**4.2 Paradoxical low flow low gradient severe AS with preserved ejection fraction (stage D3)**

Patients with paradoxical LFLG AS fare better than patients with classical LFLG AS [5, 18, 48]. The PARTNER I cohort B is the only randomized trial that reports better survival after TAVR compared to medical management [47], all other studies

#### **Figure 17.**

*Algorithm for the management of classical (reduced left ventricular ejection fraction) low-flow, low-gradient aortic stenosis. AoV, aortic valve; BAV, balloon aortic valvuloplasty; MDCT, multi-detector computed tomography; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement. Reproduced with permission from Clavel et al. [32].*

**23**

**Figure 18.**

*Low Flow Low Gradient Severe Aortic Stenosis: Diagnosis and Treatment*

being observational. AVR reduces mortality by 57% in patients with paradoxical

LVEF is a relatively poor and misleading parameter in assessing LV function especially in paradoxical LFLG AS. Higher degree of myocardial fibrosis documented either by cardiac magnetic resonance imaging or global longitudinal strain are independent risk factors for mortality in patients with paradoxical LFLG AS

The role of plasma brain natriuretic peptide (BNP) in risk stratification of patients with paradoxical LFLG AS is unclear [30]. Owing to significant LV concentric remodeling and small LV cavities, the LV wall stress may even be normal, thus the extent of myocardial stretch and release of BNP may not accurately reflect the severity of impairment of myocardial structure/function in these

A systematic heart team approach is recommended to optimize outcomes (**Figure 18**). Aortic valve replacement should be considered in symptomatic patients with paradoxical LFLG and true severe AS. TAVR may be superior to SAVR in patients with paradoxical LFLG AS [47]. Certain factors intrinsic to patients with paradoxical LFLG AS pose higher surgical risks compared to patients with high gradient AS. These include higher prevalence in female sex, older age, systemic hypertension, atrial fibrillation, restrictive LV physiology and smaller aortic annulus that predisposes to patient prosthesis mismatch [52–54]. TAVR was associated

*Algorithm for the management of paradoxical (preserved left ventricular ejection fraction) low-flow, lowgradient aortic stenosis. AVAi, indexed aortic valve area; MR, mitral regurgitation; MS, mitral stenosis; TR,* 

*tricuspid regurgitation. Reproduced with permission from Clavel et al. [32].*

*DOI: http://dx.doi.org/10.5772/intechopen.84435*

LFLG AS [49].

[50, 51].

patients.

*Low Flow Low Gradient Severe Aortic Stenosis: Diagnosis and Treatment DOI: http://dx.doi.org/10.5772/intechopen.84435*

*Aortic Stenosis - Current Perspectives*

**fraction (stage D3)**

A comprehensive risk stratification algorithm that takes into consideration risk scores (STS), frailty indices, major organ compromise and procedure specific impediments is used by the heart team to risk stratify the patient. Ideally the risk stratification process may also take into consideration specific factors that are not mentioned in the guidelines. These include preoperative NHYA class >III, low trans-aortic gradient (<20 mmHg), absence of flow reserve and reduced global longitudinal strain. A reduced global longitudinal strain, by itself suggests high

Palliative balloon aortic valvuloplasty and medical management should be considered in patients with an expected life expectancy <1 year (**Figure 17**). In patients with classical LFLG severe AS with prohibitive and high surgical risk TAVR is recommended. In patients with intermediate surgical risk, SAVR or TAVR may be considered depending heart team evaluation; depending on other factors such as frailty, major organ compromise and procedure specific impediments (hostile

Patients with paradoxical LFLG AS fare better than patients with classical LFLG AS [5, 18, 48]. The PARTNER I cohort B is the only randomized trial that reports better survival after TAVR compared to medical management [47], all other studies

*Algorithm for the management of classical (reduced left ventricular ejection fraction) low-flow, low-gradient aortic stenosis. AoV, aortic valve; BAV, balloon aortic valvuloplasty; MDCT, multi-detector computed tomography; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.* 

**4.2 Paradoxical low flow low gradient severe AS with preserved ejection** 

risk, independent of risk scores (STS/Euroscore) [8, 9, 12].

chest in case of SAVR or vascular access route for TAVR).

**22**

**Figure 17.**

*Reproduced with permission from Clavel et al. [32].*

being observational. AVR reduces mortality by 57% in patients with paradoxical LFLG AS [49].

LVEF is a relatively poor and misleading parameter in assessing LV function especially in paradoxical LFLG AS. Higher degree of myocardial fibrosis documented either by cardiac magnetic resonance imaging or global longitudinal strain are independent risk factors for mortality in patients with paradoxical LFLG AS [50, 51].

The role of plasma brain natriuretic peptide (BNP) in risk stratification of patients with paradoxical LFLG AS is unclear [30]. Owing to significant LV concentric remodeling and small LV cavities, the LV wall stress may even be normal, thus the extent of myocardial stretch and release of BNP may not accurately reflect the severity of impairment of myocardial structure/function in these patients.

A systematic heart team approach is recommended to optimize outcomes (**Figure 18**). Aortic valve replacement should be considered in symptomatic patients with paradoxical LFLG and true severe AS. TAVR may be superior to SAVR in patients with paradoxical LFLG AS [47]. Certain factors intrinsic to patients with paradoxical LFLG AS pose higher surgical risks compared to patients with high gradient AS. These include higher prevalence in female sex, older age, systemic hypertension, atrial fibrillation, restrictive LV physiology and smaller aortic annulus that predisposes to patient prosthesis mismatch [52–54]. TAVR was associated

#### **Figure 18.**

*Algorithm for the management of paradoxical (preserved left ventricular ejection fraction) low-flow, lowgradient aortic stenosis. AVAi, indexed aortic valve area; MR, mitral regurgitation; MS, mitral stenosis; TR, tricuspid regurgitation. Reproduced with permission from Clavel et al. [32].*

with better 1-year survival compared with SAVR in patients with paradoxical LFLG AS in the PARTNER-I Cohort A trial. Further studies are needed to confirm the potential superiority of TAVR versus SAVR in this subset of patients.
