake, pVO2).
• To assess the correlation between resting and stress-induced right heart function parameters.

Main Methods:

• Fifteen LVAD patients (HeartMate II/3) underwent echocardiography and maximal cardiopulmonary exercise testing.
• Contrast-enhanced 4D CCT scans were performed at rest and immediately after a 2-minute exercise challenge.
• Right atrial ejection fraction (RAEF) and right ventricular ejection fraction (RVEF) were calculated at rest and during stress.

Main Results:

• Resting RAEF was 18±9% and RVEF was 36±8%; stress RAEF was 19±10% and RVEF was 37±8%.
• Neither resting nor stress RAEF or RVEF showed a significant correlation with peak oxygen uptake (pVO2).
• Strong correlations were observed between resting and stress RAEF (r=0.87) and RVEF (r=0.76), indicating consistency in right heart function measurements.

Conclusions:

• Resting right heart systolic function (RAEF and RVEF) reliably predicts function under stress in LVAD patients.
• Right heart systolic function, as measured by RVEF and RAEF, is not directly associated with exercise capacity in this cohort.
• 4D CCT is a valuable tool for assessing dynamic changes in right heart function in LVAD recipients.