Outcomes of Transcatheter Aortic Valve Replacement Patients With Different Transvalvular Flow-Gradient Patterns.

ABSTRACT

Low-flow low-gradient (LF-LG) aortic stenosis (AS) may occur with preserved or depressed left ventricular ejection fraction (LVEF). Both situations represent the most challenging subset of patients to manage and generally have a poor prognosis. Few and controversial data exist on the outcomes of these patients compared with normal flow-high gradient (NF-HG) AS after transcatheter aortic valve replacement (TAVR). We sought to characterize different transvalvular flow-gradient patterns and to examine their prognostic value after TAVR. We enrolled 1,208 patients with severe AS and categorized as follow 976 patients NF-HG (mean aortic pressure gradient [MPG] ≥40 mm Hg), 107 paradoxical LF-LG (pLF-LG, MPG <40 mm Hg, LVEF ≥50%, stroke volume index <35 ml/m2), and 125 classical LF-LG (cLF-LG) (MPG <40 mm Hg, LVEF <50%, stroke volume index <35 ml/m2). When compared with NF-HG and pLF-LG, cLF-LG had a worse symptomatic status (New York Heart Association III to IV 86% vs 62% and 67%, p <0.001), a higher prevalence of eccentric hypertrophy and a higher level of LV global afterload reflected by a higher valvuloarterial impedance. Valvular function after TAVR was excellent over time in all patients. While 30-day mortality (p = 0.911) did not differ significantly among groups, cLF-LG had a lower 5-year survival rate (LF-LG 50% vs pLF-LG 62% and NF-HG 68%, p <0.05). cLF-LG was associated with a hazard ratio for mortality of 2.41 (95% confidence interval 1.65 to 3.52, p <0.001). In conclusion, TAVR is an effective procedure regardless of transvalvular flow-gradient patterns. However, special care should be given to characterized hemodynamic of AS, as patients with pLF-LG had similar survival rates than patients with NF-HG, whereas cLF-LG is associated with a twofold increased risk of mortality at 5-year follow-up.