Comparison of the results in Normal Flow High Gradient and Low Flow Low Gradient patients after correction of pronounced aortic stenosis with Ozaki procedure in the long-term observation

Abstract

Relevance.It has been proven that patients with Low Flow Low Gradient (LFLG) after aortic valve replacement with biological or mechanical prostheses have a higher mortality rate and the number of adverse events compared with patients with Normal Flow High Gradient (NFHG). However, there are currently no comparative studies of patients with NFHG and LFLG after the Ozaki procedure. The better hemodynamic properties of autopericardial cusps compared with biological prostheses can more favorably influence the results in patients with LFLG in the short and long-term follow-up periods.
 Aim.1. Compare the hospit and long-term results of patients of the LFLG group with the results of patients of the NFHG group after the Ozaki procedure. 2. Identify predictors of hospital and long-term mortality in patients with LFLG.
 Materials and methods.All patients have been divided into two groups. Group 1: 137 patients with NFHG and signs of classic aortic stenosis: AVA1 cm2, Gmean40, SV index 35 ml/m2and normal left ventricle (LV) ejection fraction. Group 2. 71 patients with LFLG and underestimation of the average gradient indices (Gmean40) despite a decrease in the aortic valve aperture AVA1 cm2amid a decrease in the index of stroke volume 35 ml/m2and LV systolic function.
 Results.Hospital mortality after surgical correction of AV stenosis was significantly higher in patients of group 2: 3 (4.2%) patients and 1 (0.7%) patients, respectively (p=0.002). Survival at the maximum follow-up period for patients with LFLG was significantly lower than in the group of patients with NFHG 88.6 (95% confidence interval CI 4449.6) and 97.8 (95% CI 48.951), respectively (p=0.009). According to the results of the Cox regression analysis, the independent predictors of mortality in the long-term follow-up of patients with LFLG are the SV odds ratio 0.8 (95% CI 0.91.1);p=0.008 and the global longitudinal LV deformation (GLS) odds ratio 0.56 (95% CI 0.471.1);p=0.01.
 Conclusions.1. After the Ozaki procedure, patients with the LFLG group have higher risks of adverse events, both at the hospital stage and in the long-term follow-up, compared to patients with NFHG. 2. The duration of ischemia and LV mass are predictors of hospital mortality in the LFLG group of patients. 3. Predictors of long-term mortality in patients with LFLG are LV stroke volume index and global longitudinal LV deformation.