Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction

Abstract

Background— Retrospective studies have suggested that patients with a low transvalvular gradient in the presence of an aortic valve area <1.0 cm 2 and normal ejection fraction may represent a subgroup with an advanced stage of aortic valve disease, reduced stroke volume, and poor prognosis requiring early surgery. We therefore evaluated the outcome of patients with low-gradient “severe” stenosis (defined as aortic valve area <1.0 cm 2 and mean gradient ≤40 mm Hg) in the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Methods and Results— Outcome in patients with low-gradient “severe” aortic stenosis was compared with outcome in patients with moderate stenosis (aortic valve area 1.0 to 1.5 cm 2 ; mean gradient 25 to 40 mm Hg). The primary end point of aortic valve events included death from cardiovascular causes, aortic valve replacement, and heart failure due to aortic stenosis. Secondary end points were major cardiovascular events and cardiovascular death. In 1525 asymptomatic patients (mean age, 67±10 years; ejection fraction, ≥55%), baseline echocardiography revealed low-gradient severe stenosis in 435 patients (29%) and moderate stenosis in 184 (12%). Left ventricular mass was lower in patients with low-gradient severe stenosis than in those with moderate stenosis (182±64 versus 212±68 g; P <0.01). During 46 months of follow-up, aortic valve events occurred in 48.5% versus 44.6%, respectively ( P =0.37; major cardiovascular events, 50.9% versus 48.5%, P =0.58; cardiovascular death, 7.8% versus 4.9%, P =0.19). Low-gradient severe stenosis patients with reduced stroke volume index (≤35 mL/m 2 ; n=223) had aortic valve events comparable to those in patients with normal stroke volume index (46.2% versus 50.9%; P =0.53). Conclusions— Patients with low-gradient “severe” aortic stenosis and normal ejection fraction have an outcome similar to that in patients with moderate stenosis.

Impact of Vascular Hemodynamics on Aortic Stenosis Evaluation: New Insights Into the Pathophysiology of Normal Flow—Small Aortic Valve Area—Low Gradient Pattern

“…The most frequent discordant situation is the combination of a small AVA (˂1.0 cm 2 ), consistent with a severe AS, with a low MG or V peak (˂40 mm Hg or <4 m/s) rather consistent with the presence of a moderate AS. In daily practice, these discordant findings may lead to inadequate assessment of the actual severity of the disease and thus to an inappropriate therapeutic management, which may, in turn, have a negative impact on patient outcome 6, 7, 8…”

Low-flow aortic stenosis and preserved left ventricular ejection fraction

“…In addition, a preserved LV ejection fraction ([50 %) does not exclude the presence of myocardial systolic dysfunction and low trans-valvular flow in AS. Potential causes of discordance between AVA and gradient in patients with preserved LV ejection fraction include: (a) measurement errors; (b) small body size; (c) paradoxical low-flow AS; and (d) inconsistent grading related to intrinsic discrepancies in guidelines criteria [4,6,7,10,11]. First of all, patients with small body size and LV dimensions may exhibit a lower transvalvular pressure gradient because of a lower, albeit normal, stroke volume.…”

“…It is important to recognise this entity in order not to deny surgery to a symptomatic patient with small AVA and LG. Indeed, in this category, though the benefit of surgery is not proven, AVR may probably be beneficial in selected symptomatic patients [7,[20][21][22][23]. Of note, the current 2006 American College of Cardiology/ LG AS and preserved LV ejection fraction only after careful confirmation of severe AS [24].…”

“…The most commonly described entity is the paradoxical low-flow, low-gradient severe AS state, in which the stroke volume is unexpectedly reduced, despite preserved LV ejection fraction. In daily practice, misdiagnosing this clinical condition might lead to an inappropriate timing of follow-up with an unnecessary delay of aortic valve replacement (AVR), which may, in turn, have a negative impact on patient outcome [5][6][7].…”

Transcutanous aortic valve replacement with Medtronic CoreValve in a publicprivate partnership hospital complex

“…However, in symptomatic patients the prognosis is dismal with survival rates of 15 -50% at 5 years. (3)(4)(5) Aortic valve replacement is the definitive therapy for severe AS.However, many patients with AS and coexisting conditions are not candidates for surgical aortic valve replacement. In the Euro Heart Survey 33% of 216 patients >75 years presenting with symptomatic severe AS were not referred for surgery.…”