Differential impact of ventricular-arterial coupling on left ventricular function in patients with acute myocardial infarction: a comparison between preserved and reduced ejection fraction.

Background: Ventricular-arterial coupling (VAC) plays a crucial role in the initiation and progression of heart failure in patients with coronary artery disease. The influence of VAC on left ventricular (LV) function may vary depending on LV systolic function. This study investigated the relationship between VAC and LV function in patients with acute myocardial infarction (AMI), stratified by ejection fraction (EF).

Methods: Echocardiographic indices of LV volumes, systolic function, and diastolic function were measured using standard techniques. Effective arterial elastance (E_A) was calculated based on stroke volume derived from the LV outflow waveform. Effective LV end-systolic elastance was determined using the single-beat method. The central aortic pressure waveform was recorded via applanation tonometry. Characteristic impedance (Zc) of the aortic root was calculated using Fourier transformation of both aortic pressure and flow waveforms.

Results: A total of 85 patients (mean age, 58.5 ± 10.6 years) with AMI were enrolled. They were classified into two groups: those with reduced EF (< 50%, 27 patients) and those with preserved EF (≥ 50%, 58 PATIENTS). In the adjusted linear regression analysis, E' velocity was significantly associated with VAC (β = -0.310, P = 0.008) in the preserved EF group but not in the reduced EF group. LV global longitudinal strain showed significant positive associations with VAC (β = 0.505, P < 0.001), E_A index (β = 0.536, P < 0.001), and Zc (β = 0.344, P = 0.018) exclusively in the preserved EF group.

Conclusions: The distinct influence of EF status on the relationships between hemodynamic parameters and LV diastolic and systolic functions suggests a differential interplay between arterial and ventricular dynamics depending on LV systolic function.