Measurement of myocardial extracellular volume fraction in patients with heart failure with preserved ejection fraction using dual-energy computed tomography.

Objectives: To measure the myocardial extracellular volume (ECV) in patients with heart failure with preserved ejection fraction (HFpEF) using dual-energy computed tomography with late iodine enhancement (LIE-DECT) and to evaluate the relationship between ECV and risk of HFpEF and cardiac structure and function.

Methods: A total of 112 consecutive patients with HFpEF and 80 consecutive subjects without heart disease (control group) who underwent LIE-DECT were included. All patients were divided into ischaemic and non-ischaemic groups according to the LIE patterns detected using iodine maps. The ischaemic scar burden was calculated in the ischaemic HFpEF group. Iodine maps and haematocrit were used to measure ECV in the non-ischaemic HFpEF group and remote ECV of the non-scarred myocardium in the ischaemic HFpEF group, respectively. Cardiac structural and functional variables were collected.

Results: ECV in patients with non-ischaemic HFpEF (n = 77) and remote ECV in patients with ischaemic HFpEF (n = 35) were significantly higher than those in control subjects (p < 0.001). Multivariate logistic regression analysis revealed that after adjusting for age, sex, body mass index, smoking, and drinking, a higher ECV/remote ECV was still associated with non-ischaemic HFpEF and ischaemic HFpEF (p < 0.001). A positive correlation was established between ECV and cardiac structural and functional variables (p < 0.05) in all participants. Subgroup analysis showed that ECV/remote ECV and ischaemic scar burden positively correlated with heart failure classification in the HFpEF subgroup (p < 0.05).

Conclusion: ECV/remote ECV elevation was significantly associated with non-ischaemic and ischaemic HFpEF. Remote ECV and LIE may have synergistic effects in the risk assessment of ischaemic HFpEF.

Key Points: • ECV/remote ECV elevation is associated not only with non-ischaemic HFpEF but also with ischaemic HFpEF. • ECV/remote ECV and ischaemic scar burden are correlated with cardiac structure and function.