Supplementary Material for: The Utility of Flow Rate Compared with Left Ventricular Stroke Volume Index in the Hemodynamic Classification of Severe Aortic Stenosis with Preserved Ejection Fraction

<b><i>Objectives:</i></b> To substitute the stroke volume index (SVi) with flow rate (FR) in the hemodynamic classification of severe aortic stenosis (AS) with preserved ejection fraction (EF), in order to evaluate its prognostic value. <b><i>Methods:</i></b> A total of 529 patients (78.8 ± 9.8 years old, 44.1% males) with isolated severe AS (aortic valve area, AVA < 1 cm<sup>2</sup>), EF ≥50%, in sinus rhythm, who underwent transthoracic echocardiography, were stratified by FR (≥/< 200 mL/s) and mean pressure gradient (MG) (≥/< 40 mm Hg): FR<sub>normal</sub>/MG<sub>high</sub>, FR<sub>low</sub>/MG<sub>high</sub>, FR<sub>normal</sub>/MG<sub>low</sub>, and FR<sub>low</sub>/MG<sub>low</sub>. <b><i>Results:</i></b> Aortic valve replacement was more frequently performed in the FR<sub>normal</sub>/MG<sub>high</sub> than in the FR<sub>low</sub>/MG<sub>low</sub> group (69.3 vs. 47%, respectively, <i>p</i> < 0.0001), yielding a similar survival benefit across all four groups. Over a median follow-up of 51 ± 29 months, there were 249 deaths. In highly adjusted models, the FR<sub>low</sub>/MG<sub>low</sub> group had a higher all-cause mortality (HR = 1.7, 95% CI: 1.1–2.6, <i>p</i> = 0.02) than patients with FR<sub>normal</sub>/MG<sub>high</sub>. FR had a stronger association with AVA than SVi (<i>r</i> = 0.51 vs. 0.41, respectively, <i>p</i> = 0.0002), and a similar predictive value for death (AUC = 0.57 and 0.58, respectively, <i>p</i> = 0.88). <b><i>Conclusions:</i></b> The FR<sub>low</sub>/MG<sub>low</sub> subset of AS is associated with the worst prognosis, and FR is not superior to SVi in the hemodynamic classification of severe AS.