Multimodality imaging and systemic biomarkers in classical low-flow low-gradient aortic stenosis: key findings for cardiac remodeling evaluation

Background

Elevated levels of troponin I (hsTnT) and B-type natriuretic peptide (BNP) have been related with poor prognosis in patients with LFLG-AS. Biomarkers are less expensive, more practical and more accessible than imaging tests, so their use can be an alternative to imaging in the evaluation of patients with LFLG-AS.

Purpose

The aim of the present study is to assess multimodality imaging findings according to systemic biomarkers (i.e. hsTnT and BNP) in Low-Flow, Low-Gradient Aortic Stenosis (LFLG-AS) and reduced left ventricular ejection fraction (LVEF) patients.

Methods

Prospective study with LFLG-AS patients (LVEF <50%, aortic valve area ≤1,0 cm2 and mean gradient <40 mmHg) that underwent hsTNnT, BNP, cardiac magnetic resonance (CMR) with T1 mapping and 2 dimensional echocardiogram (2DEcho). All patients also underwent dobutamine stress echocardiogram to define aortic stenosis severity. Patients were divided into 3 groups according to BNP and hsTnT levels: Group 1: BNP and hsTnT levels below median (BNP <395 pg/ml and TnI-Ultra <0.042 ng/ml); Group 2: BNP or hsTnT higher than median; and Group 3: both hsTnT and BNP higher than median.

Results

49 patients with LFLG-AS were included (Group 1: 17 patients, Group 2: 14 patients and Group 3: 18 patients). Clinical characteristics (including risk scores) were not able to stratify these groups. Patients with elevation of both biomarkers had lower valvuloarterial impedance (P=0.03), lower LVEF (P=0.02), less moderate/severe mitral (P=0.01) and tricuspid regurgitation (P<0.01) by 2DEcho. CMR identified a progressive increase (from Group 1 to 3) of right and left chamber volumes; reduction in right and left ejection fraction and a marked increase in myocardial fibrosis assessed by extracellular volume (ECV) and indexed extracellular volume (iECV) (Figure 1).

Conclusion

Higher levels of BNP and hsTnT in LFLG-AS patients were associated with worse multi-modality imaging parameters and can be a surrogate of cardiac remodeling.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): No funding

P3702Aortic stenosis and inappropriate myocardial hypertrophy: is there a difference related to gender?

Introduction

Degenerative aortic valve presents distinct patterns according to gender. Inappropriate myocardial hypertrophy in response to severe aortic stenosis (AS) and their clinical repercussions is of recent interest.

Purpose

To evaluate the influence of gender on the pattern of ventricular remodelling in patients with AS and inappropriate ventricular hypertrophy.

Methods

Retrospective study, analysing clinical and echocardiographic characteristics of 145 patients, between 2008 and 2018, with severe aortic stenosis and inappropriate ventricular hypertrophy, defined as septal wall thickness greater than 14 mm.

Results

Women were 42% of the patients, with higher mean age compared to men (75.23±12.78 vs 70.01±12.59 years, p=0.01), lower body surface (1.68±0.17 vs 1.94±0.68 m2, p=0.004), lower ventricular volumes (94.33±32.88x3856±23.81 vs 122.68±43.24x50.34±28.10 ml/m2, p<0.001), increased LV wall thickness (0.65±0.19 vs 0.58±0.10, p<0.001). There were no differences in LV mass (163.22±37.92 vs 170.51±39.08g, p=0.26), septal wall thickness (16.08±1.63 vs 15.71±1.02mm, p=0.24), posterior wall thickness (13.35±1.63 vs 13.67±1.58mm, p=0.23), left ventricular ejection fraction (61.31±10.36 vs 58.92±10.33%, p=0.17), indexed aortic valve area (0.41±0.10 x 0.39±0.08 cm/m2, p=0.23), medium transaortic gradient (57.50±16.42 x 55.08±17.11mmHg, p=0.39), BNP (896.28±1432.44 x 591.09±1007.71pg/ml, p=0.365) and troponin I (7.17±26.36 x 1.01±2.64 mcg/L, p=0.29). The difference between the septum and posterior wall indexed to the body surface was significantly higher in women (1.60±1.06 x 1.10±0.83 mm/m2, p=0.02), as well as the septal wall thickness indexed by the body surface (9.60±1.40 x 8.48±1.30 mm/m2, p<0.001).

Conclusions

Septal wall thickness indexed by body surface and difference between septum and the posterior wall in ventricles with smaller volumes suggest that myocardial hypertrophy in response to severe AS is more severe in women than in men. Since inappropriate myocardial hypertrophy is a predictor of outcomes in AS, it is possible that the optimal timing for valve replacement should be earlier in women.