Morphometric and Serum Biochemical Analysis of Myocardial Fibrosis in Patients with Valvular Heart Disease

Introduction: Aortic stenosis (AS) and aortic regurgitation (AR) patients develop both myocardial hypertrophia and fibrosis. B-type natriuretic peptide (BNP) and troponin are biomarkers whose value in aortic valvular heart disease (VHD) remains controversial. Cardiac magnetic resonance (CMR) imaging can detect replacement myocardial fibrosis (MF) by using late gadolinium enhancement (LGE), and diffuse MF by using extracellular volume (ECV) based measures (relative - ECV fraction - and absolute - indexed ECV) calculated from T1 mapping. Data evaluating the relationship of these biomarkers with both types of MF are scarce in AS, and are missing in AR patients. Hypothesis: There is an association between preoperative BNP and troponin and preoperative MF measures in severe aortic VHD patients. Methods: Patients with isolated severe AS or AR were prospectively recruited to be submitted to CMR before surgery, including LGE and ECV measures quantifications. They also collected blood samples for quantification of BNP and high sensitivity T troponin. The relationship between biomarkers and MF parameters was evaluated using linear regression and nonparametric conventional tests. Results: The study population included 99 patients, 67 with AS and 32 with AR. BNP median was 63 (39-103) pg/mL and troponin median was 17 (5-34) ng/L, no difference between AS and AR (p=0.31 and p=0.88, respectively). BNP and troponin were associated with presence of LGE. BNP median was 47 (32-87) pg/mL without LGE vs. 87 (47-190) pg/mL with LGE (p=0.002). Troponin median was 13 (5-25) ng/L without LGE vs. 30 (10-71) ng/L with LGE (p=0.001). Regarding ECV measures, patients with ECV fraction higher than 28.25% had higher BNP levels (p<0.001) and patients with indexed ECV higher than 24.21mL/m 2 had higher troponin levels (p=0.015) (Figure 1). Conclusions: BNP and troponin are associated with quantity of MF in patients with severe aortic VHD with indication of intervention.

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Abstract 16762: Post-Operative Prognostic Prediction of Different Myocardial Fibrosis Measures in Severe Aortic Valvular Heart Disease

Circulation ◽

10.1161/circ.142.suppl_3.16762 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Lucas J Pires ◽

Vitor E Rosa ◽

THAMARA C MORAIS ◽

Antonio S de Santis ◽

Joao Ricardo C Fernandes ◽

...

Keyword(s):

Heart Disease ◽

Clinical Outcomes ◽

Myocardial Fibrosis ◽

Valvular Heart Disease ◽

Cox Regression ◽

Extracellular Volume ◽

Functional Class ◽

Diffuse Myocardial Fibrosis ◽

Class Iii

Introduction: Aortic stenosis (AS) and aortic regurgitation (AR) patients develop myocardial remodeling characterized by hypertrophia and fibrosis. Cardiac magnetic resonance (CMR) imaging can detect the presence of replacement myocardial fibrosis, by using late gadolinium enhancement (LGE), and diffuse myocardial fibrosis, by using extracellular volume (ECV) based measures (relative - ECV fraction - and absolute - indexed ECV) calculated from T1 mapping. There are only few studies with AS patients and scarce data with AR patients showing an association between fibrosis and post-operative clinical outcomes. Hypothesis: There is an association between preoperative myocardial fibrosis measures and post-operative clinical outcomes in severe aortic valvular heart disease (VHD) patients submitted to surgical intervention. Methods: Patients with isolated severe AS or AR were prospectively recruited to be submitted to CMR before indicated surgery, including LGE and ECV measures quantifications. All patients were submitted to conventional surgery and were followed during post-operative period. Results: The study population included 99 patients, 67 with AS and 32 with AR. After a median post-operative follow up of 12.3 (3.2-24.4) months, the presence of LGE areas, found in 32 patients (32.3%), independently predicted post-operative combined events (global mortality or STS morbidity events or persistent NYHA functional class III-IV) during follow up in univariate and multivariate Cox regression analyses (HR 3.96, 95%CI 1.76-8.91, p<0.01). Kaplan-Meier curve is presented in Figure 1. ECV fraction (HR 1.02, 95%CI 0.96-1.09, p=0.55) or indexed ECV (HR 1.00, 95%CI 0.97-1.03, p=0.86) did not predict post-operative combined events. Conclusions: Presence of replacement myocardial fibrosis, but not diffuse myocardial fibrosis, in preoperative CMR predicts post-operative combined clinical events in severe VHD patients submitted to surgery.

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