Elsevier

The American Journal of Cardiology

Volume 128, 1 August 2020, Pages 151-158
The American Journal of Cardiology

Progression of Normal Flow Low Gradient “Severe” Aortic Stenosis With Preserved Left Ventricular Ejection Fraction

https://doi.org/10.1016/j.amjcard.2020.05.003Get rights and content

Normal-flow low-gradient severe aortic stenosis (NF-LG-SAS), defined by an aortic valve area (AVA) <1 cm², mean pressure gradient (MPG) <40 mm Hg and indexed stroke volume ≥35 ml/m², is the most prevalent form of low-gradient aortic stenosis (AS) with preserved ejection fraction (PEF). However, the true severity of AS in these patients is controversial. The aim of this Doppler echocardiographic study was to investigate changes over time in the hemodynamic severity of patients with NF-LG-SAS with PEF. We retrospectively identified 96 patients who had 2 Doppler echocardiographic examinations without an intervening event. After a median follow-up of 25 (interquartile range 15 to 52) months, progression was observed, with increased transaortic MPG (from 28 [25 to 33] to 39 [34 to 50] mm Hg; p<0.001), peak aortic jet velocity (from 3.46 [3.20 to 3.64] to 4.01 [3.70 to 4.39] m/s; p<0.001), and decreased AVA (from 0.87 [0.82 to 0.94] to 0.72 [0.62 to 0.81] cm²; p<0.001). Median annual rates of progression were 4.3 (1.7 to 8.1) mm Hg/year, 0.25 (0.08 to 0.44) m/s/year, and −0.05 (−0.10 to −0.02) cm²/year, respectively. There was no significant change in left ventricular ejection fraction over time (p = 0.74). At follow-up, 46 patients (48%) acquired the features of classical high-gradient severe AS (MPG ≥40 mm Hg). This study shows that most patients with NF-LG-SAS with PEF exhibit significant hemodynamic progression of AS severity without EF impairment. These findings suggest that NF-LG-SAS with PEF is an “intermediate” stage between moderate AS and classical high-gradient severe AS requiring close monitoring.

Section snippets

Methods

We retrospectively identified all cases of NF-LG-SAS with preserved LVEF diagnosed from 2005 to 2015 at the echocardiography laboratories of three academic centers (Amiens, Lille, and Brussels). Inclusion criteria were (1) the presence of NF-LG “severe” AS with preserved LVEF diagnosed by transthoracic echocardiography based on the following criteria: AVA <1 cm², mean pressure gradient (MPG) <40 mm Hg, indexed stroke volume ≥35 ml/m², and LVEF ≥50% and (2) availability of a second follow-up

Results

The baseline demographic and clinical characteristics of the 96 patients are presented in Table 1. The median age was 79 years, with a predominance of women (62%). More than 75% of the study population had hypertension, one-quarter had diabetes mellitus, and almost 40% had coronary artery disease. The Charlson co-morbidity index and Euroscore II were low at echocardiographic diagnosis, with a median of 3 and 2.01, respectively. Patients were mostly asymptomatic or pauci-symptomatic (83%) at

Discussion

We demonstrate significant hemodynamic progression over time in NF-LG-SAS with preserved LVEF. Indeed, at follow-up, we observed worsening of at least 1 parameter of AS severity quantification (MPG, peak aortic jet velocity, or AVA) in >80% of patients. Mean MPG and peak aortic jet velocity were significantly higher at follow-up than at baseline (p <0.001 both), with 48% of patients developing the hemodynamic profile of HG-SAS. Median annual rates of progression of MPG and peak aortic jet

Author Contribution

The contribution of the authors is as follows:

Design of the study: Tribouilloy.

Acquisition of data: All authors.

Analysis and interpretation of data: Chadha, Bohbot, Tribouilloy.

Drafting of the manuscript: Chadha, Bohbot, Tribouilloy;

Critical revision for important intellectual content: All authors.

Statistical analysis: Chadha, Bohbot.

Study supervision: Tribouilloy, Maréchaux, Vanoverschelde.

Disclosures

The authors have no conflicts of interest to disclose.

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  • Cited by (0)

    Funding: None.

    GC and YB contributed equally to this study and are joint first authors.

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