Assessment of the prognostic significance of low gradient severe aortic stenosis and preserved left ventricular function requires the integration of the consistency of stroke volume calculation and clinical data

Abstract

Background:This study was to evaluate the prognostic significance of low gradient severe aortic stenosis (LG SAS) and preserved left ventricular ejection fraction (LVEF) with the integration of echocardiographic and clinical data. Methods:The study included 172 patients with LG SAS (AVAi ≤ 0.6 cm 2 /m 2 , mean aortic pressure gradient < 40 mm Hg) and LVEF (≥ 50%). LV outflow tract diameters were measured at both the aortic valve annulus and 5 mm below the annulus for the measurement consistency. Patients were divided into the low flow LG SAS (LF/LG SAS: SVi < 35mL/m 2 and AVAi ≤ 0.6 cm 2 /m 2 ) and normal-flow LG SAS groups (NF/LG SAS: SVi ≥ 35mL/m 2 and AVAi ≤ 0.6 cm 2 /m 2 ). Echocardiographic findings and clinical data were systematically analyzed with mean follow-up of 3.0 ± 1.6 years.Results: LF/LG SAS had significantly smaller AVAi, lower SVi, a higher prevalence of atrial fibrillation (28% vs 12% P = .01) and diabetes (47% vs 27% P = .007) and lower 3-year cumulative survival than NF/LG SAS. Multivariable analysis showed that dyspnea, renal dysfunction (CI 1.42-3.99, P < .01), left atrial diameter, and SVi were independently associated with an increased risk for all-cause mortality. Aortic valve intervention (AVI) improved survival in LF/LG SAS (68% vs 48%, P < .05) in comparison with medical management (HR: 4.20, CI: 1.12-15.76, P = .03), but only modestly in NF/LG SAS (75% vs 65% P > .05). Conclusion:Outcome of LG SAS was independently associated with clinical characteristics. AVI likely improved outcome of LF/LG SAS who had high-risk clinical characteristics and unfavorable echocardiographic findings. K E Y W O R D Saortic stenosis, aortic valve area, aortic valve intervention, echocardiography, stroke volume

Regarding “Estimation of Stroke Volume and Aortic Valve Area in Patients with Aortic Stenosis: A Comparison of Echocardiography versus Cardiovascular Magnetic Resonance”

“…We used multi-LVOT diameter measurements to address the importance of consistency of SV calculation for an AS outcome study. 4 Both Guzzetti et al and our studies showed three types of LVOT shapes. However, the percentages of each type vary with patient selections.…”

“…The distance from the coaptation point perpendicular to the interventricular septum, also known as the ''C-sept'' distance, has also emerged as an independent risk factor for SAM and LVOTobstruction after MV repair, 2,3 as well as after surgical or transcatheter aortic valve replacement 4,5 and in patients with hypertrophic cardiomyopathy. 6 While the description of methodology of C-sept measurement is incomplete in some of these studies, Maslow et al, 2 in their seminal study that has identified C-sept < 2.5 cm as an independent risk factor for SAM after MV repair, describe the measurement as performed in early systole.…”

Echocardiography and EuroSCORE II for the stratification of low-gradient severe aortic stenosis and preserved left ventricular ejection fraction

“…A recent study showed that AVA impacts prognosis only in those with high-gradient AS and preserved LVEF and whether AVA truly adds prognostic information over V max or MPG is not clear in patients with LG SAS [ 34 ]. Although different theories and explanations have been proposed, the inherent variability in calculating SV by echocardiography may have a significant impact on the accuracy in diagnosing true SAS and/or classifying flow state in some patients [ 16 , 35 ]. With the limitations of echocardiography in determining the true severity of AS based on AVA and in the absence of a high pressure gradient, conservative management of LG SAS patients with low EuroSCORE II may be considered as an option in a medium-term with close follow-up.…”

“…With such a discrepancy in natural history, the choice of treatment of LG SAS needs further investigation [ 15 ]. Our prior study showed echocardiographic and clinical characteristics may play a role in prediction of prognosis in low-gradient AS [ 16 ]. Therefore, we hypothesized that clinical outcome in patients with LG SAS and preserved LVEF may be associated with multiple risk factors, comorbidities and certain echocardiographic features.…”

Echocardiographic Investigation of Low-Flow State in a Hispanic/Latino Population

“…2,3 Prior studies have reported that LFS was associated with unfavorable outcomes in patients with low-flow severe AS. [4][5][6][7][8] Although a high prevalence of low-flow, lowgradient AS (approximately 30%) has been reported for decades, the prevalence of LFS in populations without valvular disease has not been systematically investigated. Traditionally, the pathophysiology of LFS has been often attributed to LV dysfunction leading to low SV.…”