Electrocardiographic markers of adverse left ventricular remodeling and myocardial fibrosis in severe aortic stenosis

Abstract

Abstract Background. The optimal timing for aortic valve replacement (AVR) in aortic stenosis (AS) is still controversial and may be guided by markers of adverse left ventricular (LV) remodeling. We aim to assess electrocardiographic (ECG) strain patterns in relation to adverse LV remodeling and myocardial fibrosis. Methods. A total of 83 symptomatic severe AS patients (age 66.5 ± 8.6, 42% male) scheduled for surgical AVR underwent preoperative cardiovascular magnetic resonance (CMR) with T1 mapping and echocardiography with global longitudinal strain (GLS) analysis. Collagen volume fraction (CVF) was measured in myocardial biopsies (71) sampled at the time of AVR. The 12-lead ECG was performed preoperatively and 3 and 12 months postoperatively. Results. ECG strain-positive patients (prevalence of 43.4%) had more severe AS, increased LV mass, higher levels of brain natriuretic peptides (BNP) and high-sensitivity troponin I, lower GLS, and lower LV ejection fraction (LVEF). Patients with ECG strain had more diffuse fibrosis, as evident by higher native T1 values (974.8 ± 33.6 ms vs 946.5 ± 28.2 ms, p < 0.001). ECG strain was the only predictor of increased LV mass index on multivariate regression analysis (OR = 7.10, 95% CI 1.46–34.48, p = 0.015). Patients with persistent ECG strain at 1 year following AVR had larger LV volumes and mass, lower GLS, lower LVEF, higher BNP levels, and more histological fibrosis (CVF 12.5% vs. 7.3%, p = 0.009) at baseline assessment. Conclusion. ECG strain is a marker of adverse structural and functional LV remodeling and interstitial myocardial fibrosis. Lack of improvement in ECG strain following AVR indicates more advanced baseline LV injury and higher levels of myocardial fibrosis.