Table 1

Role of imaging techniques in assessing the left ventricle in patients with aortic stenosis

AdvantagesDisadvantages
Echocardiography
 LV mass and RWT

  • Easy to access

  • Useful for classification of LV remodelling

  • Prognostic value

  • Less accurate and reproducible estimation of LV mass compared with CMR

 LV ejection fraction

  • Mandatory in the decision-making process

  • Established prognostic value in AS

  • Difficult to measure in patients with suboptimal acoustic window

  • Unable to detect early LV dysfunction

 Myocardial velocities, strain ad strain rate (TDI derived)

  • Early markers of LV dysfunction especially when assessed during or after exercise in asymptomatic patients with AS

  • Angle dependent

  • Do not reflect global LV function in patients with segmental wall motion abnormalities

  • Partial dependence on the LV afterload

 Global longitudinal strain (STE)

  • Detects global LV dysfunction

  • An early marker or LV decompensation

  • Prognostic value in AS

  • Inter-vendor variability

  • Lack of clear thresholds to determine LV dysfunction

CMR imaging
 LGE

  • Robust observational prognostic data

  • Qualitative as well as quantitative assessment is of value

  • Access to CMR

  • Use of gadolinium contrast

  • Unable to detect early, reversible interstitial fibrosis

     

 Native T1

  • No requirement for gadolinium contrast

  • Global assessment of myocardial tissue composition

  • Early assessment of reversible fibrosis

  • Access to CMR

  • Lack of established cut-offs for normal and disease states

     

 ECV%

  •  Differentiates between intracellular and extracellular components of myocardium

  •  Dynamic pre-AVR and post-AVR

  •  Early assessment of reversible fibrosis

  •  Access to CMR

  •  Use of gadolinium contrast

     

Cardiac CT
 ECV

  •  Moderate correlation with collagen volume fraction and CMR ECV%

  •  Potentially no requirement for blood sampling (synthetic ECV)

  •  Integration into routine TAVI workflow

  •  Iodinated contrast

  •  Ionising radiation

 GLS

  •  Good correlation with CT-derived ejection fraction

  •  Moderate correlation with echocardiography-derived GLS

  •  Potential prognostic relevance

  •  Iodinated contrast

  •  Ionising radiation

  •  Multiphase acquisition

  •  Adequate image quality required

  • AS, aortic stenosis; AVR, aortic valve replacement; CMR, cardiac magnetic resonance; ECV%, extracellular volume fraction; GLS, global longitudinal strain; LGE, late gadolinium enhancement; LV, left ventricular; RWT, relative wall thickness; STE, speckle tracking echocardiography; TAVI, transcatheter aortic valve implantation; TDI, tissue Doppler imaging.