Impact of myocardial fibrotic changes assessed by magnetic resonance imaging on early postoperative outcomes after aortic valve replacement
E Averina, D S Troschin, V E Larionova, A S Zvonareva, S A Alexandrova, D S Marchenko, S A Donakanyan, I I AverinaAbstract
Background
Aortic stenosis is the most common acquired valvular heart disease, characterized by pronounced hypertrophic remodeling and an high risk of sudden cardiac death. Visualization of focal fibrosis (late gadolinium enhancement, LGE) and diffuse fibrosis (extracellular volume fraction, ECV) using magnetic resonance imaging (MRI) enables risk stratification and facilitates the selection of the optimal treatment strategy and timing of surgical intervention. Diffuse myocardial fibrosis may be reversible, and its dynamics may determine long-term prognosis.
Purpose
To assess the prognostic value of diffuse and focal myocardial fibrosis assessed by MRI for early postoperative outcomes in patients with aortic stenosis undergoing aortic valve replacement (AVR).
Methods
Between 2018 and 2024, 59 patients who underwent contrast-enhanced MRI prior to AVR were analyzed. Quantification of focal fibrosis (LGE) and diffuse fibrosis (ECV) was performed. Patients were divided into two groups based on the occurrence of a composite primary endpoint, including death (n = 8) or acute heart failure (n = 25).
Results
MRI analysis revealed significant myocardial remodeling in patients with complicated postoperative outcomes. The complicated (n = 25) and uncomplicated (n = 34) groups differed significantly in MRI parameters: left ventricular ejection fraction (LVEF) 40.00% (34.00; 73.00) vs. 65.00% (49.75; 76.75), p = 0.028; right ventricular ejection fraction (RVEF) 50.00% (43.00; 61.00) vs. 59.40% (49.25; 66.75), p = 0.046; left ventricular end-systolic volume (LVESV) 143.00 (35.00; 201.00) ml vs. 44.50 (25.50; 91.50) ml, p = 0.006; LV myocardial mass 228.00 (193.00; 284.00) g vs. 178.50 (145.75; 236.50) g, p = 0.022; LGE 7.00 (5.00–12.00) % vs. 5.25 (4.00–7.00) %, p = 0.02; ECV 25.92% (23.17; 27.93) vs. 22.88% (21.58; 23.88), p < 0.05. In multivariate analysis, the random forest model demonstrated the highest predictive accuracy (ROC AUC = 0.87). Feature clustering identified independent predictors of complicated postoperative outcomes: male sex, cardiopulmonary bypass time, peak aortic valve gradient and ECV (p < 0.05). A peak gradient <90 mm Hg was associated with a 3.25-fold increased risk (OR 3.25; 95% CI 1.07–9.83; p < 0.05), male sex with a 4.5-fold increase (OR 4.5; 95% CI 1.37–14.78; p < 0.05), cardiopulmonary bypass time >145 minutes with a 6-fold increase (OR 6.0; 95% CI 1.86–19.40; p < 0.05), and ECV >24.33% with the highest risk increase (OR 7.71; 95% CI 2.35–25.31; p < 0.05). ROC analysis demonstrated for ECV a sensitivity of 66.7% and specificity of 79.4%.
Conclusions
Diffuse myocardial fibrosis, as assessed by MRI, is the most powerful independent predictor of adverse early postoperative outcomes after aortic valve replacement. These findings highlight the importance of monitoring and optimization of therapeutic strategies in patients with elevated diffuse myocardial fibrosis.