Table 1 Patient characteristics and echocardiographic measurements in low-flow (SVI < 35 ml/m²) versus normal-flow (SVI ≥ 35 ml/m²) severe AS (AVA ≤ 0.1) with preserved LVEF (>50%).

Age

73.5 (±13.8)

69.9 (±13.5)

3.6 (0.6–6.6)

0.020

Height (cm)

164.6 (±19.7)

156.0 (±17.2)

8.6 (−3.7–20.8)

0.169

Weight (kg)

60.5 (±12.4)

58.8 (±13.3)

1.6 (−1.2–4.5)

0.268

BSA (m²)

1.63 (±0.29)

1.59 (±0.25)

0.03 (−0.01–0.10)

0.136

Hypertension

68.5%

61.9%

1.34 (0.791–1.32)

0.275

Diabetes mellitus

47.8%

35.6%

1.66 (1.01–2.75)

0.047

Hyperlipidaemia

55.4%

41.8%

1.74 (1.05–2.86)

0.030

Atrial fibrillation

11.9%

7.2%

1.41 (0.634–3.16)

0.396

Ischaemic heart disease

34.8%

28.4%

1.34 (0.793–2.29)

0.269

Chronic kidney disease

20.6%

10.8%

2.14 (1.08–4.22)

0.025

Left ventricular ejection fraction (%)

65.2 (±7.5)

66.5 (±7.2)

−1.3 (−2.9–0.3)

0.116

End-diastolic volume (ml)

70.8 (±17.7)

113.0 (±26.0)

−42.2 (−47.4 – −37.6)

<0.001

Stroke volume index (ml/m²)

28.3 (±5.9)

46.7 (±9.5)

−18.3 (−20.2–16.4)

<0.001

Left ventricular mass index (g/m²)

100.3 (±31.4)

129.8 (±36.2)

−29.5 (−37.3 – −21.7)

<0.001

End-systolic wall stress (x 10³ dyn/cm²)

65.0 (±28.3)

76.3 (±36.2)

−11.3 (−23.0–0.4)

0.058

Aortic valve area (cm²)

0.77 (±0.17)

0.78 (±0.17)

−0.01 (−0.05–0.03)

0.633

Transaortic mean pressure gradient (mmHg)

34.1 (±19.8)

36.7 (±20.3)

−2.6 (−7.0–1.9)

0.260

Transaortic peak velocity (cm/s)

367.5 (±94.6)

383.2 (±96.2)

−15.7 (−36.9–5.4)

0.144

E (cm/s)

83.8 (±31.5)

89.4 (±30.7)

−5.7 (−12.5–1.2)

0.104

A (cm/s)

89.9 (±42.1)

89.7 (±38.6)

0.2 (−8.6–9.0)

0.965

E/A ratio

2.03 (±1.01)

0.94 (±0.77)

1.1 (−0.8–3.0)

0.264

Deceleration time (ms)

203.1 (±91.4)

211.0 (±83.7)

−7.9 (−27.0–11.2)

0.415

Septal e’

5.39 (±3.65)

5.02 (±3.64)

0.37 (−0.44–1.17)

0.371

Septal E/e’

13.3 (±8.5)

12.4 (±9.2)

0.87 (−1.21–2.95)

0.411

Lateral e’

6.27 (±3.90)

5.70 (4.00)

0.57 (−0.31–1.44)

0.204

Lateral E/e’

10.73 (±6.12)

10.53 (±7.32)

0.20 (−1.43–1.83)

0.809

Septal S’ (cm/s)

5.50 (±3.27)

4.98 (±3.42)

0.52 (−0.22–1.27)

0.166

Lateral S’ (cm/s)

6.51 (±3.90)

5.86 (±3.86)

0.65 (−0.20–1.51)

0.133

Stroke work loss (%)

25.7 (±16.2)

28.1 (±18.0)

−2.4 (−6.2–1.5)

0.223

Systemic arterial compliance (ACU)

0.49 (±0.20)

0.81 (±0.36)

−0.32 (−0.39–0.26)

<0.001

Global LV contractility index, dσ*/dtmax

2.73 (±1.27)

2.41 (±1.00)

0.31 (−0.08–0.72)

0.117

Aortic valve resistance (dyn s /cm²)

198.7 (±155.0)

190.7 (±162.5)

8.0 (−27.3–43.3)

0.656

Valvuloarterial impedance (mmHg/ml/m²)

5.48 (±4.36)

3.04 (±0.79)

2.44 (1.86–3.02)

<0.001

Lateral E:e’/EDV (ml^-1)

0.165 (±0.130)

0.098 (±0.072)

0.066 (0.044–0.089)

<0.001